952 results
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2. Quantitative regeneration: Skoog and Miller revisited.
- Author
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Melnyk, Charles W.
- Subjects
AUXIN ,CYTOKININS ,PLANT propagation ,TISSUE culture ,PLANT growth - Abstract
In 1957, Skoog and Miller published their seminal work on the effects of hormones upon plant growth. By varying the concentrations of auxin and cytokinin, they observed dramatic differences in shoot and root growth fromtobacco stem cultures.Their finding that quantitative differences in hormone concentrations could dramatically alter the fate of developing organs provided a foundation for understanding organ formation and tissue regeneration. Their in vitro assays established plant propagation techniques that were critical for regenerating transgenic plants. Here, I discuss their original paper, what led to their findings and its impact on our understanding of hormone interactions, howplants regenerate and in vitro tissue culture techniques. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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3. Cytokinins enhance the metabolic activity of in vitro-grown catmint (Nepeta nuda L.).
- Author
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Zhiponova M, Yordanova Z, Zaharieva A, Ivanova L, Gašić U, Mišić D, Aničić N, Skorić M, Petrović L, Rusanov K, Rusanova M, Mantovska D, Tsacheva I, Petrova D, Yocheva L, Hinkov A, Mihaylova N, Hristozkova M, Georgieva Z, Karcheva Z, Krumov N, Todorov D, Shishkova K, Vassileva V, Chaneva G, and Kapchina-Toteva V
- Subjects
- Purines metabolism, Benzyl Compounds pharmacology, Cinnamates metabolism, Cinnamates pharmacology, Rosmarinic Acid, Caffeic Acids metabolism, Depsides metabolism, Plant Growth Regulators metabolism, Plant Growth Regulators pharmacology, Plant Shoots metabolism, Plant Shoots drug effects, Gene Expression Regulation, Plant drug effects, Cytokinins metabolism
- Abstract
The phytohormones cytokinins are essential mediators of developmental and environmental signaling, primarily during cell division and endophytic interactions, among other processes. Considering the limited understanding of the regulatory mechanisms that affect the growth and bioactivity of the medicinal plant Nepeta nuda (Lamiaceae), our study aimed to explore how cytokinins influence the plant's metabolic status. Exogenous administration of active cytokinin forms on in vitro N. nuda internodes stimulated intensive callus formation and de novo shoot regeneration, leading to a marked increase in biomass. This process involved an accumulation of oxidants, which were scavenged by peroxidases using phenolics as substrates. The callus tissue formed upon the addition of the cytokinin 6-benzylaminopurine (BAP) acted as a sink for sugars and phenolics during the allocation of nutrients between the culture medium and regenerated plants. In accordance, the cytokinin significantly enhanced the content of polar metabolites and their respective in vitro biological activities compared to untreated in vitro and wild-grown plants. The BAP-mediated accumulation of major phenolic metabolites, rosmarinic acid (RA) and caffeic acid (CA), corresponded with variations in the expression levels of genes involved in their biosynthesis. In contrast, the accumulation of iridoids and the expression of corresponding biosynthetic genes were not significantly affected. In conclusion, our study elucidated the mechanism of cytokinin action in N. nuda in vitro culture and demonstrated its potential in stimulating the production of bioactive compounds. This knowledge could serve as a basis for further investigations of the environmental impact on plant productivity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2024
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4. Longistylin A from Cajanus cajan (L.) Millsp. disturbs glycerophospholipid metabolism and cytokinin biosynthesis of Nocardia seriolae.
- Author
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Zhao L, Yao L, Liu M, Qiu S, He J, Lin J, Tao Z, Lu Y, Deng S, Chen H, and Qiu SX
- Subjects
- Microbial Sensitivity Tests, Plant Leaves, Cajanus, Nocardia metabolism, Nocardia drug effects, Cytokinins pharmacology, Cytokinins biosynthesis, Cytokinins metabolism, Glycerophospholipids metabolism, Glycerophospholipids biosynthesis, Anti-Bacterial Agents pharmacology
- Abstract
Ethnopharmacological Relevance: Nocardiosis is an uncommon infectious disease that bears certain similarities to tuberculosis, with a continuous increase in its incidence and a poor prognosis. In traditional Chinese medicine, the leaves of Cajanus cajan (L.) Millsp. are employed to treat wounds, malaria, coughs, and abdominal pain., Aim of the Study: In this study, we investigated the effects and mechanisms of longistylin A (LGA), a natural stilbene isolated from C. cajan, as a potential antibiotic against nocardiosis., Materials and Methods: LGA was isolated from the leaves of C. cajan and assessed using a minimum bactericidal concentration (MBC) determination against Nocardia seriolae. Multi-omics analysis encompassing genes, proteins, and metabolites was conducted to investigate the impact of LGA treatment on N. seriolae. Additionally, quantitative analysis of 40 cytokinins in N. seriolae mycelium was performed to assess the specific effects of LGA treatment on cytokinin levels. Cryo-scanning electron microscopy was utilized to examine morphological changes induced by LGA treatment, particularly in the presence of exogenous trans-zeatin-O-glucoside (tZOG). The therapeutic effect of LGA was investigated by feeding N. seriolae-infected largemouth bass., Results: LGA exhibited significant efficacy against N. seriolae, with MBC value of 2.56 μg/mL. Multi-omics analysis revealed that LGA disrupted glycerophospholipid metabolism and hormone biosynthesis by notably reducing the expression of glycerol-3-phosphate dehydrogenase and calmodulin-like protein. Treatment with LGA markedly disrupted 12 distinct cytokinins in N. seriolae mycelium. Additionally, the addition of exogenous tZOG counteracted the inhibitory effects of LGA on filamentous growth, resulting in mycelial elongation and branching. Furthermore, LGA treatment improved the survival rate of largemouth bass infected with N. seriolae., Conclusions: We found for the first time that LGA from C. cajan exhibited significant efficacy against N. seriolae by interfering with glycerophospholipid metabolism and cytokinin biosynthesis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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5. Systemic strategies for cytokinin biosynthesis and catabolism in Arabidopsis roots and leaves under prolonged ammonium nutrition.
- Author
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Dziewit K, Amakorová P, Novák O, Szal B, and Podgórska A
- Subjects
- Gene Expression Regulation, Plant, Arabidopsis metabolism, Cytokinins metabolism, Cytokinins biosynthesis, Plant Leaves metabolism, Plant Roots metabolism, Ammonium Compounds metabolism
- Abstract
Cytokinins are growth-regulating plant hormones that are considered to adjust plant development under environmental stresses. During sole ammonium nutrition, a condition known to induce growth retardation of plants, altered cytokinin content can contribute to the characteristic ammonium toxicity syndrome. To understand the metabolic changes in cytokinin pools, cytokinin biosynthesis and degradation were analyzed in the leaves and roots of mature Arabidopsis plants. We found that in leaves of ammonium-grown plants, despite induction of biosynthesis on the expression level, there was no active cytokinin build-up because they were effectively routed toward their downstream catabolites. In roots, cytokinin conjugation was also induced, together with low expression of major synthetic enzymes, resulting in a decreased content of the trans-zeatin form under ammonium conditions. Based on these results, we hypothesized that in leaves and roots, cytokinin turnover is the major regulator of the cytokinin pool and does not allow active cytokinins to accumulate. A potent negative-regulator of root development is trans-zeatin, therefore its low level in mature root tissues of ammonium-grown plants may be responsible for occurrence of a wide root system. Additionally, specific cytokinin enhancement in apical root tips may evoke a short root phenotype in plants under ammonium conditions. The ability to flexibly regulate cytokinin metabolism and distribution in root and shoot tissues can contribute to adjusting plant development in response to ammonium stress., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Kacper Dziewit reports financial support was provided by University of Warsaw. Anna Podgorska reports a relationship with University of Warsaw that includes: employment. Bozena Szal reports a relationship with University of Warsaw that includes: employment. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Masson SAS.)
- Published
- 2024
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6. microRNA regulates cytokinin induced parthenocarpy in cucumber (Cucumis sativus L.).
- Author
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Sharif R, Zhu Y, Huang Y, Sohail H, Li S, Chen X, and Qi X
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- Fruit genetics, Fruit metabolism, RNA, Plant genetics, RNA, Plant metabolism, Phenylurea Compounds pharmacology, Pyridines, Cucumis sativus genetics, Cucumis sativus metabolism, MicroRNAs genetics, MicroRNAs metabolism, Cytokinins metabolism, Gene Expression Regulation, Plant
- Abstract
Parthenocarpy is one of the most important agronomic traits for fruit yield in cucumbers. However, the precise gene regulation and the posttranscriptional mechanism are elusive. In the presented study, one parthenocarpic line DDX and non-parthenocarpic line ZK were applied to identify the microRNAs (miRNAs) involved in parthenocarpic fruit formation. The differential expressed miRNAs among parthenocarpic fruit of forchlorfenuron (CPPU) treated ZK (ZK-CPPU), pollinated ZK (ZK-P), non-pollinated DDX (DDX-NP) were compared with the non-parthenocarpic fruits of non-pollinated ZK (ZK-NP). It indicated 98 miRNAs exhibited differential expression were identified. Notably, a significant proportion of these miRNAs were enriched in the signal transduction pathway of plant hormones, as identified by the KEGG pathway analysis. qRT-PCR validation indicated that CsmiR156 family was upregulated in the ZK-NP while downregulated in ZK-CPPU, ZK-P, and DDX-NP at 1 day after anthesis. Meanwhile, the opposite trend was observed for CsmiR164a. In ZK-CPPU, ZK-P, and DDX-NP, CsmiRNA156 genes (CsSPL16 and CsARR9-like) were upregulated while CsmiRNA164a genes (CsNAC6, CsCUC1, and CsNAC100) were downregulated. The GUS and dual luciferase assay validated that CsmiR156a inhibited while CsmiR164a induced their target genes' transcription. This study presents novel insights into the involvement of CsmiR156a and CsmiR164a in the CK-mediated posttranscriptional regulation of cucumber parthenocarpy, which will aid future breeding programs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)
- Published
- 2024
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7. CEPs suppress auxin signaling but promote cytokinin signaling to inhibit root growth in Arabidopsis.
- Author
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Zhang Y, Duan X, Wang Z, Lv Y, Qi W, Li L, Luo L, and Xuan W
- Subjects
- Plant Growth Regulators metabolism, Peptide Hormones metabolism, Peptide Hormones genetics, Arabidopsis growth & development, Arabidopsis metabolism, Arabidopsis genetics, Cytokinins metabolism, Indoleacetic Acids metabolism, Signal Transduction, Plant Roots growth & development, Plant Roots metabolism, Arabidopsis Proteins metabolism, Arabidopsis Proteins genetics, Gene Expression Regulation, Plant
- Abstract
C-terminally encoded peptides (CEPs) are peptide hormones that function as mobile signals coordinating crucial developmental programs in plants. Previous studies have revealed that CEPs exert negative regulation on root development through interaction with CEP receptors (CEPRs), CEP DOWNSTREAMs (CEPDs), the cytokinin receptor ARABIDOPSIS HISTIDINE KINASE (AHKs) and the transcriptional repressor Auxin/Indole-3-Acetic Acid (AUX/IAA). However, the precise molecular mechanisms underlying CEPs-mediated regulation of root development via auxin and cytokinin signaling pathways still necessitate further detailed investigation. In this study, we examined prior research and elucidated the underlying molecular mechanisms. The results showed that both synthetic AtCEPs and overexpression of AtCEP5 markedly supressed primary root elongation and lateral root (LR) formation in Arabidopsis. Molecular biology and genetics elucidated how CEPs inhibit root growth by suppressing auxin signaling while promoting cytokinin signaling. In summary, this study elucidated the inhibitory effects of AtCEPs on Arabidopsis root growth and provided insights into their potential molecular mechanisms, thus enhancing our comprehension of CEP-mediated regulation of plant growth and development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
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8. Concurrent improvement of rice grain yield and abiotic stress tolerance by overexpression of cytokinin activating enzyme LONELY GUY (OsLOG).
- Author
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Rathore RS, Mishra M, Pareek A, and Singla-Pareek SL
- Subjects
- Plants, Genetically Modified, Edible Grain growth & development, Edible Grain genetics, Gene Expression Regulation, Plant, Meristem growth & development, Meristem genetics, Meristem metabolism, Droughts, Oryza genetics, Oryza enzymology, Oryza growth & development, Oryza metabolism, Cytokinins metabolism, Plant Proteins metabolism, Plant Proteins genetics, Stress, Physiological
- Abstract
Meristem activity is important for normal plant growth as well as adaptive plastic development under abiotic stresses. Cytokinin has been recognized to have a major role in regulating meristem function which is controlled by cytokinin activating enzymes by fine-tuning the concentrations and spatial distribution of its bioactive forms. It was previously reported that LONELY GUY (LOG) acts in the direct activation pathway of cytokinin in rice shoot meristems. LOG has a cytokinin specific phosphoribohydrolase activity, which transforms inactive cytokinin nucleotides into active free bases. Here, we explored the role of OsLOG in controlling meristem activity mediated by cytokinin and its effects on growth, development, and stress resilience of rice plants. Overexpression of OsLOG in rice led to significant alterations in cytokinin levels in the inflorescence meristem, leading to enhanced plant growth, biomass and grain yield under both non-stress as well as stress conditions such as drought and salinity. Moreover, our study provides insight into how overexpression of OsLOG improves the ability of plants to withstand stress. The OsLOG-overexpressing lines exhibit reduced accumulation of H
2 O2 along with elevated antioxidant enzyme activities, thereby maintaining better redox homeostasis under stress conditions. This ultimately reduces the negative impact of stresses on grain yield and improves harvest index, as evidenced by observations in the OsLOG-overexpressing lines. In summary, our study emphasizes the diverse role of OsLOG, not only in regulating plant growth and yield via cytokinin but also in enhancing adaptability to abiotic stresses. This highlights its potential to improve crop yield and promote sustainable agriculture., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)- Published
- 2024
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9. HSP90 acts as a senomorphic target in senescent retinal pigmental epithelial cells
- Author
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Baixue Liu, Yuxuan Wang, Hongmei Mu, Mingjun Jiang, Guohui Shang, Xuhui Liu, Yingwei Lu, Xiaolin Jia, Xuyan Peng, Mengjiao Xue, Dan-Dan Chen, Fengyan Zhang, and Yanzhong Hu
- Subjects
Senescence ,Aging ,Cytokinins ,Lactams, Macrocyclic ,Cellular homeostasis ,β-galactosidase ,Retinal Pigment Epithelium ,Retina ,Cell Line ,chemistry.chemical_compound ,Macular Degeneration ,Senotherapeutics ,Benzoquinones ,Cytotoxic T cell ,HSP90 ,Animals ,Humans ,HSP90 Heat-Shock Proteins ,HIF1α ,senotheray ,Cells, Cultured ,Cellular Senescence ,biology ,Retinal ,Epithelial Cells ,Cell Biology ,Hydrogen Peroxide ,Hsp90 ,Macaca mulatta ,In vitro ,Cell biology ,Vascular endothelial growth factor A ,chemistry ,biology.protein ,NF-kb ,Protein stabilization ,Research Paper - Abstract
The senescence of retinal pigment epithelial (RPE) cells is associated with age-related macular degeneration (AMD), a leading cause of blindness in the world. HSP90 is a predominant chaperone that regulates cellular homeostasis under divergent physio-pathological conditions including senescence. However, the role of HSP90 in senescent RPE cells still remains unclear. Here, we reported that HSP90 acts as a senomorphic target of senescent RPE cells in vitro. Using H2O2-induced senescent ARPE-19 cells and replicative senescent primary RPE cells from rhesus monkey, we found that HSP90 upregulates the expression of IKKα, and HIF1α in senescent ARPE-19 cells and subsequently controls the induction of distinct senescence-associated inflammatory factors. Senescent ARPE-19 cells are more resistant to the cytotoxic HSP90 inhibitor IPI504 (IC50 = 36.78 μM) when compared to normal ARPE-19 cells (IC50 = 6.16 μM). Administration of IPI504 at 0.5–5 μM can significantly inhibit the induction of IL-1β, IL-6, IL-8, MCP-1 and VEGFA in senescent ARPE-19 and the senescence-mediated migration of retinal capillary endothelial cells in vitro. In addition, we found that inhibition of HSP90 by IPI504 reduces SA-β-Gal’s protein expression and enzyme activity in a dose-dependent manner. HSP90 interacts with and regulates SA-β-Gal protein stabilization in senescent ARPE-19 cells. Taken together, these results suggest that HSP90 regulates the SASP and SA-β-Gal activity in senescent RPE cells through associating with distinctive mechanism including NF-κB, HIF1α and lysosomal SA-β-Gal. HSP90 inhibitors (e.g. IPI504) could be a promising senomorphic drug candidate for AMD intervention.
