Search

To explore the signal transduction pathway that TaRHA2b gene is involved in regulating, yeast two-hybrid system was used to screen and identify proteins interacting with TaRHA2b. The homogenized cDNA library was constructed from the embryo of mixed barley. The decoy protein vector pGBKT7- TaRHA2b was constructed and transformed into yeast AH109 cells for self-activation detection. Candidate positive clones were screened by one to one yeast co-transfection, SD/-Leu/-Trp and SD/-Leu/- Trp/-Ade/-His medium screening and β-galactosidase chromogenic reaction. The in vitro co-transfection and GST-pull down experiments were used for further verification. The homogenized cDNA library of the barley embryos with titer of 1.2 106 cfu/ml and storage capacity of 1.1 106 was successfully constructed. The inserted fragment size was between 1000-3000 bp. The plasmids of the cDNA library were extracted and sequenced on a large scale, and 5000 plasmids were obtained. The decoy vector without self-activation function was successfully constructed. The x-gal filter paper of eighty-four hybrid clones showed strong blue color and forty-nine pieces of effective sequence information were obtained. Eight of them were selected for co-transfection verification. YTH2450 was selected for GST-pull down verification. The results showed that they were positive hybrid clones. TaRHA2b interacted with YTH2450 and other proteins. The information of above genes could be used for genetic improvement of crops, further improving the adaptability of crops to the environment. [ABSTRACT FROM AUTHOR]

This study was conducted during 2019-2020 on the vegetative shoots of date palm Phoenix dactylifera L. cultivar 'Barhee', which were grown on MS salt media containing sodium chloride (0-25-50-100-150-200 mM) supplemented with 5% sucrose. Genetic variances were assessed using molecular markers RAPD using 8 random primers. The RAPD analysis did not result a polymorphism between the amplified bundles and the absence of genetic differences. The primer (OPE-19 and OPD-10) scored the lowest similarity rate 97%, while the genetic matching was 100% in the other primers. The morphological indicators recorded a significant and gradual decrease in the growth indicators (buds number, bud length and stem length) and a significant increase in (bud diameter and branches number) in the propagation and elongation stages. Also, the chemical growth indicators recorded an increase in the chemical content (abscisic acid and proline), the effect of Sodium chloride was negative on photosynthesis, as the chlorophyll content gradually decreased with increasing sodium chloride concentration. [ABSTRACT FROM AUTHOR]

UV-B stress can affect plant growth at different levels, and although there is a multitude of evidence confirming the effects of UV-B radiation on plant photosynthesis, there are fewer studies using physiological assays in combination with multi-omics to investigate photosynthesis in alpine plants under stressful environments. Golden 2-like (G2-like/GLK) transcription factors (TFs) are highly conserved during evolution and may be associated with abiotic stress. In this paper, we used Handy-PEA and Imaging-PAM Maxi to detect chlorophyll fluorescence in leaves of Rhododendron chrysanthum Pall. (R. chrysanthum) after UV-B stress, and we also investigated the effect of abscisic acid (ABA) on photosynthesis in plants under stress environments. We used a combination of proteomics, widely targeted metabolomics, and transcriptomics to study the changes of photosynthesis-related substances after UV-B stress. The results showed that UV-B stress was able to impair the donor side of photosystem II (PSII), inhibit electron transfer and weaken photosynthesis, and abscisic acid was able to alleviate the damage caused by UV-B stress to the photosynthetic apparatus. Significant changes in G2-like transcription factors occurred in R. chrysanthum after UV-B stress, and differentially expressed genes localized in the Calvin cycle were strongly correlated with members of the G2-like TF family. Multi-omics assays and physiological measurements together revealed that G2-like TFs can influence photosynthesis in R. chrysanthum under UV-B stress by regulating the Calvin cycle. This paper provides insights into the study of photosynthesis in plants under stress, and is conducive to the adoption of measures to improve photosynthesis in plants under stress to increase yield. [ABSTRACT FROM AUTHOR]

The integration of abscisic acid (ABA) into a chitosan–alginate gel blend unveils crucial insights into the formation and stability of these two substances. ABA, a key phytohormone in plant growth and stress responses, is strategically targeted for controlled release within these complexes. This study investigates the design and characterization of this novel controlled-release system, showcasing the potential of alginate–chitosan gel blends in ABA delivery. Computational methods, including molecular dynamics simulations, are employed to analyze the structural effects of microencapsulation, offering valuable insights into complex behavior under varying conditions. This paper focuses on the controlled release of ABA from these complexes, highlighting its strategic importance in drug delivery systems and beyond. This controlled release enables targeted and regulated ABA delivery, with far-reaching implications for pharmaceuticals, agriculture, and plant stress response studies. While acknowledging context dependency, the paper suggests that the liberation or controlled release of ABA holds promise in applications, urging further research and experimentation to validate its utility across diverse fields. Overall, this work significantly contributes to understanding the characteristics and potential applications of chitosan–alginate complexes, marking a noteworthy advancement in the field of controlled-release systems. [ABSTRACT FROM AUTHOR]

The presence of the ozone hole increases the amount of UV radiation reaching a plant's surface, and UV-B radiation is an abiotic stress capable of affecting plant growth. Rhododendron chrysanthum Pall. (R. chrysanthum) grows in alpine regions, where strong UV-B radiation is present, and has been able to adapt to strong UV-B radiation over a long period of evolution. We investigated the response of R. chrysanthum leaves to UV-B radiation using widely targeted metabolomics and transcriptomics. Although phytohormones have been studied for many years in plant growth and development and adaptation to environmental stresses, this paper is innovative in terms of the species studied and the methods used. Using unique species and the latest research methods, this paper was able to add information to this topic for the species R. chrysanthum. We treated R. chrysanthum grown in a simulated alpine environment, with group M receiving no UV-B radiation and groups N and Q (externally applied abscisic acid treatment) receiving UV-B radiation for 2 days (8 h per day). The results of the MN group showed significant changes in phenolic acid accumulation and differential expression of genes related to phenolic acid synthesis in leaves of R. chrysanthum after UV-B radiation. We combined transcriptomics and metabolomics data to map the metabolic regulatory network of phenolic acids under UV-B stress in order to investigate the response of such secondary metabolites to stress. L-phenylalanine, L-tyrosine and phenylpyruvic acid contents in R. chrysanthum were significantly increased after UV-B radiation. Simultaneously, the levels of 3-hydroxyphenylacetic acid, 2-phenylethanol, anthranilate, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, α-hydroxycinnamic acid and 2-hydroxy-3-phenylpropanoic acid in this pathway were elevated in response to UV-B stress. In contrast, the study in the NQ group found that externally applied abscisic acid (ABA) in R. chrysanthum had greater tolerance to UV-B radiation, and phenolic acid accumulation under the influence of ABA also showed greater differences. The contents of 2-phenylethanol, 1-o-p-coumaroyl-β-d-glucose, 2-hydroxy-3-phenylpropanoic acid, 3-(4-hydroxyphenyl)-propionic acid and 3-o-feruloylquinic ac-id-o-glucoside were significantly elevated in R. chrysanthum after external application of ABA to protect against UV-B stress. Taken together, these studies of the three groups indicated that ABA can influence phenolic acid production to promote the response of R. chrysanthum to UV-B stress, which provided a theoretical reference for the study of its complex molecular regulatory mechanism. [ABSTRACT FROM AUTHOR]

