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1.
Food Chem ; 337: 127772, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32777571

RESUMO

Chitosan can function a key role in plant resistant against Botrytis cinerea infection, while its mechanism is unclear in ripened fruits. In this study, we investigated the chitosan effect on two type of ripened fruits including strawberry and grapes (Kyoho and Shine-Muscat) when were infected with B. cinerea. Results showed that chitosan inhibited B. cinerea growth, increased phenolic compounds and cell wall composition, modulated oxidative stress and induced jasmonic acid (JA) production in ripened fruits. Data-independent acquisition (DIA) showed that 224 and 171 proteins were upregulated 1.5-fold by chitosan in Kyoho and Shine-Muscat grape, respectively. Topless-related protein 3 (TPR3) were identified and interacted with histone deacetylase 19 (HDAC19) and negatively regulated by JA and chitosan. Meanwhile, overexpression of VvTPR3 and VvHDAC19 reduced the stability of cell wall against B. cinerea in strawberry. Taken together, chitosan induces defense related genes and protect the fruit quality against Botrytis infection through JA signaling.


Assuntos
Botrytis/efeitos dos fármacos , Quitosana/farmacologia , Ciclopentanos/metabolismo , Fragaria/metabolismo , Oxilipinas/metabolismo , Vitis/metabolismo , Botrytis/fisiologia , Parede Celular/metabolismo , Fragaria/microbiologia , Frutas/metabolismo , Frutas/microbiologia , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Proteínas de Plantas/antagonistas & inibidores , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Interferência de RNA , Esporos Fúngicos/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Vitis/microbiologia
2.
Nat Commun ; 11(1): 5158, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33056992

RESUMO

Filamentous fungi differentiate along complex developmental programs directed by abiotic and biotic signals. Currently, intrinsic signals that govern fungal development remain largely unknown. Here we show that an endogenously produced and secreted fungal oxylipin, 5,8-diHODE, induces fungal cellular differentiation, including lateral branching in pathogenic Aspergillus fumigatus and Aspergillus flavus, and appressorium formation in the rice blast pathogen Magnaporthe grisea. The Aspergillus branching response is specific to a subset of oxylipins and is signaled through G-protein coupled receptors. RNA-Seq profiling shows differential expression of many transcription factors in response to 5,8-diHODE. Screening of null mutants of 33 of those transcription factors identifies three transcriptional regulators that appear to mediate the Aspergillus branching response; one of the mutants is locked in a hypo-branching phenotype, while the other two mutants display a hyper-branching phenotype. Our work reveals an endogenous signal that triggers crucial developmental processes in filamentous fungi, and opens new avenues for research on the morphogenesis of filamentous fungi.


Assuntos
Proteínas Fúngicas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação Fúngica da Expressão Gênica , Ácidos Linoleicos/metabolismo , Oxilipinas/metabolismo , Aspergillus flavus/genética , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/metabolismo , Aspergillus fumigatus/genética , Aspergillus fumigatus/crescimento & desenvolvimento , Aspergillus fumigatus/metabolismo , Proteínas Fúngicas/genética , Hifas/crescimento & desenvolvimento , Hifas/metabolismo , Magnaporthe/genética , Magnaporthe/crescimento & desenvolvimento , Magnaporthe/metabolismo , Mutação , RNA-Seq , Receptores Acoplados a Proteínas-G/genética , Receptores Acoplados a Proteínas-G/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
PLoS One ; 15(9): e0238381, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32881942

RESUMO

Small fructans improve plant tolerance for cold stress. However, the underlying molecular mechanisms are poorly understood. Here, we have demonstrated that the small fructan tetrasaccharide nystose improves the cold stress tolerance of primary rice roots. Roots developed from seeds soaked in nystose showed lower browning rate, higher root activity, and faster growth compared to seeds soaked in water under chilling stress. Comparative proteomics analysis of nystose-treated and control roots identified a total of 497 differentially expressed proteins. GO classification and KEGG pathway analysis documented that some of the upregulated differentially expressed proteins were implicated in the regulation of serine/threonine protein phosphatase activity, abscisic acid-activated signaling, removal of superoxide radicals, and the response to oxidative stress and defense responses. Western blot analysis indicated that nystose promotes the growth of primary rice roots by increasing the level of RSOsPR10, and the cold stress-induced change in RSOsPR10levelis regulated by jasmonate, salicylic acid, and abscisic acid signaling pathways in rice roots. Furthermore, OsMKK4-dependentmitogen-activated protein kinase signaling cascades may be involved in the nystose-induced cold tolerance of primary rice roots. Together, these results indicate that nystose acts as an immunostimulator of the response to cold stress by multiple signaling pathways.


