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It is not easy to directly obtain concentrations of auxin (mainly indole-3-acetic acid, or IAA) and other phytohormones in different locations of individual plants although such information is critical for the study of their functions. Here we developed a paper-based analytical device consisting of a disposable working electrode to provide a platform for direct and simultaneous detection of free IAA and salicylic acid (SA) in different parts of pea seedlings with the weights of several milligrams. The double sided conductive carbon tape modified with carbon nanotube was used as the disposable working electrodes after they were treated with oxygen plasma. Different parts of pea seedlings were applied on the surface of working electrodes for direct electrochemical detection of free IAA and SA in paper-based analytical devices. The requirement of solution volumes with only 10 microliters made it possible to quantify free IAA and SA at the level of ng. Our results suggested that large amounts of inherent IAA and SA could be lost because of complicated and time-consuming preparation of samples in traditional gas/liquid chromatography-mass spectrometry methods Our approach not only avoids such steps but also provides concentrations of IAA and SA in different zones of individual pea seedlings. The obtained results could be applied for the study of individual differences and interactions between IAA and SA in development of peas. This strategy not only paved the foundation for further investigation of regulating mechanisms of free IAA and its interaction with other phytohormones but also might provide an alternative approach for detection of free electroactive biomolecules in other living organs. [ABSTRACT FROM AUTHOR]

Dr. Manmohan Manohar Laloraya (September 1, 1932- February 18, 2023) was an outstanding teacher, researcher and administrator who mentored many scholars who themselves became leaders. He was gifted with a brilliant mind and unique research career, working with both plants and animals. He had received numerous awards and honours in his lifetime including the distinguished plant physiologist award in 1995, and being the Fellow of the National Academy of Sciences, India. We present below his brief biography, which is followed by his extraordinary research contributions on both plants and animals. We end this "In memoriam" with personal reminiscences of some of his class fellows, research collaborators, and life-long friends, and a 1958 group photograph with many at a conference. [ABSTRACT FROM AUTHOR]

• Paper-based analytical devices and microsampling for evaluation of fruit ripening. • ITO glass was used to fabricate disposable working electrodes in paper-based devices. • IAA and SA in tiny parts of tomato fruit could be differentiated during ripening. • Profiling of IAA and SA in immature and mature tomato fruit was visually compared. Fruit ripening is a progress involving many physiological changes regulated by various plant hormones such as indole-3-acetic acid (IAA) and salicylic acid (SA). The levels of these hormones in fruit with the spatial-temporal resolution can provide detailed information for the study and evaluation of the fruit ripening. Herein paper-based analytical devices and the microsampling technique were coupled for the analysis of IAA and SA in different locations of the tomato fruit during ripening. Because of its excellent electric conductivity, the ITO glass was used as the substrate of the disposable working electrodes and modified with conductive carbon cement. The ITO modified electrodes in the paper-based analytical devices were utilized for analysis of IAA and SA in tiny tomato samples obtained with the technique of microsampling. Our results showed that the amounts of IAA and SA in the locular tissue of tomato fruit decreased via time in the process of ripening. More importantly, the spatial profiling of IAA and SA in immature and mature tomatoes could be directly differentiated at the molecular level. This study suggested that low-cost paper-based electroanalytical devices could become an effective platform for rapid evaluation of the fruit ripening. [ABSTRACT FROM AUTHOR]

A rapid decrease of the plant hormone ABA under submergence is thought to be a prerequisite for the enhanced elongation of submerged shoots of rice (Oryza sativa L.). Here, we report that the level of phaseic acid (PA), an oxidized form of ABA, increased with decreasing ABA level during submergence. The oxidation of ABA to PA is catalyzed by ABA 8′-hydroxylase, which is possibly encoded by three genes (OsABA8ox1, -2 and -3) in rice. The ABA 8′-hydroxylase activity was confirmed in microsomes from yeast expressing OsABA8ox1. OsABA8ox1–green fluorescent protein (GFP) fusion protein in onion cells was localized to the endoplasmic reticulum. The mRNA level of OsABA8ox1, but not the mRNA levels of other OsABA8ox genes, increased dramatically within 1 h after submergence. On the other hand, the mRNA levels of genes involved in ABA biosynthesis (OsZEP and OsNCEDs) decreased after 1–2 h of submergence. Treatment of aerobic seedlings with ethylene and its precursor, 1-aminocyclopropane-1-carboxylate (ACC), rapidly induced the expression of OsABA8ox1, but the ethylene treatment did not strongly affect the expression of ABA biosynthetic genes. Moreover, pre-treatment with 1-methylcyclopropene (1-MCP), a potent inhibitor of ethylene action, partially suppressed induction of OsABA8ox1 expression under submergence. The ABA level was found to be negatively correlated with OsABA8ox1 expression under ACC or 1-MCP treatment. Together, these results indicate that the rapid decrease in ABA levels in submerged rice shoots is controlled partly by ethylene-induced expression of OsABA8ox1 and partly by ethylene-independent suppression of genes involved in the biosynthesis of ABA. [ABSTRACT FROM AUTHOR]