The crosstalk of phytohormones in the regulation of growth and development and the response of plants to environmental stresses is a cutting-edge research topic, especially in crop species. In this paper, we study the role and crosstalk between abscisic acid (ABA), ethylene (ET), and jasmonate (JA) in the control of germination and seedling growth in water or in standard nutrient solution and under salt stress (supplemented with 100–200 mM NaCl). The roles of ET and JA were studied using squash ET- and JA-deficient mutants aco1a and lox3a, respectively, while the crosstalk between ET, JA, and ABA was determined by comparing the expression of the key ABA, JA, and ET genes in wild-type (WT) and mutant genotypes under standard conditions and salt stress. Data showed that ET and JA are positive regulators of squash germination, a function that was found to be mediated by downregulating the ABA biosynthesis and signaling pathways. Under salt stress, aco1a germinated earlier than WT, while lox3a showed the same germination rate as WT, indicating that ET, but not JA, restricts squash germination under unfavorable salinity conditions, a function that was also mediated by upregulation of ABA. ET and JA were found to be negative regulators of plant growth during seedling establishment, although ET inhibits both the aerial part and the root, while JA inhibits only the root. Both aco1a and lox3a mutant roots showed increased tolerance to salt stress, a phenotype that was found to be mainly mediated by JA, although we cannot exclude that it is also mediated by ABA. [ABSTRACT FROM AUTHOR]

Isopentenyl diphosphate isomerase (IPI) is a key enzyme in the synthesis of isoprenoids. In this paper, the in vivo biological activity of the IPI gene from Fritillaria unibracteata (FuIPI) was investigated. Combining a color complementation experiment with High-Performance Liquid Chromatography analysis showed that the FuIPI gene could accumulate β-carotene in Escherichia coli, and Glu190 was identified as a key residue for its catalytic activity. Bioinformatics analysis together with subcellular localization indicated that the FuIPI protein was localized in chloroplasts. Compared with wild-type Arabidopsis thaliana, FuIPI transgenic plants had higher abscisic acid content and strengthening tolerance to drought and salt stress. Overall, these results indicated that the FuIPI gene had substantial biological activity in vivo, hopefully laying a foundation for its further research and application in liliaceous ornamental and medicinal plants. [ABSTRACT FROM AUTHOR]

The NDPK gene family is an important group of genes in plants, playing a crucial role in regulating energy metabolism, growth, and differentiation, cell signal transduction, and response to abiotic stress. However, our understanding of the NDPK gene family in Brassica napus L. remains limited. This paper systematically analyzes the NDPK gene family in B. napus, particularly focusing on the evolutionary differences within the species. In this study, sixteen, nine, and eight NDPK genes were identified in B. napus and its diploid ancestors, respectively. These genes are not only homologous but also highly similar in their chromosomal locations. Phylogenetic analysis showed that the identified NDPK proteins were divided into four clades, each containing unique motif sequences, with most NDPKs experiencing a loss of introns/exons during evolution. Collinearity analysis revealed that the NDPK genes underwent whole-genome duplication (WGD) events, resulting in duplicate copies, and most of these duplicate genes were subjected to purifying selection. Cis-acting element analysis identified in the promoters of most NDPK genes elements related to a light response, methyl jasmonate response, and abscisic acid response, especially with an increased number of abscisic acid response elements in B. napus. RNA-Seq results indicated that NDPK genes in B. napus exhibited different expression patterns across various tissues. Further analysis through qRT-PCR revealed that BnNDPK genes responded significantly to stress conditions such as salt, drought, and methyl jasmonate. This study enhances our understanding of the NDPK gene family in B. napus, providing a preliminary theoretical basis for the functional study of NDPK genes and offering some references for further revealing the phenomenon of polyploidization in plants. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA) and nitric oxide (NO), as unique signaling molecules, are involved in plant growth, developmental processes, and abiotic stresses. However, the interaction between ABA and NO under abiotic stresses has little been worked out at present. Therefore, this paper reviews the mechanisms of crosstalk between ABA and NO in the regulation of plants in response to environmental stresses. Firstly, ABA-NO interaction can alleviate the changes of plant morphological indexes damaged by abiotic stresses, for instance, root length, leaf area, and fresh weight. Secondly, regulatory mechanisms of interaction between ABA and NO are also summarized, such as reactive oxygen species (ROS), antioxidant enzymes, proline, flavonoids, polyamines (PAs), ascorbate-glutathione cycle, water balance, photosynthetic, stomatal movement, and post-translational modifications. Meanwhile, the relationships between ABA and NO are established. ABA regulates NO through ROS at the physiological level during the regulatory processes. At the molecular level, NO counteracts ABA through mediating post-translational modifications. Moreover, we also discuss key genes related to the antioxidant enzymes, PAs biosynthesis, ABA receptor, NO biosynthesis, and flavonoid biosynthesis that are regulated by the interaction between ABA and NO under environmental stresses. This review will provide new guiding directions for the mechanism of the crosstalk between ABA and NO to alleviate abiotic stresses. [ABSTRACT FROM AUTHOR]

Systemic acquired resistance (SAR) is an inducible disease resistance phenomenon in plant species, providing plants with broad-spectrum resistance to secondary pathogen infections beyond the initial infection site. In Arabidopsis, SAR can be triggered by direct pathogen infection or treatment with the phytohormone salicylic acid (SA), as well as its analogues 2,6-dichloroisonicotinic acid (INA) and benzothiadiazole (BTH). The SA receptor non-expressor of pathogenesis-related protein gene 1 (NPR1) protein serves as a key regulator in controlling SAR signaling transduction. Similarly, in common wheat (Triticum aestivum), pathogen infection or treatment with the SA analogue BTH can induce broad-spectrum resistance to powdery mildew, leaf rust, Fusarium head blight, and other diseases. However, unlike SAR in the model plant Arabidopsis or rice, SAR-like responses in wheat exhibit unique features and regulatory pathways. The acquired resistance (AR) induced by the model pathogen Pseudomonas syringae pv. tomato strain DC3000 is regulated by NPR1, but its effects are limited to the adjacent region of the same leaf and not systemic. On the other hand, the systemic immunity (SI) triggered by Xanthomonas translucens pv. cerealis (Xtc) or Pseudomonas syringae pv. japonica (Psj) is not controlled by NPR1 or SA, but rather closely associated with jasmonate (JA), abscisic acid (ABA), and several transcription factors. Furthermore, the BTH-induced resistance (BIR) partially depends on NPR1 activation, leading to a broader and stronger plant defense response. This paper provides a systematic review of the research progress on SAR in wheat, emphasizes the key regulatory role of NPR1 in wheat SAR, and summarizes the potential of pathogenesis-related protein (PR) genes in genetically modifying wheat to enhance broad-spectrum disease resistance. This review lays an important foundation for further analyzing the molecular mechanism of SAR and genetically improving broad-spectrum disease resistance in wheat. [ABSTRACT FROM AUTHOR]