Assuntos
Resposta ao Choque Frio/efeitos dos fármacos , Oligossacarídeos/farmacologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteômica/métodos , Transdução de Sinais/efeitos dos fármacos , Ácido Abscísico/metabolismo , Cromatografia Líquida de Alta Pressão , Resposta ao Choque Frio/genética , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/efeitos dos fármacos , Oryza/crescimento & desenvolvimento , Oxilipinas/metabolismo , Fenótipo , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Ácido Salicílico/metabolismo , Transdução de Sinais/genética , Espectrometria de Massas em Tandem
4.
PLoS Pathog ; 16(8): e1008801, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866183

RESUMO

Rice stripe virus (RSV) is one of the most destructive viral diseases affecting rice production. However, so far, only one RSV resistance gene has been cloned, the molecular mechanisms underlying host-RSV interaction are still poorly understood. Here, we show that increasing levels or signaling of brassinosteroids (BR) and jasmonic acid (JA) can significantly enhance the resistance against RSV. On the contrary, plants impaired in BR or JA signaling are more susceptible to RSV. Moreover, the enhancement of RSV resistance conferred by BR is impaired in OsMYC2 (a key positive regulator of JA response) knockout plants, suggesting that BR-mediated RSV resistance requires active JA pathway. In addition, we found that RSV infection suppresses the endogenous BR levels to increase the accumulation of OsGSK2, a key negative regulator of BR signaling. OsGSK2 physically interacts with OsMYC2, resulting in the degradation of OsMYC2 by phosphorylation and reduces JA-mediated defense to facilitate virus infection. These findings not only reveal a novel molecular mechanism mediating the crosstalk between BR and JA in response to virus infection and deepen our understanding about the interaction of virus and plants, but also suggest new effective means of breeding RSV resistant crops using genetic engineering.


Assuntos
Brassinosteroides/metabolismo , Ciclopentanos/metabolismo , Oryza , Oxilipinas/metabolismo , Plantas Geneticamente Modificadas , Transdução de Sinais , Tenuivirus , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Oryza/genética , Oryza/metabolismo , Oryza/virologia , Doenças das Plantas/genética , Doenças das Plantas/virologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Plantas Geneticamente Modificadas/virologia , Tenuivirus/genética , Tenuivirus/metabolismo
5.
PLoS One ; 15(8): e0236823, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32745143

RESUMO

Stem rot, a devastating fungal disease of peanut, is caused by Sclerotium rolfsii. RNA-sequencing approaches have been used to unravel the mechanisms of resistance to stem rot in peanut over the course of fungal infection in resistant (NRCG-CS85) and susceptible (TG37A) genotypes under control conditions and during the course of infection. Out of about 290 million reads, nearly 251 million (92.22%) high-quality reads were obtained and aligned to the Arachis duranensis and Arachis ipaensis genomes with the average mapping of 78.91% and 78.61%, respectively. In total, about 48.6% of genes were commonly regulated, while approximately 21.8% and 29.6% of uniquely regulated genes from A. duranensis and A. ipaensis genomes, respectively, were identified. Several annotated transcripts, such as receptor-like kinases, jasmonic acid pathway enzymes, and transcription factors (TFs), including WRKY, Zinc finger protein, and C2-H2 zinc finger, showed higher expression in resistant genotypes upon infection. These transcripts have a known role in channelizing the downstream of pathogen perception. The higher expression of WRKY transcripts might have induced the systemic acquired resistance (SAR) by the activation of the jasmonic acid defense signaling pathway. Furthermore, a set of 30 transcripts involved in the defense mechanisms were validated with quantitative real-time PCR. This study suggested PAMP-triggered immunity as a probable mechanism of resistance, while the jasmonic acid signaling pathway was identified as a possible defense mechanism in peanut. The information generated is of immense importance in developing more effective ways to combat the stem rot disease in peanut.