Progress in understanding the network of mechanisms involved in maize primary root growth maintenance under water deficits is reviewed. These include the adjustment of growth zone dimensions, turgor maintenance by osmotic adjustment, and enhanced cell wall loosening. The role of the hormone abscisic acid (ABA) in maintaining root growth under water deficits is also addressed. The research has taken advantage of kinematic analysis, i.e. characterization of spatial and temporal patterns of cell expansion within the root growth zone. This approach revealed different growth responses to water deficits and ABA deficiency in distinct regions of the root tip. In the apical 3 mm region, elongation is maintained at well-watered rates under severe water deficit, although only in ABA-sufficient roots, whereas the region from 3–7 mm from the apex exhibits maximum elongation in well-watered roots, but progressive inhibition of elongation in roots under water deficit. This knowledge has greatly facilitated discovery of the mechanisms involved in regulating the responses. The spatial resolution with which this system has been characterized and the physiological knowledge gained to date provide a unique and powerful underpinning for functional genomics studies. Characterization of water deficit-induced changes in transcript populations and cell wall protein profiles within the growth zone of the maize primary root is in progress. Initial results from EST and unigene analyses in the tips of well-watered and water-stressed roots highlight the strength of the kinematic approach to transcript profiling. [ABSTRACT FROM PUBLISHER]

Evidence indicating the natural occurrence of the auxin substance, phenylacetic acid (PAA), in a range of crop plants has been obtained from paper chromatography followed by bioassay and from HPLC and GLC analysis of acidic ether extracts from vegetative shoots of these plants. Confirmatory evidence for the presence of PAA in tobacco shoots has been obtained from GC-MS analysis. Quantitative estimation of the relative amounts of the two auxins, IAA and PAA, in the different shoot extracts was achieved by paper chromatography followed by gas chromatography. The amount of PAA in all six plants was found to be several times greater than that of IAA and calculation of average internal concentrations revealed that PAA is present in vegetative shoots at physiologically active concentrations. Present knowledge of the growth-regulating activity of this new natural auxin is discussed. [ABSTRACT FROM AUTHOR]

Jasmonate is a well-known defence hormone for plants, but it is also necessary for growth and development. Indeed, the identification of the COI1 receptor was based on the jasmonate-triggered response of root growth inhibition. In this special issue, a collection of review papers and two research papers discuss the current state of progress in this field, covering areas from seed germination and flowering to the Jasminum sambac genome. [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]

Drought stress (DS) is one of the abiotic stresses that plants encounter commonly in nature, which affects their life, reduces agricultural output, and prevents crops from growing in certain areas. To enhance plant tolerance against DS, abundant exogenous substances (ESs) have been attempted and proven to be effective in helping plants relieve DS. Understanding the effect of each ES on alleviation of plant DS and mechanisms involved in the DS relieving process has become a research focus and hotspot that has drawn much attention in the field of botany, agronomy, and ecology. With an extensive and comprehensive review and summary of hundred publications, this paper groups various ESs based on their individual effects on alleviating plant/crop DS with details of the underlying mechanisms involved in the DS-relieving process of: (1) synthesizing more osmotic adjustment substances; (2) improving antioxidant pathways; (3) promoting photosynthesis; (4) improving plant nutritional status; and (5) regulating phytohormones. Moreover, a detailed discussion and perspective are given in terms of how to meet the challenges imposed by erratic and severe droughts in the agrosystem through using promising and effective ESs in the right way and at the right time. [ABSTRACT FROM AUTHOR]

Elicitation, the process of stimulating plants to enhance the production of valuable secondary metabolites, has emerged as a significant avenue in the field of plant biotechnology. This review paper provides a comprehensive examination of elicitation, encompassing its mechanisms, the imperative for its utilization, and the diverse array of elicitors employed, including abiotic, biotic, and nanoparticle-based agents. By exploring the intricate signaling pathways and molecular responses triggered by external stimuli in this review, we gain insights into how plants tailor their metabolite production in reaction to their environment. Intricately intertwined with the mechanisms, the types of elicitors utilized are extensively discussed. Abiotic elicitors, encompassing physical factors and chemicals, biotic elicitors involving microbe-derived molecules, plant hormones and symbiotic microorganisms, and the emerging application of nanoparticles as elicitation agents are explored. The review further examines the application of these elicitors in both in-vitro and in-vivo cultures, showcasing their practical utility in controlled laboratory settings and real-world environments. By assessing the efficacy of diverse elicitors, this paper provides valuable insights into tailoring elicitation strategies to enhance secondary metabolite yields for various applications. Addressing the limitations and leveraging emerging technologies will undoubtedly steer elicitation research towards innovative breakthroughs, further enhancing our capacity to harness plants for sustainable and efficient secondary metabolite production. [ABSTRACT FROM AUTHOR]