- Published
- 2021
10. Small molecules mediate cellular reprogramming across two kingdoms
- Author
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Ralf Welsch, Alisher Touraev, and Klaus Palme
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Cytokinins ,Indoleacetic Acids ,AcademicSubjects/SCI01210 ,Physiology ,cell reprogramming ,fungi ,food and beverages ,rapeseed ,Plant Science ,somatic embryogenesis ,Cellular Reprogramming ,Research Papers ,glycogen synthase kinase ,small molecule inhibitors ,brassinosteroids ,cork oak ,Plant Growth Regulators ,Plant Cells ,Barley ,microspore embryogenesis ,Animals ,Growth and Development - Abstract
Inhibition of GSK-3 activity by novel small molecules enhances somatic embryogenesis efficiency by activating the brassinosteroid pathway, an innovation with high potential to improve in vitro plant regeneration for crop and forest breeding techniques., Plant in vitro regeneration systems, such as somatic embryogenesis, are essential in breeding; they permit propagation of elite genotypes, production of doubled-haploids, and regeneration of whole plants from gene editing or transformation events. However, in many crop and forest species, somatic embryogenesis is highly inefficient. We report a new strategy to improve in vitro embryogenesis using synthetic small molecule inhibitors of mammalian glycogen synthase kinase 3β (GSK-3β), never used in plants. These inhibitors increased in vitro embryo production in three different systems and species, microspore embryogenesis of Brassica napus and Hordeum vulgare, and somatic embryogenesis of Quercus suber. TDZD-8, a representative compound of the molecules tested, inhibited GSK-3 activity in microspore cultures, and increased expression of embryogenesis genes FUS3, LEC2, and AGL15. Plant GSK-3 kinase BIN2 is a master regulator of brassinosteroid (BR) signalling. During microspore embryogenesis, BR biosynthesis and signalling genes CPD, GSK-3-BIN2, BES1, and BZR1 were up-regulated and the BAS1 catabolic gene was repressed, indicating activation of the BR pathway. TDZD-8 increased expression of BR signalling elements, mimicking BR effects. The findings support that the small molecule inhibitors promoted somatic embryogenesis by activating the BR pathway, opening up the way for new strategies using GSK-3β inhibitors that could be extended to other species.
- Published
- 2021
11. Co-treatment with melatonin and ortho-topolin riboside reduces cell viability by altering metabolic profiles in non-small cell lung cancer cells.
- Author
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Lee JW, Lee H, Noh SW, and Choi HK
- Subjects
- Humans, Cell Survival, Metabolome, Glycine metabolism, Glycine pharmacology, Glycine therapeutic use, Serine metabolism, Threonine metabolism, Tyrosine metabolism, Cell Line, Tumor, Carcinoma, Non-Small-Cell Lung pathology, Lung Neoplasms pathology, Melatonin pharmacology, Melatonin therapeutic use, Cytokinins
- Abstract
Lung cancer is a highly prevalent and lethal malignancy worldwide, with non-small cell lung cancer (NSCLC) accounting for 85% of cancer-related deaths. In this study, the effects of co-treatment with melatonin and ortho-topolin riboside (oTR) on the cell viability and alteration of metabolites and transcripts were investigated in NSCLC cells using gas chromatography-mass spectrometry (GC-MS) and next-generation sequencing (NGS). The co-treatment of melatonin and oTR exhibited synergistic effects on the reduction of cell viability and alteration of metabolic and transcriptomic profiles in NSCLC cells. We observed that the co-treatment inhibited glycolytic function and mitochondria respiration, and downregulated glycine, serine and threonine metabolism alongside tyrosine metabolism in NSCLC cells. In the glycine, serine and threonine metabolism pathway, the co-treatment resulted in a significant 8.4-fold reduction in the expression level of the SDS gene, which encodes the enzyme responsible for the breakdown of serine to pyruvate. Moreover, co-treatment decreased the gene expression of TH, DDC, and CYP1A1 in tyrosine metabolism. Additionally, we observed that the co-treatment resulted in a significant 146.9-fold reduction in the expression of the DISC1 gene. The alteration in metabolites and transcript expressions might provide information to explain the cytotoxicity of co-treatment of melatonin and oTR in NSCLC cells. Our study presents insights into the synergistic anticancer effect of the co-treatment of melatonin and oTR, which could be a potential future therapeutic strategy for the treatment of NSCLC patients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
- Full Text
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12. Dual roles of jasmonate in adventitious rooting
- Author
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Zhengfei Yang, Xuan Pan, and Lin Xu
- Subjects
Physiology ,vegetative propagation ,Arabidopsis ,Plant Science ,Cyclopentanes ,RAP2.6L ,chemistry.chemical_compound ,Jasmonate ,Oxylipins ,biology ,AcademicSubjects/SCI01210 ,DUAL (cognitive architecture) ,biology.organism_classification ,Adventitious roots ,Research Papers ,jasmonate ,Cell biology ,respiratory tract diseases ,cytokinins ,MYC2 ,chemistry ,Cytokinin ,Growth and Development ,CKX1 ,light - Abstract
Genome-wide analysis in Arabidopsis revealed that light controls CK homeostasis during early stages of adventitious root initiation (ARI). CK and JA cooperatively inhibit ARI by inducing the transcription of the transcription factor RAP2.6L., Adventitious rooting is a de novo organogenesis process that enables plants to propagate clonally and cope with environmental stresses. Adventitious root initiation (ARI) is controlled by interconnected transcriptional and hormonal networks, but there is little knowledge of the genetic and molecular programs orchestrating these networks. Thus, we have applied genome-wide transcriptome profiling to elucidate the transcriptional reprogramming events preceding ARI. These reprogramming events are associated with the down-regulation of cytokinin (CK) signaling and response genes, which could be triggers for ARI. Interestingly, we found that CK free base (iP, tZ, cZ, and DHZ) content declined during ARI, due to down-regulation of de novo CK biosynthesis and up-regulation of CK inactivation pathways. We also found that MYC2-dependent jasmonate (JA) signaling inhibits ARI by down-regulating the expression of the CYTOKININ OXIDASE/DEHYDROGENASE1 (CKX1) gene. We also demonstrated that JA and CK synergistically activate expression of the transcription factor RELATED to APETALA2.6 LIKE (RAP2.6L), and constitutive expression of this transcription factor strongly inhibits ARI. Collectively, our findings reveal that previously unknown genetic interactions between JA and CK play key roles in ARI.
- Published
- 2021
13. Exploring potential of copper and silver nano particles to establish efficient callogenesis and regeneration system for wheat (
- Author
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Waqar Afzal, Malik, Imran, Mahmood, Abdul, Razzaq, Maria, Afzal, Ghulam Abbas, Shah, Asif, Iqbal, Muhammad, Zain, Allah, Ditta, Saeed Ahmed, Asad, Ishfaq, Ahmad, Naimatullah, Mangi, and Wuwei, Ye
- Subjects
Silver ,Nano particles ,nanotechnology ,explant ,Metal Nanoparticles ,Kinetin ,cytokinins ,callus ,mature embryo ,auxins ,tissue culture ,Copper ,Triticum ,Research Article ,Research Paper - Abstract
In vitro recalcitrance of wheat to regeneration is the major bottleneck for its improvement through callus-based genetic transformation. Nanotechnology is one of the most dynamic areas of research, which can transform agriculture and biotechnology to ensure food security on sustainable basis. Present study was designed to investigate effects of CuSO4, AgNO3 and their nanoparticles on tissue culture responses of mature embryo culture of wheat genotypes (AS-2002 and Wafaq-2001). Initially, MS-based callus induction and regeneration medium were optimized for both genotypes using various concentrations of auxin (2,4-D, IAA) and cytokinins (BAP, kinetin). The genotypes differed for embryogenic callus induction and regeneration potential. Genotype AS-2002 yielded maximum embryogenic calli in response to 3.0 mg/l 2,4-D, whereas Wafaq-2001 offered the highest embryogenic calli against 3.5 mg/l 2,4-D supplemented in the induction medium. Genotype AS-2002 showed maximum regeneration (59.33%) in response to regeneration protocol comprising 0.5 mg/l IAA, 0.3 mg/l BAP and 1.0 mg/l Kin, while Wafaq-2001 performed best in response to 0.5 mg/l IAA, 0.3 mg/l BAP and 1.5 mg/l Kin with 55.33% regeneration efficiency. The same optimized basal induction and regeneration medium for both genotypes were further used to study effects of CuSO4, AgNO3 and their nano-particles employing independent experiments. The optimized induction medium fortified with various concentrations of CuSO4 or CuNPs confirmed significant effects on frequency of embryogenic callus. Addition of either 0.020 mg/l or 0.025 mg/l CuSO4, or 0.015 mg/l CNPs showed comparable results for embryogenic callus induction and were statistically at par with embryogenic callus induction of 74.00%, 75.67% and 76.83%, respectively. Significantly higher regeneration was achieved from MS-based regeneration medium supplemented with 0.015 mg/l or 0.020 mg/l CuNPs than standard 0.025 mg/l CuSO4. In another study, the basal induction and regeneration medium were fortified with AgNO3 or AgNPs ranging from 1 to 7 mg/l along with basal regeneration media devoid of AgNO3 or AgNPs (control). The maximum embryogenic calli were witnessed from medium fortified with 3.0 mg/l or 4.0 mg/l AgNPs compared with control and rest of the treatments. The standardized regeneration medium fortified with 5.0 mg/l AgNO3 or 3.0 mg/l AgNPs showed pronounced effect on regeneration of wheat genotypes and offered maximum regeneration compared with control. The individual and combined effect of Cu and Ag nanoparticles along with control (basal regeneration media of each genotype) was also tested. Surprisingly, co-application of metallic NPs showed a significant increase in embryogenic callus formation of genotypes. Induction medium supplemented with 0.015 mg/l CuNPs + 4.0 mg/l AgNPs or 0.020 mg/l CuNPs + 2.0 mg/l AgNPs showed splendid results compared to control and other combination of Cu and Ag nanoparticles. The maximum regeneration was achieved by co-application of 0.015 mg/l CuNP and 4.0 mg/l AgNPs with 21% increment of regeneration over control. It is revealed that CuNPs and AgNPs are potential candidate to augment somatic embryogenesis and regeneration of mature embryo explants of wheat. Abbreviations: 2,4-D (2,4-dichlorophenoxyacetic acid), BAP (6-benzylaminopurine), IAA (Indole-3-acetic acid), AgNPs (silver nanoparticles), CuNPs (copper nanoparticles)
- Published
- 2021
14. Local root ABA/cytokinin status and aquaporins regulate poplar responses to mild drought stress independently of the ectomycorrhizal fungus Laccaria bicolor
- Author
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Angel M. Zamarreño, Ricardo Aroca, José María García-Mina, Elisabeth Armada, Monica Calvo-Polanco, Ministerio de Economía y Competitividad (España), and Junta de Andalucía
- Subjects
0106 biological sciences ,0301 basic medicine ,Populus trichocarpa ,Cytokinins ,Physiology ,Root water transport ,Poot water transport ,Aquaporin ,Plant Science ,Fungus ,Biology ,Aquaporins ,Plant Roots ,01 natural sciences ,Laccaria ,Soil ,Abscisic acid ,03 medical and health sciences ,chemistry.chemical_compound ,Plant Growth Regulators ,Gene Expression Regulation, Plant ,Stress, Physiological ,Laccaria bicolor ,Mycorrhizae ,Botany ,Phosphorylation ,root water transport ,urogenital system ,Inoculation ,fungi ,food and beverages ,Mild drought ,biology.organism_classification ,Research Papers ,Droughts ,Ectomycorrhiza ,Populus ,030104 developmental biology ,chemistry ,Seedlings ,Plant—Environment Interactions ,Plant Stomata ,Cytokinin ,Poplar ,010606 plant biology & botany - Abstract
Plant aquaporins and hormones regulate root water uptake in mildly stressed poplar together with the participation of fungal aquaporins from the ectomycorrhizal fungus Laccaria bicolor., The relatively better performance of mycorrhizal plants subjected to drought stress has commonly been linked to improved root water uptake through the fungal regulation of plant aquaporins and hormones. In this study, we examined the role of ectomycorrhizal fungi in plant water relations and plant hormonal balance under mild drought using split-root seedlings of Populus trichocarpa × deltoides either with or without inoculation with Laccaria bicolor. The root compartments where the drought treatment was applied had higher ABA and lower cytokinin tZR contents, and greater expression of the plant aquaporins PtPIP1;1, PtPIP1;2, PtPIP2;5, and PtPIP2;7. On the other hand, the presence of L. bicolor within the roots down-regulated PtPIP1;4, PtPIP2;3, and PtPIP2;10, and reduced the abundance of PIP2 proteins. In addition, expression of the fungal aquaporins JQ585595 and JQ585596 were positively correlated with root ABA content, while tZR content was positively correlated with PtPIP1;4 and negatively correlated with PtPIP2;7. The results demonstrate a coordinated plant–fungal system that regulates the different mechanisms involved in water uptake in ectomycorrhizal poplar plants.
- Published
- 2019
15. ABC transporter OsABCG18 controls the shootward transport of cytokinins and grain yield in rice
- Author
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Kewei Zhang, Jiangzhe Zhao, Engao Zhu, Zhang Yanjun, Mengyuan Zhang, Biao Fan, Min Ju, and Ningning Yu
- Subjects
0106 biological sciences ,0301 basic medicine ,Cytokinins ,Physiology ,long-distance translocation ,Green Fluorescent Proteins ,Nicotiana benthamiana ,ATP-binding cassette transporter ,Plant Science ,efflux transporter ,01 natural sciences ,Plant Roots ,03 medical and health sciences ,chemistry.chemical_compound ,cytokinin ,Gene Expression Regulation, Plant ,heterocyclic compounds ,Vascular tissue ,Phylogeny ,Plant Proteins ,Oryza sativa ,biology ,Chemistry ,grain yield ,fungi ,Xylem ,food and beverages ,Biological Transport ,Oryza ,biology.organism_classification ,Research Papers ,Cell biology ,030104 developmental biology ,Phenotype ,Shoot ,Cytokinin ,Mutation ,ATP-Binding Cassette Transporters ,Growth and Development ,ABC transporter ,Cytokinin transport ,rice (Oryza sativa L.) ,Edible Grain ,Plant Shoots ,010606 plant biology & botany - Abstract
Cytokinins are one of the most important phytohormones and play essential roles in multiple life processes in planta. Root-derived cytokinins are transported to the shoots via long-distance transport. The mechanisms of long-distance transport of root-derived cytokinins remain to be demonstrated. In this study, we report that OsABCG18, a half-size ATP-binding cassette transporter from rice (Oryza sativa L.), is essential for the long-distance transport of root-derived cytokinins. OsABCG18 encodes a plasma membrane protein and is primarily expressed in the vascular tissues of the root, stem, and leaf midribs. Cytokinin profiling, as well as [14C]trans-zeatin tracer, and xylem sap assays, demonstrated that the shootward transport of root-derived cytokinins was significantly suppressed in the osabcg18 mutants. Transport assays in tobacco (Nicotiana benthamiana) indicated that OsABCG18 exhibited efflux transport activities for various substrates of cytokinins. While the mutation reduced root-derived cytokinins in the shoot and grain yield, overexpression of OsABCG18 significantly increased cytokinins in the shoot and improved grain yield. The findings for OsABCG18 as a transporter for long-distance transport of cytokinin provide new insights into the cytokinin transport mechanism and a novel strategy to increase cytokinins in the shoot and promote grain yield., OsABCG18 is essential for long-distance transport of cytokinins from root to shoot, and promotes grain yield in rice.