Assuntos
Agaricales/patogenicidade , Arachis/genética , Doenças das Plantas , Imunidade Vegetal/genética , Arachis/microbiologia , Ciclopentanos/metabolismo , Proteínas de Ligação a DNA/genética , Genes de Plantas , Genótipo , Oxilipinas/metabolismo , Fosfotransferases (Aceptor do Grupo Fosfato)/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/genética , Proteínas de Plantas/genética , RNA-Seq , Transdução de Sinais/genética , Fatores de Transcrição/genética
6.
PLoS Biol ; 18(8): e3000830, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32810128

RESUMO

Plants are attacked by herbivores, which often specialize on different tissues, and in response, have evolved sophisticated resistance strategies that involve different types of chemical defenses frequently targeted to different tissues. Most known phytohormones have been implicated in regulating these defenses, with jasmonates (JAs) playing a pivotal role in complex regulatory networks of signaling interactions, often generically referred to as "cross talk." The newly identified class of phytohormones, strigolactones (SLs), known to regulate the shoot architecture, remain unstudied with regard to plant-herbivore interactions. We explored the role of SL signaling in resistance to a specialist weevil (Trichobaris mucorea) herbivore of the native tobacco, Nicotiana attenuata, that attacks the root-shoot junction (RSJ), the part of the plant most strongly influenced by alterations in SL signaling (increased branching). As SL signaling shares molecular components, such as the core F-box protein MORE AXILLARY GROWTH 2 (MAX2), with another new class of phytohormones, the karrikins (KARs), which promote seed germination and seedling growth, we generated transformed lines, individually silenced in the expression of NaMAX2, DWARF 14 (NaD14: the receptor for SL) and CAROTENOID CLEAVAGE DIOXYGENASE 7 (NaCCD7: a key enzyme in SL biosynthesis), and KARRIKIN INSENSITIVE 2 (NaKAI2: the KAR receptor). The mature stems of all transgenic lines impaired in the SL, but not the KAR signaling pathway, overaccumulated anthocyanins, as did the stems of plants attacked by the larvae of weevil, which burrow into the RSJs to feed on the pith of N. attenuata stems. T. mucorea larvae grew larger in the plants silenced in the SL pathway, but again, not in the KAI2-silenced plants. These phenotypes were associated with elevated JA and auxin (indole-3-acetic acid [IAA]) levels and significant changes in the accumulation of defensive compounds, including phenolamides and nicotine. The overaccumulation of phenolamides and anthocyanins in the SL pathway-silenced plants likely resulted from antagonism between the SL and JA pathway in N. attenuata. We show that the repressors of SL signaling, suppressor of max2-like (NaSMXL6/7), and JA signaling, jasmonate zim-domain (NaJAZs), physically interact, promoting NaJAZb degradation and releasing JASMONATE INSENSITIVE 1 (JIN1/MYC2) (NaMYC2), a critical transcription factor promoting JA responses. However, the increased performance of T. mucorea larvae resulted from lower pith nicotine levels, which were inhibited by increased IAA levels in SL pathway-silenced plants. This inference was confirmed by decapitation and auxin transport inhibitor treatments that decreased pith IAA and increased nicotine levels. In summary, SL signaling tunes specific sectors of specialized metabolism in stems, such as phenylpropanoid and nicotine biosynthesis, by tailoring the cross talk among phytohormones, including JA and IAA, to mediate herbivore resistance of stems. The metabolic consequences of the interplay of SL, JA, and IAA signaling revealed here could provide a mechanism for the commonly observed pattern of herbivore tolerance/resistance trade-offs.


Assuntos
Herbivoria/fisiologia , Interações Hospedeiro-Parasita , Lactonas/metabolismo , Caules de Planta/metabolismo , Caules de Planta/parasitologia , Transdução de Sinais , Tabaco/metabolismo , Tabaco/parasitologia , Animais , Antocianinas/metabolismo , Ciclopentanos/metabolismo , Ácidos Indolacéticos/metabolismo , Larva , Metabolômica , Oxilipinas/metabolismo , Proteínas de Plantas/metabolismo , Interferência de RNA , Gorgulhos/fisiologia
7.
Plant Mol Biol ; 104(4-5): 397-410, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32803476