Abscisic acid (ABA), a plant hormone, is crucial for regulating various physiological and developmental processes in plants, including adaptation to biotic and abiotic stresses. Recent advancements have significantly contributed to our understanding of ABA's biosynthetic pathway, transport, signaling pathway, and metabolism. To overcome the limitations of natural ABA, scientists have developed broad-spectrum and highly active agonists of ABA receptors. However, the practical application of these receptor agonists as agrochemicals still faces several challenges. On the other hand, some ABA antagonists have also been developed to differentiate the functional differences among various receptors more accurately. This can help design ABA agonists that can selectively activate specific physiological responses, thereby eliminating the undesired physiological effects induced by ABA. This paper aims to provide a comprehensive overview of the current ABA receptor agonists and antagonists to assist in developing novel ABA functional analogs with improved efficacy and simpler chemical structures that are suitable for agricultural applications. [ABSTRACT FROM AUTHOR]

Simple Summary: In this paper, the mechanism of circular RNAs influence on leaf color of Quercus mongolica was proposed for the first time. It was determined that a total of 88 circRNAs were differentially expressed and five phytohormones were significantly altered. As a result, this article identified a total of 16 circRNAs that may be involved in regulating the color of Quercus mongolica leaves. CircRNAs may affect the color of Quercus mongolica leaves by interacting with auxin, cytokinin, gibberellin, ethylene, and abscisic acid. This provides a theoretical basis for the cultivation of new varieties of colorful foliage species. Circular RNAs (circRNAs) are important regulatory molecules involved in various biological processes. However, the potential function of circRNAs in the turning red process of Quercus mongolica leaves is unclear. This study used RNA-seq data to identify 6228 circRNAs in leaf samples from four different developmental stages and showed that 88 circRNAs were differentially expressed. A correlation analysis was performed between anthocyanins and the circRNAs. A total of 16 circRNAs that may be involved in regulating the colour of Mongolian oak leaves were identified. CircRNAs may affect the colour of Q. mongolica leaves by regulating auxin, cytokinin, gibberellin, ethylene, and abscisic acid. This study revealed the potential role of circRNAs in the colour change of Q. mongolica leaves. [ABSTRACT FROM AUTHOR]

Abiotic stress is an adverse environmental factor that severely affects plant growth and development, and plants have developed complex regulatory mechanisms to adapt to these unfavourable conditions through long-term evolution. In recent years, many transcription factor families of genes have been identified to regulate the ability of plants to respond to abiotic stresses. Among them, the AP2/ERF (APETALA2/ethylene responsive factor) family is a large class of plant-specific proteins that regulate plant response to abiotic stresses and can also play a role in regulating plant growth and development. This paper reviews the structural features and classification of AP2/ERF transcription factors that are involved in transcriptional regulation, reciprocal proteins, downstream genes, and hormone-dependent signalling and hormone-independent signalling pathways in response to abiotic stress. The AP2/ERF transcription factors can synergise with hormone signalling to form cross-regulatory networks in response to and tolerance of abiotic stresses. Many of the AP2/ERF transcription factors activate the expression of abiotic stress-responsive genes that are dependent or independent of abscisic acid and ethylene in response to abscisic acid and ethylene. In addition, the AP2/ERF transcription factors are involved in gibberellin, auxin, brassinosteroid, and cytokinin-mediated abiotic stress responses. The study of AP2/ERF transcription factors and interacting proteins, as well as the identification of their downstream target genes, can provide us with a more comprehensive understanding of the mechanism of plant action in response to abiotic stress, which can improve plants' ability to tolerate abiotic stress and provide a more theoretical basis for increasing plant yield under abiotic stress. [ABSTRACT FROM AUTHOR]

Pre-harvest sprouting (PHS), the germination of seeds on the plant prior to harvest, poses significant challenges to agriculture. It not only reduces seed and grain yield, but also impairs the commodity quality of the fruit, ultimately affecting the success of the subsequent crop cycle. A deeper understanding of PHS is essential for guiding future breeding strategies, mitigating its impact on seed production rates and the commercial quality of fruits. PHS is a complex phenomenon influenced by genetic, physiological, and environmental factors. Many of these factors exert their influence on PHS through the intricate regulation of plant hormones responsible for seed germination. While numerous genes related to PHS have been identified in food crops, the study of PHS in vegetable crops is still in its early stages. This review delves into the regulatory elements, functional genes, and recent research developments related to PHS in vegetable crops. Meanwhile, this paper presents a novel understanding of PHS, aiming to serve as a reference for the study of this trait in vegetable crops. [ABSTRACT FROM AUTHOR]

Heavy metal (HM) stress poses a global risk to crops, ecological systems, and human health. It disrupts cellular ionic equilibrium, cell membrane integrity, metabolic balance, and the activities of enzymes and proteins, severely impacting physiological processes, plant development, and agricultural productivity. Although plants naturally activate defense mechanisms to mitigate the adverse effects of HM stress, they cannot completely prevent them. Phytohormones counter HM toxicity, aiding growth. External application and internal regulation via signaling/biosynthesis genes offer defense against HM-induced damage. A pivotal signaling molecule in plant adaptive responses to environmental stressors, including HM toxicity, is abscisic acid (ABA). Despite ABA's role in abiotic stress responses such as drought and salinity, its function and crosstalk with other phytohormones under HM stress remain poorly understood. Nonetheless, exogenously applied ABA serves as a strategic approach to enhancing plants' resistance to HM toxicity by promoting osmolyte accumulation and reinforcing antioxidant activity. ABA significantly regulates various plant growth and metabolic activities under diverse environmental conditions. This review highlights the effects of HM stress on plants and explores ABA involvement in production, signaling, catabolism, and transport within plant tissues. The purpose of this paper is to shed light on the complex interplay between the metabolism of ABA, its signaling, and its interactions with other phytohormones (e.g., auxins, gibberellins, and ethylene) during HM exposure. Furthermore, we delve into the function of ABA to mitigate HM stress and elucidate its interactions with other phytohormones. [ABSTRACT FROM AUTHOR]

