Simultaneous determination of five plant hormones in cotton leaves using QuEChERS combined with HPLC‒MS/MS

Background Plant hormones profoundly influence cotton growth,development,and responses to various stresses.Therefore,there is a pressing need for an efficient assay to quantify these hormones in cotton.In this groundbreaking study,we have established QuEChERS-HPLC‒MS/MS method,for the simultaneous detection of multiple plant hormones in cotton leaves,allowing the analysis and quantification of five key plant hormones.Results Sample extraction and purification employed 0.1%acetic acid in methanol and C18 for optimal recovery of plant hormones.The method applied to cotton demonstrated excellent linearity across a concentration range of 0.05–1 mg・L−1,with linear regression coefficients exceeding 0.99.The limits of quantification(LOQs)were 20μg・kg−1 for GA3 and 5μg・kg−1 for the other four plant hormones.Recovery rates for the five plant hormones matrix spiked at levels of 5,10,100,and 1000μg・kg−1 were in the range of 79.07%to 98.97%,with intraday relative standard deviations(RSDs)ranging from 2.11%to 8.47%.The method was successfully employed to analyze and quantify the five analytes in cotton leaves treated with plant growth regulators.Conclusion The study demonstrates that the method is well-suited for the determination of five plant hormones in cotton.It exhibits excellent selectivity and sensitivity in detecting field samples,thus serving as a robust tool for indepth research into cotton physiology.

Defensive Role of Plant Hormones in Advancing Abiotic Stress-Resistant Rice Plants

Consistent climatic perturbations have increased global environmental concerns, especially the impacts of abiotic stresses on crop productivity. Rice is a staple food crop for the majority of the world’s population. Abiotic stresses, including salt, drought, heat, cold and heavy metals, are potential inhibitors of rice growth and yield. Abiotic stresses elicit various acclimation responses that facilitate in stress mitigation. Plant hormones play an important role in mediating the growth and development of rice plants under optimal and stressful environments by activating a multitude of signalling cascades to elicit the rice plant’s adaptive responses. The current review describes the role of plant hormone-mediated abiotic stress tolerance in rice, potential crosstalk between plant hormones involved in rice abiotic stress tolerance and significant advancements in biotechnological initiatives including genetic engineering approach to provide a step forward in making rice resistance to abiotic stress.

-ffects of Plant Hormones on Accumulation of 133Cs in Sunflower （Helianthus annuus L.）

[Objective] This study was conducted to discuss a high efficient phytore- mediation technology for 133Cs pollution.[Method] The effects of 3 exogenous phyto- hormones on the uptake and accumulation of 133Cs in the seedlings of Helianthus annuus L., which is a kind of hyperaccumulator plant, was further studied in the pot experiments. [Result] The results indicated that the absorption, accumulation and translocation capacities of 133Cs of the sunflower plants could be improved signifi- cantly after the application of phytohormones. 133Cs contents were higher in leaves and flowers as compared with stems and roots. The accumulation capacities of phytohormones were in order of SA〉GA〉IAA. [Conclusion] The absorption capacity, translocation factor and bioaccumulation factor of 133Cs were maximum after the

Transcriptome analysis reveals effects of red and blue lightemitting diodes(LEDs)on the growth,chlorophyll fluorescence and endogenous plant hormones of potato(Solanum tuberosum L.)plantlets cultured in vitro