The environmental temperature and humidity are crucial factors for the normal growth and development of arbor tree cuttings by altering their hormone levels and influencing their physiological activities. Developing a temperature and humidity environmental model for arbor tree cuttings serves as a key technique to improve the adjustment performance of environmental parameters in facility agriculture systems and enhance the rooting rate of cuttings. This paper provides a comprehensive summary of current research on the inherent characteristics of cuttings and the factors influencing environmental temperature and humidity. It explores the mechanisms of interaction between the inherent characteristics of cuttings and the factors influencing environmental temperature and humidity. This paper investigates the interactive relationships among the factors affecting environmental temperature and humidity. It analyzes methods to improve the efficiency of constructing temperature and humidity environmental models for arbor tree cuttings. To enhance the transferability of the environmental model, the necessary physiological activities under the influence of plant hormones are generalized as common physiological traits in the growth and development of cuttings. In addition, this paper explores the factors influencing the air and substrate temperature and the humidity in facility agriculture systems as well as two types of facilities for controlling environmental temperature and humidity. Furthermore, it reviews the research progress in environmental models from both mechanistic and data-driven perspectives. This paper provides a comparative analysis of the characteristics associated with these two model categories. Building upon this, the paper summarizes and discusses methods employed in constructing temperature and humidity environmental models for arbor tree cuttings. In addition, it also anticipates the application of deep learning techniques in the construction of temperature and humidity environmental models for arbor cuttings, including utilizing machine vision technology to monitor their growth status. Finally, it proposes suggestions for building physiological models of fruit tree-like arbor cuttings at different growth stages. To enhance the transferability of environmental models, the integration of physiological models of cuttings, environmental models, and control system performance are suggested to create an environmental identification model. This paper aims to achieve control of the common physiological activities of cuttings. [ABSTRACT FROM AUTHOR]

In this study, the effect of a living bacteria (Bacillus megaterium var. phosphaticum, Azotobacter chroococcum) containing biofertilizer, made in Hungary, was investigated on the germination and dry matter production of maize seedlings in germination tests. The biofertilizer was applied in concentrations of 1 ml·L-1 and 3.5 ml·L-1. Seed and filter paper treatments were used in the experiments, completed with autoclaved biofertilizer treatment. Germination and weight of shoots and roots were evaluated. It was observed that the seed-and-filter paper treatments with biofertilizer significantly increased - by more than 20% - the numbers of the germinated seeds in comparison to the untreated control. The dry weight of the shoot and root was higher by more than 7% than the control in the case of treatments with biofertilizer. Based on this result, it was concluded that there is a positive effect of PGPB on germination, as well as it is supposed, that the applied biofertilizer treatments stimulated the germination and growth of maize by reason of excreting phytohormones and enhancing the nutrient mobilization from the seed. [ABSTRACT FROM AUTHOR]

The article reports that one of the most serious limitations to the study of naturally occurring auxins bas been the lack of any sensitive methods for their separation and chemical identification. Similar difficulties are met when dealing with the synthetic auxins, 2,4-dichlorophenoxyacetic acids where the only sensitive chemical test is completely non-specific, being given by a whole range of homologues. In the last few years, however, rapid improvements in the methods of chromatography have enabled plant physiologists to adapt this technique to the study of auxins.

The existence of cytokinins both as a free form and as a constituent of t-RNA was investigated in young fruits of Moringa pterigosperma Gaertn. Purified methanol extract was separated into butanol insoluble and butanol soluble fractions. The cytokinin(s) in the butanol insoluble fraction was tentatively identified as zeatin nucleotide. The butanol soluble fraction contained. cytokinins and was chromatographed on Sephadex LH-20 with 35% ethanol. The two active fractions from LH-20 column coincided with zeatin and zeatin riboside. Cytokinin per g tissue was high in early stages of fruit growth and then remained more or less constant. Alkaline phosphatase hydrolysis of t-RNA hydrolysate of fruit tissue showed considerable cytokinin activity. [ABSTRACT FROM AUTHOR]

Copyright of Revista Verde de Agroecologia e Desenvolvimento Sustentável is the property of Revista Verde de Agroecologia e Desenvolvimento Sustentavel 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.)

