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1.
Int J Mol Sci ; 22(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34638573

RESUMO

13-lipoxygenases (13-LOX) catalyze the dioxygenation of various polyunsaturated fatty acids (PUFAs), of which α-linolenic acid (LeA) is converted to 13-S-hydroperoxyoctadeca-9, 11, 15-trienoic acid (13-HPOT), the precursor for the prostaglandin-like plant hormones cis-(+)-12-oxophytodienoic acid (12-OPDA) and methyl jasmonate (MJ). This study aimed for characterizing the four annotated A. thaliana 13-LOX enzymes (LOX2, LOX3, LOX4, and LOX6) focusing on synthesis of 12-OPDA and 4Z,7Z,10Z)-12-[[-(1S,5S)-4-oxo-5-(2Z)-pent-2-en-1yl] cyclopent-2-en-1yl] dodeca-4,7,10-trienoic acid (OCPD). In addition, we performed interaction studies of 13-LOXs with ions and molecules to advance our understanding of 13-LOX. Cell imaging indicated plastid targeting of fluorescent proteins fused to 13-LOXs-N-terminal extensions, supporting the prediction of 13-LOX localization to plastids. The apparent maximal velocity (Vmax app) values for LOX-catalyzed LeA oxidation were highest for LOX4 (128 nmol·s-1·mg protein-1), with a Km value of 5.8 µM. A. thaliana 13-LOXs, in cascade with 12-OPDA pathway enzymes, synthesized 12-OPDA and OCPD from LeA and docosahexaenoic acid, previously shown only for LOX6. The activities of the four isoforms were differently affected by physiologically relevant chemicals, such as Mg2+, Ca2+, Cu2+ and Cd2+, and by 12-OPDA and MJ. As demonstrated for LOX4, 12-OPDA inhibited enzymatic LeA hydroperoxidation, with half-maximal enzyme inhibition at 48 µM. Biochemical interactions, such as the sensitivity of LOX toward thiol-reactive agents belonging to cyclopentenone prostaglandins, are suggested to occur in human LOX homologs. Furthermore, we conclude that 13-LOXs are isoforms with rather specific functional and regulatory enzymatic features.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Lipoxigenase/metabolismo , Acetatos/metabolismo , Sequência de Aminoácidos , Ciclopentanos/metabolismo , Ácidos Graxos Insaturados/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Ácidos Linoleicos/metabolismo , Oxilipinas/metabolismo
2.
BMC Plant Biol ; 21(1): 450, 2021 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615468

RESUMO

BACKGROUND: Methyl jasmonate (MeJA), which has been identified as a lipid-derived stress hormone, mediates plant resistance to biotic/abiotic stress. Understanding MeJA-induced plant defense provides insight into how they responding to environmental stimuli. RESULT: In this work, the dynamic network analysis method was used to quantitatively identify the tipping point of growth-to-defense transition and detect the associated genes. As a result, 146 genes were detected as dynamic network biomarker (DNB) members and the critical defense transition was identified based on dense time-series RNA-seq data of MeJA-treated Arabidopsis thaliana. The GO functional analysis showed that these DNB genes were significantly enriched in defense terms. The network analysis between DNB genes and differentially expressed genes showed that the hub genes including SYP121, SYP122, WRKY33 and MPK11 play a vital role in plant growth-to-defense transition. CONCLUSIONS: Based on the dynamic network analysis of MeJA-induced plant resistance, we provide an important guideline for understanding the growth-to-defense transition of plants' response to environment stimuli. This study also provides a database with the key genes of plant defense induced by MeJA.


Assuntos
Acetatos/metabolismo , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Estresse Fisiológico/genética , Estresse Fisiológico/fisiologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Estudo de Associação Genômica Ampla
3.
Molecules ; 26(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34500623

RESUMO

Lignans are the main secondary metabolites synthetized by Linum species as plant defense molecules. They are also valuable for human health, in particular, for their potent antiviral and antineoplastic properties. In this study, the adventitious root cultures of three Linum species (L. flavum, L. mucronatum and L. dolomiticum) were developed to produce aryltetralin lignans. The effect of two elicitors, methyl jasmonate and coronatine, on aryltetralin lignans production was also evaluated. The adventitious root cultures from L. dolomiticum were obtained and analyzed for the first time and resulted as the best producer for all the aryltetralins highlighted in this system: Podophyllotoxin, 6-methoxypodophyllotoxin and 6-methoxypodophyllotoxin-7-O-ß-glucoside, the last showing a productivity of 92.6 mg/g DW. The two elicitors differently affected the production of the 6-methoxypodophyllotoxin and 6-methoxypodophyllotoxin-7-O-ß-glucoside.