Copyright of Guihaia is the property of Guihaia Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydrogen sulfide (H2S) and abscisic acid (ABA), as a signaling molecule and stress hormone, their crosstalk-induced thermotolerance in maize seedlings and its underlying mechanism were elusive. In this paper, H2S and ABA crosstalk as well as the underlying mechanism of crosstalk-induced thermotolerance in maize seedlings were investigated. The data show that endogenous levels of H2S and ABA in maize seedlings could be mutually induced by regulating their metabolic enzyme activity and gene expression under non-heat stress (non-HS) and HS conditions. Furthermore, H2S and ABA alone or in combination significantly increase thermotolerance in maize seedlings by improving the survival rate (SR) and mitigating biomembrane damage. Similarly, the activity of the reactive oxygen species (ROS)-scavenging system, including enzymatic antioxidants catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (POD), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), and superoxide dismutase (SOD), as well as the non-enzymatic antioxidants reduced ascorbic acid (AsA), carotenoids (CAR), flavone (FLA), and total phenols (TP), was enhanced by H2S and ABA alone or in combination in maize seedlings. Conversely, the ROS level (mainly hydrogen peroxide and superoxide radical) was weakened by H2S and ABA alone or in combination in maize seedlings under non-HS and HS conditions. These data imply that the ROS-scavenging system played an essential role in H2S-ABA crosstalk-induced thermotolerance in maize seedlings. [ABSTRACT FROM AUTHOR]

Global agricultural demand and the impact of fluctuating climatic conditions including global warming have catastrophically limited crop productivity and immensely outstretched the market value of agricultural products leading to acute inflation. The effect of desiccation or drought stress in plants is manifested at three levels viz. morphological, biochemical, and molecular and plants possess their own molecular and signaling arsenal to combat or ameliorate various stresses. For decades, stress-tolerant cultivars have been investigated and modulation of polyamine (PA) signaling was found to play a major role in attenuating environmental stresses including drought as major abiotic stress. PA metabolism pathways with their ability to crosstalk with both primary and secondary metabolic pathways have been correlated with several other responses such as seed germination, plant growth, development, defense, hormonal regulation, stress tolerance, and crop yield. Recent transcriptomic and metabolomic approaches have expanded the knowledge on the regulation of stress-induced biochemical, molecular, and physiological alterations. To fully comprehend the intricate biochemical network of plant stress physiology, it is necessary to identify exact responses against specific stress stimuli, interpret concurrent epigenetic alterations, and use molecular switching. The present review encompasses recent updates on drought tolerance mechanisms mediated by diverse polyamines playing significant roles in metabolic regulation, oxidative stress management, and systematic stress-reversal signaling. Besides, the drought stress-reversal role of polyamines and their cross-talks with other signaling molecules have also been documented. Gene, enzyme, and transcription factor (TF) functional features were retrieved from the published papers involving transgenic or mutant plants with over-expression or loss-of-function investigations. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The contribution of Eucalyptus globulus plantations to timber production for pulp, paper and energy production may be hampered by climate change. It is expected that Eucalyptus productivity may be affected through drought stress and changes to both pathogen distribution/pathogenicity and host–pathogen interactions. The impact of the fungal pathogen Neofusicoccum kwambonambiense on E. globulus, causing cankers and dieback, is well known but the impact of drought on disease development is still understudied. Our aim was to study the effect of drought on N. kwambonambiense infection by inoculating E. globulus plants under well‐watered conditions or with water limitation. Non‐infected plants for both water regimes were also analysed. Morphophysiological, biochemical and hormonal parameters were assessed 65 days post‐inoculation. Inoculation under conditions of water stress decreased water potential and photosynthetic efficiency and increased abscisic acid, jasmonic acid and lipid peroxidation. Water‐stressed infected plants also showed higher fungal colonization and external lesion length in comparison with well‐watered inoculated plants. Our results indicate that drought increased E. globulus predisposition to N. kwambonambiense infection and may also have promoted a change in the lifestyle of the fungus. Identifying host–pathogen interaction responses under different stress conditions is necessary to provide knowledge for decision‐making in the management of forest systems in general and of Eucalyptus production in particular. [ABSTRACT FROM AUTHOR]

Summary: Eurya honey (EH) is produced from the nectar of Eurya. In this paper, the physicochemical properties (moisture, free acidity, pH, 5‐hydroxymethylfurfural, conductivity, sugar, and colour) of EH were systematically studied for the first time. The total phenols and flavonoids were determined by spectrophotometry, and the contents were 40.29 ± 4.17 mg GAE/100 g and 12.44 ± 0.62 mg RE/100 g, respectively. A total of 232 compounds were identified, and 30 of them were quantified by ultra‐performance liquid chromatography coupled with quadrupole/time‐of‐flight mass spectrometry (UPLC‐Q/TOF‐MS). The potential markers of EH were abscisic acid (21.3–103.4 μg/100 g), gallic acid (6.9–220.2 μg/100 g), tricoumaroyl spermidine (284.2–518.1 μg/100 g), and kaempferol (15.0–258.7 μg/100 g). EH showed antioxidant capacities in DPPH free radical‐scavenging activity (IC50: 42.87–131.26 mg mL−1), ferric reducing antioxidant capacity (23.22–112.24 μmol FeSO4·7H2O/100 g), and ABTS radical‐scavenging activity assays (9.51–31.21 μmol Trolox/100 g). [ABSTRACT FROM AUTHOR]

Background: The drought condition is responsible for considerable losses in soybean production, which in turn may result in billionaire losses. After drought perception, plants activate a cascade of protecting genes against water deficit (WD), many of which are responsive to abscisic acid, the most important phytohormone to plants' adaptation. This work aimed to recover abscisic acid (ABA)-responsive differentially expressed genes (DEG) from an RNA-Seq, carried out from leaves and roots of drought-sensitive (BR16) and tolerant (Embrapa 48) soybean cultivars under mild (MiWD), moderate (MoWD), and severe (SWD) water-deficit treatments. Enriched ABA-responsive pathways important to drought tolerance in soybean were also identified. Results: In drought-sensitive and tolerant soybean cultivars, approximately 75% of genes were identified as ABA-responsive by containing more than two ABRE (ABA-responsive elements) in the promoter region. Most of these genes were positively regulated. Roots were the tissue with more ABA-responsive genes and pathways triggered in response to WD in both cultivars, although, on the tolerant cultivar, these pathways were higher expressed. The most important enriched ABA pathways observed in the roots of both cultivars were involved in sugar and sulfur amino acid biosynthesis, osmoregulation, and crosstalk among ABA and ethylene, jasmonate, auxin, and cytokinin. Other pathways enriched were involved in phytoalexin production, ROS homeostasis, and membrane stability by glycerolipid and glycerophospholipid production. ABA-responsive genes were also ordered based on their expression profile in tissue and cultivar, and nine confidence groups could be observed. More than 80% of these clustered genes showed the same regulation profile under MiWd, MoWD, and SWD treatments. Activation of ABA biosynthesis under water deficit was validated by RT-qPCR by increasing the expression level of NCED3, an important enzyme in this pathway, and GOLS, a known ABA-responsive gene. Conclusions: A robust catalog of ABA-responsive genes was made available in this work. Considering ABA's role in drought-response mechanisms, the genes in the groups pointed out in this study would be reliable candidates to be used in strategies to develop soybean lines more tolerant to drought. This paper, presented for the first time, ABA-responsive genes and ABA-enriched pathways in contrasting soybean cultivars for drought tolerance. [ABSTRACT FROM AUTHOR]