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- 2019
16. Crosstalk between cytokinin and ethylene signaling pathways regulates leaf abscission in cotton in response to chemical defoliants
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Xianlong Zhang, Baoqi Li, Heng Sun, Jie Kong, Xiyan Yang, Dawei Zhang, Yu Gao, Nusireti Wusiman, Lin Chen, Jiao Xu, Weinan Sun, and Haijiang Xu
- Subjects
0106 biological sciences ,0301 basic medicine ,Ethylene ,Cytokinins ,Physiology ,Plant Science ,Cotton ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Abscission ,Organophosphorus Compounds ,Plant Growth Regulators ,GhCKX3 ,Thiadiazoles ,heterocyclic compounds ,defoliant ,leaf abscission ,ethylene signaling ,Gossypium ,biology ,Defoliants, Chemical ,Phenylurea Compounds ,Defoliant ,fungi ,cytokinin signaling ,food and beverages ,Ethylenes ,biology.organism_classification ,Research Papers ,Cell biology ,Plant Leaves ,Crosstalk (biology) ,030104 developmental biology ,chemistry ,Cytokinin ,Plant hormone ,Growth and Development ,Zeatin ,010606 plant biology & botany ,Ethephon ,Signal Transduction - Abstract
Enhanced cytokinin signaling results in delayed defoliation and a reduced response to ethylene in cotton treated with thidiazuron and ethephon, with crosstalk between cytokinin and ethylene signaling playing an important regulatory role., Abscission is a process that allows plants to shed tissues or organs via cell separation, and occurs throughout the life cycle. Removal of leaves through the use of chemical defoliants is very important for mechanical harvesting of cotton (Gossypium hirsutum). However, our knowledge of the molecular mechanisms of the defoliation response involved is limited. In this study, RNA-seq was conducted in order to profile the differentially expressed genes (DEGs) between cultivars X50 (sensitive to chemical defoliants) and X33 (relatively insensitive) at different time points after treatment with thidiazuron and ethephon (TE). A total of 2434 DEGs were identified between the two cultivars across the different time-points. Functional categories according to GO and KEGG analyses revealed that plant hormone signal transduction and zeatin biosynthesis were involved in the response to TE. Cytokinin oxidase/dehydrogenase (CKX) genes and ethylene-related genes were up-regulated following TE treatment, and were associated with increased level of ethylene, especially in cultivar X50. Down-regulation of GhCKX3 resulted in delayed defoliation and a reduced ethylene response. The results show that crosstalk between cytokinin and ethylene regulates cotton defoliation, and provide new insights into the molecular mechanisms underlying the mode of action of defoliants in cotton.
- Published
- 2019
17. GhNAC83 inhibits corm dormancy release by regulating ABA signaling and cytokinin biosynthesis in Gladiolus hybridus
- Author
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Jiahui Liang, Sonia Gazzarrini, Yujie Jin, Mingfang Yi, Wenjing Wu, Chen Liu, Eliana Vonapartis, Jian Wu, and Junna He
- Subjects
0106 biological sciences ,0301 basic medicine ,dormancy ,Cytokinins ,Physiology ,Corm ,Plant Science ,01 natural sciences ,Iridaceae ,03 medical and health sciences ,chemistry.chemical_compound ,Gladiolus ,Abscisic acid ,Plant Proteins ,biology ,NAC ,gladiolus ,organic chemicals ,fungi ,Seed dormancy ,food and beverages ,biology.organism_classification ,Plant Dormancy ,Research Papers ,Cell biology ,Bulb ,corm ,Plant Tubers ,030104 developmental biology ,chemistry ,ABA ,Cytokinin ,Dormancy ,Growth and Development ,Zeatin ,010606 plant biology & botany ,Abscisic Acid ,Signal Transduction - Abstract
GhNAC83 inhibits corm dormancy release in Gladiolus hybridus by promoting ABA signaling and inhibiting CK biosynthesis., Corm dormancy is an important trait for breeding in many bulb flowers, including the most cultivated Gladiolus hybridus. Gladiolus corms are modified underground stems that function as storage organs and remain dormant to survive adverse environmental conditions. Unlike seed dormancy, not much is known about corm dormancy. Here, we characterize the mechanism of corm dormancy release (CDR) in Gladiolus. We identified an important ABA (abscisic acid) signaling regulator, GhPP2C1 (protein phosphatase 2C1), by transcriptome analysis of CDR. GhPP2C1 expression increased during CDR, and silencing of GhPP2C1 expression in dormant cormels delayed CDR. Furthermore, we show that GhPP2C1 expression is directly regulated by GhNAC83, which was identified by yeast one-hybrid library screening. In planta assays show that GhNAC83 is a negative regulator of GhPP2C1, and silencing of GhNAC83 promoted CDR. As expected, silencing of GhNAC83 decreased the ABA level, but also dramatically increased cytokinin (CK; zeatin) content in cormels. Binding assays demonstrate that GhNAC83 associates with the GhIPT (ISOPENTENYLTRANSFERASE) promoter and negatively regulates zeatin biosynthesis. Taken together, our results reveal that GhNAC83 promotes ABA signaling and synthesis, and inhibits CK biosynthesis pathways, thereby inhibiting CDR. These findings demonstrate that GhNAC83 regulates the ABA and CK pathways, and therefore controls corm dormancy.
- Published
- 2018
18. A genome-wide association study reveals cytokinin as a major component in the root defense responses against Ralstonia solanacearum
- Author
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Wolfgang Busch, Roger de Pedro-Jové, Ondřej Novák, Marc Valls, Alejandro Alonso-Díaz, Hannah M Berry, Núria S. Coll, Santosh B. Satbhai, Christian Göschl, Cristiana T. Argueso, Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Austrian Academy of Sciences, Department of Agriculture (US), CSIC - Unidad de Recursos de Información Científica para la Investigación (URICI), and Consejo Superior de Investigaciones Científicas (España)
- Subjects
0106 biological sciences ,0301 basic medicine ,Cytokinins ,Mecanismes de defensa en les plantes ,Physiology ,Arabidopsis ,Plant Science ,01 natural sciences ,chemistry.chemical_compound ,GWAS ,Plant defenses ,Pathogen ,Genetics ,Ralstonia solanacearum ,biology ,Bacterial wilt ,food and beverages ,Salicylic acid ,Research Papers ,Phenotype ,defense ,Cytokinin ,salicylic acid ,cytokinin ,03 medical and health sciences ,Immunity ,Defense ,Gene ,Plant Diseases ,hormones ,AcademicSubjects/SCI01210 ,fungi ,Àcid salicílic ,root ,biology.organism_classification ,Arrels (Botànica) ,Hormones ,Roots (Botany) ,immune system ,030104 developmental biology ,Immune system ,chemistry ,Root ,Plant—Environment Interactions ,Immunitat de les plantes ,Plants immunity ,Genome-Wide Association Study ,010606 plant biology & botany - Abstract
Bacterial wilt caused by the soil-borne pathogen Ralstonia solancearum is economically devastating, with no effective methods to fight the disease. This pathogen invades plants through their roots and colonizes their xylem, clogging the vasculature and causing rapid wilting. Key to preventing colonization are the early defense responses triggered in the host’s root upon infection, which remain mostly unknown. Here, we have taken advantage of a high-throughput in vitro infection system to screen natural variability associated with the root growth inhibition phenotype caused by R. solanacearum in Arabidopsis during the first hours of infection. To analyze the genetic determinants of this trait, we have performed a genome-wide association study, identifying allelic variation at several loci related to cytokinin metabolism, including genes responsible for biosynthesis and degradation of cytokinin. Further, our data clearly demonstrate that cytokinin signaling is induced early during the infection process and cytokinin contributes to immunity against R. solanacearum. This study highlights a new role for cytokinin in root immunity, paving the way for future research that will help in understanding the mechanisms underpinning root defenses., This work was supported by the Spanish Ministry of Economy and Competitiveness grant nos RyC 2014-16158, AGL2016-78002-R, and PID2019-108595RB-I00/AEI/10.13039/501100011033 to NSC, and through the ‘Severo Ochoa Programme for Centres of Excellence in R&D’ (SEV-2015-0533). We also acknowledge financial support from the CERCA Programme/Generalitat de Catalunya, from the Austrian Academy of Sciences through the Gregor Mendel Institute (WB and SBS) and from funding for CTA and HMB by the United States Department of Agriculture (USDA) grant no. COL00781., We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).
- Published
- 2021
19. Insights into the role of phytohormones in plant female germline cell specification.
- Author
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Cai H, Liu L, Ma S, Aslam M, and Qin Y
- Subjects
- Gibberellins, Indoleacetic Acids, Germ Cells, Plant Growth Regulators, Cytokinins
- Abstract
Germline specification is a fundamental process in plant reproduction, and the Megaspore Mother Cell (MMC), is a critical cell that differentiates and develops into the female gametophyte. While numerous studies have investigated the molecular mechanisms underlying female germline specification, previous reviews have mainly focused on gene regulatory networks, epigenetic pathways, and small RNAs, neglecting the potential contribution of phytohormones to this process. This review aims to address this gap by highlighting recent advances in MMC formation and discussing the roles of specific phytohormones in female germline specialization. Here, we provide a comprehensive overview of the functions of phytohormones in the formation of MMC and their effects on female gametophyte development. Specifically, it examines the roles of gibberellins (GAs), brassinosteroids (BRs), auxins, and cytokinin, in MMC development. Understanding the function of phytohormones in MMC development is essential for comprehending the complex mechanisms underlying plant reproduction. This review adds valuable insights to the existing knowledge on MMC development, providing a new perspective for future research in the field of plant reproduction., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
- Published
- 2023
- Full Text
- View/download PDF
20. Phytohormones: structural and functional relationship to purine nucleotides and some pharmacologic agents
- Author
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W Robert Williams
- Subjects
0106 biological sciences ,0301 basic medicine ,Purine ,Cell signaling ,Cytokinins ,Plant Science ,Cyclopentanes ,Biology ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Plant Growth Regulators ,Auxin ,Brassinosteroid ,Nucleotide ,Jasmonate ,Oxylipins ,Purine Nucleotides ,chemistry.chemical_classification ,Indoleacetic Acids ,food and beverages ,Gibberellins ,030104 developmental biology ,chemistry ,Biochemistry ,Second messenger system ,010606 plant biology & botany ,Hormone ,Research Paper ,Abscisic Acid ,Signal Transduction - Abstract
Structural components of second messenger signaling (nucleotides and associated enzyme systems) within plant and animal cells have more in common than the hormones that initiate metabolic and functional changes. Neurotransmitters and hormones of mammalian pharmacologic classes relate to purine nucleotides in respect of chemical structure and the molecular changes they initiate. This study compares the molecular structures of purine nucleotides with compounds from the abscisic acid, auxin, brassinosteroid, cytokinin, gibberellin, and jasmonate classes by means of a computational program. The results illustrate how phytohomones relate to each other through the structures of nucleotides and cyclic nucleotides. Molecular similarity within the phytohormone structures relates to synergism, antagonism and the modulation of nucleotide function that regulates germination and plant development. As with the molecular evolution of mammalian hormones, cell signaling and cross-talk within the phytohormone classes is purine nucleotide centered.
- Published
- 2020
21. CBL-interacting protein kinase 25 contributes to root meristem development
- Author
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Mukesh Kumar Meena, Debasis Chattopadhyay, Vineeta Tripathi, and Niraj Kumar Vishwakarma
- Subjects
DNA, Bacterial ,0106 biological sciences ,0301 basic medicine ,Auxin efflux ,Cytokinins ,Physiology ,Meristem ,Arabidopsis ,Plant Science ,Protein Serine-Threonine Kinases ,Plant Roots ,01 natural sciences ,cytokinin ,03 medical and health sciences ,chemistry.chemical_compound ,Plant Growth Regulators ,Gene Expression Regulation, Plant ,Auxin ,Gene expression ,heterocyclic compounds ,Protein kinase A ,chemistry.chemical_classification ,Regulation of gene expression ,Indoleacetic Acids ,biology ,Arabidopsis Proteins ,fungi ,PIN ,food and beverages ,root ,biology.organism_classification ,Research Papers ,SHY2 ,Cell biology ,030104 developmental biology ,chemistry ,Cytokinin ,Growth and Development ,CIPK25 ,auxin ,Signal Transduction ,010606 plant biology & botany - Abstract
CIPK25, a calcium-regulated protein kinase, plays an important role in the co-ordination of auxin and cytokinin signaling in root meristem development., Co-ordination of auxin and cytokinin activities determines root meristem size during post-embryonic development. Calcineurin B-like proteins (CBLs) and their interacting protein kinases (CIPKs) constitute signaling modules that relay calcium signals. Here we report that CIPK25 is involved in regulating the root meristem size. Arabidopsis plants lacking CIPK25 expression displayed a short root phenotype and a slower root growth rate with fewer meristem cells. This phenotype was rescued by restoration of CIPK25 expression. CIPK25 interacted with CBL4 and -5, and displayed strong gene expression in the flower and root, except in the cell proliferation domain in the root apical meristem. Its expression in the root was positively and negatively regulated by auxin and cytokinin, respectively. The cipk25 T-DNA insertion line was compromised in auxin transport and auxin-responsive promoter activity. The cipk25 mutant line showed altered expression of auxin efflux carriers (PIN1 and PIN2) and an Aux/IAA family gene SHY2. Decreased PIN1 and PIN2 expression in the cipk25 mutant line was completely restored when combined with a SHY2 loss-of-function mutation, resulting in recovery of root growth. SHY2 and PIN1 expression was partially regulated by cytokinin even in the absence of CIPK25, suggesting a CIPK25-independent cytokinin signaling pathway(s). Our results revealed that CIPK25 plays an important role in the co-ordination of auxin and cytokinin signaling in root meristem development.