Assuntos
Linho/metabolismo , Lignanas/biossíntese , Raízes de Plantas/metabolismo , Acetatos/metabolismo , Aminoácidos/biossíntese , Ciclopentanos/metabolismo , Indenos , Oxilipinas/metabolismo , Podofilotoxina/análogos & derivados , Podofilotoxina/biossíntese
4.
Int J Mol Sci ; 22(17)2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34502445

RESUMO

The dried root of Salvia miltiorrhiza is a renowned traditional Chinese medicine that was used for over 1000 years in China. Salvianolic acid B (SalB) is the main natural bioactive product of S. miltiorrhiza. Although many publications described the regulation mechanism of SalB biosynthesis, few reports simultaneously focused on S. miltiorrhiza root development. For this study, an R2R3-MYB transcription factor gene (SmMYB52) was overexpressed and silenced, respectively, in S. miltiorrhiza sterile seedlings. We found that SmMYB52 significantly inhibited root growth and indole-3-acetic acid (IAA) accumulation, whereas it activated phenolic acid biosynthesis and the jasmonate acid (JA) signaling pathway. Quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed that SmMYB52 suppressed the transcription levels of key enzyme-encoding genes involved in the IAA biosynthetic pathway and activated key enzyme-encoding genes involved in the JA and phenolic acid biosynthesis pathways. In addition, yeast one-hybrid (Y1H) and dual-luciferase assay showed that SmMYB52 directly binds to and activates the promoters of several key enzyme genes for SalB biosynthesis, including SmTAT1, Sm4CL9, SmC4H1, and SmHPPR1, to promote the accumulation of SalB. This is the first report of a regulator that simultaneously affects root growth and the production of phenolic acids in S. miltiorrhiza.


Assuntos
Benzofuranos/metabolismo , Regulação da Expressão Gênica de Plantas , Salvia miltiorrhiza/metabolismo , Fatores de Transcrição/metabolismo , Ciclopentanos/metabolismo , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Salvia miltiorrhiza/crescimento & desenvolvimento
5.
Int J Mol Sci ; 22(18)2021 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-34576007

RESUMO

Seedless fruit is a feature appreciated by consumers. The ovule abortion process is highly orchestrated and controlled by numerous environmental and endogenous signals. However, the mechanisms underlying ovule abortion in pear remain obscure. Here, we found that gibberellins (GAs) have diverse functions during ovules development between seedless pear '1913' and seeded pear, and that GA4+7 activates a potential programmed cell death process in '1913' ovules. After hormone analyses, strong correlations were determined among jasmonic acid (JA), ethylene and salicylic acid (SA) in seedless and seeded cultivars, and GA4+7 treatments altered the hormone accumulation levels in ovules, resulting in significant correlations between GA and both JA and ethylene. Additionally, SA contributed to ovule abortion in '1913'. Exogenously supplying JA, SA or the ethylene precursor 1-aminocyclopropane-1-carboxylic acid promoted 'Bartlett' seed death. The regulatory mechanism in which ethylene controls ovule death has been demonstrated; therefore, JA's role in regulating '1913' ovule abortion was investigated. A further study identified that the JA signaling receptor MYC2 bound the SENESCENCE-ASSOCIATED 39 promoter and triggered its expression to regulate ovule abortion. Thus, we established ovule abortion-related relationships between GA and the hormones JA, ethylene and SA, and we determined their synergistic functions in regulating ovule death.


Assuntos
Apoptose/efeitos dos fármacos , Ciclopentanos/farmacologia , Etilenos/farmacologia , Giberelinas/farmacologia , Óvulo Vegetal/metabolismo , Oxilipinas/farmacologia , Pyrus/metabolismo , Ciclopentanos/metabolismo , Etilenos/metabolismo , Giberelinas/metabolismo , Oxilipinas/metabolismo
6.
Int J Mol Sci ; 22(18)2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34575953