One of the favorite issues for the ecologists and physiologists is searching the effects of the environmental factors (i.e. salinity, temperature, drought, rainfall, etc.) in the plants. In the present paper, the response of the enzymatic and non-enzymatic antioxidants in different populations of Pistacia atlantica and Pistacia khinjuk were investigated under different climatic conditions. Ten trees of any population of P. atlantica and P. khinjuk were garnered from diverse locations of Iran in September, 2017. The leaf samples were transferred to the laboratory using liquid nitrogen and were frozen for analysis of enzymatic and non-enzymatic antioxidants in different populations. According to the soil and climatic analyses, Jebalbarez, Sangan and Anjirk are more stressful compared to other regions. Generally, our results unveiled that the contents of protein, proline and total soluble sugar like compatible osmolytes in some populations of P. atlantica are higher than those of P. khinjuk. The antioxidant enzyme activities including superoxide dismutase, peroxidase and polyphenol oxidase were more in P. khinjuk. The activity of key enzymes in the biosynthesis pathway of the phenolic compounds in P. khinjuk was more than that of P. atlantica. Furthermore, the content of non-enzymatic antioxidants such as phenol, flavonoids and tocopherols in P. atlantica was higher than that of P. khinjuk. The respiratory enzymes (e.g. aconitase, fumarase and succinate dehydrogenase) had high activity in P. khinjuk. P. atlantica used more non-enzymatic systems; however, P. khinjuk applied the enzymatic system in response to different climatic conditions. In conclusion, the present study revealed that P. atlantica used more of the osmoregulation and non-enzymatic system; however, P. khinjuk utilized the enzymatic antioxidant system and the respiratory enzymes in response to the ecophysiological conditions. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Karrikins are a group of chemicals found in plant-derived smoke from burning plant material. To date, scientists have concentrated on their effect on seed germination in plants sensitive to smoke. However, there are reports on the effect of karrikins on the physiology and morphology of plants that do not occur in fire areas and are not naturally treated by smoke. These chemicals positively affect the biometric parameters of in vitro cultured plants. Their effect on pollen germination rate in several species has been recently confirmed. They interact with plant growth regulators, enhancing their effects, for example, using them together with auxins, cytokinins, gibberellins, abscisic acid, or ethylene. This paper reviews the present research on karrikins and proposes perspectives for further investigations and applying these chemicals in horticultural production as a new group of plant growth regulators. [ABSTRACT FROM AUTHOR]

This paper explores the potential of nano seed priming with calcium oxide nanoparticles in maintaining the redox status in carom (Trachyspermum ammi L.) plants by modulating non-enzymatic antioxidants and enzymatic antioxidants. Calcium oxide nanoparticles were prepared in four testing regimes comprising 25, 50, 75, and 100 ppm along with the control treatment of 0 ppm (distilled water). Priming was performed by soaking the carom seeds in the aerated water, and plants were grown under split plots corresponding to drought and water. Seed priming with 75 ppm CaONPs reduced hydrogen peroxide, malondialdehyde contents and electrolyte leakage by 23.3%, 35.9% and 31.6%, respectively, in the water-stressed carom plants. The glutathione s-transferase, superoxide dismutase and peroxidase functions improved under water stress by 42.3%, 24.1% and 44.8%, respectively, in the carom plants raised through 100 ppm primed seeds with CaO_NPs. Priming induced better Ca2+ signaling, which affected the enzymes of the ascorbate glutathione cycle, enabling them to maintain redox status in the carom plants exposed to drought stress. The morpho-agronomic traits of carom plants in terms of number of umbels, hundred seeds weights, shoot and root length and biomass improved significantly upon seed priming treatments. Seed priming with CaO_NPs is a viable strategy to combat reactive oxygen species-mediated damages in the carom plants. [ABSTRACT FROM AUTHOR]

High levels of cadmium (Cd) in soil can cause crop yield reduction or death. Cadmium accumulation in crops affects human and animal health as it passes through the food chain. Therefore, a strategy is needed to enhance the tolerance of crops to this heavy metal or reduce its accumulation in crops. Abscisic acid (ABA) plays an active role in plants' response to abiotic stress. The application of exogenous ABA can reduce Cd accumulation in shoots of some plants and enhance the tolerance of plants to Cd; therefore, ABA may have good application prospects. In this paper, we reviewed the synthesis and decomposition of ABA, ABA-mediated signal transduction, and ABA-mediated regulation of Cd-responsive genes in plants. We also introduced physiological mechanism underlying Cd tolerance because of ABA. Specifically, ABA affects metal ion uptake and transport by influencing transpiration and antioxidant systems, as well as by affecting the expression of metal transporter and metal chelator protein genes. This study may provide a reference for further research on the physiological mechanism of heavy metal tolerance in plants. [ABSTRACT FROM AUTHOR]

Roots are important organs of plants. Plants rely on roots for water, nutrients, and organic salts. In the whole root system, lateral roots (LRs) account for a large proportion and are critical to the development of the plant. Many environmental factors affect LR development. Therefore, a systematic understanding of these factors can provide a theoretical basis for creating optimal growth conditions for plants. In this paper, the factors affecting LR development are systematically and comprehensively summarized, and the molecular mechanism and regulatory network of LR development are described. Changes in the external environment not only lead to hormone homeostasis in plants but also affect the composition and activity of rhizosphere microbial communities, which in turn affect plants' nitrogen and phosphorus uptake and growth dynamics. LR development is influenced by hormone levels and external environment. In particular, auxin and abscisic acid coordinate with each other to maintain normal LR development. Of course, changes in the external environment are also important for root development, and they affect the intrinsic hormone levels of plants by affecting the accumulation and transport of hormones. For example, nitrogen, phosphorus, reactive oxygen species, nitric oxide, water, drought, light, and rhizosphere microorganisms affect LR development and plant tolerance in a variety of ways, including regulating hormone levels. This review summarizes the factors affecting LR development and the regulatory network and points out the direction for future research. [ABSTRACT FROM AUTHOR]

Microalgae are now widely applied in municipal (YH_3) and industrial sewage (YH_4) treatments. Through integrated omics analysis, we studied the similarities and differences at the molecular level between the two different types of sewage treatment processes. The most significantly enriched gene ontology (GO) terms in both types of sewage treatments were the ribosome, photosynthesis, and proteasome pathways. The results show that the pathways of differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were enriched for photosynthesis, glyoxylate and dicarboxylate metabolism, and carbon fixation in photosynthetic organisms. Considering YH_3 vs. YH_4, the metabolism of citrate, sedoheptulose-7P, and succinate was significantly upregulated. In addition, the results showed that the pathways of DEGs and DAMs were enriched in terms of amino acid metabolism and carotenoid biosynthesis in YH_4 vs. YH_3. The metabolism of S-Adenosyl-L-homocysteine was significantly downregulated, 2-oxobutanoate was significantly upregulated and downregulated, and the metabolism of abscisic acid glucose ester (ABA-GE) was also significantly upregulated. Overall, the results of this paper will help to improve the basic knowledge of the molecular response of microalgae to sewage treatments, and help design a response strategy based on microalgae for complex, mixed sewage treatments. [ABSTRACT FROM AUTHOR]