Exploring plant behavior at the cellular scale in a minimally invasive manner is critical to understanding plant adaptation to the environment. Phytohormones play vital regulatory roles in multiple aspects of plant growth and development and acclimation to environmental changes. Since the biosynthesis, modification, transportation, and degradation of plant hormones in plants change with time and space, their content level and distribution are highly dynamic. To monitor the production, transport, perception, and distribution of phytohormones within undamaged tissues, we require qualitative and quantitative tools endowed with remarkably high temporal and spatial resolution. Fluorescent probes are regarded as excellent tools for widespread plant imaging because of their high sensitivity and selectivity, reproducibility, real-time in situ detection, and uncomplicated mechanism elucidation. In this review, we provide a systematical overview of the progress in the sensing and imaging of phytohormone fluorescent probes and fluorescently labeled phytohormones to their receptors in plants. Moreover, forthcoming viewpoints and possible applications of these fluorescent probes within the realm of plants are also presented. We hold the conviction that the new perspective brought by this paper can promote the development of fluorescent probes, enabling them to have better detection performance in plant hormone imaging. [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]

Highlights • The conductive carbon tape electrode was modified with pencil trace by hand. • The nanostructure of carbon tape could keep the handed pencil trace. • The modified electrodes could be used to screen SA in tomato leaves. • SA in infected and normal tomato leaves could be differentiated in real time. Abstract Plants encounter phytopathogens frequently and phytohormones (such as salicylic acid, SA) are critical for their corresponding defensive functions. Monitoring SA in real time could help us understand its regulation mechanisms more clearly. Previously we have demonstrated that carbon tape working electrodes modified with carbon nanotubes could be utilized for quantification of SA in tomato leaf samples with the weights at the level of micrograms. Herein inexpensive pencils were used to modify the carbon tape with the pencil trace as the working electrodes by hand drawing. The pencil types and the trace layers were optimized for screening SA, implying that the carbon tape could maintain the handed pencil trace with its nanostructure. The carbon tape electrodes modified with handed pencil trace were integrated in the paper-based devices for real time monitoring SA in tomato leaves infected by Pseudomonas syringae pv. Tomato DC3000 (pst DC3000). Our results showed that the contents of SA in the surrounding area of the infection center increased significantly after inoculation of pst DC3000 within 24 h. The modification of working electrodes with handed pencil trace provided a low cost and effective method for sensitive detection of SA. The similar approach and platform might be extended for more biochemical applications. [ABSTRACT FROM AUTHOR]

The article outlines the collaborative work on auxin binding to TIR1 that activated the cascade of chemical responses in plants by Ning Zheng, biologist, and Mark Estelle, plant biologist. An overview of the study of crystalline structure of TIR1, the role of inositol phosphate molecule as co-factor, structure of TIR1 bound to a number of different auxin analogues and the usefulness of the study in drug discovery, is presented.

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]

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Astragalus sikokianus is a rare Japanese perennial of the seashore that was reported to be extinct in the wild. The small seed size and deep dormancy of A. sikokianus make it difficult for direct seeding restoration in aspects of seed handling, transport, planting, and seedling establishment. For the large-scale economic restoration of dormant small-seeded species, seed pelleting combined with the breaking of dormancy was studied. Physiological (prechilling and plant hormones) and physical (hot water, hydrochloric acid, and sulfuric acid) seed dormancy break treatments were evaluated. The dormant broken seeds were used for pelleting. The effects of the substrate, pellet sizes, and their interactions on germination were measured. The scarification of five rubs of seeds placed between sandpapers completely broke the physical dormancy of A. sikokianus. Seed coat impermeability inhibited germination. Pelleted seeds ranging from 2.0 to 4.0 mm in diameter showed more than 90% germination on filter paper. The germination of the pelleted seeds was measured in commercial, field, and sand soil conditions. The highest germination was shown in sand (70–74% GP), regardless of the pellet size, whereas unpelleted scarified seeds germinated only 48%. These results suggest that small-seeded species with physical dormancy can be used for seed-based restoration after seed pelleting. [ABSTRACT FROM AUTHOR]

The impact of toxic elements (TEs) contaminating the root zone of Lupinus angustifolius L. on enzymatic activities, nitrification rate, and changes in the root system was evaluated. Lupine was cultivated in a pot experiment using two types of soil - control and contamination (with a high degree of arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) contamination). After harvesting lupine biomass, enzyme activities (β-glucosidase, acid phosphatase, arylsulphatase, lipase, chitinase, cellobiohydrolase, alanine aminopeptidase, and leucine aminopeptidase) in soils were analysed. Enzyme activities decreased with TE soil contamination. According to our results, arylsulphatase was found to be the most sensitive soil enzyme to TEs. The nitrification rate is closely related to soil contamination and plant activity, as it stimulates microbial growth and multiplication through root exudates. The close correlations confirmed this relationship (r = 0.73-0.99). An increasing trend in TE contents in the roots was observed with soil contamination. Plant hormones are crucial in regulating root growth and development under stress conditions. The levels of determined phytohormones in our experiment (auxins, abscisic acid (ABA), salicylic acid (SA), and bioactive cytokinins (bCKs)) were lower in the contamination compared to the control. Correlations confirmed a significant negative relationship between the TE content in the roots and the contents of phytohormones (auxins: r = -0.96 to -0.97; ABA: r = -0.83 to -0.86; SA: r = -0.95 to -0.99, bCKs: r = -0.87 to -0.93). The ratios of these hormones (not their absolute values) appear to be the determining factor for regulating root development and protecting plants from oxidative stress. [ABSTRACT FROM AUTHOR]