RESUMO

KEY MESSAGE: Enhanced bioactive JA (JA-Ile) accumulation in OsJAZ9 overexpressing rice helps plants tolerate K deficiency. Potassium (K) represents up to 10% of the plant's total dry biomass, and its deficiency makes plants highly susceptible to both abiotic and biotic stresses. K shortage results in the inhibition of root and shoots growth, but the underlying mechanism of this response is unclear. Our RNA-Seq and qPCR analysis suggested leading roles for JA pathway genes under K deficiency in rice. Notably, K deficiency and JA application produced similar phenotypic and transcriptional responses. Here, we integrated molecular, physiological and morphological studies to analyze the role of OsJAZ9 in JA homeostasis and K deficiency responses. We raised OsJAZ9 over-expression, knockdown, transcriptional reporter, translational reporter and C-terminal deleted translational reporter lines in rice to establish the role of JA signaling in K ion homeostasis. JA profiling revealed significantly increased JA-Ile levels in OsJAZ9 OE lines under K deficiency. Furthermore, we established that OsJAZ9 overexpression and knockdown result in K deficiency tolerance and sensitivity, respectively, by modulating various K transporters and root system architecture. Our data provide evidence on the crucial roles of OsJAZ9 for improving K deficiency tolerance in rice by altering JA levels and JA responses.


Assuntos
Ciclopentanos/metabolismo , Oryza/metabolismo , Oxilipinas/metabolismo , Proteínas de Plantas/metabolismo , Potássio/metabolismo , Regulação da Expressão Gênica de Plantas , Homeostase , Isoleucina/análogos & derivados , Isoleucina/metabolismo , Oryza/efeitos dos fármacos , Oryza/genética , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Potássio/farmacologia
8.
Gene ; 758: 144942, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32640309

RESUMO

WUSCHEL-related homeobox4 (WOX4) plays important roles in vascular formation and adventitious root (AR) development. Here, we cloned the WOX4 from the AR of Larix kaempferi, whose cDNA is 1452 bp in length and encodes 483 amino acids. LkWOX4 is mainly expressed in the layer formation area of the stem at 10 days after cutting and its expression levels in the middles and ends of the ARs were higher than that in the AR tips. The fused protein LkWOX4-GFP localized in the nucleus. The heterologous overexpression of LkWOX4 in 84 K poplar significantly increased AR numbers and decreased AR lengths. In LkWOX4 plants, the endogenous jasmonic acid and abscisic acid contents significantly decreased in stems, while the auxin, jasmonic acid and abscisic acid contents significantly increased in ARs. RNA-Seq of those LkWOX4 overexpression poplar plants showed that the expression of plant hormone signaling genes (ARF2, ARF3, ARF7 and ARF18), rooting-related transcription factors (WOX5, LBD29 and SCR) and root development-related genes (CYCD3, GRF1 and TAA1) were affected. Moreover, we found that LkWOX4 interacts with LkPAT18, LkACBP6, and LkCIP7 using yeast two hybrid screening. Thus, we found LkWOX4 involves in the AR initiation and development, which might be regulated through the IAA, JA and ABA signaling pathways.


Assuntos
Proteínas de Homeodomínio/genética , Larix/crescimento & desenvolvimento , Meristema/crescimento & desenvolvimento , Organogênese Vegetal/genética , Fatores de Transcrição/genética , Ácido Abscísico/metabolismo , Clonagem Molecular , Ciclopentanos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica de Plantas/genética , Ácidos Indolacéticos/metabolismo , Larix/genética , Meristema/genética , Oxilipinas/metabolismo , Transdução de Sinais/genética
9.
Food Chem ; 332: 127406, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615387

RESUMO

Hot peppers are sensitive to low temperature, and seed browning significantly reduces the fruit quality. This study aims to clarify the mechanisms of seed browning in terms of metabolite changes. Metabolites were analysed during a 30-day-storage period at 2 °C and 10 °C. Gamma-aminobutyric acid, tyrosine, phenylalanine, and isoleucine concentrations were significantly higher at 2 °C storage than at 10 °C. Reactive oxygen species (ROS) generation was associated with seed browning. Transcription of jasmonic acid synthesis and ROS scavenging genes were higher in hot peppers stored at 2 °C than those stored at 10 °C. This study elucidated the mechanisms underlying seed browning and chill damage in hot peppers during storage at low temperatures and our findings may help improve hot peppers' quality following harvesting.