- Published
- 2018
22. CUP-SHAPED COTYLEDON1 (CUC1) and CUC2 regulate cytokinin homeostasis to determine ovule number in Arabidopsis
- Author
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Ondřej Novák, Lucia Colombo, Eva Benková, Mara Cucinotta, Silvia Manrique, and Candela Cuesta
- Subjects
0106 biological sciences ,0301 basic medicine ,Cytokinins ,food.ingredient ,Physiology ,Arabidopsis ,Plant Science ,01 natural sciences ,cytokinin ,03 medical and health sciences ,chemistry.chemical_compound ,food ,pistil development ,Homeostasis ,transcriptional regulation ,Ovule ,Gene ,Transcription factor ,hormones ,biology ,Arabidopsis Proteins ,fungi ,food and beverages ,biology.organism_classification ,Research Papers ,Phenotype ,Cell biology ,ovule development ,030104 developmental biology ,chemistry ,Cytokinin ,Growth and Development ,Cotyledon ,010606 plant biology & botany - Abstract
CUC1 and CUC2 regulate ovule and seed number by modulating the expression of genes involved in the balance between active and inactive forms of glycosylated cytokinin., Seeds derive from ovules upon fertilization and therefore the total number of ovules determines the final seed yield, a fundamental trait in crop plants. Among the factors that co-ordinate the process of ovule formation, the transcription factors CUP-SHAPED COTYLEDON 1 (CUC1) and CUC2 and the hormone cytokinin (CK) have a particularly prominent role. Indeed, the absence of both CUC1 and CUC2 causes a severe reduction in ovule number, a phenotype that can be rescued by CK treatment. In this study, we combined CK quantification with an integrative genome-wide target identification approach to select Arabidopsis genes regulated by CUCs that are also involved in CK metabolism. We focused our attention on the functional characterization of UDP-GLUCOSYL TRANSFERASE 85A3 (UGT85A3) and UGT73C1, which are up-regulated in the absence of CUC1 and CUC2 and encode enzymes able to catalyse CK inactivation by O-glucosylation. Our results demonstrate a role for these UGTs as a link between CUCs and CK homeostasis, and highlight the importance of CUCs and CKs in the determination of seed yield.
- Published
- 2018
23. Cytokinin perception in potato: new features of canonical players
- Author
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Irina A. Getman, Georgy A. Romanov, Dmitry V. Arkhipov, Dmitry I. Osolodkin, Sergey N. Lomin, Ekaterina M. Savelieva, Yulia A. Myakushina, and Oksana O. Kolachevskaya
- Subjects
0106 biological sciences ,0301 basic medicine ,Sucrose ,Cytokinins ,Physiology ,Receptors, Cell Surface ,Plant Science ,Biology ,Genes, Plant ,01 natural sciences ,Genome ,CHASE domain-containing histidine kinase ,cytokinin ,03 medical and health sciences ,Arabidopsis ,Gene expression ,heterocyclic compounds ,Amino Acid Sequence ,Promoter Regions, Genetic ,Receptor ,Peptide sequence ,Gene ,Alleles ,Phylogeny ,Solanum tuberosum ,Genetics ,Sequence Homology, Amino Acid ,Homozygote ,fungi ,cytokinin signaling ,cytokinin receptor ,food and beverages ,biology.organism_classification ,Research Papers ,030104 developmental biology ,Crop Molecular Genetics ,gene expression ,potato ,Ploidy ,Signal transduction ,hormone perception ,Biotechnology ,Signal Transduction ,010606 plant biology & botany - Abstract
Potato genes for putative cytokinin receptors were cloned and expressed. The proteins displayed properties of cytokinin receptors, and their expression in planta was organ specific and sensitive to growth conditions and sucrose content., Potato is the most economically important non-cereal food crop. Tuber formation in potato is regulated by phytohormones, cytokinins (CKs) in particular. The present work studied CK signal perception in potato. The sequenced potato genome of doubled monoploid Phureja was used for bioinformatic analysis and as a tool for identification of putative CK receptors from autotetraploid potato cv. Désirée. All basic elements of multistep phosphorelay required for CK signal transduction were identified in the Phureja genome, including three genes orthologous to three CK receptor genes (AHK 2–4) of Arabidopsis. As distinct from Phureja, autotetraploid potato contains at least two allelic isoforms of each receptor type. Putative receptor genes from Désirée plants were cloned, sequenced and expressed, and the main characteristics of encoded proteins were determined, in particular their consensus motifs, modelled structure, ligand-binding properties, and ability to transmit CK signals. In all studied aspects the predicted sensor histidine kinases met the requirements for genuine CK receptors. Expression of potato CK receptors was found to be organ-specific and sensitive to growth conditions, particularly to sucrose content. Our results provide a solid basis for further in-depth study of CK signaling system and biotechnological improvement of potato.
- Published
- 2018
24. Auxin–cytokinin interactions in the regulation of correlative inhibition in two-branched pea seedlings
- Author
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Andrey A. Kotov and Liudmila M. Kotova
- Subjects
0106 biological sciences ,0301 basic medicine ,Cytokinins ,Physiology ,Plant Science ,Correlative inhibition ,xylem sap ,01 natural sciences ,Hypocotyl ,Pisum ,03 medical and health sciences ,chemistry.chemical_compound ,Sativum ,Auxin ,Botany ,heterocyclic compounds ,Pisum sativum ,chemistry.chemical_classification ,Indoleacetic Acids ,biology ,fungi ,two-branched pea seedlings ,Peas ,food and beverages ,Xylem ,biology.organism_classification ,Research Papers ,030104 developmental biology ,chemistry ,Seedlings ,transport ,Shoot ,Second messenger system ,Cytokinin ,Growth and Development ,indole-3-acetic acid ,Plant Shoots ,010606 plant biology & botany - Abstract
In a two-branched pea system, growth and IAA export from branches are controlled by a xylem cytokinin feedback loop regulated by apical auxin., A model system of 10–12 day-old, two-branched (2-B) pea (Pisum sativum L. cv. Adagumsky) seedlings was used to study the roles of endogenous auxin indole-3-acetic acid (IAA) and cytokinins (CKs) in the interaction between the shoots. The IAA export activity (IEA) from shoots was 2-fold higher in one-branched (1-B) plants with one shoot removed than in the 2-B plants, while tZ-type cytokinin contents in xylem sap were 4-fold greater in the 1-B plants than in 2-B plants. Exogenous 6-benzylaminopurine introduced into the vascular stream of one shoot enhanced its IEA. Therefore, xylem cytokinin appears to control both growth and IEA in branches. In the hypocotyls of 1-B and 2-B plants, IAA contents were equal in both cases, while the levels of tZ-type cytokinins were different. These data do not agree with the well-supported role of auxin in down-regulating CK content. The observed paradox may be explained by assuming that a steady-state IAA level in the hypocotyls is feedback regulated via xylem cytokinin, which controls the delivery of IAA from the shoots. As a result, the level of IAA in the hypocotyl is most likely maintained at a threshold below which a decrease in auxin content can switch on CK synthesis that will increase xylem cytokinin levels, thereby stabilizing the level of IAA in the hypocotyl. Therefore, our results suggest that correlative inhibition in the 2-B pea system is a function of an IAA/CK feedback loop, in which cytokinin essentially acts as a second messenger for IAA.
- Published
- 2018
25. Optimization of polar distribution of GhPIN3a in the ovule epidermis improves cotton fiber development
- Author
-
Zhiyuan Zhang and Gaofu Mei
- Subjects
Cytokinins ,Physiology ,Plant Science ,eXtra Botany ,Insights ,cotton ,Plant Epidermis ,chemistry.chemical_compound ,cytokinin ,Gene Expression Regulation, Plant ,fiber initiation ,Botany ,GhPIN3a ,heterocyclic compounds ,Fiber ,Cotton Fiber ,Ovule ,Plant Proteins ,Gossypium ,Epidermis (botany) ,Indoleacetic Acids ,polar auxin transport ,fungi ,food and beverages ,Research Papers ,chemistry ,Cytokinin ,Growth and Development ,Polar auxin transport ,Epidermis ,auxin - Abstract
Auxin-dependent cell expansion is crucial for initiation of fiber cells in cotton (Gossypium hirsutum), which ultimately determines fiber yield and quality. However, the regulation of this process is far from being well understood. In this study, we demonstrate an antagonistic effect between cytokinin (CK) and auxin on cotton fiber initiation. In vitro and in planta experiments indicate that enhanced CK levels can reduce auxin accumulation in the ovule integument, which may account for the defects in the fiberless mutant xu142fl. In turn, supplementation with auxin can recover fiber growth of CK-treated ovules and mutant ovules. We further found that GhPIN3a is a key auxin transporter for fiber-cell initiation and is polarly localized to the plasma membranes of non-fiber cells, but not to those of fiber cells. This polar localization allows auxin to be transported within the ovule integument while specifically accumulating in fiber cells. We show that CKs antagonize the promotive effect of auxin on fiber cell initiation by undermining asymmetric accumulation of auxin in the ovule epidermis through down-regulation of GhPIN3a and disturbance of the polar localization of the protein., Cytokinin antagonizes the promotive effect of auxin on cotton fiber initiation by disrupting the localization of GhPIN3a, which mediates asymmetric accumulation of auxin in the ovule epidermis.
- Published
- 2019
26. Haustorium initiation in the obligate parasitic plant Phelipanche ramosa involves a host-exudated cytokinin signal
- Author
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Sandra Pelletier, Lukáš Spíchal, Philippe Delavault, Fabrice Monteau, Marc-Marie Lechat, Estelle Billard, Vincent Goyet, Philippe Simier, Jean-Bernard Pouvreau, Grégory Montiel, Muriel Bahut, Université de Nantes (UN), Institut de Recherche en Horticulture et Semences (IRHS), Université d'Angers (UA)-Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes-Atlantique (ONIRIS), Palacky University Olomouc, French Ministry of Education and Research, Region Pays de Loire (RFI Objectif Vegetal project), and Ministry of Education, Youth and Sports of the Czech Republic (National Program of Sustainability) LO1204
- Subjects
[SDV.SA]Life Sciences [q-bio]/Agricultural sciences ,0106 biological sciences ,0301 basic medicine ,angiosperme ,Cytokinins ,genetic structures ,Physiology ,acide abscisique ,Plant Science ,01 natural sciences ,root exudates ,Plant Roots ,Phelipanche ramosa ,Transcriptome ,chemistry.chemical_compound ,Plant Growth Regulators ,méristème racinaire ,Haustorium ,heterocyclic compounds ,Vegetal Biology ,biology ,food and beverages ,histidine kinase ,[SDV.BV.BOT]Life Sciences [q-bio]/Vegetal Biology/Botanics ,Research Papers ,Agricultural sciences ,3. Good health ,Botanique ,haustorium ,Cytokinin ,gène candidat ,Growth and Development ,récepteur ,microarray ,psychological phenomena and processes ,Botanics ,root development ,Phytopathology and phytopharmacy ,Parasitic plant ,03 medical and health sciences ,Botany ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,Gene ,Allelopathy ,parasitic plant ,Obligate ,Brassica napus ,broomrape ,cytokinins ,Host (biology) ,Orobanche ,fungi ,biology.organism_classification ,Phytopathologie et phytopharmacie ,[SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy ,arabidopsis ,030104 developmental biology ,chemistry ,Biologie végétale ,Sciences agricoles ,010606 plant biology & botany - Abstract
The formation of the haustorium in holoparasitic plants as demonstrated in Phelipanche ramosa is initiated through perception of a host-exudated cytokinin and a cytokinin signaling response., The heterotrophic lifestyle of parasitic plants relies on the development of the haustorium, a specific infectious organ required for attachment to host roots. While haustorium development is initiated upon chemodetection of host-derived molecules in hemiparasitic plants, the induction of haustorium formation remains largely unknown in holoparasitic species such as Phelipanche ramosa. This work demonstrates that the root exudates of the host plant Brassica napus contain allelochemicals displaying haustorium-inducing activity on P. ramosa germinating seeds, which increases the parasite aggressiveness. A de novo assembled transcriptome and microarray approach with P. ramosa during early haustorium formation upon treatment with B. napus root exudates allowed the identification of differentially expressed genes involved in hormone signaling. Bioassays using exogenous cytokinins and the specific cytokinin receptor inhibitor PI-55 showed that cytokinins induced haustorium formation and increased parasite aggressiveness. Root exudates triggered the expression of cytokinin-responsive genes during early haustorium development in germinated seeds, and bio-guided UPLC-ESI(+)-/MS/MS analysis showed that these exudates contain a cytokinin with dihydrozeatin characteristics. These results suggest that cytokinins constitutively exudated from host roots play a major role in haustorium formation and aggressiveness in P. ramosa.
- Published
- 2017
27. Transcriptional regulatory network of WOX11 is involved in the control of crown root development, cytokinin signals, and redox in rice
- Author
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Yu Zhao, Qian Zhang, Wei Jiang, Shaoli Zhou, Huazhi Song, and Dao-Xiu Zhou
- Subjects
0106 biological sciences ,0301 basic medicine ,Cytokinins ,root development ,Physiology ,Cytokinin ,Plant Science ,Root hair ,Biology ,01 natural sciences ,Plant Roots ,Transcriptome ,03 medical and health sciences ,chemistry.chemical_compound ,Gene Expression Regulation, Plant ,Botany ,Electrophoretic mobility shift assay ,transcriptional regulation ,Gene Regulatory Networks ,Transcription factor ,Gene ,Plant Proteins ,rice ,Lateral root ,food and beverages ,Oryza ,WOX11 ,Cell biology ,030104 developmental biology ,chemistry ,redox ,Chromatin immunoprecipitation ,Oxidation-Reduction ,010606 plant biology & botany ,Research Paper ,Signal Transduction - Abstract
Rice WOX11 plays a regulatory role high in the hierarchy of control of multiple processes such as hormone signaling, stress response, redox, and metabolism during crown root development., The rice root system is mainly composed of post-embryonic shoot-borne roots called crown roots. WOX11, encoding a WUSCHEL-related homeobox domain transcription factor, is a key regulator of crown root growth and development in rice (Oryza sativa. L). In addition to specifically activating crown root development, WOX11 is also involved in lateral root initiation, root hair formation, and abiotic stresses. However, the gene regulatory network downstream of WOX11 remains largely unknown. Here, we studied the transcriptome of wox11 root tips by RNA-Seq and determined direct WOX11-binding targets by bioinformatic and biochemical analysis. The transcriptomic analysis revealed 664 differentially expressed genes, which covered a wide range of functions related to root development, cytokinin homeostasis/signaling, stress response, and redox metabolic processes. Bioinformatic analysis also revealed that the WOX11-binding motif was distributed over 41% (273/664) of the differentially expressed genes, and was mostly enriched in the promoter and intron regions. We used qRT-PCR and/or in situ hybridization to confirm co-expression of some of the WOX11-regulated genes in crown root development. We also used electrophoretic mobility shift assay and chromatin immunoprecipitation with anti-WOX11 antibody to validate direct regulation of these genes by WOX11. The analysis identified several genes that acted downstream of WOX11 in controlling crown root formation, cytokinin signaling, stress response, and redox metabolism. This work built a hierarchical regulatory model of WOX11 in rice crown root development.
- Published
- 2017
28. AHP2, AHP3, and AHP5 act downstream of CKI1 in Arabidopsis female gametophyte development
- Author
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Venkatesan Sundaresan, Zhenning Liu, Xiaolin Yu, Li Yuan, and Xiaoya Song
- Subjects
0106 biological sciences ,0301 basic medicine ,Egg cell ,Cytokinins ,Physiology ,Mutant ,Arabidopsis ,female gametophyte development ,Flowers ,Plant Science ,Biology ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,Botany ,medicine ,Ovule ,Gametophyte ,histidine phosphotransfer proteins ,Arabidopsis Proteins ,Phosphotransferases ,Embryo ,biology.organism_classification ,Research Papers ,3. Good health ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Cytokinin ,Phosphorylation ,Growth and Development ,Protein Kinases ,Signal Transduction ,010606 plant biology & botany - Abstract
Only AHP2, AHP3, and AHP5 are downstream targets of CKI1 in regulating Arabidopsis female gametophyte development., Histidine phosphotransfer proteins (HPs) are key elements of the two-component signaling system, which act as a shuttle to transfer phosphorylation signals from histidine kinases (HKs) to response regulators (RRs). CYTOKININ INDEPENDENT 1 (CKI1), a key regulator of central cell specification in the Arabidopsis female gametophyte, activates the cytokinin signaling pathway through the Arabidopsis histidine phosphotransfer proteins (AHPs). There are five HP genes in Arabidopsis, AHP1–AHP5, but it remains unknown which AHP genes act downstream of CKI1 in Arabidopsis female gametophyte development. Promoter activity analysis of AHP1–AHP5 in embryo sacs revealed AHP1, AHP2, AHP3, and AHP5 expression in the central cell. Phenotypic studies of various combinations of ahp mutants showed that triple mutations in AHP2, AHP3, and AHP5 resulted in defective embryo sac development. Using cell-specific single and double markers in the female gametophyte, the ahp2-2 ahp3 ahp5-2/+ triple mutant ovules showed loss of central cell and antipodal cell fates and gain of egg cell or synergid cell attributes, resembling the cki1 mutant phenotypes. These data suggest that AHP2, AHP3, and AHP5 are the major factors acting downstream of CKI1 in the two-component cytokinin signaling pathway to promote Arabidopsis female gametophyte development.