RESUMO

Jasmonate ZIM-domain (JAZ) proteins are key repressors of a jasmonic acid signaling pathway. They play essential roles in the regulation of plant growth and development, as well as environmental stress responses. However, this gene family has not been explored in sweet potato. In this study, we identified 14, 15, and 14 JAZs in cultivated hexaploid sweet potato (Ipomoea batatas, 2n = 6x = 90), and its two diploid relatives Ipomoea trifida (2n = 2x = 30) and Ipomoea triloba (2n = 2x = 30), respectively. These JAZs were divided into five subgroups according to their phylogenetic relationships with Arabidopsis. The protein physiological properties, chromosome localization, phylogenetic relationship, gene structure, promoter cis-elements, protein interaction network, and expression pattern of these 43 JAZs were systematically investigated. The results suggested that there was a differentiation between homologous JAZs, and each JAZ gene played different vital roles in growth and development, hormone crosstalk, and abiotic stress response between sweet potato and its two diploid relatives. Our work provided comprehensive comparison and understanding of the JAZ genes in sweet potato and its two diploid relatives, supplied a theoretical foundation for their functional study, and further facilitated the molecular breeding of sweet potato.


Assuntos
Ciclopentanos/metabolismo , Ipomoea batatas/genética , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Proteínas Repressoras/genética , Mapeamento Cromossômico , Regulação da Expressão Gênica de Plantas/genética , Genoma de Planta/genética , Estudo de Associação Genômica Ampla , Ipomoea batatas/crescimento & desenvolvimento , Filogenia , Estresse Fisiológico/genética , Fatores de Transcrição/genética
7.
Molecules ; 26(18)2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34577094

RESUMO

Among rare earth elements, cerium has the unique ability of regulating the growth of plant cells and the biosynthesis of metabolites at different stages of plant development. The signal pathways of Ce3+-mediated ginsenosides biosynthesis in ginseng hairy roots were investigated. At a low concentration, Ce3+ improved the elongation and biomass of hairy roots. The Ce3+-induced accumulation of ginsenosides showed a high correlation with the reactive oxygen species (ROS), as well as the biosynthesis of endogenous methyl jasmonate (MeJA) and ginsenoside key enzyme genes (PgSS, PgSE and PgDDS). At a Ce3+ concentration of 20 mg L-1, the total ginsenoside content was 1.7-fold, and the total ginsenosides yield was 2.7-fold that of the control. Malondialdehyde (MDA) content and the ROS production rate were significantly higher than those of the control. The activity of superoxide dismutase (SOD) was significantly activated within the Ce3+ concentration range of 10 to 30 mg L-1. The activity of catalase (CAT) and peroxidase (POD) strengthened with the increasing concentration of Ce3+ in the range of 20-40 mg L-1. The Ce3+ exposure induced transient production of superoxide anion (O2•-) and hydrogen peroxide (H2O2). Together with the increase in the intracellular MeJA level and enzyme activity for lipoxygenase (LOX), there was an increase in the gene expression level of MeJA biosynthesis including PgLOX, PgAOS and PgJMT. Our results also revealed that Ce3+ did not directly influence PgSS, PgSE and PgDDS activity. We speculated that Ce3+-induced ROS production could enhance the accumulation of ginsenosides in ginseng hairy roots via the direct stimulation of enzyme genes for MeJA biosynthesis. This study demonstrates a potential approach for understanding and improving ginsenoside biosynthesis that is regulated by Ce3+-mediated signal transduction.


Assuntos
Acetatos/metabolismo , Cério/farmacologia , Ciclopentanos/metabolismo , Ginsenosídeos/biossíntese , Oxilipinas/metabolismo , Panax/química , Panax/metabolismo , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Ginsenosídeos/análise , Panax/efeitos dos fármacos , Panax/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
8.
Int J Mol Sci ; 22(17)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34502018

RESUMO

Gibberellin 2-oxidase (GA2ox) plays an important role in the GA catabolic pathway and the molecular function of the OsGA2ox genes in plant abiotic stress tolerance remains largely unknown. In this study, we functionally characterized the rice gibberellin 2-oxidase 8 (OsGA2ox8) gene. The OsGA2ox8 protein was localized in the nucleus, cell membrane, and cytoplasm, and was induced in response to various abiotic stresses and phytohormones. The overexpression of OsGA2ox8 significantly enhanced the osmotic stress tolerance of transgenic rice plants by increasing the number of osmotic regulators and antioxidants. OsGA2ox8 was differentially expressed in the shoots and roots to cope with osmotic stress. The plants overexpressing OsGA2ox8 showed reduced lengths of shoots and roots at the seedling stage, but no difference in plant height at the heading stage was observed, which may be due to the interaction of OsGA2ox8 and OsGA20ox1, implying a complex feedback regulation between GA biosynthesis and metabolism in rice. Importantly, OsGA2ox8 was able to indirectly regulate several genes associated with the anthocyanin and flavonoid biosynthetic pathway and the jasmonic acid (JA) and abscisic acid (ABA) biosynthetic pathway, and overexpression of OsGA2ox8 activated JA signal transduction by inhibiting the expression of jasmonate ZIM domain-containing proteins. These results provide a basis for a future understanding of the networks and respective phenotypic effects associated with OsGA2ox8.