Assuntos
Capsicum/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Aminoácidos/análise , Aminoácidos/metabolismo , Cromatografia Líquida de Alta Pressão , Temperatura Baixa , Ciclopentanos/metabolismo , Armazenamento de Alimentos , Frutas/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Oxilipinas/metabolismo , Análise de Componente Principal , Sementes/metabolismo , Ácido gama-Aminobutírico/análise , Ácido gama-Aminobutírico/metabolismo
10.
PLoS One ; 15(7): e0235795, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645115

RESUMO

To investigate the growth, physiological changes and mechanism of drought resistance of Camellia oleifera GWu-2 under drought stress conditions, changes in the main growth and physiological indices of GWu-2 under different water gradients were studied. Factor analysis was used to study the differences between indicators under different water gradients, and correlation analysis was implemented to analyze the relationship between different factors. We observed that the growth state, enzyme secretion, stomatal morphology and leaf osmotic adjustment substances were significantly affected by drought stress. In particular, increases in leaf abscisic acid (ABA), indole acetic acid (IAA) and methyl jasmonate (MeJA) contents under drought stress were negatively correlated with the stomatal opening degree, and the ratio of ZR/GA3 was significantly correlated with the growth and physiological indicators of GWu-2, indicating that different hormones respond differently to drought stress and have different functions in the growth regulation and drought resistance of GWu-2. We concluded that the drought resistance mechanism of GWu-2 was controlled by maintaining root growth to obtain the necessary water, increasing the contents of osmotic substances of leaves to maintain water holding capacity, reducing the transpiration of water by increasing leaf ABA, IAA and MeJA content to close stomata and reducing the damage caused by drought by increasing the activity of superoxide dismutase (SOD).


Assuntos
Aclimatação , Camellia/fisiologia , Ácido Abscísico/metabolismo , Acetatos/metabolismo , Camellia/crescimento & desenvolvimento , Ciclopentanos/metabolismo , Secas , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Estômatos de Plantas/crescimento & desenvolvimento , Estômatos de Plantas/fisiologia , Estresse Fisiológico , Água/metabolismo
11.
Artigo em Inglês | MEDLINE | ID: mdl-32717531

RESUMO

Oxylipins, which are circulating bioactive lipids generated from polyunsaturated fatty acids (PUFAs) by cyclooxygenase, lipooxygenase and cytochrome P450 enzymes, have diverse effects on endothelial cells. Although studies of the effects of oxylipins on endothelial cell function are accumulating, a review that provides a comprehensive compilation of current knowledge and recent advances in the context of vascular homeostasis is lacking. This is the first compilation of the various in vitro, ex vivo and in vivo reports to examine the effects and potential mechanisms of action of oxylipins on endothelial cells. The aggregate data indicate docosahexaenoic acid-derived oxylipins consistently show beneficial effects related to key endothelial cell functions, whereas oxylipins derived from other PUFAs exhibit both positive and negative effects. Furthermore, information is lacking for certain oxylipin classes, such as those derived from α-linolenic acid, which suggests additional studies are required to achieve a full understanding of how oxylipins affect endothelial cells.


Assuntos
Células Endoteliais/metabolismo , Ácidos Graxos Insaturados/metabolismo , Oxilipinas/metabolismo , Ácido 8,11,14-Eicosatrienoico/metabolismo , Ácido Araquidônico/metabolismo , Dieta , Ácido Eicosapentaenoico/metabolismo , Humanos , Ácido Linoleico/metabolismo
13.
PLoS One ; 15(6): e0234738, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32544205

RESUMO

Tuber mustard, which is the raw material of Fuling pickle, is a crop with great economic value. However, during growth and development, tuber mustard is frequently attacked by the pathogen Plasmodiophora brassicae and frequently experiences salinity stress. Jasmonic acid (JA) is a hormone related to plant resistance to biotic and abiotic stress. Jasmonate ZIM domain proteins (JAZs) are crucial components of the JA signaling pathway and play important roles in plant responses to biotic and abiotic stress. To date, no information is available about the characteristics of the JAZ family genes in tuber mustard. Here, 38 BjJAZ genes were identified in the whole genome of tuber mustard. The BjJAZ genes are located on 17 of 18 chromosomes in the tuber mustard genome. The gene structures and protein motifs of the BjJAZ genes are conserved between tuber mustard and Arabidopsis. The results of qRT-PCR analysis showed that BjuA030800 was specifically expressed in root, and BjuA007483 was specifically expressed in leaf. In addition, 13 BjJAZ genes were transiently induced by P. brassicae at 12 h, and 7 BjJAZ genes were induced by salt stress from 12 to 24 h. These results provide valuable information for further studies on the role of BjJAZ genes in the regulation of plant growth and development and in the response to biotic and abiotic stress.