Red and blue light illumination has been reported to significantly affect plantlet growth.Potato is an important food and feed crop in the world and potato plantlet cultured in vitro plays an important role in potato production.However,few studies have documented the effects of red and blue light on the growth of potato plantlets revealed at the transcriptome level.The objective of this study was to determine the growth and physiological responses of potato plantlets cultured in vitro under monochromatic red(RR),monochromatic blue(BB)as well as combined red and blue(RB)LEDs using the RNA-Seq technique.In total,3150 and 814 differentially expressed genes(DEGs)were detected in potato plantlets under RR and BB,respectively,compared to RB(used as control).Compared to the control,the DEGs enriched in"photosynthesis"and"photosynthesis-antenna proteins"metabolic pathways were up-regulated and down-regulated by BB and RR,respectively,which might be responsible for the increases and decreases of maximum quantum yield(F_(v)/F_(m)),photochemical quantum yield(φ_(PSII)),photochemical quenching(q_(P))and electron transfer rate(ETR)in BB and RR,respectively.Potato plantlets exhibited dwarfed stems and extended leaves under BB,whereas elongated stems and small leaves were induced under RR.These dramatically altered plantlet phenotypes were associated with variable levels of endogenous plant hormones gibberellin(GAs),indoleacetic acid(IAA)and cytokinins(CKs),as assessed in stems and leaves of potato plantlets.In addition,monochromatic red and blue LEDs trigged the opposite expression profiles of DEGs identified in the"plant hormone signal transduction"metabolic pathway,which were closely related to the endogenous plant hormone levels in potato plantlets.Our results provide insights into the responses of potato plantlets cultured in vitro to red and blue LEDs at the transcriptomic level and may contribute to improvements in the micro-propagation of potato plantlets cultured in vitro from the light spectrum aspect.

Plant Hormone Resistance and Agronomic Characteristics of the MT10 Mutant in Rice

The MT10 mutant plants had resistances to auxin.Under light and dark culture,the roots of MT10 seedlings had shown less lateral roots and short lateral roots.In soil,MT10 seedlings had shown not only no changed agronomic characteristics but also no significant difference with WT.

Identification of the Regulator of G-Protein Signaling Protein Responsive to Plant Hormones and Abiotic Stresses in Brassica napus

Regulator of G protein signaling proteins （RGS） accelerate the rate of GTP hydrolysis by Gαproteins, thus acting as negative regulators of G-protein signaling. Studies on Arabidopsis and soybean have proven that RGS proteins are physiologically important in plants and contribute to the signaling pathways regulated by different stimuli. Brassica napus is an important agriculturally relevant plant, the wildly planted oilseed rape in the world, which possesses an identiifed Gα, Gβand Gγsubunits. In the present study, we identiifed and characterized a Brassica napus RGS gene, BnRGS1, which contained an open reading frame of 1 380 bp encoding a putative 52.6 kDa polypeptide of 459 amino acids, within seven putative transmembrane domains in the N-terminal and RGS box in the C-terminal. BnRGS1 is located on the membrane in onion epidermal cells and tobacco leaves, and interacts with BnGA1 in the mating-based split-ubiquitin system. The expression levels of BnRGS1 were quite different in different tissues and developmental stages, and induced by abscisic acid （ABA） and indole-3-acetic acid （IAA）. The effects of gibberellin （GA3） and brassinolide （BR） on the expression of BnRGS1 were irregular under the concentrations tested. Moreover, the transcript level of BnRGS1 was also induced by polyethylene glycol （PEG）, whereas remained little changed by 200 mmol L-1 NaCl. These results suggested that the BnRGS1 may be involved in B. napus response to plant hormone signaling and abiotic stresses.

Effects of Different Plant Hormones for Microbial Degradation of PASHs and Diesel under Aerobic Conditions

The effects of plant hormones for biodegradation of polycyclic aromatic sulfur heterocycles(PASHs)and diesel fuel were studied.Indole butyric acid(IBA)and gibberellin were found to promote biodegradation of DBT and diesel,respectively.Concentrations of plant hormones,pH,temperature,soil moisture and substrate concentrations were optimized in microbial metabolic processes.Two main factors including temperature and IBA concentration were determined by factor analysis in DBT biodegradation.And soil moisture and diesel concentration were important factors in diesel biodegradation.Binding sites between cell surface and DBT or diesel components were performed by molecular operating environment(MOE).This study suggested that plant hormones could be applied to effectively remove pollutants in environment.