Assuntos
Regulação da Expressão Gênica de Plantas , Oxigenases de Função Mista/genética , Oryza/enzimologia , Proteínas de Plantas/genética , Transdução de Sinais , Estresse Fisiológico , Ácido Abscísico/metabolismo , Antocianinas/biossíntese , Vias Biossintéticas , Ciclopentanos/metabolismo , Flavonoides/biossíntese , Oxigenases de Função Mista/metabolismo , Oxigenases de Função Mista/fisiologia , Especificidade de Órgãos , Oryza/genética , Oryza/metabolismo , Oryza/fisiologia , Pressão Osmótica , Oxilipinas/metabolismo , Raízes de Plantas , Plântula
9.
Int J Mol Sci ; 22(18)2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34575927

RESUMO

The indole-3-pyruvic acid pathway is the main route for auxin biosynthesis in higher plants. Tryptophan aminotransferases (TAA1/TAR) and members of the YUCCA family of flavin-containing monooxygenases catalyze the conversion of l-tryptophan via indole-3-pyruvic acid to indole-3-acetic acid (IAA). It has been described that jasmonic acid (JA) locally produced in response to mechanical wounding triggers the de novo formation of IAA through the induction of two YUCCA genes, YUC8 and YUC9. Here, we report the direct involvement of a small number of basic helix-loop-helix transcription factors of the MYC family in this process. We show that the JA-mediated regulation of the expression of the YUC8 and YUC9 genes depends on the abundance of MYC2, MYC3, and MYC4. In support of this observation, seedlings of myc knockout mutants displayed a strongly reduced response to JA-mediated IAA formation. Furthermore, transactivation assays provided experimental evidence for the binding of MYC transcription factors to a particular tandem G-box motif abundant in the promoter regions of YUC8 and YUC9, but not in the promoters of the other YUCCA isogenes. Moreover, we demonstrate that plants that constitutively overexpress YUC8 and YUC9 show less damage after spider mite infestation, thereby underlining the role of auxin in plant responses to biotic stress signals.


Assuntos
Proteínas de Arabidopsis/genética , Ciclopentanos/metabolismo , Oxigenases de Função Mista/genética , Motivos de Nucleotídeos , Oxilipinas/metabolismo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-myc/metabolismo , Estresse Fisiológico/genética , Fatores de Ligação G-Box , Regulação da Expressão Gênica de Plantas , Ácidos Indolacéticos/metabolismo , Ligação Proteica
10.
Int J Mol Sci ; 22(15)2021 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-34360691

RESUMO

Two-line hybrid rice systems represent a new technical approach to utilizing the advantages of rice hybrids. However, the mechanism underlying the male sterile-line fertility transition in rice remains unclear. Peiai 64S (PA64S) is a photoperiod- and thermo-sensitive genic male sterile (PTGMS) line in which male sterility manifests at an average temperature above 23.5 °C under long-day (LD) conditions. Nongken 58S (NK58S) is a LD-sensitive genic male sterile (PGMS) rice that is sterile under LD conditions (above 13.75 h-day). In contrast, D52S is a short-day (SD)-PGMS line that manifests male sterility under SD conditions (below 13.5 h-day). In this study, we obtained fertile and sterile plants from all three lines and performed transcriptome analyses on the anthers of the plants. Gene ontology (GO) analysis suggested that the differentially expressed genes identified were significantly enriched in common terms involved in the response to jasmonic acid (JA) and in JA biosynthesis. On the basis of the biochemical and molecular validation of dynamic, tissue-specific changes in JA, indole-3-acetic acid (IAA) levels, gibberellin (GA) levels, and JA biosynthetic enzyme activities and expression, we proposed that JA could play a pivotal role in viable pollen production through its initial upregulation, constant fluctuation and leaf-spikelet signaling under certain fertility-inducing conditions. Furthermore, we also sprayed methyl jasmonate (MEJA) and salicylhydroxamic acid (SHAM) on the plants, thereby achieving fertility reversal in the PGMS lines NK58S and D52S, with 12.91-63.53% pollen fertility changes. Through qPCR and enzyme activity analyses, we identified two key enzymes-allene oxide synthase (AOS) and allene oxide cyclase (AOC)-that were produced and upregulated by 20-500-fold in PGMS in response to spraying; the activities of these enzymes reversed pollen fertility by influencing the JA biosynthetic pathway. These results provide a new understanding of hormone interactions and networks in male-sterile rice based on the role of JA that will help us to better understand the potential regulatory mechanisms of fertility development in rice in the future.