Cabbage (Brassica oleracea L. var. capitata L.) is an important cruciferous vegetable, which is rich in dietary fiber, vitamins, beta-carotene and even good for cancer prevention. So, it is widely planted around the world. However, in the production of cabbage, the property of head-splitting not only reduces the appearance quality and commercial value of cabbage but also easily infects the area with head-splitting by germs, resulting in yield reduction, even no yield, and economic losses. For the head-splitting of cabbage, this paper introduced the causes, evaluation methods and indexes, and anatomic properties and reviewed some QTLs that have been obtained. But the cabbage molecular research of head-splitting is still in its infancy compared with other vegetable plants. Head-splitting is greatly affected by water. Although the cultivation and management methods can reduce the head-splitting rate, genetic improvement of head-splitting is still the most economic and efficient way in the long run. Therefore, the changes in the substances regulating cell water potential, the development of cell wall, ductility and toughness, calcium ion-regulated pectinase and cellulase activities, expansin genes, and even the ETH and ABA pathways related to maturation and abscission can provide ideas and directions for future gene mining and mechanism analysis for head-splitting tolerance, and thus accelerate the molecular breeding process. [ABSTRACT FROM AUTHOR]

Plants often suffer from hypoxic stress due to flooding caused by extreme weather. Hypoxia usually leads to restricted oxygen supply and alters metabolic patterns from aerobic to anaerobic. Cucumber roots are fragile and highly sensitive to damage from hypoxic stress. The purpose of this study was to investigate the regulatory mechanism of exogenous calcium alleviating hypoxic stress in cucumber through transcriptome and small RNAs analysis. Three treatments were performed in this paper, including untreated-control (CK), hypoxic stress (H), and hypoxic stress + exogenous calcium treatment (H + Ca2+). A large number of differentially expressed genes (DEGs) were identified, 1,463 DEGs between CK vs H, 3,399 DEGs between H vs H + Ca2+, and 5,072 DEGs between CK vs H + Ca2+, respectively. KEGG analysis of DEGs showed that exogenous calcium could activate hormone signaling pathways (ethylene, ABA, IAA and cytokinin), transcription factors (MYB, MYB-related, bHLH, bZIP, and WRKY), calcium signaling and glycolysis pathway to mitigating hypoxic stress in cucumber seedlings. Additionally, miRNA and their target genes were detected and predicted between treatments. The target genes of these miRNAs revealed that auxin, cellulose synthase, and mitochondrial ribosomal related genes (Csa2G315390, Csa6G141390, Csa4G053280, and Csa6G310480) probably play in the improvement of the hypoxic tolerance of cucumber seedlings through exogenous calcium application. In short, our data adds new information to the mechanism of exogenous calcium mitigation of hypoxic stress injury in cucumber seedlings at transcriptional and posttranscriptional levels. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abiotic/biotic stresses pose a major threat to agriculture and food security by impacting plant growth, productivity and quality. The discovery of extensive transcription of large RNA transcripts that do not code for proteins, termed long non-coding RNAs (lncRNAs) with sizes larger than 200 nucleotides in length, provides an important new perspective on the centrality of RNA in gene regulation. In plants, lncRNAs are widespread and fulfill multiple biological functions in stress response. In this paper, the research advances on the biological function of lncRNA in plant stress response were summarized, like as Natural Antisense Transcripts (NATs), Competing Endogenous RNAs (ceRNAs) and Chromatin Modification etc. And in plants, lncRNAs act as a key regulatory hub of several phytohormone pathways, integrating abscisic acid (ABA), jasmonate (JA), salicylic acid (SA) and redox signaling in response to many abiotic/biotic stresses. Moreover, conserved sequence motifs and structural motifs enriched within stress-responsive lncRNAs may also be responsible for the stress-responsive functions of lncRNAs, it will provide a new focus and strategy for lncRNA research. Taken together, we highlight the unique role of lncRNAs in integrating plant response to adverse environmental conditions with different aspects of plant growth and development. We envisage that an improved understanding of the mechanisms by which lncRNAs regulate plant stress response may further promote the development of unconventional approaches for breeding stress-resistant crops. [ABSTRACT FROM AUTHOR]