Research and Applicationon Plant Hormone--Abscisic Acid, ABA

Abscisic Acid (ABA), along with ethylene, gibberellins, cytokinins and auxins, is regarded as five kinds of important plant hormone. ABA was first isolated from cotton bud by Addcott Ohhuma’s group in 1963. Until 1965, its plane structure was determined. It was formally named as Abscisic acid in "the International Conference of Plant Regulator" in 1967. Scientists all over the world have made a long-term unremitting effort

What factors control plant height?

Plant height(PH)is one of the most important components of the plant ideotype,and it affects plant biomass,yield,lodging resistance,and the ability to use mechanized harvesting.Since many complex pathways controlling plant growth and development remain poorly understood,we are still unable to obtain the most ideal plants solely through breeding efforts.PH can be influenced by genotype,plant hormonal regulation,environmental conditions,and interactions with other plants.Here,we comprehensively review the factors influencing PH,including the regulation of PH-related developmental processes,the genetics and QTLs contributing to PH,and the hormone-regulated molecular mechanisms for PH.Additionally,the symbiotic influence of grafting on PH is discussed,focusing on the molecular regulation of gene expression and genetics.Finally,we propose strategies for applying recent findings to breeding for better PH,highlight some knowledge gaps,and suggest potential directions for future studies.

Relationship Between Heterosis and Endogenous Plant Hormones in Liriodendron

To investigate the possible involvement of endogenous plant hormones in heterosis of Liriodendron interspecific hybrid, growth traits and contents of endogenous GA 1/3 (gibberellin A 1, A 3), IAA (indole_3_acetic acid) and iPA (isopentenyl adenine) of tulip tree ( L. chinense (Hemsl.) Sarg.), yellow poplar ( L. tulipifera L.) and their interspecific hybrid ( L. chinense × L. tulipifera ) were examined. Results showed that: (1) the heterosis in height growth trait of the interspecific hybrid was mainly caused by the reletively greater elongation of internodes. Although the uppermost three internodes had the potential of elongation, the first one, which had the greatest elongation amount, contributed to the heterosis of the height growth trait; (2) the contents of endogenous GA 1/3 , IAA and iPA were greatly different among tulip tree, yellow poplar and their interspecific hybrid. All of the three interspecific hybrid families studied significantly contained higher amount of endogenous GA 1/3 and iPA in the uppermost first internode than their parental species. And thus, a correlation between the contents of endogenous GA 1/3 and iPA, and hybrid vigor for height growth trait in Liriodendron was observed; (3) the rankings of endogenous GA 1/3 and iPA contents in the uppermost first internode of three hybrid families studied were not similar to the ranking for height of 3_year_old trees. Therefore, the contents of endogenous GA 1/3 and iPA in the uppermost first internode could not be used in predicting hybrid vigor among hybrid families.

Epigenetic Modifications and Plant Hormone Action

The action of phytohormones in plants requires the spatiotemporal regulation of their accumulation and responses at various levels. Recent studies reveal an emerging relationship between the function of phytohormones and epigenetic modifications. In particular, evidence suggests that auxin biosynthesis, transport, and signal transduction is modulated by microRNAs and epigenetic factors such as histone modification, chromatin remodeling, and DNA methylation. Furthermore, some phytohormones have been shown to affect epigenetic modifications. These findings are shedding light on the mode of action of phytohormones and are opening up a new avenue of research on phytohormones as well as on the mech- anisms reaulatino eoioenetic modifications.