- Published
- 2017
29. Analysis of CFB, a cytokinin-responsive gene of Arabidopsis thaliana encoding a novel F-box protein regulating sterol biosynthesis
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Hubert Schaller, Laetitia B. B. Martin, Thomas Schmülling, Anne Cortleven, Jan Erik Leuendorf, and Wolfram G. Brenner
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DNA, Bacterial ,0106 biological sciences ,0301 basic medicine ,F-box protein ,Cytokinins ,cycloartenol synthase ,Albinism ,Physiology ,Recombinant Fusion Proteins ,Ubiquitin-Protein Ligases ,Green Fluorescent Proteins ,Mutant ,Arabidopsis ,Plant Science ,Protein degradation ,Plant Roots ,01 natural sciences ,cytokinin ,03 medical and health sciences ,chloroplast ,Gene Expression Regulation, Plant ,sterol biosynthesis ,Botany ,Arabidopsis thaliana ,heterocyclic compounds ,plastid ,Intramolecular Transferases ,Lateral root formation ,Alleles ,Phylogeny ,biology ,Arabidopsis Proteins ,Chemistry ,F-Box Proteins ,fungi ,Phytosterols ,food and beverages ,biology.organism_classification ,Fusion protein ,Ubiquitin ligase ,Cell biology ,030104 developmental biology ,Cycloartenol synthase ,biology.protein ,lipids (amino acids, peptides, and proteins) ,Research Paper ,Protein Binding ,010606 plant biology & botany - Abstract
Albinotic inflorescence stems of Arabidopsis plants overexpressing the cytokinin-responsive gene Cytokinin-induced F-box encoding (CFB) phenocopy the sterol biosynthesis mutant cas1-1 and accumulate 2,3-oxidosqualene, suggesting a link between cytokinin and sterol biosynthesis., Protein degradation by the ubiquitin–26S proteasome pathway is important for the regulation of cellular processes, but the function of most F-box proteins relevant to substrate recognition is unknown. We describe the analysis of the gene Cytokinin-induced F-box encoding (CFB, AT3G44326), identified in a meta-analysis of cytokinin-related transcriptome studies as one of the most robust cytokinin response genes. F-box domain-dependent interaction with the E3 ubiquitin ligase complex component ASK1 classifies CFB as a functional F-box protein. Apart from F-box and transmembrane domains, CFB contains no known functional domains. CFB is expressed in all plant tissues, predominantly in root tissue. A ProCFB:GFP-GUS fusion gene showed strongest expression in the lateral root cap and during lateral root formation. CFB-GFP fusion proteins were mainly localized in the nucleus and the cytosol but also at the plasma membrane. cfb mutants had no discernible phenotype, but CFB overexpressing plants showed several defects, such as a white upper inflorescence stem, similar to the hypomorphic cycloartenol synthase mutant cas1-1. Both CFB overexpressing plants and cas1-1 mutants accumulated the CAS1 substrate 2,3-oxidosqualene in the white stem tissue, the latter even more after cytokinin treatment, indicating impairment of CAS1 function. This suggests that CFB may link cytokinin and the sterol biosynthesis pathway.
- Published
- 2017
30. Cytokinin activity increases stomatal density and transpiration rate in tomato
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Ziv Attia, David Weiss, and Mika Farber
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0301 basic medicine ,Cytokinins ,Physiology ,stomata ,Cytokinin ,Arabidopsis ,Plant Science ,drought ,Biology ,tomato ,03 medical and health sciences ,chemistry.chemical_compound ,Solanum lycopersicum ,Guard cell ,Botany ,Arabidopsis thaliana ,Genetically modified tomato ,Transpiration ,Pavement cells ,Oxidase test ,integumentary system ,Dehydration ,Reverse Transcriptase Polymerase Chain Reaction ,fungi ,food and beverages ,Plant Transpiration ,biology.organism_classification ,Plants, Genetically Modified ,Plant Leaves ,030104 developmental biology ,chemistry ,Plant Stomata ,transpiration ,Solanum ,stomatal density ,Oxidoreductases ,Cell Division ,Research Paper - Abstract
Highlight Manipulation of cytokinin levels in tomato plants affected transpiration rate. While the hormone had no effect on stomatal movement, it increased stomatal density by promoting epidermal cell division., Previous studies on cytokinin (CK) and drought have suggested that the hormone has positive and negative effects on plant adaptation to restrictive conditions. This study examined the effect of CK on transpiration, stomatal activity, and response to drought in tomato (Solanum lycopersicum) plants. Transgenic tomato plants overexpressing the Arabidopsis thaliana CK-degrading enzyme CK oxidase/dehydrogenase 3 (CKX3) maintained higher leaf water status under drought conditions due to reduced whole-plant transpiration. The reduced transpiration could be attributed to smaller leaf area and reduced stomatal density. CKX3-overexpressing plants contained fewer and larger pavement cells and fewer stomata per leaf area than wild-type plants. In addition, wild-type leaves treated with CK exhibited enhanced transpiration and had more pavement cells and increased numbers of stomata per leaf area than untreated leaves. Manipulation of CK levels did not affect stomatal movement or abscisic acid-induced stomatal closure. Moreover, we found no correlation between stomatal aperture and the activity of the CK-induced promoter Two-Component Signaling Sensor (TCS) in guard cells. Previous studies have shown that drought reduces CK levels, and we propose this to be a mechanism of adaptation to water deficiency: the reduced CK levels suppress growth and reduce stomatal density, both of which reduce transpiration, thereby increasing tolerance to prolonged drought conditions.
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- 2016
31. Root-shoot communication in tomato plants: cytokinin as a signal molecule modulating leaf photosynthetic activity
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Petr Tarkowski, Veronika Turečková, Noga Glanz-Idan, and Shmuel Wolf
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0106 biological sciences ,0301 basic medicine ,Sucrose ,Cytokinins ,Physiology ,Cytokinin ,Plant Science ,tomato ,xylem ,Photosynthesis ,01 natural sciences ,Plant Roots ,03 medical and health sciences ,chemistry.chemical_compound ,Solanum lycopersicum ,photosynthesis ,Carbon fixation ,fungi ,Xylem ,food and beverages ,Carbohydrate ,Riboside ,source–sink relationship ,Research Papers ,Plant Leaves ,Horticulture ,030104 developmental biology ,chemistry ,Shading ,Plant Shoots ,leaf development ,010606 plant biology & botany ,Signal Transduction ,Photosynthesis and Metabolism - Abstract
Partial defoliation up-regulated photosynthesis and down-regulated expression of sucrose export-related genes in tomato leaves, and increased trans-zeatin riboside in the roots, implicating this cytokinin in root–shoot signaling., Photosynthetic activity is affected by exogenous and endogenous inputs, including source–sink balance. Reducing the source to sink ratio by partial defoliation or heavy shading resulted in significant elevation of the photosynthetic rate in the remaining leaf of tomato plants within 3 d. The remaining leaf turned deep green, and its area increased by almost 3-fold within 7 d. Analyses of photosynthetic activity established up-regulation due to increased carbon fixation activity in the remaining leaf, rather than due to altered water balance. Moreover, senescence of the remaining leaf was significantly inhibited. As expected, carbohydrate concentration was lower in the remaining leaf than in the control leaves; however, expression of genes involved in sucrose export was significantly lower. These results suggest that the accumulated fixed carbohydrates were primarily devoted to increasing the size of the remaining leaf. Detailed analyses of the cytokinin content indicated that partial defoliation alters cytokinin biosynthesis in the roots, resulting in a higher concentration of trans-zeatin riboside, the major xylem-translocated molecule, and a higher concentration of total cytokinin in the remaining leaf. Together, our findings suggest that trans-zeatin riboside acts as a signal molecule that traffics from the root to the remaining leaf to alter gene expression and elevate photosynthetic activity.
- Published
- 2019
32. Ethylene-independent promotion of photomorphogenesis in the dark by cytokinin requires COP1 and the CDD complex
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Thomas Schmülling, Stephanie Ehret, Anne Cortleven, and Henrik Johansson
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0106 biological sciences ,0301 basic medicine ,Cytokinins ,Light Signal Transduction ,Physiology ,Ubiquitin-Protein Ligases ,Arabidopsis ,Plant Science ,Skotomorphogenesis ,01 natural sciences ,Hypocotyl ,500 Naturwissenschaften und Mathematik::570 Biowissenschaften ,Biologie::576 Genetik und Evolution ,03 medical and health sciences ,chemistry.chemical_compound ,cytokinin ,Plant Growth Regulators ,Gene Expression Regulation, Plant ,500 Naturwissenschaften und Mathematik::580 Pflanzen (Botanik)::580 Pflanzen (Botanik) ,ethylene ,Arabidopsis thaliana ,heterocyclic compounds ,biology ,light signaling ,Arabidopsis Proteins ,fungi ,arabidopsis thaliana ,Intracellular Signaling Peptides and Proteins ,food and beverages ,Ethylenes ,biology.organism_classification ,Research Papers ,Cell biology ,photomorphogenesis ,Light intensity ,030104 developmental biology ,chemistry ,two-component signaling system ,Cytokinin ,Ubiquitin-Conjugating Enzymes ,Photomorphogenesis ,Plant hormone ,Growth and Development ,010606 plant biology & botany - Abstract
Cytokinin promotes photomorphogenesis independent of ethylene, acting through the two-component signaling system and requiring a functional light-signaling system., The transition of skotomorphogenesis to photomorphogenesis is induced by the perception of light, and is characterized by the inhibition of hypocotyl elongation and opening of cotyledons. Although it is known that the plant hormone cytokinin inhibits hypocotyl elongation in dark-grown Arabidopsis plants when applied in high concentrations, it is unclear to what extent this response is the result of cytokinin alone or cytokinin-induced ethylene production. Here, we show that cytokinin-induced inhibition of hypocotyl elongation is largely independent of ethylene and suggest a close connection between the cytokinin two-component system and the light-signaling networks. We show that this cytokinin signal is mainly mediated through the cytokinin receptor ARABIDOPSIS HISTIDINE KINASE3 and the ARABIDOPSIS RESPONSE REGULATOR1 in combination with ARR12. Interestingly, mutation of CONSTITUTIVELY PHOTOMORPOGENIC1 (COP1), DE-ETIOLATED1, and CYTOKININ INSENSITIVE4/COP10 renders plants insensitive to cytokinin, and these factors are indispensable for the transcriptional response during cytokinin-induced de-etiolation, indicating that a functional light-signaling pathway is essential for this cytokinin response. In addition, the effect of cytokinin on hypocotyl elongation is strongly dependent on the light conditions, with higher light intensities causing a switch in the response to cytokinin from an inhibitor to a promoter of hypocotyl elongation.
- Published
- 2019
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33. Sucrose is an early modulator of the key hormonal mechanisms controlling bud outgrowth in Rosa hybrida
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Marion Lecerf, Thomas Péron, François Barbier, Stéphanie Boutet-Mercey, Jessica Bertheloot, Benoit Porcheron, Sylvie Citerne, Hanaé Roman, Soulaiman Sakr, Quentin Barrière, Jakub Rolčík, Rémi Lemoine, José Gentilhomme-Le Gourrierec, Nathalie Leduc, Maria-Dolores Perez-Garcia, Institut de Recherche en Horticulture et Semences (IRHS), AGROCAMPUS OUEST-Institut National de la Recherche Agronomique (INRA)-Université d'Angers (UA), Laboratory of Growth Regulators, Palacky University and Institute of Experimental Botany ASCR, Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Laboratoire de catalyse en chimie organique (LACCO), Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Écophysiologie des Plantes sous Stress environnementaux (LEPSE), Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), SFR QUASAV 4207, Lab Biol & Pathol Vegetales, PRES Université Nantes Angers Le Mans (UNAM), Centre de Recherche des Cordeliers (CRC), Université Paris Diderot - Paris 7 (UPD7)-École pratique des hautes études (EPHE)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM), Universidad de Salamanca, Salamanca, Spain, Universidad de Salamanca, Ecologie et biologie des interactions (EBI), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Université d'Angers (UA)-Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Laboratory of Growth Regulators [Univ Palacký] (LGR), Faculty of Science [Univ Palacký], Palacky University Olomouc-Palacky University Olomouc-Institute of Experimental Botany of the Czech Academy of Sciences (IEB / CAS), Czech Academy of Sciences [Prague] (CAS)-Czech Academy of Sciences [Prague] (CAS), Sucres & Echanges Végétaux-Environnement (SEVE), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Écophysiologie des Plantes sous Stress environnementaux ( LEPSE ), Centre international d'études supérieures en sciences agronomiques ( Montpellier SupAgro ) -Institut National de la Recherche Agronomique ( INRA ) -Institut national d’études supérieures agronomiques de Montpellier ( Montpellier SupAgro ), Université Nantes Angers Le Mans, Centre de Recherche des Cordeliers ( CRC ), Université Paris Diderot - Paris 7 ( UPD7 ) -École pratique des hautes études ( EPHE ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Université Paris Descartes - Paris 5 ( UPD5 ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ), Institut de Recherche en Horticulture et Semences ( IRHS ), Université d'Angers ( UA ) -Institut National de la Recherche Agronomique ( INRA ) -AGROCAMPUS OUEST, Institut Jean-Pierre Bourgin ( IJPB ), Institut National de la Recherche Agronomique ( INRA ) -AgroParisTech, Ecologie et biologie des interactions ( EBI ), Université de Poitiers-Centre National de la Recherche Scientifique ( CNRS ), and Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)
- Subjects
[ SDV.BV ] Life Sciences [q-bio]/Vegetal Biology ,Sucrose ,sugar signaling ,Physiology ,Mutant ,Flowers ,strigolactones ,Plant Science ,Biology ,Rosa ,Rosa sp ,Bud burst ,Pisum ,chemistry.chemical_compound ,Plant Growth Regulators ,Gene Expression Regulation, Plant ,Auxin ,shoot branching ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,Arabidopsis thaliana ,Sugar ,ComputingMilieux_MISCELLANEOUS ,Plant Proteins ,2. Zero hunger ,chemistry.chemical_classification ,Indoleacetic Acids ,fungi ,food and beverages ,Biological Transport ,sugar signalling ,biology.organism_classification ,Hedgehog signaling pathway ,cytokinins ,chemistry ,Biochemistry ,sugar ,Cytokinin ,auxin ,Research Paper ,Signal Transduction - Abstract
Highlight Recent research shows that sugar availability triggers bud outgrowth. This paper further demonstrates that the effect of sucrose involves changes in the hormonal network related to bud outgrowth, and identifies potential hormones involved in sugar control., Sugar has only recently been identified as a key player in triggering bud outgrowth, while hormonal control of bud outgrowth is already well established. To get a better understanding of sugar control, the present study investigated how sugar availability modulates the hormonal network during bud outgrowth in Rosa hybrida. Other plant models, for which mutants are available, were used when necessary. Buds were grown in vitro to manipulate available sugars. The temporal patterns of the hormonal regulatory network were assessed in parallel with bud outgrowth dynamics. Sucrose determined bud entrance into sustained growth in a concentration-dependent manner. Sustained growth was accompanied by sustained auxin production in buds, and sustained auxin export in a DR5::GUS-expressing pea line. Several events occurred ahead of sucrose-stimulated bud outgrowth. Sucrose upregulated early auxin synthesis genes (RhTAR1, RhYUC1) and the auxin efflux carrier gene RhPIN1, and promoted PIN1 abundance at the plasma membrane in a pPIN1::PIN1-GFP-expressing tomato line. Sucrose downregulated both RwMAX2, involved in the strigolactone-transduction pathway, and RhBRC1, a repressor of branching, at an early stage. The presence of sucrose also increased stem cytokinin content, but sucrose-promoted bud outgrowth was not related to that pathway. In these processes, several non-metabolizable sucrose analogues induced sustained bud outgrowth in R. hybrida, Pisum sativum, and Arabidopsis thaliana, suggesting that sucrose was involved in a signalling pathway. In conclusion, we identified potential hormonal candidates for bud outgrowth control by sugar. They are central to future investigations aimed at disentangling the processes that underlie regulation of bud outgrowth by sugar.