Bacteria from the genus Pantoea have been reported to be widely distributed in rice paddy environments with contradictory roles. Some strains promoted rice growth and protected rice from pathogen infection or abiotic stress, but other strain exhibited virulence to rice, even causing severe rice disease. In order to effectively utilize Pantoea in rice production, this paper analyzed the mechanisms underlying beneficial and harmful effects of Pantoea on rice growth. The beneficial effect of Pantoea on rice plants includes growth promotion, abiotic alleviation and disease inhibition. The growth promotion may be mainly attributed to nitrogen-fixation, phosphate solubilization, plant physiological change, the biosynthesis of siderophores, exopolysaccharides, 1-aminocyclopropane-1-carboxylic acid deaminase and phytohormones, including cytokinin, indole-3-acetic acid (IAA), auxins, abscisic acid and gibberellic acid, while the disease inhibition may be mainly due to the induced resistance, nutrient and spatial competition, as well as the production of a variety of antibiotics. The pathogenic mechanism of Pantoea can be mainly attributed to bacterial motility, production of phytohormones such as IAA, quorum sensing-related signal molecules and a series of cell wall-degrading enzymes, while the pathogenicity-related genes of Pantoea include genes encoding plasmids, such as the pPATH plasmid, the hypersensitive response and pathogenicity system, as well as various types of secretion systems, such as T3SS and T6SS. In addition, the existing scientific problems in this field were discussed and future research prospects were proposed. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Rice sulfite reductase (OsSiR) is important protein in reducing sulfite to sulfide. In this paper, it is aimed to shed light on OsSiR's probable structure, function, and expression using in silico methods and test its responses under drought and salt stresses. Moreover, it was also analyzed if OsSiR was structurally different from other SiR proteins. We estimated that OsSiR lacks ribbon–helix–helix DNA-binding motif allowing it to bind to DNA; therefore, it was probably localized in stroma as a non-nucleoid-type protein. Also, we found that OsSiR expression was regulated by JA in roots and by crosstalk of JA and ABA in shoots. RT-qPCR results showed that there was 20% increase in the expression of OsSiR at 3rd h of the salt treatment. However, OsSiR was downregulated when exposed to drought stress and salt stress for longer periods of time, respectively. OsSiR has a high post-translational potential because of its high phosphorylation sites. This may be originating from the most prevalent residue, Gly, facilitating its binding to phosphates in OsSiR. Our docking results showed that ligand binding residues of OsSiR (Arg159, Thr162, Gln167, and Pro501) were also active site residues of OsSiR. Both two domains of OsSiR interacted with sulfite and the number of the residues in 4Fe–4S domain (PF01077) was higher. The findings in this study are important in terms of structural and expressional studies of rice SiR (OsSiR) and can be used for SiR proteins in sorghum (Sorghum bicolor), maize (Zea mays), and foxtail millet (Setaria italica), which are closely related and highly similar to OsSiR in terms of sequence and predicted 3D structure. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Seed dormancy and germination determine the beginning of the life cycle of plants, and the phytohormone ABA plays a crucial role in regulation of seed dormancy and germination. However, the upstream regulatory mechanism of ABA metabolism during dormancy releasing is still remain elusive. In this paper, we present a novel mechanism of OsNAC2 in controlling ABA metabolism and regulation of seed dormancy. OsNAC2 highly expressed during seed development and germination, and overexpression of OsNAC2 strengthened seed dormancy and suppressed germination. Moreover, exogenous phytohormone treatment showed that OsNAC2 acted upstream of GA signaling and downstream of ABA signaling. Additionally, overexpression of OsNAC2 inhibited ABA degradation and increased ABA content during early germination. Further molecular analysis revealed that OsNAC2 directly bound to the ABA metabolism genes promoter and inhibits their transcription in rice protoplasts. These finding could help us explain the genetic regulation mechanism of ABA metabolism during dormancy release and germination in rice. • OsNAC2 exhibits high expression levels in ungerminated rice seed embryos, followed by a rapid decline during germination. • Overexpressing OsNAC2 inhibits ABA degradation, maintaining elevated ABA during dormancy release. • OsNAC2 orchestrates hormone responses, including GA, ABA and JA pathways. • OsNAC2 directly binds to the promoters of ABA metabolism genes, thereby exerting transcriptional repression in rice. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alternative splicing (AS) exists in eukaryotes to increase the complexity and adaptability of systems under biophysiological conditions by increasing transcriptional and protein diversity. As a classic hormone, abscisic acid (ABA) can effectively control plant growth, improve stress resistance, and promote dormancy. At the transcriptional level, ABA helps plants respond to the outside world by regulating transcription factors through signal transduction pathways to regulate gene expression. However, at the post-transcriptional level, the mechanism by which ABA can regulate plant biological processes by mediating alternative splicing is not well understood. Therefore, this paper briefly introduces the mechanism of ABA-induced alternative splicing and the role of ABA mediating AS in plant response to the environment and its own growth. [ABSTRACT FROM AUTHOR]

The article of Wei et al. [[5]] focuses on the genome-wide identification of the ERF transcription factor family and the functional analysis of the drought-stress-responsive genes in I Melilotus albus i ( I Ma i ). Plant adaptation to soil drought is a topic that is currently under investigation. The study conducted by Han et al. [[3]] reports the genome-wide identification of the I AP2/ERF i ( I APETALA2/Ethylene Responsive Factor i ) gene family, associated with abiotic stress in I Dendrobium catenatum i ( I Dc i ). [Extracted from the article]

Fruit quality traits of sweet watermelon (Citrullus lanatus var. lanatus) are crucial for new product development and commercialization. Sweet watermelon fruit quality traits are affected by the compositions of phytochemical compounds, phytohormones, and fruit flesh firmness which are affected by genes, the growing environment and their interaction. These compositions determine fruit ripening, eating quality, and postharvest shelf-life. Knowledge of the genetic profile and analyses of quality traits in watermelon is vital to develop improved cultivars with enhanced nutritional compositions, consumer-preferred traits, and extended storage life. This review aims to present the opportunities and progress made on the genetic analysis of fruit quality traits in watermelon as a guide for quality breeding based on economic and end-user attributes. The first section of the review highlights the genetic mechanisms involved in the biosynthesis of phytochemical compounds (i.e., sugars, carotenoids, amino acids, organic acids, and volatile compounds), phytohormones (i.e., ethylene and abscisic acid) and fruit flesh structural components (i.e., cellulose, hemicellulose, and pectin) elicited during watermelon fruit development and ripening. The second section pinpoints the progress on the development of molecular markers and quantitative trait loci (QTL) analysis for phytochemical compounds, phytohormones and fruit quality attributes. The review presents gene-editing technology and innovations associated with fruit quality traits for selection and accelerated cultivar development. Finally, the paper discussed gene actions conditioning fruit ripening in citron watermelon (C. lanatus var. citroides [L. H. Bailey] Mansf. ex Greb.) as reference genetic resources to guide current and future breeding. Information presented in this review is useful for watermelon variety design, product profiling and development to serve the diverse value chains of the crop. An overview of phytochemical compounds, phytohormones and flesh textural properties influencing fruit quality of watermelon fruit, and developed genomic and genetic resources for fruit quality breeding. [ABSTRACT FROM AUTHOR]

Background: Small interfering RNAs (siRNAs) target homologous genomic DNA sequences for cytosine methylation, known as RNA-directed DNA methylation (RdDM), plays an important role in transposon control and regulation of gene expression in plants. Repressor of silencing 1 (ROS1) can negatively regulate the RdDM pathway. Results: In this paper, we investigated the molecular mechanisms by which an upstream regulator ACD6 in the salicylic acid (SA) defense pathway, an ABA pathway-related gene ACO3, and GSTF14, an endogenous gene of the glutathione S-transferase superfamily, were induced by various abiotic stresses. The results demonstrated that abiotic stresses, including water deficit, cold, and salt stresses, induced demethylation of the repeats in the promoters of ACD6, ACO3, and GSTF14 and transcriptionally activated their expression. Furthermore, our results revealed that ROS1-mediated DNA demethylation plays an important role in the process of transcriptional activation of ACD6 and GSTF14 when Arabidopsis plants are subjected to cold stress. Conclusions: This study revealed that ROS1 plays an important role in the molecular mechanisms associated with genes involved in defense pathways in response to abiotic stresses. [ABSTRACT FROM AUTHOR]

In the course of evolution, plants have developed numerous specific regulatory signal pathways, which are hormonal for the most part. Phytohormones comprise not only such generally recognized endogenous growth regulators as abscisic acid, auxins, cytokinins, gibberellins, brassinosteroids (BS), ethylene, salicylic acid (SA), and jasmonates but also recently described derivatives of apocarotenoids—strigolactones (SL). Signal pathways interact at the level of biosynthesis of messengers and their translocation as well as upon activation of target genes. Since abiotic and biotic environmental stressors negatively influence plant productivity, understanding of molecular mechanisms of regulation induced by stress agents may help researchers to produce stress-resistant and high-yielding plants using molecular techniques. This paper is a review of present-day literature dealing with the interaction and interference of nonhormonal and hormonal signals regulating growth and development of plants under ever-changing environmental conditions. [ABSTRACT FROM AUTHOR]