Structure and Activity of Strigolactones： New Plant Hormones with a Rich Future

Strigolactones （SLs） constitute a new class of plant hormones which are active as germination stimulants for seeds of parasitic weeds of Striga, Orobanche, and Pelipanchi spp, in hyphal branching of arbuscular mycorrhizal （AM） fungi and as inhibitors of shoot branching. In this review, the focus is on molecular features of these SLs. The occurrence of SLs in root exudates of host plants is described. The naming protocol for SL according to the International Union of Pure and Applied Chemistry （IUPAC） rules and the ＇at a glance＇ method is explained. The total synthesis of some natural SLs is described with details for all eight stereoisomers of strigol. The problems encountered with assign- ing the correct structure of natural SLs are analyzed for orobanchol, alectrol, and solanacol. The structure-activity relationship of SLs as germination stimulants leads to the identification of the bioactiphore of SLs. Together with a tentative mechanism for the mode of action, a model has been derived that can be used to design and prepare active SL analogs. This working model has been used for the preparation of a series of new SL analogs such as Nijmegen-1, and analogs derived from simple ketones, keto enols, and saccharine. The serendipitous finding of SL mimics which are derived from the D-ring in SLs （appropriately substituted butenolides） is reported. For SL mimics, a mode of action is proposed as well. Recent new results support this proposal. The stability of SLs and SL analogs towards hydrolysis is described and some details of the mechanism of hydrolysis are discussed as well. The attempted isolation of the protein receptor for germination and the current status concerning the biosynthesis of natural SLs are briefly discussed. Some non-SLs as germinating agents are mentioned. The structure-activity relationship for SLs in hyphal branching of AM fungi and in repression of shoot branching is also analyzed. For each of the principle functions, a working model for the design of new active SL analogs is described and its applicability and implications are discussed. It is shown that the three principal functions use a distinct perception system. The importance of stereochemistry for bioactivity has been described for the various functions.

Synergistic effects of plant hormones on spontaneous late-ripening mutant of'Jinghong'peach detected by transcriptome analysis

Objectives:Peach(Prunus persica L.)is an ancient fruit tree that originated from China.It is the climacteric fruit belonging to genus Prunus in family Rosaceae.Ethylene,which is produced during ripening,accelerates fruit softening,and therefore peaches cannot be stored for a long time.Materials and Methods:To study the mechanism of fruit late ripening,transcriptome analysis of the fruit of a late-ripening mutant of'Jinghong'peach was performed to identify genes and pathways involved in fruit late ripening.Results:A total of 1805,1511,and 2309 genes were found to be differentially expressed in W2_vs_M1,W3_vs_M2,and W3_vs_M3,respectively.Functional enrichment analysis of the differentially expressed genes showed they were related to carotenoid biosynthesis,starch and sucrose metabolism plant hormone signal transduction,flavonoid biosynthesis,and photosynthesis.The expression trends of ripening-related genes that encode transcription factors and plant hormone signal transduction-related genes that encode enzymes were similar.Conclusions:It will help to elucidate the transcriptional regulatory network of fruit development in the spontaneous late-ripening mutant of‘Jinghong’peach and provide a theoretical basis for understanding the molecular regulatory mechanism of fruit ripening.

Shaping Small Bioactive Molecules to Untangle Their Biological Function： A Focus on Fluorescent Plant Hormones

Modern biology overlaps with chemistry in explaining the structure and function of all cellular processes at the molecular level. Plant hormone research is perfectly located at the interface between these two disciplines, taking advantage of synthetic and computational chemistry as a tool to decipher the complex biological mechanisms regulating the action of plant hormones. These small signaling molecules regulate a wide range of developmental processes, adapting plant growth to ever changing environmental conditions. The synthesis of small bioactive molecules mimicking the activity of endogenous hormones allows us to unveil many molec- ular features of their functioning, giving rise to a new field, plant chemical biology. In this framework, fluores- cence labeling of plant hormones is emerging as a successful strategy to track the fate of these challenging molecules inside living organisms. Thanks to the increasing availability of new fluorescent probes as well as advanced and innovative imaging technologies, we are now in a position to investigate many of the dynamic mechanisms through which plant hormones exert their action. Such a deep and detailed comprehension is mandatory for the development of new green technologies for practical applications. In this review, we sum- marize the results obtained so far concerning the fluorescent labeling of plant hormones, highlighting the basic steps leading to the design and synthesis of these compelling molecular tools and their applications.