- Published
- 2015
34. A protocol for the development and maintenance of Coffea arabica (L.) cell suspension cultures.
- Author
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Di Bonaventura, Azzurra, Marchetti, Stefano, Petrussa, Elisa, Braidot, Enrico, Colomban, Silvia, Navarini, Luciano, and Zancani, Marco
- Abstract
Coffea spp. are remarkable sources of phytochemicals, but the lack of a well-defined culture medium aimed at the induction of non-embryogenic and friable callus hampers the establishment of plant cell suspension cultures for large-scale production of valuable compounds. In this paper, we describe a one-medium protocol suitable to obtain both callus and cell suspension cultures from leaves of two elite cultivars of C. arabica. The protocol was developed through an iterative process involving the determination of the best concentration of auxin and cytokinin, their optimal ratio, as well as the most effective molecule of either hormone class. Young leaves were found to be a good and easy-to-use explant source for callus induction and proliferation, provided that a cytokinin was present in association with a chlorinated auxin in a full strength, semi-solid MS medium. The best results were obtained by hormone concentration and combination of 1 mg/L of both kinetin and 2,4,5-trichlorophenoxyacetic acid. The same ratio of these growth regulators was conveniently used for the development and stabilization of cell suspension cultures in liquid MS medium. When grown in darkness, stabilized suspension cultures showed a fine and homogeneous texture, with a 10-fold biomass increase within 25 days and a cell viability > 90%. In addition, the phytochemical profile revealed the presence of the most widely studied coffee compounds. The protocol can be applied to obtain adequate amounts of cell biomass for use in physiological studies concerning the production of secondary metabolites.Key messages: A protocol for callus induction and undifferentiated cell suspensions establishment in Coffea arabica was developed. This technique represents a useful tool for in vitro production of remarkable phytochemicals from coffee. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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35. Function of the Golgi-located phosphate transporter PHT4;6 is critical for senescence-associated processes in Arabidopsis
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Lilia Lemke, H. Ekkehard Neuhaus, Ondřej Novák, Benjamin Jung, Enrico Martinoia, Miroslav Strnad, Sebastian Hassler, University of Zurich, and Neuhaus, H Ekkehard
- Subjects
0106 biological sciences ,0301 basic medicine ,Senescence ,Chlorophyll ,Aging ,senescence ,Cytokinins ,Light ,Physiology ,salicylic acid ,Mutant ,Arabidopsis ,Golgi Apparatus ,Plant Science ,580 Plants (Botany) ,01 natural sciences ,03 medical and health sciences ,chemistry.chemical_compound ,cytokinin ,10126 Department of Plant and Microbial Biology ,Gene Expression Regulation, Plant ,1110 Plant Science ,sugars ,Golgi ,Phosphate Transport Proteins ,10211 Zurich-Basel Plant Science Center ,Gene ,phosphate ,biology ,Arabidopsis Proteins ,fungi ,food and beverages ,1314 Physiology ,Phosphate ,biology.organism_classification ,Cytosol ,030104 developmental biology ,Biochemistry ,chemistry ,Cytokinin ,Intracellular ,Ammonium ,010606 plant biology & botany ,Research Paper - Abstract
Highlight Plants with altered intracellular Pi compartmentation surprisingly show accelerated dark-induced senescence. We propose that low cytosolic phosphate concentrations are of critical importance for proper plant development., The phosphate transporter PHT4;6 locates to the trans-Golgi compartment, and its impaired activity causes altered intracellular phosphate compartmentation, leading to low cytosolic Pi levels, a blockage of Golgi-related processes such as protein glycosylation and hemicellulose biosynthesis, and a dwarf phenotype. However, it was unclear whether altered Pi homeostasis in pht4;6 mutants causes further cellular problems, typically associated with limited phosphate availability. Here we report that pht4;6 mutants exhibit a markedly increased disposition to induce dark-induced senescence. In control experiments, in which pht4;6 mutants and wild-type plants developed similarly, we confirmed that accelerated dark-induced senescence in mutants is not a ‘pleiotropic’ process associated with the dwarf phenotype. In fact, accelerated dark-induced senescence in pht4;6 mutants correlates strongly with increased levels of toxic NH4 + and higher sensitivity to ammonium, which probably contribute to the inability of pht4;6 mutants to recover from dark treatment. Experiments with modified levels of either salicylic acid (SA) or trans-zeatin (tZ) demonstrate that altered concentrations of these compounds in pht4;6 plants act as major cellular mediators for dark-induced senescence. This conclusion gained further support from the notion that the expression of the pht4;6 gene is, in contrast to genes coding for major phosphate importers, substantially induced by tZ. Taken together, our findings point to a critical function of PHT4;6 to control cellular phosphate levels, in particular the cytosolic Pi availability, required to energize plant primary metabolism for proper plant development. Phosphate and its allocation mediated by PHT4;6 is critical to prevent onset of dark-induced senescence.
- Published
- 2016
36. Stimulation ofiptoverexpression as a tool to elucidate the role of cytokinins in high temperature responses ofArabidopsis thaliana
- Author
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Jana Dobrá, Eva Ge, Jan Novák, Petre I. Dobrev, Martin Černý, Radomira Vankova, Jan Skalák, Marie Hronková, Břetislav Brzobohatý, and Petr Jedelský
- Subjects
Proteomics ,0106 biological sciences ,0301 basic medicine ,Cytokinins ,Hot Temperature ,Arabidopsis thaliana ,Physiology ,Arabidopsis ,Plant Science ,Plant Roots ,01 natural sciences ,Dexamethasone ,proteome ,heat stress ,Transcriptome ,Abscisic acid ,cytokinin ,03 medical and health sciences ,chemistry.chemical_compound ,Plant Growth Regulators ,Gene Expression Regulation, Plant ,Gene expression ,heterocyclic compounds ,Heat shock ,Alkyl and Aryl Transferases ,biology ,Gene Expression Profiling ,fungi ,food and beverages ,biology.organism_classification ,Molecular biology ,030104 developmental biology ,chemistry ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Proteome ,Cytokinin ,isopentenyltransferase ,Heat-Shock Response ,Plant Shoots ,Research Paper ,Signal Transduction ,010606 plant biology & botany - Abstract
Highlight Decisive role for cytokinins in stimulation of transpiration during the early heat stress response was demonstrated. Longer term positive effects of cytokinins were associated with elevation of stress- and photosynthesis-related proteins and transcripts., Cytokinins (CKs) are phytohormones regulating plant growth and development as well as response to the environment. In order to evaluate their function in heat stress (HS) responses, the effect of CK elevation was determined during three types of HS – targeted to shoots, targeted to roots and applied to the whole plant. The early (30min) and longer term (3h) responses were followed at the hormonal, transcriptomic and proteomic levels in Arabidopsis transformants with dexamethasone-inducible expression of the CK biosynthetic gene isopentenyltransferase (ipt) and the corresponding wild-type (Col-0). Combination of hormonal and phenotypic analyses showed transient up-regulation of the CK/abscisic acid ratio, which controls stomatal aperture, to be more pronounced in the transformant. HS responses of the root proteome and Rubisco-immunodepleted leaf proteome were followed using 2-D gel electrophoresis and MALDI-TOF/TOF. More than 100 HS-responsive proteins were detected, most of them being modulated by CK increase. Proteome and transcriptome analyses demonstrated that CKs have longer term positive effects on the stress-related proteins and transcripts, as well as on the photosynthesis-related ones. Transient accumulation of CKs and stimulation of their signal transduction in tissue(s) not exposed to HS indicate that they are involved in plant stress responses.
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- 2016
37. Enhancing cytokinin synthesis by overexpressingiptalleviated drought inhibition of root growth through activating ROS-scavenging systems inAgrostis stolonifera
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Xunzhong Zhang, Patrick Burgess, Yi Xu, and Bingru Huang
- Subjects
0106 biological sciences ,0301 basic medicine ,Alternative respiration ,Cytokinins ,Agrostis stolonifera ,Physiology ,Ascorbic Acid ,Plant Science ,Plant Roots ,01 natural sciences ,Antioxidants ,Electrolytes ,chemistry.chemical_compound ,Agrostis ,Gene Expression Regulation, Plant ,Superoxides ,Malondialdehyde ,Biomass ,2. Zero hunger ,chemistry.chemical_classification ,biology ,drought stress ,food and beverages ,Free Radical Scavengers ,Catalase ,Plants, Genetically Modified ,Glutathione ,6. Clean water ,Droughts ,Cytokinin ,Antioxidant ,Research Paper ,Nitroprusside ,Cell Respiration ,Real-Time Polymerase Chain Reaction ,Superoxide dismutase ,03 medical and health sciences ,Stress, Physiological ,parasitic diseases ,Botany ,RNA, Messenger ,ROS scavenging system ,Reactive oxygen species ,Alkyl and Aryl Transferases ,Superoxide Dismutase ,root respiration ,fungi ,qRT-PCR ,15. Life on land ,Ascorbic acid ,biology.organism_classification ,030104 developmental biology ,chemistry ,turfgrass ,biology.protein ,Reactive Oxygen Species ,010606 plant biology & botany - Abstract
Highlight The relationship between an adenine isopentenyltransferase transgene, reactive oxygen species (ROS) content and the ROS-scavenging system, mechanistically contributing to improved root growth under drought stress in creeping bentgrass, is discussed., Drought stress limits root growth and inhibits cytokinin (CK) production. Increases in CK production through overexpression of isopentenyltransferase (ipt) alleviate drought damages to promote root growth. The objective of this study was to investigate whether CK-regulated root growth was involved in the alteration of reactive oxygen species (ROS) production and ROS scavenging capacity under drought stress. Wild-type (WT) creeping bentgrass (Agrostis stolonifera L. ‘Penncross’) and a transgenic line (S41) overexpressing ipt ligated to a senescence-activated promoter (SAG12) were exposed to drought stress for 21 d in growth chambers. SAG12-ipt transgenic S41 developed a more extensive root system under drought stress compared to the WT. Root physiological analysis (electrolyte leakage and lipid peroxidation) showed that S41 roots exhibited less cellular damage compared to the WT under drought stress. Roots of SAG12-ipt transgenic S41 had significantly higher endogenous CK content than the WT roots under drought stress. ROS (hydrogen peroxide and superoxide) content was significantly lower and content of total and free ascorbate was significantly higher in S41 roots compared to the WT roots under drought stress. Enzymatic assays and transcript abundance analysis showed that superoxide dismutase, catalase, peroxidase, and dehydroascorbate reductase were significantly higher in S41 roots compared to the WT roots under drought stress. S41 roots also maintained significantly higher alternative respiration rates compared to the WT under drought stress. The improved root growth of transgenic creeping bentgrass may be facilitated by CK-enhanced ROS scavenging through antioxidant accumulation and activation of antioxidant enzymes, as well as higher alternative respiration rates when soil water is limited.
- Published
- 2016
38. Proteomic and metabolomic integration reveals the effects of pre-flowering cytokinin applications on central carbon metabolism in table grape berries.
- Author
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Olmedo P, Núñez-Lillo G, Vidal J, Leiva C, Rojas B, Sagredo K, Arriagada C, Defilippi BG, Pérez-Donoso AG, Meneses C, Carpentier S, Pedreschi R, and Campos-Vargas R
- Subjects
- Fruit metabolism, Proteomics, Metabolomics, Cytokinins, Vitis metabolism
- Abstract
Consumers around the world prefer high quality table grapes. To achieve higher quality traits at ripening, grapevine producers apply different plant growth regulators. The synthetic cytokinin forchlorfenuron N-(2-chloro-4-pyridinyl)-N'-phenylurea (CPPU) is widely used, its effect on grape quality is poorly understood. We hypothesized that the use of CPPU in pre-flowering can lead to changes in the metabolism that affects grape quality at harvest. Therefore, we investigated the role of CPPU applications on the quality of grapes by integrating proteomics and metabolomics. CPPU-treated grapevines showed a significant increase in berry size and firmness. Proteomic analyses indicated that CPPU-treated berries accumulated enzymes associated with carbohydrate metabolism, glycolysis, and tricarboxylic acid (TCA) cycle at harvest. Metabolomic analyses showed shifts in the abundance of compounds associated with carbohydrate metabolism and TCA cycle in CPPU-treated grapes. These findings suggest that CPPU applications modulate central carbon metabolism, improving grape berry quality., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)
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- 2023
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39. A Gene Regulatory Network for Cellular Reprogramming in Plant Regeneration
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Lewis G Watt, Anne-Maarit Bågman, Sebastian E. Ahnert, Tatsuya Takahashi, Siobhan M. Brady, David S. Favero, Michitaro Shibata, Keiko Sugimoto, Bart Rymen, Akira Iwase, Duncan Coleman, Momoko Ikeuchi, Ikeuchi, Momoko [0000-0001-9474-5131], Shibata, Michitaro [0000-0002-7008-8437], Favero, David S [0000-0002-6879-0323], Brady, Siobhan M [0000-0001-9424-8055], and Apollo - University of Cambridge Repository
- Subjects
0301 basic medicine ,Cytokinins ,Physiology ,Apetala 2 ,Callus formation ,Plant Biology & Botany ,Gene regulatory network ,Cytokinin ,Plant Biology ,Plant Science ,Biology ,Regenerative Medicine ,Genes, Plant ,Promoter Regions ,03 medical and health sciences ,Genetic ,Plant Cells ,Genetics ,2.1 Biological and endogenous factors ,Regeneration ,Auxin ,Gene Regulatory Networks ,Aetiology ,Enhancer ,Promoter Regions, Genetic ,Transcription factor ,Indoleacetic Acids ,Arabidopsis Proteins ,Regeneration (biology) ,fungi ,food and beverages ,Cell Biology ,General Medicine ,Plant ,Plants ,Cellular Reprogramming ,Special Issue – Regular Papers ,Cell biology ,Wound stress ,030104 developmental biology ,Genes ,Biochemistry and Cell Biology ,Regulatory Pathway ,Reprogramming ,Biotechnology ,Transcription Factors - Abstract
Wounding triggers organ regeneration in many plant species, and application of plant hormones, such as auxin and cytokinin, enhances their regenerative capacities in tissue culture. Recent studies have identified several key players mediating wound- and/or plant hormone-induced cellular reprogramming, but the global architecture of gene regulatory relationships underlying plant cellular reprogramming is still far from clear. In this study, we uncovered a gene regulatory network (GRN) associated with plant cellular reprogramming by using an enhanced yeast one-hybrid (eY1H) screen systematically to identify regulatory relationships between 252 transcription factors (TFs) and 48 promoters. Our network analyses suggest that wound- and/or hormone-invoked signals exhibit extensive cross-talk and regulate many common reprogramming-associated genes via multilayered regulatory cascades. Our data suggest that PLETHORA 3 (PLT3), ENHANCER OF SHOOT REGENERATION 1 (ESR1) and HEAT SHOCK FACTOR B 1 (HSFB1) act as critical nodes that have many overlapping targets and potentially connect upstream stimuli to downstream developmental decisions. Interestingly, a set of wound-inducible APETALA 2/ETHYLENE RESPONSE FACTORs (AP2/ERFs) appear to regulate these key genes, which, in turn, form feed-forward cascades that control downstream targets associated with callus formation and organ regeneration. In addition, we found another regulatory pathway, mediated by LATERAL ORGAN BOUNDARY/ASYMMETRIC LEAVES 2 (LOB/AS2) TFs, which probably plays a distinct but partially overlapping role alongside the AP2/ERFs in the putative gene regulatory cascades. Taken together, our findings provide the first global picture of the GRN governing plant cell reprogramming, which will serve as a valuable resource for future studies.