The postharvest lifespan of horticultural products is closely related to loss of nutritional quality, accompanied by a rapid decline in shelf life, commercial value, and marketability. Melatonin (MT) application not only maintains quality but also delays senescence in horticultural products. This paper reviews biosynthesis and metabolism of endogenous MT, summarizes significant effects of exogenous MT application on postharvest horticultural products, examines regulatory mechanisms of MT‐mediated effects, and provides an integrated review for understanding the positive role of MT in senescence delay and quality maintenance. As a multifunctional molecule, MT coordinates other signal molecules, such as ABA, ETH, JA, SA, NO, and Ca2+, to regulate postharvest ripening and senescence. Several metabolic pathways are involved in regulation of MT during postharvest senescence, including synthesis and signal transduction of plant hormones, redox homeostasis, energy metabolism, carbohydrate metabolism, and degradation of pigment and cell wall components. Moreover, MT regulates expression of genes related to plant hormones, antioxidant systems, energy generation, fruit firmness and colour, membrane integrity, and carbohydrate storage. Consequently, MT could become an emerging and eco‐friendly preservative to extend shelf life and maintain postharvest quality of horticultural products. [ABSTRACT FROM AUTHOR]

In response to different degrees of mechanical injury, certain plant cells re-enter the division cycle to provide cells for tissue replenishment, tissue rejoining, de novo organ formation, and/or wound healing. The intermediate tissue formed by the dividing cells is called a callus. Callus formation can also be induced artificially in vitro by wounding and/or hormone (auxin and cytokinin) treatments. The callus tissue can be maintained in culture, providing starting material for de novo organ or embryo regeneration and thus serving as the basis for many plant biotechnology applications. Due to the biotechnological importance of callus cultures and the scientific interest in the developmental flexibility of somatic plant cells, the initial molecular steps of callus formation have been studied in detail. It was revealed that callus initiation can follow various ways, depending on the organ from which it develops and the inducer, but they converge on a seemingly identical tissue. It is not known, however, if callus is indeed a special tissue with a defined gene expression signature, whether it is a malformed meristem, or a mass of so-called "undifferentiated" cells, as is mostly believed. In this paper, I review the various mechanisms of plant regeneration that may converge on callus initiation. I discuss the role of plant hormones in the detour of callus formation from normal development. Finally, I compare various Arabidopsis gene expression datasets obtained a few days, two weeks, or several years after callus induction and identify 21 genes, including genes of key transcription factors controlling cell division and differentiation in meristematic regions, which were upregulated in all investigated callus samples. I summarize the information available on all 21 genes that point to the pre-meristematic nature of callus tissues underlying their wide regeneration potential. [ABSTRACT FROM AUTHOR]

Copyright of Biotechnology Bulletin is the property of Biotechnology Bulletin 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.)

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.)

Plant hormones are important in the control of physiological and developmental processes including seed germination, senescence, flowering, stomatal aperture, and ultimately the overall growth and yield of plants. Many currently available methods to quantify such growth regulators quickly and accurately require extensive sample purification using complex analytic techniques. Herein we used ultra-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) to create and validate the prediction of hormone concentrations made using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectral profiles of both freeze-dried ground leaf tissue and extracted xylem sap of Japanese knotweed (Reynoutria japonica) plants grown under different environmental conditions. In addition to these predictions made with partial least squares regression, further analysis of spectral data was performed using chemometric techniques, including principal component analysis, linear discriminant analysis, and support vector machines (SVM). Plants grown in different environments had sufficiently different biochemical profiles, including plant hormonal compounds, to allow successful differentiation by ATR-FTIR spectroscopy coupled with SVM. ATR-FTIR spectral biomarkers highlighted a range of biomolecules responsible for the differing spectral signatures between growth environments, such as triacylglycerol, proteins and amino acids, tannins, pectin, polysaccharides such as starch and cellulose, DNA and RNA. Using partial least squares regression, we show the potential for accurate prediction of plant hormone concentrations from ATR-FTIR spectral profiles, calibrated with hormonal data quantified by UHPLC-HRMS. The application of ATR-FTIR spectroscopy and chemometrics offers accurate prediction of hormone concentrations in plant samples, with advantages over existing approaches. [ABSTRACT FROM AUTHOR]