A comparative genomic analysis of plant hormone related genes in different species

Plant hormones are small molecules that play important roles throughout the life span of a plant, known as auxin, gibberellin, cyto- kinin, abscisic acid, ethylene, jasmonic acid, salicylic acid, and brassinosteroid. Genetic and molecular studies in the model organism Arabidopsis thaliana have revealed the individual pathways of various plant hormone responses. In this study, we selected 479 genes that were convincingly associated with various hormone actions based on genetic evidence. By using these 479 genes as queries, a genome-wide search for their orthologues in several species （microorganisms, plants and animals） was performed. Meanwhile, a com- parative analysis was conducted to evaluate their evolutionary relationship. Our analysis revealed that the metabolisms and functions of plant hormones are generally more sophisticated and diversified in higher plant species. In particular, we found that several phytohor- mone receptors and key signaling components were not present in lower plants or animals. Meanwhile, as the genome complexity in- creases, the orthologue genes tend to have more copies and probably gain more diverse functions. Our study attempts to introduce the classification and phylogenic analysis of phytohormone related genes, from metabolism enzymes to receptors and signaling components, in different species.

Fluctuations of Endogenous Hormones in Isolated Rice Embryos During Embryogenesis and Early Stages of Germination

Fluctuations of levels of several endogenous plant hormones in isolated rice ( Oryza sativa ssp. japonica) embryos during early and mid-embryogenesis and early stages of germination were studied by enzyme-linked immunosorbent assay (ELISA). Embryos were collected at different days after pollination (DAP) and different days after imbibition (DAI) of mature seeds. The contents of gibberellin(1) (GA(1)), abscisic acid (ABA), isopentenyladenine and isopentenyladenosine ( iPAs), zeatin and zeatin riboside ( ZRs) were immunochemically assayed. The GA(1) level was the highest among all hormones tested. The variations of GA(1) levels were opposite with the ABA levels, with some exceptions. During early and mid-embryogenesis, the levels of GA(1) and ABA were the highest at 4 DAP. From 8 to 18 DAP, GA(1) level declined, whereas the ABA level increased. During germination, GA(1) level increased at 2 DAI whereas simultaneously the ABA content decreased. The highest ratio of GA(1)/ABA was observed at 2 DAI The levels of iPAs and ZRs were maxima in the embryos at 4 DAP, decreased to a very low level and maintained constant thereafter. Our results provide further evidence that GA(1) plays an important role in the early stages of embryo development and germination. The balance between GA(1) and ABA, rather than their absolute contents, controls these processes throughout the development, whereas iPAs and ZRs may play important roles in early embryogenesis. The use of isolated embryos as starting material avoids the usual interferences with other tissues such as the endosperm. In addition, this is the first report dealing with the hormonal balance of early-embryos in rice.

Silencing of early auxin responsive genes MdGH3-2/12 reduces the resistance to Fusarium solani in apple

Apple replant disease(ARD)has led to severe yield and quality reduction in the apple industry.Fusarium solani(F.solani)has been identified as one of the main microbial pathogens responsible for ARD.Auxin(indole-3-acetic acid,IAA),an endogenous hormone in plants,is involved in almost all plant growth and development processes and plays a role in plant immunity against pathogens.Gretchen Hagen3(GH3)is one of the early/primary auxin response genes.The aim of this study was to evaluate the function of MdGH3-2 and MdGH3-12 in the defense response of F.solani by treating MdGH3-2/12 RNAi plants with F.solani.The results show that under F.solani infection,RNAi of MdGH3-2/12 inhibited plant biomass accumulation and exacerbated root damage.After inoculation with F.solani,MdGH3-2/12 RNAi inhibited the biosynthesis of acid-amido synthetase.This led to the inhibition of free IAA combining with amino acids,resulting in excessive free IAA accumulation.This excessive free IAA altered plant tissue structure,accelerated fungal hyphal invasion,reduced the activity of antioxidant enzymes(SOD,POD and CAT),increased the reactive oxygen species(ROS)level,and reduced total chlorophyll content and photosynthetic ability,while regulating the expression of PR-related genes including PR1,PR4,PR5 and PR8.It also changed the contents of plant hormones and amino acids,and ultimately reduced the resistance to F.solani.In conclusion,these results demonstrate that MdGH3-2 and MdGH3-12 play an important role in apple tolerance to F.solani and ARD.