Assuntos
Genoma de Planta , Mostardeira/genética , Proteínas de Plantas/genética , Proteínas Repressoras/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Família Multigênica , Mostardeira/metabolismo , Oxilipinas/metabolismo , Filogenia , Folhas de Planta/metabolismo , Proteínas de Plantas/classificação , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Domínios Proteicos , RNA de Plantas/metabolismo , Proteínas Repressoras/classificação , Proteínas Repressoras/metabolismo , Estresse Fisiológico
14.
Ecotoxicol Environ Saf ; 201: 110735, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32480163

RESUMO

Methyl jasmonate (Me-JA) is a plant growth regulator known for modulating plant responses to various abiotic and biotic stresses. The unavoidable arsenic (As) contamination in rice (Oryza sativa) results in reduced crop yield and greater carcinogenic risk to humans. The present work examines the significance of Me-JA induced molecular signaling and tolerance towards arsenic toxicity in rice. The arsenite (AsIII; 25 µM) stress hampered the overall growth and development of the rice seedling. However, the co-application (25 µM AsIII+0.25 µM Me-JA) resulted in increased biomass, chlorophyll content, enhanced antioxidant enzyme activities as compared to AsIII treated plants. The co-application also demonstrated a marked decrease in malondialdehyde content, electrolyte leakage and accumulation of total AsIII content (root + shoot) as compared to AsIII treated plants. The co-application also modulated the expression of genes involved in downstream JA signaling pathway (OsCOI, OsJAZ3, OsMYC2), AsIII uptake (OsLsi1, OsLsi2, OsNIP1;1, OsNIP3;1), translocation (OsLsi6, and OsINT5) and detoxification (OsNRAMP1, OsPCS2, and OsABCC2) which revealed the probable adaptive response of the rice plant to cope up arsenic stress. Our findings reveal that Me-JA alleviates AsIII toxicity by modulating signaling components involved in As uptake, translocation, and detoxification and JA signaling in rice. This study augments our knowledge for the future use of Me-JA in improving tolerance against AsIII stress.


Assuntos
Acetatos/farmacologia , Arsênico/toxicidade , Ciclopentanos/farmacologia , Oryza/efeitos dos fármacos , Oxilipinas/farmacologia , Reguladores de Crescimento de Planta/farmacologia , Acetatos/metabolismo , Arsênico/metabolismo , Arsenitos/metabolismo , Arsenitos/toxicidade , Transporte Biológico , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Humanos , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estresse Fisiológico/efeitos dos fármacos
15.
Gene ; 756: 144920, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32593720

RESUMO

Basic helix-loop-helix (bHLH) transcription factors play essential roles in myriad regulatory processes, including secondary metabolism. In this study with Salvia miltiorrhiza, we isolated and characterized SmbHLH53, which encodes a bHLH family member. Expression of this gene was significantly induced by wounding and multiple hormones, including methyl jasmonic acid; transcript levels were highest in the leaves and roots. Phylogenetic analysis indicated that SmbHLH53 clusters withAtbHLH17 and AtbHLH13, two negative regulators of jasmonate (JA) responses, and is localized in the nucleus and cell membrane. Yeast two-hybrid and bimolecular fluorescent complementation assays indicated that SmbHLH53 forms a homodimer as well as a heterodimer with SmbHLH37. It also interacts with both SmJAZs1/3/8 and SmMYC2, the core members of the JA signal pathway. Unexpectedly, we noted that overexpression of SmbHLH53 did not significantly influence the concentrations of rosmarinic acid and salvianolic acid B in transgenic plants. Results from yeast one-hybrid assays showed that SmbHLH53 binds to the promoters of SmTAT1, SmPAL1, and Sm4CL9, the key genes for enzymes in the pathway for phenolic acid synthesis. Assays of transient transcriptional activity demonstrated that SmbHLH53 represses the promoter of SmTAT1 while activating the promoter of Sm4CL9. Thus, the present work revealed that SmbHLH53 may play dual roles in regulating the genes for enzymes in the pathway for Sal B biosynthesis.