- Published
- 2018
40. Fruit-localized phytochromes regulate plastid biogenesis, starch synthesis and carotenoid metabolism in tomato
- Author
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Luciano Freschi, Ricardo Ernesto Bianchetti, Magdalena Rossi, Diego Demarco, Eduardo Purgatto, Scarlet Santos Monteiro, Bruno Silvestre Lira, Christophe Rothan, Universidade de São Paulo (USP), Biologie du fruit et pathologie (BFP), and Université Bordeaux Segalen - Bordeaux 2-Institut National de la Recherche Agronomique (INRA)-Université Sciences et Technologies - Bordeaux 1
- Subjects
0106 biological sciences ,0301 basic medicine ,Cytokinins ,Light Signal Transduction ,Physiology ,fleshy fruit ,Plant Science ,tomato ,01 natural sciences ,03 medical and health sciences ,cytokinin ,Solanum lycopersicum ,Plant Growth Regulators ,CAROTENOIDES ,Gene expression ,Transcriptional regulation ,Gene silencing ,[SDV.BV]Life Sciences [q-bio]/Vegetal Biology ,Plastids ,fleshy fruits ,Plastid ,2. Zero hunger ,phytochrome ,Phytochrome ,biology ,Indoleacetic Acids ,starch ,fungi ,food and beverages ,Ripening ,biology.organism_classification ,Research Papers ,Carotenoids ,carotenoid ,Cell biology ,plastid division ,030104 developmental biology ,Fruit ,Growth and Development ,Solanum ,auxin ,Biogenesis ,010606 plant biology & botany - Abstract
Fruit-localized phytochromes and their downstream signaling cascades not only modulate chloroplast biogenesis in immature tomato fruits but also regulate sugar and carotenoid accumulation, two essential features of tomato fruit quality., Light signaling has long been reported to influence fruit biology, although the regulatory impact of fruit-localized photoreceptors on fruit development and metabolism remains unclear. Studies performed in phytochrome (PHY)-deficient tomato (Solanum lycopersicum) mutants suggest that SlPHYA, SlPHYB2, and to a lesser extent SlPHYB1 influence fruit development and ripening. By employing fruit-specific RNAi-mediated silencing of SlPHY genes, we demonstrated that fruit-localized SlPHYA and SlPHYB2 play contrasting roles in regulating plastid biogenesis and maturation in tomato. Our data revealed that fruit-localized SlPHYA, rather than SlPHYB1 or SlPHYB2, positively influences tomato plastid differentiation and division machinery via changes in both light and cytokinin signaling-related gene expression. Fruit-localized SlPHYA and SlPHYB2 were also shown to modulate sugar metabolism in early developing fruits via overlapping, yet distinct, mechanisms involving the co-ordinated transcriptional regulation of genes related to sink strength and starch biosynthesis. Fruit-specific SlPHY silencing also drastically altered the transcriptional profile of genes encoding light-repressor proteins and carotenoid-biosynthesis regulators, leading to reduced carotenoid biosynthesis during fruit ripening. Together, our data reveal the existence of an intricate PHY–hormonal interplay during fruit development and ripening, and provide conclusive evidence on the regulation of tomato quality by fruit-localized phytochromes.
- Published
- 2018
41. Strigolactones as an auxiliary hormonal defence mechanism against leafy gall syndrome inArabidopsis thaliana
- Author
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Sofie Goormachtig, Danny Vereecke, Cedrick Matthys, Elisabeth Stes, Annick De Keyser, Stefaan Werbrouck, Koichi Yoneyama, Kris Audenaert, and Stephen Depuydt
- Subjects
Cytokinins ,Physiology ,Mutant ,Arabidopsis ,Strigolactone ,Plant Science ,ACTS DOWNSTREAM ,ANALOG GR24 ,Lactones ,RHODOCOCCUS-FASCIANS INFECTION ,Rhodococcus fascians ,BUD OUTGROWTH ,Plant Growth Regulators ,Gene Expression Regulation, Plant ,Auxin ,Botany ,Rhodococcus ,Gall ,Gram-positive phytopathogen ,Leafy ,Plant Diseases ,chemistry.chemical_classification ,biology ,Arabidopsis Proteins ,SYMPTOM DEVELOPMENT ,PLANT DEVELOPMENT ,witches' broom ,fungi ,Biology and Life Sciences ,BOX PROTEIN MAX2 ,Gene Expression Regulation, Developmental ,food and beverages ,witches’ broom ,MEDICAGO-TRUNCATULA ,biology.organism_classification ,Cell biology ,Plant Leaves ,Metabolic pathway ,chemistry ,SIGNAL INTEGRATION ,Apical dominance ,RESPONSES ,Research Paper - Abstract
Highlight To antagonize the developmental process initiated by Rhodococcus fascians and in response to the bacterial cytokinins, Arabidopsis activates its strigolactone response, partially suppressing shoot branching in the rosette., Leafy gall syndrome is the consequence of modified plant development in response to a mixture of cytokinins secreted by the biotrophic actinomycete Rhodococcus fascians. The similarity of the induced symptoms with the phenotype of plant mutants defective in strigolactone biosynthesis and signalling prompted an evaluation of the involvement of strigolactones in this pathology. All tested strigolactone-related Arabidopsis thaliana mutants were hypersensitive to R. fascians. Moreover, treatment with the synthetic strigolactone mixture GR24 and with the carotenoid cleavage dioxygenase inhibitor D2 illustrated that strigolactones acted as antagonistic compounds that restricted the morphogenic activity of R. fascians. Transcript profiling of the MORE AXILLARY GROWTH1 (MAX1), MAX2, MAX3, MAX4, and BRANCHED1 (BRC1) genes in the wild-type Columbia-0 accession and in different mutant backgrounds revealed that upregulation of strigolactone biosynthesis genes was triggered indirectly by the bacterial cytokinins via host-derived auxin and led to the activation of BRC1 expression, inhibiting the outgrowth of the newly developing shoots, a typical hallmark of leafy gall syndrome. Taken together, these data support the emerging insight that balances are critical for optimal leafy gall development: the long-lasting biotrophic interaction is possible only because the host activates a set of countermeasures—including the strigolactone response—in reaction to bacterial cytokinins to constrain the activity of R. fascians.
- Published
- 2015
42. Cytokinin-dependent secondary growth determines root biomass in radish (Raphanus sativusL.)
- Author
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Ji-Young Lee, Khushboo Rastogi, Sang-Hun Oh, Suhyoung Park, Jung Hun Lee, and Geupil Jang
- Subjects
Cytokinins ,Physiology ,Secondary growth ,Raphanus ,Plant Science ,Ipomoea ,Plant Roots ,cytokinin ,chemistry.chemical_compound ,Nutrient ,Inbred strain ,Gene Expression Regulation, Plant ,Arabidopsis ,Botany ,Biomass ,Cambium ,Plant Proteins ,biology ,fungi ,Raphanus sativus ,Gene Expression Regulation, Developmental ,food and beverages ,secondary growth ,biology.organism_classification ,root biomass ,chemistry ,Cytokinin ,Cell Division ,Research Paper ,Transcription Factors - Abstract
Highlight Comparative studies using Arabidopsis and radish (Raphanus sativus) found that cytokinin-mediated regulatory programmes in the cambium are important for the radial growth of radish roots and its variations., The root serves as an essential organ in plant growth by taking up nutrients and water from the soil and supporting the rest of the plant body. Some plant species utilize roots as storage organs. Sweet potatoes (Ipomoea batatas), cassava (Manihot esculenta), and radish (Raphanus sativus), for example, are important root crops. However, how their root growth is regulated remains unknown. In this study, we characterized the relationship between cambium and radial root growth in radish. Through a comparative analysis with Arabidopsis root expression data, we identified putative cambium-enriched transcription factors in radish and analysed their expression in representative inbred lines featuring distinctive radial growth. We found that cell proliferation activities in the cambium positively correlated with radial growth and final yields of radish roots. Expression analysis of candidate transcription factor genes revealed that some genes are differentially expressed between inbred lines and that the difference is due to the distinct cytokinin response. Taken together, we have demonstrated for the first time, to the best of our knowledge, that cytokinin-dependent radial growth plays a key role in the yields of root crops.
- Published
- 2015
43. E151 (sym15), a pleiotropic mutant of pea (Pisum sativum L.), displays low nodule number, enhanced mycorrhizae, delayed lateral root emergence, and high root cytokinin levels
- Author
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James M. C. Jones, Lindsey K. Clairmont, Emily S. Macdonald, R. J. Neil Emery, Frédérique C. Guinel, and Catherine A. Weiner
- Subjects
0106 biological sciences ,Cytokinins ,mycorrhiza formation ,Physiology ,Mutant ,infection thread ,Plant Science ,Plant Root Nodulation ,01 natural sciences ,Plant Epidermis ,Rhizobia ,Pisum ,Abscisic acid ,cytokinin ,03 medical and health sciences ,chemistry.chemical_compound ,Mycorrhizae ,Ammonium Compounds ,Botany ,root development ,nodulation ,Plant Proteins ,030304 developmental biology ,2. Zero hunger ,0303 health sciences ,Nitrates ,biology ,pea mutant ,Lateral root ,Peas ,Wild type ,food and beverages ,Genetic Pleiotropy ,legume ,biology.organism_classification ,Cell biology ,epidermal–cortex interface ,Phenotype ,chemistry ,Seedlings ,Mutation ,Cytokinin ,Root Nodules, Plant ,Research Paper ,010606 plant biology & botany - Abstract
Highlight The phenotype of the E151 pea mutant, unique among known legume mutants, provides the first evidence for a promoting role for cytokinins in the development of the mycorrhizal symbiosis., In legumes, the formation of rhizobial and mycorrhizal root symbioses is a highly regulated process which requires close communication between plant and microorganism. Plant mutants that have difficulties establishing symbioses are valuable tools for unravelling the mechanisms by which these symbioses are formed and regulated. Here E151, a mutant of Pisum sativum cv. Sparkle, was examined to characterize its root growth and symbiotic defects. The symbioses in terms of colonization intensity, functionality of micro-symbionts, and organ dominance were compared between the mutant and wild type. The endogenous cytokinin (CK) and abscisic acid (ABA) levels and the effect of the exogenous application of these two hormones were determined. E151 was found to be a low and delayed nodulator, exhibiting defects in both the epidermal and cortical programmes though a few mature and functional nodules develop. Mycorrhizal colonization of E151 was intensified, although the fungal functionality was impaired. Furthermore, E151 displayed an altered lateral root (LR) phenotype compared with that of the wild type whereby LR emergence is initially delayed but eventually overcome. No differences in ABA levels were found between the mutant and the wild type, but non-inoculated E151 exhibited significantly high CK levels. It is hypothesized that CK plays an essential role in differentially mediating the entry of the two micro-symbionts into the cortex; whereas it would inhibit the entry of the rhizobia in that tissue, it would promote that of the fungus. E151 is a developmental mutant which may prove to be a useful tool in further understanding the role of hormones in the regulation of beneficial root symbioses.
- Published
- 2015
44. Differences between winter oilseed rape (Brassica napus L.) cultivars in nitrogen starvation-induced leaf senescence are governed by leaf-inherent rather than root-derived signals
- Author
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Fabian Koeslin-Findeklee, Walter J. Horst, Eric van der Graaff, Thomas Roitsch, and Martin Becker
- Subjects
Chlorophyll ,Senescence ,Nitrogen ,leaf senescence ,Zeatin ,Physiology ,nitrogen efficiency ,Brassica ,Plant Science ,Biology ,Genes, Plant ,Plant Roots ,stay-green ,chemistry.chemical_compound ,Glucosides ,Dewey Decimal Classification::500 | Naturwissenschaften::580 | Pflanzen (Botanik) ,Gene Expression Regulation, Plant ,Botany ,Homeostasis ,nitrogen starvation ,reciprocal grafting ,Cultivar ,Photosynthesis ,Plant Proteins ,Brassica napus ,fungi ,genotypic differences ,food and beverages ,Apex (geometry) ,biology.organism_classification ,Photosynthetic capacity ,Plant Leaves ,cytokinins ,ddc:580 ,chemistry ,Seasons ,Plant nutrition ,Peptide Hydrolases ,Signal Transduction ,Research Paper - Abstract
Highlight The homeostasis of biologically active cytokinins was the predominant leaf-inherent factor for winter oilseed rape cultivar-differences in nitrogen starvation-induced leaf senescence and thus nitrogen efficiency., Nitrogen (N) efficiency of winter oilseed rape (Brassica napus L.) line-cultivars (cvs.), defined as high grain yield under N limitation, has been primarily attributed to maintained N uptake during reproductive growth (N uptake efficiency) in combination with delayed senescence of the older leaves accompanied with maintained photosynthetic capacity (functional stay-green). However, it is not clear whether genotypic variation in N starvation-induced leaf senescence is due to leaf-inherent factors and/or governed by root-mediated signals. Therefore, the N-efficient and stay-green cvs. NPZ-1 and Apex were reciprocally grafted with the N-inefficient and early-senescing cvs. NPZ-2 and Capitol, respectively and grown in hydroponics. The senescence status of older leaves after 12 days of N starvation assessed by SPAD, photosynthesis and the expression of the senescence-specific cysteine protease gene SAG12-1 revealed that the stay-green phenotype of the cvs. NPZ-1 and Apex under N starvation was primarily under the control of leaf-inherent factors. The same four cultivars were submitted to N starvation for up to 12 days in a time-course experiment. The specific leaf contents of biologically active and inactive cytokinins (CKs) and the expression of genes involved in CK homeostasis revealed that under N starvation leaves of early-senescing cultivars were characterized by inactivation of biologically active CKs, whereas in stay-green cultivars synthesis, activation, binding of and response to biologically active CKs were favoured. These results suggest that the homeostasis of biologically active CKs was the predominant leaf-inherent factor for cultivar differences in N starvation-induced leaf senescence and thus N efficiency.