Assuntos
Ciclopentanos/metabolismo , Oxirredutases Intramoleculares/genética , Oryza/metabolismo , Oxilipinas/metabolismo , Pólen/crescimento & desenvolvimento , Transdução de Sinais , Acetatos/farmacologia , Ciclopentanos/farmacologia , Fertilidade , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/fisiologia , Oxilipinas/farmacologia , Proteínas de Plantas/genética , Pólen/metabolismo , Salicilamidas/farmacologia
11.
Nat Commun ; 12(1): 4804, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376671

RESUMO

Plants respond to warm temperature by increased elongation growth of organs to enhance cooling capacity. Phytohormones, such as auxin and brassinosteroids, regulate this growth process. However, our view on the players involved in warm temperature-mediated growth remains fragmentary. Here, we show that warm temperature leads to an increased expression of JOXs and ST2A, genes controlling jasmonate catabolism. This leads to an elevated 12HSO4-JA level and consequently to a reduced level of bioactive jasmonates. Ultimately this results in more JAZ proteins, which facilitates plant growth under warm temperature conditions. Taken together, understanding the conserved role of jasmonate signalling during thermomorphogenesis contributes to ensuring food security under a changing climate.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Ciclopentanos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Oxilipinas/metabolismo , Temperatura , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Plantas Geneticamente Modificadas , Transdução de Sinais
12.
BMC Plant Biol ; 21(1): 360, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34362300

RESUMO

BACKGROUND: Dendrobium catenatum belongs to the Orchidaceae, and is a precious Chinese herbal medicine. In the past 20 years, D. catenatum industry has developed from an endangered medicinal plant to multi-billion dollar grade industry. The necrotrophic pathogen Sclerotium delphinii has a devastating effection on over 500 plant species, especially resulting in widespread infection and severe yield loss in the process of large-scale cultivation of D. catenatum. It has been widely reported that Jasmonate (JA) is involved in plant immunity to pathogens, but the mechanisms of JA-induced plant resistance to S. delphinii are unclear. RESULTS: In the present study, the role of JA in enhancing D. catenatum resistance to S. delphinii was investigated. We identified 2 COI1, 13 JAZ, and 12 MYC proteins in D. catenatum genome. Subsequently, systematic analyses containing phylogenetic relationship, gene structure, protein domain, and motif architecture of core JA pathway proteins were conducted in D. catenatum and the newly characterized homologs from its closely related orchid species Phalaenopsis equestris and Apostasia shenzhenica, along with the well-investigated homologs from Arabidopsis thaliana and Oryza sativa. Public RNA-seq data were investigated to analyze the expression patterns of D. catenatum core JA pathway genes in various tissues and organs. Transcriptome analysis of MeJA and S. delphinii treatment showed exogenous MeJA changed most of the expression of the above genes, and several key members, including DcJAZ1/2/5 and DcMYC2b, are involved in enhancing defense ability to S. delphinii in D. catenatum. CONCLUSIONS: The findings indicate exogenous MeJA treatment affects the expression level of DcJAZ1/2/5 and DcMYC2b, thereby enhancing D. catenatum resistance to S. delphinii. This research would be helpful for future functional identification of core JA pathway genes involved in breeding for disease resistance in D. catenatum.


Assuntos
Basidiomycota/patogenicidade , Ciclopentanos/metabolismo , Dendrobium/microbiologia , Oxilipinas/metabolismo , Imunidade Vegetal/fisiologia , Proteínas de Plantas/genética , Acetatos/farmacologia , Ciclopentanos/farmacologia , Dendrobium/efeitos dos fármacos , Dendrobium/imunologia , Dendrobium/metabolismo , Resistência à Doença/genética , Regulação da Expressão Gênica de Plantas , Família Multigênica , Oxilipinas/farmacologia , Filogenia , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/imunologia , Transdução de Sinais/genética
13.
Int J Mol Sci ; 22(16)2021 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-34445272