[Objectives] The paper aimed to investigate the inhibitory effect of 5 °C low temperature treatment on seed germination of celery and its regulatory mechanism. [Methods] The seeds of Shanghai yellow heart' were treated at 5 and 20 °C to explore the germination, gibberellin(GA) and abscisic acid(ABA) contents, the dynamic changes of key genes expression in metabolic pathways, and the dynamic changes of starch and soluble sugar contents. [Results]5 °C low temperature treatment significantly inhibited the seed germination rate, seedling emergence rate, relative water absorption and embryo growth of celery, while 20 °C treatment could rapidly promote the seed germination. And after the seeds treated at 5 °C for 15 days were transferred to 20 °C (T5-20 treatment), the seeds could quickly recover their germination vitality, which indicated that 5 °C low temperature did not cause irreversible damage to the seeds. The results of seed vitality staining also indicated that low temperature did not cause damage to the embryo structure. Low temperature at 5 °C also markedly inhibited the synthesis of GA during germination, and the expression of related metabolism and downstream genes was also markedly inhibited, while 20°C treatment significantly promoted the synthesis of GA, and the high expression of GA3ox1 gene in seeds treated at 20 °C and T5-20 meant that it might play a key role in the synthesis of GA. ABA content showed a dynamic change in 5 °C treatment, but GA/ABA showed a downward trend in adults. The expression of the ABA degrading gene CYP707A1 had a significant negative correlation with ABA content in the middle and late stages of seed germination 5 °C treatment. In addition, 5 °C also significantly inhibited the sugar metabolism capacity of celery seeds. The starch content of celery seeds treated at 5 °C was significantly higher than that treated at 20 °C, but the soluble sugar content was significantly lower than that treated at 20 °C. [Conclusions] Low temperature at 5 °C induced secondary dormancy of celery seeds. GA/ABA might be an with low temperature. in important signal of celery seeds' response to ambient temperature, and GA3ox1 and CYP707A1 were potential key genes to cope. [ABSTRACT FROM AUTHOR]

The presence of the ozone hole increases the amount of UV radiation reaching a plant’s surface, and UV-B radiation is an abiotic stress capable of affecting plant growth. Rhododendron chrysanthum Pall. (R. chrysanthum) grows in alpine regions, where strong UV-B radiation is present, and has been able to adapt to strong UV-B radiation over a long period of evolution. We investigated the response of R. chrysanthum leaves to UV-B radiation using widely targeted metabolomics and transcriptomics. Although phytohormones have been studied for many years in plant growth and development and adaptation to environmental stresses, this paper is innovative in terms of the species studied and the methods used. Using unique species and the latest research methods, this paper was able to add information to this topic for the species R. chrysanthum. We treated R. chrysanthum grown in a simulated alpine environment, with group M receiving no UV-B radiation and groups N and Q (externally applied abscisic acid treatment) receiving UV-B radiation for 2 days (8 h per day). The results of the MN group showed significant changes in phenolic acid accumulation and differential expression of genes related to phenolic acid synthesis in leaves of R. chrysanthum after UV-B radiation. We combined transcriptomics and metabolomics data to map the metabolic regulatory network of phenolic acids under UV-B stress in order to investigate the response of such secondary metabolites to stress. L-phenylalanine, L-tyrosine and phenylpyruvic acid contents in R. chrysanthum were significantly increased after UV-B radiation. Simultaneously, the levels of 3-hydroxyphenylacetic acid, 2-phenylethanol, anthranilate, 2-hydroxycinnamic acid, 3-hydroxycinnamic acid, α-hydroxycinnamic acid and 2-hydroxy-3-phenylpropanoic acid in this pathway were elevated in response to UV-B stress. In contrast, the study in the NQ group found that externally applied abscisic acid (ABA) in R. chrysanthum had greater tolerance to UV-B radiation, and phenolic acid accumulation under the influence of ABA also showed greater differences. The contents of 2-phenylethanol, 1-o-p-coumaroyl-β-d-glucose, 2-hydroxy-3-phenylpropanoic acid, 3-(4-hydroxyphenyl)-propionic acid and 3-o-feruloylquinic ac-id-o-glucoside were significantly elevated in R. chrysanthum after external application of ABA to protect against UV-B stress. Taken together, these studies of the three groups indicated that ABA can influence phenolic acid production to promote the response of R. chrysanthum to UV-B stress, which provided a theoretical reference for the study of its complex molecular regulatory mechanism.

Nowadays, crop insufficiency resulting from soil salinization is threatening the world. On the basis that soil salinization has become a worldwide problem, studying the mechanisms of plant salt tolerance is of great theoretical and practical significance to improve crop yield, to cultivate new salt-tolerant varieties, and to make full use of saline land. Based on previous studies, this paper reviews the damage of salt stress to plants, including suppression of photosynthesis, disturbance of ion homeostasis, and membrane peroxidation. We have also summarized the physiological mechanisms of salt tolerance, including reactive oxygen species (ROS) scavenging and osmotic adjustment. Four main stress-related signaling pathways, salt overly sensitive (SOS) pathway, calcium-dependent protein kinase (CDPK) pathway, mitogen-activated protein kinase (MAPKs) pathway, and abscisic acid (ABA) pathway, are included. We have also enumerated some salt stress-responsive genes that correspond to physiological mechanisms. In the end, we have outlined the present approaches and techniques to improve salt tolerance of plants. All in all, we reviewed those aspects above, in the hope of providing valuable background knowledge for the future cultivation of agricultural and forestry plants. [ABSTRACT FROM AUTHOR]

Plant mortality is a complex process influenced by both biotic and abiotic factors. In recent decades, widespread mortality events have been attributed to increasing drought severity, which has motivated research to examine the physiological mechanisms of drought-induced mortality, particularly hydraulic failure. Drought-based mortality mechanisms are further influenced by plant interactions with biota such as neighboring plants, insect pests, and microbes. In this review, we highlight some of the most influential papers addressing these biotic interactions and their influence on plant mortality. Plant–plant interactions can be positive (facilitation), neutral, or negative (competition), depending on drought intensity and neighbor identity. For example, stand-scale mortality likely increases with basal area (an index of competition). However, the diversity of forest stands matters, as more diverse forests suffer less mortality from drought than species-poor forests. Dense forest stands also increase bark beetle attack frequency, which can exacerbate drought stress and mortality, particularly for fast-growing species with lower defense allocation. In some cases, however, drought stress can alleviate biotic attack, depending on feedbacks between plant and pest physiology. Finally, plant interactions with beneficial microorganisms can increase drought tolerance, reduce the likelihood of mortality, and even extend plant distributions into drier habitats. Our review suggests more work is needed in natural herbaceous plant communities as well as dry tropical ecosystems where mortality mechanisms are less understood. Overall, relatively few studies directly link biotic interactions with the physiological mechanisms of mortality. Simultaneous manipulations of biotic interactions and measurements of physiological thresholds (e.g., xylem cavitation) are needed to fully represent biotic interactions in predictive models of plant mortality. [ABSTRACT FROM AUTHOR]