- Published
- 2015
45. Cytokinin as a positional cue regulating lateral root spacing in Arabidopsis
- Author
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Eswarayya Ramireddy, Ling Chang, and Thomas Schmülling
- Subjects
root branching ,Cytokinins ,Arabidopsis thaliana ,Physiology ,Mutant ,root system architecture ,Regulator ,Arabidopsis ,Plant Science ,lateral root ,Plant Roots ,chemistry.chemical_compound ,cytokinin ,Plant Growth Regulators ,Transcription (biology) ,Primordium ,heterocyclic compounds ,Plant Proteins ,biology ,Lateral root ,fungi ,lateral root spacing ,food and beverages ,biology.organism_classification ,Cell biology ,Pericycle ,Biochemistry ,chemistry ,Cytokinin ,Research Paper - Abstract
Highlight Cytokinin synthesis gene expression patterns and mutant phenotypes show the relevance of cytokinins in generating a paracrine signal to regulate lateral root spacing, which is important in shaping root system architecture., The root systems of plants have developed adaptive architectures to exploit soil resources. The formation of lateral roots (LRs) contributes to root system architecture. Roots of plants with a lower cytokinin status form LR primordia (LRP) in unusually close proximity, indicating a role for the hormone in regulating the positioning of LRs along the main root axis. Data obtained from cytokinin-synthesis mutants of Arabidopsis thaliana combined with gene expression analysis indicate that cytokinin synthesis by IPT5 and LOG4 occurring early during LRP initiation generates a local cytokinin signal abbreviating LRP formation in neighbouring pericycle cells. In addition, IPT3, IPT5, and IPT7 contribute to cytokinin synthesis in the vicinity of existing LRP, thus suppressing initiation of new LRs. Interestingly, mutation of CYP735A genes required for trans-zeatin biosynthesis caused strong defects in LR positioning, indicating an important role for this cytokinin metabolite in regulating LR spacing. Further it is shown that cytokinin and a known regulator of LR spacing, the receptor-like kinase ARABIDOPSIS CRINKLY4 (ACR4), operate in a non-hierarchical manner but might exert reciprocal control at the transcript level. Taken together, the results suggest that cytokinin acts as a paracrine hormonal signal in regulating root system architecture.
- Published
- 2015
46. Plant membrane assays with cytokinin receptors underpin the unique role of free cytokinin bases as biologically active ligands
- Author
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Sergey N. Lomin, Thomas Schmülling, Mikhail Yu. Steklov, Dmitry M. Krivosheev, Dmitry V. Arkhipov, Dmitry I. Osolodkin, and Georgy A. Romanov
- Subjects
Models, Molecular ,Cytokinins ,Arabidopsis thaliana ,Histidine Kinase ,Physiology ,Arabidopsis ,Gene Expression ,Receptors, Cell Surface ,Plant Science ,Plasma protein binding ,Biology ,Endoplasmic Reticulum ,Ligands ,Zea mays ,Cell membrane ,chemistry.chemical_compound ,cytokinin ,Tobacco ,medicine ,heterocyclic compounds ,pH sensor ,receptor binding assay ,Receptor ,Plant Proteins ,Arabidopsis Proteins ,fungi ,Cell Membrane ,food and beverages ,cytokinin receptor ,ligand specificity ,Hydrogen-Ion Concentration ,Ligand (biochemistry) ,biology.organism_classification ,Molecular Docking Simulation ,medicine.anatomical_structure ,chemistry ,Biochemistry ,Docking (molecular) ,Cytokinin ,plant assay system ,Signal transduction ,Protein Kinases ,Research Paper ,Protein Binding ,Signal Transduction - Abstract
Highlight Cytokinin receptors studied in a novel plant assay system recognize cytokinin ribosides poorly, unlike cytokinin bases. Molecular modelling explained this receptor feature. Some receptors were suggested to function as pH sensors., Cytokinin receptors play a key role in cytokinin-dependent processes regulating plant growth, development, and adaptation; therefore, the functional properties of these receptors are of great importance. Previously the properties of cytokinin receptors were investigated in heterologous assay systems using unicellular microorganisms, mainly bacteria, expressing receptor proteins. However, within microorganisms receptors reside in an alien environment that might distort the receptor properties. Therefore, a new assay system has been developed allowing studies of individual receptors within plant membranes (i.e. closer to their natural environment). The main ligand-binding characteristics of receptors from Arabidopsis [AHK2, AHK3, and AHK4] and maize (ZmHK1) were refined in this new system, and the properties of full-length Arabidopsis receptor AHK2 were characterized for the first time. Ligand specificity profiles of receptors towards cytokinin bases were comparable with the profiles retrieved in bacterial assay systems. In contrast, cytokinin-9-ribosides displayed a strongly reduced affinity for receptors in the plant assay system, indicating that ribosides as the common transport form of cytokinins have no or very weak cytokinin activity. This underpins the central role of free bases as the sole biologically active cytokinin compounds. According to molecular modelling and docking studies, N 9-ribosylation alters the bonding pattern in cytokinin–receptor interaction and prevents β6–β7 loop movement important for tight hormone binding. A common feature of all receptors was a greatly reduced ligand binding at low (5.0–5.5) pH. The particularly high sensitivity of ZmHK1 to pH changes leads to the suggestion that some cytokinin receptors may play an additional role as pH sensors in the lumen of the endoplasmic reticulum.
- Published
- 2015
47. CsIPT1b and CsUGT85A2 delay female corolla opening in cucumber by regulating the content of cytokinins.
- Author
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Xiaoli Li, Haonan Cui, Xiaofei Song, Chengzhen Sun, Zhuo Ding, Xueyun Zhu, Xiaofeng Liu, and Liying Yan
- Subjects
CUCUMBERS ,COROLLA (Botany) ,CYTOKININS ,FOOD marketing ,RIBOSIDES - Abstract
Corolla opening is essential for the propagation of unisexual flowering plants, meanwhile commodity fruits with opening corolla have higher commodity value in cucumber fresh food market. Until now, there is little research on the mechanism of corolla opening in cucumber. In a previous paper, we identified a unique cucumber (Cucumis sativus) line ('6457') that possesses super ovaries and shows delayed corolla opening when nutrient supplies are abundant. We also previously showed that the expression of CsIPT1b (isopentenyl transferase) and CsUGT85A2 (cytokinin glycosyltransferase) is correlated with the delayed opening of the female corolla. Here, we investigated the mechanism of delayed female corolla opening in cucumber by conducting transgenic experiments, hormone assays, and yeast one-hybrid assays. CsIPT1b and CsUGT85A2 positively and negatively regulated delayed female corolla opening, respectively. In CsIPT1b-overexpressing plants and CsUGT85A2 knockout plants, the content of the trans-zeatin riboside, trans-zeatin, and N6-isopentenyladenosine was increased. Overall, our findings indicate that CsIPT1b and CsUGT85A2 were important regulators of the timing of female corolla opening. These genes could thus be targets to cucumber molecular breeding of fruit with flowers remaining on the tip. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. Ectopic overexpression of the cell wall invertase gene CIN1 leads to dehydration avoidance in tomato
- Author
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Francisco Pérez-Alfocea, Elena Cantero-Navarro, María E. Balibrea, Günther Zellnig, Dominik K. Großkinsky, Alfonso Albacete, Eric van der Graaff, José Antonio Hernández, Wolfram Weckwerth, Cristina Martínez-Andújar, Lena Fragner, Michel Edmond Ghanem, Roque Bru, María de la Cruz González, Cintia Lucía Arias, Thomas Roitsch, Universidad de Sevilla. Departamento de Bioquímica Vegetal y Biología Molecular, Ministerio de Ciencia e Innovación (MICIN). España, Universidad de Alicante. Departamento de Agroquímica y Bioquímica, and Proteómica y Genómica Funcional de Plantas
- Subjects
0106 biological sciences ,Sucrose ,Physiology ,tomato ,Plant Science ,source sink relationships ,01 natural sciences ,Ectopic Gene Expression ,purl.org/becyt/ford/1 [https] ,chemistry.chemical_compound ,Solanum lycopersicum ,Cell Wall ,Gene Expression Regulation, Plant ,Source–sink relationships ,ethylene ,Photosynthesis ,Plant Proteins ,chemistry.chemical_classification ,2. Zero hunger ,0303 health sciences ,drought stress ,food and beverages ,Bioquímica y Biología Molecular ,Plants, Genetically Modified ,Droughts ,source–sink relationships ,cytokinins ,Biochemistry ,Cell wall invertase ,Corrigendum ,CIENCIAS NATURALES Y EXACTAS ,Research Paper ,Stomatal conductance ,Biology ,Ciencias Biológicas ,Chenopodium ,03 medical and health sciences ,Hexose ,Water-use efficiency ,purl.org/becyt/ford/1.6 [https] ,Ciencias de las Plantas, Botánica ,030304 developmental biology ,beta-Fructofuranosidase ,Abiotic stress ,fungi ,Metabolism ,15. Life on land ,Plant Leaves ,Invertase ,chemistry ,Sourcesink relationships ,010606 plant biology & botany - Abstract
© The Author 2014. Drought stress conditions modify source-sink relations, thereby influencing plant growth, adaptive responses, and consequently crop yield. Invertases are key metabolic enzymes regulating sink activity through the hydrolytic cleavage of sucrose into hexose monomers, thus playing a crucial role in plant growth and development. However, the physiological role of invertases during adaptation to abiotic stress conditions is not yet fully understood. Here it is shown that plant adaptation to drought stress can be markedly improved in tomato (Solanum lycopersicum L.) by overexpression of the cell wall invertase (cwInv) gene CIN1 from Chenopodium rubrum. CIN1 overexpression limited stomatal conductance under normal watering regimes, leading to reduced water consumption during the drought period, while photosynthetic activity was maintained. This caused a strong increase in water use efficiency (up to 50%), markedly improving water stress adaptation through an efficient physiological strategy of dehydration avoidance. Drought stress strongly reduced cwInv activity and induced its proteinaceous inhibitor in the leaves of the wild-type plants. However, the CIN1-overexpressing plants registered 3- to 6-fold higher cwInv activity in all analysed conditions. Surprisingly, the enhanced invertase activity did not result in increased hexose concentrations due to the activation of the metabolic carbohydrate fluxes, as reflected by the maintenance of the activity of key enzymes of primary metabolism and increased levels of sugar-phosphate intermediates under water deprivation. The induced sink metabolism in the leaves explained the maintenance of photosynthetic activity, delayed senescence, and increased source activity under drought stress. Moreover, CIN1 plants also presented a better control of production of reactive oxygen species and sustained membrane protection. Those metabolic changes conferred by CIN1 overexpression were accompanied by increases in the concentrations of the senescence-delaying hormone trans-zeatin and decreases in the senescence-inducing ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) in the leaves. Thus, cwInv critically functions at the integration point of metabolic, hormonal, and stress signals, providing a novel strategy to overcome drought-induced limitations to crop yield, without negatively affecting plant fitness under optimal growth conditions.
- Published
- 2014
49. From synthesis to the biological effect of isoprenoid 2'-deoxyriboside and 2',3'-dideoxyriboside cytokinin analogues.
- Author
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Matušková V, Zatloukal M, Pospíšil T, Voller J, Vylíčilová H, Doležal K, and Strnad M
- Subjects
- Humans, Ribose, Cytokinins pharmacology, Terpenes
- Abstract
Isoprenoid cytokinins are a class of naturally occurring plant signaling molecules. A series of prepared compounds derived from isoprenoid cytokinins (isopentenyladenine, trans-zeatin and cis-zeatin) with attached 2'-deoxy-d-ribose or 2',3'-dideoxy-d-ribose at the N
9 position of the purine were prepared and their biological activities were examined. Different synthetic approaches were employed. The final compounds were characterized with variety of physicochemical methods (TLC, HPLC-MS, and NMR) and their cytokinin activity was determined in classical bioassays such as Amaranthus, tobacco callus, detached wheat leaf senescence and Arabidopsis thaliana root elongation inhibition assay. In addition, compounds were screened for activation of the cytokinin signaling pathway (bacterial receptor, competitive ligand binding and ARR5::GUS assay) to provide a detailed assessment of CK structure-activity relationship. The prepared compounds were found to be non-toxic to human cells and the majority of assays exhibited the highest activity of free bases while 2',3'-dideoxyribosides had very weak or no activity. In contrast to the free bases, all 2'-deoxyriboside derivatives were not toxic to tobacco callus even at the highest tested concentration (10-4 moL/l) and compound 1 (iPdR) induced betacyanin synthesis at higher concentration even stronger than iP free base in the Amaranthus bioassay. The general cytokinin activity pattern base > riboside >2'-deoxyriboside > 2',3'-dideoxyriboside was distinguished., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)- Published
- 2023
- Full Text
- View/download PDF
50. Hormonal requirements for effective induction of microspore embryogenesis in triticale (× Triticosecale Wittm.) anther cultures
- Author
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Ewa Dubas, Piotr Waligórski, Iwona Żur, Michał Dziurka, Monika Krzewska, and Franciszek Janowiak
- Subjects
Plant Somatic Embryogenesis Techniques ,Cytokinins ,Genotype ,Stamen ,Endogeny ,Plant Science ,Biology ,Poaceae ,Clofibric Acid ,Abscisic acid ,chemistry.chemical_compound ,Plant Growth Regulators ,Microspore ,Auxin ,Triiodobenzoic Acids ,Botany ,Regeneration ,Cells, Cultured ,chemistry.chemical_classification ,Principal Component Analysis ,Original Paper ,Indoleacetic Acids ,Microspore embryogenesis ,fungi ,food and beverages ,Biological Transport ,Triticale ,General Medicine ,Immunohistochemistry ,Cold Temperature ,Hormonal homeostasis ,Microscopy, Fluorescence ,chemistry ,Pollen ,Auxins ,Kinetin ,Zeatin ,Edible Grain ,Agronomy and Crop Science - Abstract
Key message Effective microspore embryogenesis in triticale is determined by a specific hormonal homeostasis: low value of IAA/cytokinins, IAA/ABA and cytokinins/ABA ratios as well as proper endogenous/exogenous auxin balance, which favours androgenic structure formation and green plant regeneration ability. Abstract The concentration of plant growth regulators (PGRs): auxins (Auxs), cytokinins (CKs) and abscisic acid (ABA) was measured in anthers of eight DH lines of triticale (× Triticosecale Wittm.), and associated with microspore embryogenesis (ME) responsiveness. The analysis was conducted on anthers excised from control tillers at the phase optimal for ME induction and then after ME-initiating tillers treatment (21 days at 4 °C). In control, IAA predominated among Auxs (11–39 nmol g−1 DW), with IBA constituting only 1 % of total Auxs content. The prevailing isoforms of CKs were cis isomers of zeatin (121–424 pmol g−1 DW) and zeatin ryboside (cZR, 146–432 pmol g−1 DW). Surprisingly, a relatively high level (10–64 pmol g−1 DW) of kinetin (KIN) was detected. Cold treatment significantly changed the levels of all analysed PGRs. The anthers of ‘responsive’ DH lines contained higher concentrations of IBA, cis and trans zeatin, cZR and ABA, and lower amount of IAA and KIN in comparison with ‘recalcitrant’ genotypes. However, the effects of exogenous ABA, p-chlorophenoxyisobutyric acid (PCIB) and 2,3,5-triiodobenzoic acid treatments suggest that none of the studied PGRs acts alone in the acquisition of embryogenic competency, which seems to be an effect of concerted PGRs crosstalk. The initiation of ME required a certain threshold level of ABA. A crucial prerequisite for high ME effectiveness was a specific PGRs homeostasis: lower Auxs level in comparison with CKs and ABA, and lower CKs/ABA ratio. A proper balance between endogenous Auxs in anthers and exogenous Auxs supplied by culture media was also essential. Electronic supplementary material The online version of this article (doi:10.1007/s00299-014-1686-4) contains supplementary material, which is available to authorized users.
- Published
- 2014
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