[Objective] The paper aimed to explore the function of the phosphoproteinase 1 (EbPP1) gene related to the number of leaves in Erigeron breviscapus, which lays the foundation for revealing the molecular mechanisms of E. breviscapus leaf number and flowering time. [Method) The EbPP1 gene from the leaves of E. breviscapus was cloned and constructed into the plant overexpression vector RP101. The dip- ping flower method was used to infect newly bolted Arabidopsis thaliana plants for heterologous expression, several T1, T2 and T, generations of A. thaliana positive plants were obtained through screening. Finally, the number of leaves and flowering time of T3 generation positive plants were counted. The expression level of EbPPI was detected by RT-qPCR, and the endogenous hormone content of A. thaliana plants was measured. [Result] The full-length EbPP1 gene was successfully cloned and overexpression vector RP101-GFP EbPP1 was constructed for this gene, cloned stable genetic transformation had been achieved in A. thaliana, and 24 positive EbPPI transgenic plants were obtained in the T3 generation. Real time fluorescence quantitative analysis was performed on the T3 generation positive plants, and RT-qPCR results showed that the EbPP1 gene was overexpressed in the transgenic A. thaliana, with its expression level increasing from 1.034 in the wild type to 136.33; Transgenic A. thaliana exhibited phenotypic characteristics of increased leaf number and delayed flowering time; Quantitative determination of endogenous hormone content in plants by LC-MS showed that the content of various hormones such as indole-3-carboxylic acid (ICA) and gibberellin-24 (GA24) in T3 transgenic A. thaliana were significantly higher than that in the wild type, with the precursor substance of growth hormone L-tryptophan (TRP) being particularly significant, reaching three times that of the wild type. [Conclusion] Suc- cessfully, the heterologously EbPPI gene is expressed in A. thaliana plants. Compared with wild A. thaliana plants, transgenic A. thaliana plants have an increased number of leaves, increase its expression of EbPPI gene, and increase endogenous hormone content. Based on the above results, it is suggested that EbPP1 may affect the number of leaves and flowering time of E. breviscapus by regulating plant hormone levels. The study lays the foundation for further analyzing the mechanisms related to the development of leaf number and flowering molecular mechanisms of E. breviscapus, and also provides a certain genetic basis for the breeding of high-quality E. breviscapus varieties. [ABSTRACT FROM AUTHOR]

The phytohormone auxin is at times called the master regulator of plant processes and has been shown to be a central player in embryo development, the establishment of the polar axis, early aspects of seedling growth, as well as growth and organ formation during later stages of plant development. The Plant Cell has been key, since the inception of the journal, to developing an understanding of auxin biology. Auxin-regulated plant growth control is accomplished by both changes in the levels of active hormones and the sensitivity of plant tissues to these concentration changes. In this historical review, we chart auxin research as it has progressed in key areas and highlight the role The Plant Cell played in these scientific developments. We focus on understanding auxin-responsive genes, transcription factors, reporter constructs, perception, and signal transduction processes. Auxin metabolism is discussed from the development of tryptophan auxotrophic mutants, the molecular biology of conjugate formation and hydrolysis, indole-3-butyric acid metabolism and transport, and key steps in indole-3-acetic acid biosynthesis, catabolism, and transport. This progress leads to an expectation of a more comprehensive understanding of the systems biology of auxin and the spatial and temporal regulation of cellular growth and development. This review focus is on the developments in the auxin and ties the critical papers in The Plant Cell to the overall development of auxin-related concepts during the time period. [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.)

Drought is a major factor that limiting mung bean development. To clarify the molecular mechanism of mung bean in response to drought stress, 2 mung bean groups were established, the experimental group (drought-treated) and the control group (normal water management). With prominent difference of 2 groups in stomatal conductance, relative water content and phenotype, leaf samples were collected at 4 stages, and the physiological index of MDA, POD, chlorophyll, and soluble proteins were estimated. RNA-seq was used to obtain high quality data of samples, and differentially expressed genes were identified by DESeq2. With GO and KEGG analysis, DEGs were enriched into different classifications and pathways. WGCNA was used to detect the relationship between physiological traits and genes, and qPCR was performed to confirm the accuracy of the data. We obtained 169.49 Gb of clean data from 24 samples, and the Q30 of each date all exceeded 94%. In total, 8963 DEGs were identified at 4 stages between the control and treated samples, and the DEGs were involved in most biological processes. 1270 TFs screened from DEGs were clustered into 158 TF families, such as AP2, RLK-Pelle-DLSVA, and NAC TF families. Genes related to physiological traits were closely related to plant hormone signaling, carotenoid biosynthesis, chlorophyll metabolism, and protein processing. This paper provides a large amount of data for drought research in mung bean. [ABSTRACT FROM AUTHOR]