RESUMO

As sessile organisms, plants must tolerate various environmental stresses. Plant hormones play vital roles in plant responses to biotic and abiotic stresses. Among these hormones, jasmonic acid (JA) and its precursors and derivatives (jasmonates, JAs) play important roles in the mediation of plant responses and defenses to biotic and abiotic stresses and have received extensive research attention. Although some reviews of JAs are available, this review focuses on JAs in the regulation of plant stress responses, as well as JA synthesis, metabolism, and signaling pathways. We summarize recent progress in clarifying the functions and mechanisms of JAs in plant responses to abiotic stresses (drought, cold, salt, heat, and heavy metal toxicity) and biotic stresses (pathogen, insect, and herbivore). Meanwhile, the crosstalk of JA with various other plant hormones regulates the balance between plant growth and defense. Therefore, we review the crosstalk of JAs with other phytohormones, including auxin, gibberellic acid, salicylic acid, brassinosteroid, ethylene, and abscisic acid. Finally, we discuss current issues and future opportunities in research into JAs in plant stress responses.


Assuntos
Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Plantas/metabolismo , Estresse Fisiológico
14.
Int J Mol Sci ; 22(13)2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34201662

RESUMO

Gene expression and phytohormone contents were measured in response to elevating ascorbate in the absence of other confounding stimuli such as high light and abiotic stresses. Young Arabidopsis plants were treated with 25 mM solutions of l-galactose pathway intermediates l-galactose (l-gal) or l-galactono-1,4-lactone (l-galL), as well as L-ascorbic acid (AsA), with 25 mM glucose used as control. Feeding increased rosette AsA 2- to 4-fold but there was little change in AsA biosynthetic gene transcripts. Of the ascorbate recycling genes, only Dehydroascorbate reductase 1 expression was increased. Some known regulatory genes displayed increased expression and included ANAC019, ANAC072, ATHB12, ZAT10 and ZAT12. Investigation of the ANAC019/ANAC072/ATHB12 gene regulatory network revealed a high proportion of ABA regulated genes. Measurement of a subset of jasmonate, ABA, auxin (IAA) and salicylic acid compounds revealed consistent increases in ABA (up to 4.2-fold) and phaseic acid (PA; up to 5-fold), and less consistently certain jasmonates, IAA, but no change in salicylic acid levels. Increased ABA is likely due to increased transcripts for the ABA biosynthetic gene NCED3. There were also smaller increases in transcripts for transcription factors ATHB7, ERD1, and ABF3. These results provide insights into how increasing AsA content can mediate increased abiotic stress tolerance.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Ácido Ascórbico/metabolismo , Glutationa Transferase/genética , Reguladores de Crescimento de Plantas/metabolismo , Estresse Fisiológico/fisiologia , Ácido Abscísico/metabolismo , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/metabolismo , Ascorbato Oxidase/genética , Ascorbato Oxidase/metabolismo , Ácido Ascórbico/genética , Ciclopentanos/metabolismo , Galactose/farmacologia , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Glutationa Transferase/metabolismo , Ácidos Hexurônicos/metabolismo , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/genética , Sesquiterpenos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
Methods Mol Biol ; 2328: 203-214, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34251628

RESUMO

Plants use different regulatory modules in response to changes in their surroundings. With the transcriptomic approaches governing all research areas, an integrative, fast, and sensitive approach toward validating genes of interest becomes a critical step prior to functional studies in planta. This chapter describes a detailed method for a quantitative analysis of transcriptional readouts of defense response genes using tobacco leaves as a transient system. The method uses Luciferase reporter assays to monitor activities of defense pathway promoters. Under normal conditions, the JASMONATE ZIM-DOMAIN (JAZ) proteins repress defense genes by preventing their expression. Here, we will provide a detailed protocol on the use of a dual-luciferase system to analyze activities of various defense response promoters simultaneously. We will use two well-characterized modules from the Jasmonic acid (JA) defense pathway; the JAZ3 repressor protein and the promoters of three of JA responsive genes, MYC2, 3 and 4. This assay revealed not only differences in promoter strength but also provided quantitative insights on the JAZ3 repression of MYCs in a quantitative manner.