Assuntos
Benzofuranos/metabolismo , Salvia miltiorrhiza/genética , Salvia miltiorrhiza/metabolismo , Transdução de Sinais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/análise , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Vias Biossintéticas , Núcleo Celular/química , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Filogenia , Proteínas de Plantas/análise , Proteínas de Plantas/metabolismo , Regiões Promotoras Genéticas , Mapas de Interação de Proteínas , Multimerização Proteica , Salvia miltiorrhiza/enzimologia , Metabolismo Secundário
16.
Artigo em Inglês | MEDLINE | ID: mdl-32278958

RESUMO

Cymbidium faberi Rolfe (Orchidaceae) is an herbaceous plant native to China, where it has a long history of cultivation owing to its beautiful flower pattern and floral fragrance. Previously, we conducted a transcriptome analysis of the flower and vegetative buds to elucidate the mechanisms of flower development in C. faberi. In the present study, we found nine secondary metabolic pathways through the KEGG pathway database that were related to the biosynthesis of methyl jasmonate (MeJA) and other volatile organic compounds. qRT-PCR was performed to analyze the expression levels of four key genes in the MeJA pathway. Among these, CfJMT (jasmonic acid carboxyl methyltransferase) had higher transcript levels in sepals, petals and labella than in other tissues. CfJMT was cloned from the petals of full-bloom flowers of C. faberi. The predicted CfJMT protein sequence contains conserved jasmonic acid methyl transferase-7 domains, indicating that it belongs to the SABATH protein family. The CfJMT coding sequence driven by the CaMV35S promoter was successfully transformed into Petunia hybrida through an Agrobacterium-mediated method. Although MeJA could not be detected in either wild-type or transgenic petunia plants, the leaves of the transgenic plants were smaller than those of wild-type plants and pollen development was abnormal. These results indicate that heterologous expression of CfJMT may change the levels of endogenous jasmonic acid and other hormones, but that the content of MeJA is not increased significantly by transformation with CfJMT alone. Thus, other related genes and regulation factors may play important roles in this process.


Assuntos
Acetatos , Ciclopentanos , Regulação da Expressão Gênica de Plantas , Orchidaceae , Oxilipinas , Petunia , Acetatos/metabolismo , China , Ciclopentanos/metabolismo , Flores/genética , Genes de Plantas/genética , Orchidaceae/genética , Orchidaceae/metabolismo , Oxilipinas/metabolismo , Petunia/genética , Petunia/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-32305819

RESUMO

The biotrophic fungus Phakopsora pachyrhizi is currently the major pathogen affecting soybean production worldwide. It has already been suggested for the non-host interaction between P. pachyrhizi and Arabidopsis thaliana that the fungus in early infection induces jasmonic acid (JA) pathway to the detriment of the salicylic acid (SA) pathway as a mechanism to the establishment of infection. In this study, we verified that this mechanism might also be occurring during the compatible interaction in soybean (Glycine max L. Merril). It was demonstrated that P. pachyrhizi triggers a JA pathway during the early and late stages of infection in a susceptible soybean cultivar. The expression of the GmbZIP89 was induced in a biphasic profile, similarly to other JA responsive genes, which indicates a new marker gene for this signaling pathway. Additionally, plants silenced for GmbZIP89 (iGmZIP89) by the virus-induced gene silencing (VIGS) approach present lower severity of infection and higher expression of pathogenesis related protein 1 (PR1). The lower disease severity showed that the iGmbZIP89 plants became more resistant to infection. These data corroborate the hypothesis that the GmbZIP89 may be a resistance negative regulator. In conclusion, we demonstrated that P. pachyrhizi mimics a necrotrophic fungus and activates the JA/ET pathway in soybean. It is possible to suppose that its direct penetration on epidermal cells or fungal effectors may modulate the expression of target genes aiming the activation of the JA pathway and inhibition of SA defense.


Assuntos
Ciclopentanos , Interações Hospedeiro-Patógeno , Oxilipinas , Phakopsora pachyrhizi , Transdução de Sinais , Soja , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Interações Hospedeiro-Patógeno/fisiologia , Oxilipinas/metabolismo , Phakopsora pachyrhizi/fisiologia , Doenças das Plantas/microbiologia , Soja/microbiologia
18.
Plant Mol Biol ; 103(4-5): 489-505, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32306368