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]

As a typical plant hormone, indole‐3‐acetic acid (IAA) can regulate the biological activities including division, growth and differentiation of plant cells. In this paper, a MXene and multi‐walled carbon nanotubes composite was prepared by self‐assembly procedure, which was modified on screen‐printed electrode (SPE) to construct a wireless portable electrochemical sensor. Electrochemical investigations of IAA were studied by cyclic voltammetry and an irreversible oxidation process could be observed. The excellent electroanalytical method of IAA was realized on the modified SPE with the detection range as 0.05–125.0 μmol/L and the detection limit as 16.7 nmol/L. The sensor was used for IAA content analysis in different part of pea seedlings with satisfactory results. [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]

With a very diverse structure and small molecules, phytohormones are regulators of plant growth and development. Despite the fact that they are synthesized by plants in small quantities, they are highly active physiologically. According to their action, phytohormones can be divided into two categories, as either activators of plant growth and development or as inhibitors, with auxins and cytokinins belonging to the former group. Auxins are synthesized by plants in the apical meristems of shoots, but also in young leaves, seeds, and fruits. They stimulate the elongation growth of shoots and initiate the production of adventitious and lateral roots. Cytokinins, in turn, are formed in root tips and in unripe fruits and seeds. These hormones are responsible for stimulating the growth of lateral shoots, they also stimulate cytokinesis and, consequently, cell division. The aim of this review paper is to present the progress of the research on the effect of selected auxins and cytokinins on crops, considering the prospect of using them in plant growing methods. [ABSTRACT FROM AUTHOR]

Mitogen-activated protein kinase kinase kinase (MAPKKK, MAP3K) is located upstream of the mitogen-activated protein kinase (MAPK) cascade pathway and is responsible for receiving and transmitting external signals to the downstream MAPKKs. Although a large number of MAP3K genes play important roles in plant growth and development, and response to abiotic and biotic stresses, only a few members' functions and cascade signaling pathways have been clarified, and the downstream MAPKKs and MAPKs of most MAP3Ks are still unknown. As more and more signaling pathways are discovered, the function and regulatory mechanism of MAP3K genes will become clearer. In this paper, the MAP3K genes in plants were classified and the members and basic characteristics of each subfamily of MAP3K were briefly described. Moreover, the roles of plant MAP3Ks in regulating plant growth and development and stress (abiotic and biotic) responses are described in detail. In addition, the roles of MAP3Ks involved in plant hormones signal transduction pathway were briefly introduced, and the future research focus was prospected. [ABSTRACT FROM AUTHOR]

Low temperature is an important limiting factor in the environment that affects the distribution, growth and development of warm-season grasses. Transcriptome sequencing has been widely used to mine candidate genes under low-temperature stress and other abiotic stresses. However, the molecular mechanism of centipedegrass in response to low-temperature stress was rarely reported. To understand the molecular mechanism of centipedegrass in response to low-temperature stress, we measured physiological indicators and sequenced the transcriptome of centipedegrass under different stress durations. Under cold stress, the SS content and APX activity of centipedegrass increased while the SOD activity decreased; the CAT activity, POD activity and flavonoid content first increased and then decreased; and the GSH-Px activity first decreased and then increased. Using full-length transcriptome and second-generation sequencing, we obtained 38.76 G subreads. These reads were integrated into 177,178 isoforms, and 885 differentially expressed transcripts were obtained. The expression of AUX_IAA and WRKY transcription factors and HSF transcription-influencing factors increased during cold stress. Through KEGG enrichment analysis, we determined that arginine and proline metabolism, plant circadian rhythm, plant hormone signal transduction and the flavonoid biosynthesis pathways played important roles in the cold stress resistance of centipedegrass. In addition, by using weighted gene coexpression network analysis (WGCNA), we determined that the turquoise module was significantly correlated with SS content and APX activity, while the blue module was significantly negatively correlated with POD and CAT activity. This paper is the first to report the response of centipedegrass to cold stress at the transcriptome level. Our results help to clarify the molecular mechanisms underlying the cold tolerance of warm-season grasses. [ABSTRACT FROM AUTHOR]

Microalgae is a promising metabolism microorganism for the fixation of CO2 from industrial gas while accumulating microalgae biomass. The process of CO2 fixation by microalgae is able to be significantly improved by the regulation of phytohormones. However, the complex metabolic mechanism of microalgae regulated by phytohormones and abiotic stress on CO2 fixation deserves to be explored. To systematically understand the existing status and establish a foundation for promoting the technology, this paper reviews investigations on the metabolic mechanism of microalgae regulated by phytohormones. The influences of nitrogen stress, light intensity stress, heavy metal stress, and salinity stress on CO2 fixation and lipid production are summarized. In addition, a comprehensive overview of the multistage regulation of phytohormones and abiotic stress on CO2 fixation and lipid production through microalgae is presented. The recent advances in CO2 transfer reinforcement and light transmission reinforcement in photobioreactors are discussed. This review provides an insight into the enhancement of CO2 fixation by microalgae regulated by phytohormones, abiotic stress, and mass transfer in multistage photobioreactors. [ABSTRACT FROM AUTHOR]