Assuntos
Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Folhas de Planta/metabolismo , Proteínas Repressoras/metabolismo , Tabaco/metabolismo , Agrobacterium tumefaciens/metabolismo , Primers do DNA , Genes myc/genética , Luciferases/genética , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas , Domínios Proteicos/genética , Proteínas Repressoras/genética , Tabaco/genética
16.
Nat Commun ; 12(1): 4327, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34267202

RESUMO

Trivalent rare earth elements (REEs) are widely used in agriculture. Aerially applied REEs enter leaf epidermal cells by endocytosis and act systemically to improve the growth of the whole plant. The mechanistic basis of their systemic activity is unclear. Here, we show that treatment of Arabidopsis leaves with trivalent lanthanum [La(III)], a representative of REEs, triggers systemic endocytosis from leaves to roots. La(III)-induced systemic endocytosis requires AtrbohD-mediated reactive oxygen species production and jasmonic acid. Systemic endocytosis impacts the accumulation of mineral elements and the development of roots consistent with the growth promoting effects induced by aerially applied REEs. These findings provide insights into the mechanistic basis of REE activity in plants.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/efeitos dos fármacos , Endocitose/efeitos dos fármacos , Lantânio/farmacologia , NADPH Oxidases/metabolismo , Arabidopsis/citologia , Proteínas de Arabidopsis/genética , Ciclopentanos/metabolismo , Endocitose/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Fluorescência Verde/genética , Minerais/metabolismo , NADPH Oxidases/genética , Oxilipinas/metabolismo , Células Vegetais/efeitos dos fármacos , Folhas de Planta/citologia , Folhas de Planta/efeitos dos fármacos , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , Transdução de Sinais
17.
BMC Plant Biol ; 21(1): 306, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193042

RESUMO

BACKGROUND: Outbreaks of insect pests in paddy fields cause heavy losses in global rice yield annually, a threat projected to be aggravated by ongoing climate warming. Although significant progress has been made in the screening and cloning of insect resistance genes in rice germplasm and their introgression into modern cultivars, improved rice resistance is only effective against either chewing or phloem-feeding insects. RESULTS: In this study, the results from standard and modified seedbox screening, settlement preference and honeydew excretion tests consistently showed that Qingliu, a previously known leaffolder-resistant rice variety, is also moderately resistant to brown planthopper (BPH). High-throughput RNA sequencing showed a higher number of differentially expressed genes (DEGs) at the infestation site, with 2720 DEGs in leaves vs 181 DEGs in sheaths for leaffolder herbivory and 450 DEGs in sheaths vs 212 DEGs in leaves for BPH infestation. The leaf-specific transcriptome revealed that Qingliu responds to leaffolder feeding by activating jasmonic acid biosynthesis genes and genes regulating the shikimate and phenylpropanoid pathways that are essential for the biosynthesis of salicylic acid, melatonin, flavonoids and lignin defensive compounds. The sheath-specific transcriptome revealed that Qingliu responds to BPH infestation by inducing salicylic acid-responsive genes and those controlling cellular signaling cascades. Taken together these genes could play a role in triggering defense mechanisms such as cell wall modifications and cuticular wax formation. CONCLUSIONS: This study highlighted the key defensive responses of a rarely observed rice variety Qingliu that has resistance to attacks by two different feeding guilds of herbivores. The leaffolders are leaf-feeder while the BPHs are phloem feeders, consequently Qingliu is considered to have dual resistance. Although the defense responses of Qingliu to both insect pest types appear largely dissimilar, the phenylpropanoid pathway (or more specifically phenylalanine ammonia-lyase genes) could be a convergent upstream pathway. However, this possibility requires further studies. This information is valuable for breeding programs aiming to generate broad spectrum insect resistance in rice cultivars.


Assuntos
Herbivoria/fisiologia , Oryza/genética , Oryza/parasitologia , Floema/parasitologia , Folhas de Planta/parasitologia , Transcriptoma/genética , Animais , Parede Celular/metabolismo , Ciclopentanos/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Hemípteros/fisiologia , Metabolismo dos Lipídeos , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Ácido Salicílico/metabolismo , Ácido Chiquímico/metabolismo , Transcrição Genética
18.
Plant Cell Rep ; 40(8): 1331-1343, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34086069

RESUMO

Aluminium (Al) is one of the most abundant metals in earth crust, which becomes toxic to the plants growing in acidic soil. Phytohormones like ethylene, auxin, cytokinin, abscisic acid, jasmonic acid and gibberellic acid are known to play important role in regulating Al toxicity tolerance in plants. Exogenous applications of auxin, cytokinin and abscisic acid have shown significant effect on Al-induced root growth inhibition. Moreover, ethylene and cytokinin act synergistically with auxin in responding against Al toxicity. A number of studies showed that phytohormones play vital roles in controlling root responses to Al toxicity by modulating reactive oxygen species (ROS) signalling, cell wall modifications, organic acid exudation from roots and expression of Al responsive genes and transcription factors. This review provides a summary of recent studies related to involvement of phytohormone signalling and cross-talk with other pathways in regulating response against Al toxicity in plants.