Broad Hormonal Responses Induced by Aluminum in Roots of Dwarf Transgenics of Solanum lycopersicum L. cv “Micro-Tom”

The spatial pattern distribution of plant hormones in response to aluminum (Al) toxicity in roots remains to be shown. This study was performed to assess the root hormonal accumulation and gene expression in response to Al toxicity in five transgenic miniature dwarf tomatoes cv. Micro-Tom (MT). MT and MT transgenics to acid indole acetic, cytokinin, gibberellin, abscisic acid and ethylene were cultivated in nutrient solutions containing different Al concentrations. Root growth elongation was measured and cellular damage was visualized by staining Evans’s blue. The GUS reporter gene staining technique was used to visualize hormonal changes in MT apex root tissues. Data indicated that the MT is sensitive to Al that induced significant growth inhibition and cellular damage. Al concentration of 27 μM was significantly toxic, inducing root apex darkening and inhibition of root development. The qualitative evaluation of GUS reporter gene expression showed intense crosstalk among all hormones studied, underscoring the complexity of signaling induced by Al in apex roots. Results point out to a major understanding of the hormonal signaling in response to Al toxicity, which may induce a change of root growth and architecture with growth inhibition and cell constraints modulated by all different hormones evaluated.

Origin, evolution, and molecular function of DELLA proteins in plants

Gibberellic acid(GA), a ubiquitous phytohormone, has various effects on regulators of plant growth and development. GAs promote growth by overcoming growth restraint mediated by DELLA proteins(DELLAs). DELLAs, in the GRAS family of plant-specific nuclear proteins, are nuclear transcriptional regulators harboring a unique N-terminal GA perception region for binding the GA receptor GIBBERELLIN INSENSITIVE DWARF1(GID1) and a C-terminal GRAS domain necessary for GA repression activity via interaction with multiple regulatory proteins. The N-terminal conserved region of DELLAs evolved to form a mode of GID1/DELLA-mediated GA signaling originating in bryophytes and ferns. Binding of GA to GID1 increases the affinity between DELLAs and a SCF E3 ubiquitin–ligase complex, thus promoting the eventual destruction of DELLAs by the 26 S proteasome. DELLAs negatively regulate GA response by releasing transcription factors to directly activate downstream genes and indirectly regulate GA biosynthesis genes increasing GA responsiveness and feedback control by promoting GID1 transcription. GA communicates extensively with other plant hormones and uses crosstalk to regulate plant growth and development. In this review, we summarize current understanding of evolutionary DELLA-mediated gibberellin signaling and functional diversification of DELLA, focusing primarily on interactions of DELLAs with diverse phytohormones.

Functions of Plant Growth Substances in the Growth of Dendrobium officinale Kimura et Migo

[Objectives] To study the effects of plant growth substance on the growth and development of Dendrobium officinale Kimura et Migo. [Methods] Comparative methods were applied to study the effects of plant growth substance on the growth and development of D. officinale Kimura et Migo. [Results] Plant growth regulators play an important role in the process of tissue culture rapid propagation of D. officinale Kimura et Migo,and the main regulatory pathways are as follows.( i) Plant growth regulators promote the growth and development of D. officinale Kimura et Migo through regulating the changes of its endogenous hormones.( ii) Plant growth regulators affect the accumulation of polysaccharide content in D. officinale Kimura et Migo through regulating the changes in chlorophyll content and enzymes involved in sucrose metabolism.( iii) Plant growth regulators can increase the activity of antioxidant enzymes of D. officinale Kimura et Migo,to increase its stress resistance. [Conclusions]Using molecular biology techniques,combined with the changes of plant hormones in D. officinale Kimura et Migo,and analysis on key enzyme in the synthesis of plant hormones and gene expression,it is feasible to study the rules o changes in the content of active content of D. officinale Kimura et Migo.