Introduction: The relationship between pesticide exposure and the occurrence of many chronic diseases, including cancer, is confirmed by literature data. Methods: In this review, through the analysis of more than 70 papers, we explore an increase in oxidative stress level caused by exposure to environmental pollutants and the protective effects of plant-origin antioxidants. Results and discussion: One of the molecular mechanisms, by which pesticides affect living organisms is the induction of oxidative stress. However, recently many plant-based dietary ingredients with antioxidant properties have been considered as a chemopreventive substances due to their ability to remove free radicals. Such a food component must meet several conditions: eliminate free radicals, be easily absorbed and function at an appropriate physiological level. Its main function is to maintain the redox balance and minimize the cellular damage caused by ROS. Therefore, it should be active in aqueous solutions and membrane domains. These properties are characteristic for phenolic compounds and selected plant hormones. Phenolic compounds have proven antioxidant properties, while increasing number of compounds from the group of plant hormones with a very diverse chemical structure turn out to act as antioxidants, being potential food ingredients that can eliminate negative effects of pesticides. [ABSTRACT FROM AUTHOR]

Brassinolide (BR) is the "sixth class" plant hormone, which plays an important role in various physiological and biochemical processes of plants. The wide variety of functions of Pinellia ternata means that there is huge demand for it and thus it is in short supply. This paper mainly assessed the changes of yield and quality in P. ternata at different stages after BR treatments by principal component analysis, in order to improve the yield and quality of P. ternata and at the same time determine the best harvest time. The results showed that the tuber yield of P. ternata was significantly increased by BR treatments at different stages (except for the 15th day). After the 15th, 45th, 60th, 75th, 90th, and 105th day of treatments, the tuber yield of P. ternata reached peak values at 0.10 (0.65 g), 0.50 (1.97 g), 0.50 (1.98 g), 1.00 (2.37 g), 1.00 (2.84 g), and 2.00 mg/L (3.76 g) BR treatment, respectively. The optimal harvest time was the 75th day after 0.10, 0.50, and 1.00 mg/L BR treatments, which not only significantly improved the yield of P. ternata, but also retained high level of total alkaloids in the tubers (20.89, 5.37, and 13.44%) and bulbils (9.74, 20.42, and 13.62%), high total flavone content in the tubers (17.66, 16.26, and 12.74%) and bulbils (52.63, 12.79, and 38.69%), and high β-sitosterol content in the tubers (25.26, 16.65, and 0.62%) of P. ternata, compared with the control, respectively. [ABSTRACT FROM AUTHOR]

Microalgal energy storage compounds (carbohydrates, lipids, etc.) can serve as renewable feedstocks for biofuels and biobased chemicals. Traditional methods of inducing the accumulation of energy storage compounds in microalgae, such as abiotic stress (high light intensity, high salinity, nutrient limitation, heavy metals, etc.), can affect the growth of microalgae and limit their efficient accumulation of energy storage materials. Plant hormones are a class of small molecular substances that act as chemical messengers to coordinate plant cell activities and regulate the physiological and metabolic activities of microalgae, including promoting microalgal cell proliferation, improving stress resistance, and enhancing photosynthetic activity, thereby increasing algal biomass and lipid, chlorophyll and protein content. This paper reviews the recent research progress on regulation of the accumulation of energy storage compounds in microalgae by adding exogenous plant hormones combined with abiotic stress, discusses the mechanism of plant hormones regarding the accumulation of energy storage compounds in microalgae, and proposes future research needs. [ABSTRACT FROM AUTHOR]

This article describes my involvement in the development of genetics as an essential tool in the integrated study of plant biology. My research comes from a strong background in plant genetics based on my education as a plant breeder at Wageningen University and collaborations with plant physiologists and molecular geneticists in Wageningen and the wider scientific community. It initially involved the isolation and physiological characterization of mutants defective in biosynthesis or mode of action of plant hormones, photoreceptors and traits such as flowering time in both Arabidopsis and tomato. I also generated a genetic map of Arabidopsis. Subsequently, the exploitation of natural variation became a main area of interest, including the molecular identification of underlying genetic differences. The integration of various disciplines and the adoption of Arabidopsis as a main model species contributed strongly to the impressive progress in our knowledge of plant biology over the past 40 years. [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]