Assuntos
Alumínio/toxicidade , Reguladores de Crescimento de Plantas/metabolismo , Plantas/efeitos dos fármacos , Plantas/metabolismo , Ácido Abscísico/metabolismo , Ciclopentanos/metabolismo , Citocininas/metabolismo , Etilenos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Raízes de Plantas/citologia , Raízes de Plantas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos
19.
Plant Cell Rep ; 40(8): 1495-1512, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34089089

RESUMO

KEY MESSAGE: Expression pattern indicates that JA biosynthesis pathway via regulating JA levels might control root system architecture to improve nutrient use efficiency (NUE) and N, P, K+ deficiency tolerance in rice. Deficiencies of macronutrients (N, P and K+) and consequent excessive use of fertilizers have dramatically reduced soil fertility. It calls for development of nutrient use efficient plants. Plants combat nutrient deficiencies by altering their root system architecture (RSA) to enhance the acquisition of nutrients from the soil. Amongst various phytohormones, Jasmonic acid (JA) is known to regulate plant root growth and modulate RSA. Therefore, to understand the role of JA in macronutrient deficiency in rice, expression pattern of JA biosynthesis genes was analyzed under N, P and K+ deficiencies. Several members belonging to different families of JA biosynthesis genes (PLA1, LOX, AOS, AOC, OPR, ACX and JAR1) showed differential expression exclusively in one nutrient deficiency or in multiple nutrient deficiencies. Expression analysis during developmental stages showed that several genes expressed significantly in vegetative tissues, particularly in root. In addition, JA biosynthesis genes were found to have significant expression under the treatment of different phytohormones, including Auxin, cytokinin, gibberellic acid (GA), abscisic acid (ABA), JA and abiotic stresses, such as drought, salinity and cold. Analysis of promoters of these genes revealed various cis-regulatory elements associated with hormone response, plant development and abiotic stresses. These findings suggest that JA biosynthesis pathway by regulating the level of JA might control the RSA thus, it may help rice plant in combating macronutrient deficiency.


Assuntos
Ciclopentanos/metabolismo , Oryza/fisiologia , Oxilipinas/metabolismo , Proteínas de Plantas/genética , Regulação da Expressão Gênica de Plantas , Redes e Vias Metabólicas/genética , Nitrogênio/metabolismo , Oryza/efeitos dos fármacos , Fósforo/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/metabolismo , Potássio/metabolismo , Regiões Promotoras Genéticas , Estresse Fisiológico/fisiologia
20.
J Plant Physiol ; 263: 153452, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34098414

RESUMO

In plants, jasmonate ZIM-domain proteins (JAZs) act as critical regulators, interacting physically with transcription factors (TFs) and other transcriptional regulators to modulate jasmonate (JA)-responsive gene expression and participate in crosstalk with other hormone signalling pathways. Identifying novel JAZ-interacting proteins will provide new insights into JA signalling cascades in plants. Here, we performed yeast two-hybrid screening to identify 70 NtJAZ1-interacting proteins, including an A/T-rich interaction domain containing protein 1 (NtAIDP1) from JA-treated tobacco Bright Yellow-2 (BY-2) cells. NtAIDP1 is localised in the nucleus and interacts with NtJAZ1 via its C-terminal heat shock protein 20 (HSP) domain. Aside from NtJAZ1, NtAIDP1 also interacts with other JA-inducible NtJAZs, including NtJAZ2b, NtJAZ2b.2, NtJAZ5, NtJAZ7, NtJAZ11 and NtJAZ12, but not with NtJAZ3, NtJAZ3b or NtJAZ10, and interacts with NtNINJA, NtDELLA1 and NtDELLA2 in the yeast two-hybrid assay. Furthermore, NtAIDP1 binds to the AT-rich region of the GAG fragment of the putrescine N-methyltransferase 1a (NtPMT1a) promoter and activates the transcriptional activity of the GAG fragment, whereas NtMYC2a interacts with and competitively inhibits the transactivational activity of NtAIDP1 in Arabidopsis mesophyll protoplasts. Overexpression of NtAIDP1 promotes the transcription of NtPDF1.2 and NtJAZ1, but has little effect on the expression of NtPMT1a, quinolinate phosphoribosyltransferase 2 (NtQPT2), and NtMYC2a in tobacco. These results indicate that NtAIDP1 is a new component of the JA signalling pathway and is involved in JA-regulated gene expression.


Assuntos
Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/genética , Reguladores de Crescimento de Plantas/metabolismo , Tabaco/genética , Tabaco/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Regulação da Expressão Gênica de Plantas
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