RESUMO

KEY MESSAGE: Cucumber plants adapt their transcriptome and metabolome as result of spider mite infestation with opposite consequences for direct and indirect defences in two genotypes. Plants respond to arthropod attack with the rearrangement of their transcriptome which lead to subsequent phenotypic changes in the plants' metabolome. Here, we analysed transcriptomic and metabolite responses of two cucumber (Cucumis sativus) genotypes to chelicerate spider mites (Tetranychus urticae) during the first 3 days of infestation. Genes associated with the metabolism of jasmonates, phenylpropanoids, terpenoids and L-phenylalanine were most strongly upregulated. Also, genes involved in the biosynthesis of precursors for indirect defence-related terpenoids were upregulated while those involved in the biosynthesis of direct defence-related cucurbitacin C were downregulated. Consistent with the observed transcriptional changes, terpenoid emission increased and cucurbitacin C content decreased during early spider-mite herbivory. To further study the regulatory network that underlies induced defence to spider mites, differentially expressed genes that encode transcription factors (TFs) were analysed. Correlation analysis of the expression of TF genes with metabolism-associated genes resulted in putative identification of regulators of herbivore-induced terpenoid, green-leaf volatiles and cucurbitacin biosynthesis. Our data provide a global image of the transcriptional changes in cucumber leaves in response to spider-mite herbivory and that of metabolites that are potentially involved in the regulation of induced direct and indirect defences against spider-mite herbivory.


Assuntos
Cucumis sativus/imunologia , Cucumis sativus/metabolismo , Metaboloma , Infestações por Ácaros/imunologia , Infestações por Ácaros/metabolismo , Tetranychidae , Transcriptoma , Animais , Vias Biossintéticas/genética , Cucumis sativus/genética , Cucumis sativus/parasitologia , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Genoma de Planta , Genótipo , Herbivoria , Oxilipinas/metabolismo , Fenilalanina/metabolismo , Fenilpropionatos/metabolismo , Doenças das Plantas , Folhas de Planta/metabolismo , Metabolismo Secundário/genética , Terpenos/metabolismo , Fatores de Transcrição/genética , Triterpenos/metabolismo , Compostos Orgânicos Voláteis/metabolismo
19.
Proc Natl Acad Sci U S A ; 117(11): 6205-6215, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123086

RESUMO

The jasmonate (JA)-pathway regulators MYC2, MYC3, and MYC4 are central nodes in plant signaling networks integrating environmental and developmental signals to fine-tune JA defenses and plant growth. Continuous activation of MYC activity is potentially lethal. Hence, MYCs need to be tightly regulated in order to optimize plant fitness. Among the increasing number of mechanisms regulating MYC activity, protein stability is arising as a major player. However, how the levels of MYC proteins are modulated is still poorly understood. Here, we report that MYC2, MYC3, and MYC4 are targets of BPM (BTB/POZ-MATH) proteins, which act as substrate adaptors of CUL3-based E3 ubiquitin ligases. Reduction of function of CUL3BPM in amiR-bpm lines, bpm235 triple mutants, and cul3ab double mutants enhances MYC2 and MYC3 stability and accumulation and potentiates plant responses to JA such as root-growth inhibition and MYC-regulated gene expression. Moreover, MYC3 polyubiquitination levels are reduced in amiR-bpm lines. BPM3 protein is stabilized by JA, suggesting a negative feedback regulatory mechanism to control MYC activity, avoiding harmful runaway responses. Our results uncover a layer for JA-pathway regulation by CUL3BPM-mediated degradation of MYC transcription factors.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas Culina/metabolismo , Ciclopentanos/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Oxilipinas/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Proteínas Culina/genética , Retroalimentação Fisiológica , Mutação , Raízes de Plantas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Estabilidade Proteica , Proteólise , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transativadores/genética , Transativadores/metabolismo , Ubiquitinação/fisiologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-32179469

RESUMO

Drought is a major threat in agriculture and horticulture, including commercial strawberry production. Here, we compare hormonal regulation of a first-line drought stress response, namely stomatal closure, in two Fragaria x ananassa cultivars, known to differ in their drought stress phenotype. We show that the observed difference in xylem abscisic acid accumulation cannot explain the different stomatal responses under osmotic stress. Foliar abscisic acid accumulation cannot fully account for the stomatal behavior in one of both cultivars either. An indirect effect of abscisic acid on stomatal conductance via an impact on leaf hydraulic conductance, possibly mediated via aquaporins, as is recently proposed in literature, was not observed here. Next, we show that these two cultivars respond differently to jasmonic acid and one of its precursors. This difference in sensitivity of the jasmonates pathway between both cultivars may partly explain the different stomatal response. This study contributes to the understanding of the regulation of an important drought stress response in an economically important crop prone to water deficit stress.


Assuntos
Ácido Abscísico/metabolismo , Ciclopentanos/metabolismo , Fragaria/fisiologia , Pressão Osmótica , Oxilipinas/metabolismo , Estômatos de Plantas/fisiologia , Secas , Transpiração Vegetal , Água
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