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1.
Mol Plant Microbe Interact ; 32(10): 1391-1401, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31408392

RESUMO

Salicylic acid (SA) is closely related to disease resistance of plants. WRKY transcription factors have been linked to the growth and development of plants, especially under stress conditions. However, the regulatory mechanism of WRKY proteins involved in SA production and disease resistance in apple is not clear. In this study, MdPBS3.1 responded to Botryosphaeria dothidea and enhanced resistance to B. dothidea. Electrophoretic mobility shift assays, yeast one-hybrid assays, and chromatin immunoprecipitation and quantitative PCR demonstrated that MdWRKY46 can directly bind to a W-box motif in the promoter of MdPBS3.1. Glucuronidase transactivation and luciferase analysis further showed that MdWRKY46 can activate the expression of MdPBS3.1. Finally, B. dothidea inoculation in transgenic apple calli and fruits revealed that MdWRKY46 improved resistance to B. dothidea by the transcriptional activation of MdPBS3.1. Viral vector-based transformation assays indicated that MdWRKY46 elevates SA content and transcription of SA-related genes, including MdPR1, MdPR5, and MdNPR1 in an MdPBS3.1-dependent way. These findings provide new insights into how MdWRKY46 regulates plant resistance to B. dothidea through the SA signaling pathway.


Assuntos
Ascomicetos , Resistência à Doença , Regulação da Expressão Gênica de Plantas , Malus , Proteínas de Plantas , Transdução de Sinais , Ascomicetos/fisiologia , Resistência à Doença/genética , Malus/genética , Malus/microbiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Ácido Salicílico/metabolismo , Transdução de Sinais/genética
2.
Plant Sci ; 285: 200-213, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203885

RESUMO

NONRACE-SPECIFIC DISEASE RESISTANCE (NDR1) is a widely characterized gene that plays a key role in defense against multiple bacterial, fungal, oomycete and nematode plant pathogens. NDR1 is required for activation of resistance by multiple NB and LRR-containing (NLR) protein immune sensors and contributes to basal defense. The role of NDR1 in positively regulating salicylic acid (SA)-mediated plant defense responses is well documented. However, ndr1-1 plants flower earlier and show accelerated development in comparison to wild type (WT) Arabidopsis plants, indicating that NDR1 is a negative regulator of flowering and growth. Exogenous application of gibberellic acid (GA) further accelerates the early flowering phenotype in ndr1-1 plants, while the GA biosynthesis inhibitor paclobutrazol attenuated the early flowering phenotype of ndr1-1, but not to WT levels, suggesting partial resistance to paclobutrazol and enhanced GA response in ndr1-1 plants. Mass spectroscopy analyses confirmed that ndr1-1 plants have 30-40% higher levels of GA3 and GA4, while expression of various GA metabolic genes and major flowering regulatory genes is also altered in the ndr1-1 mutant. Taken together this study provides evidence of crosstalk between the ndr1-1-mediated defense and GA-regulated developmental programs in plants.


Assuntos
Arabidopsis/genética , Flores/crescimento & desenvolvimento , Giberelinas/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Proteínas de Arabidopsis/fisiologia , Resistência à Doença/genética , Resistência à Doença/fisiologia , Giberelinas/metabolismo , Mutação/genética , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Ácido Salicílico/metabolismo , Fatores de Transcrição/fisiologia , Transcriptoma , Verticillium
3.
Chemosphere ; 232: 70-75, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31152905

RESUMO

Polycyclic aromatic hydrocarbons are an important group of pollutants that are widely distributed in the environment. The present study aimed to investigate the effect of salicylic acid (a phenolic phytohormone) and mycorrhizal fungi on the growth and phytoremediation ability of tall fescue in the soil contaminated by fluoranthene. The initial concentrations of fluoranthene in this study were 100, 200, and 300 mg kg-1. The experimental treatments were included: T0 uncultivated soil; T1 cultivated soil with tall fescue; T2 cultivated soil with tall fescue + salicylic acid application; T3 cultivated soil with tall fescue + application of mycorrhizal fungi; T4 cultivated soil with tall fescue + salicylic acid and mycorrhizal fungi application; and P planting tall fescue in uncontaminated soil. The removal of fluoranthene was measured after 90 days. Furthermore, at the end of the experiment, the amount of shoot and root biomass, soil bacteria, and dehydrogenase activity were measured. According to the results, in all levels of contamination, removal of fluoranthene in cultivated treatments significantly was higher than uncultivated treatments. Increasing the concentration of fluoranthene had a negative effect on the shoot and root biomass in different treatments. Salicylic acid and mycorrhizal fungi significantly increased the shoot and root biomass and also the number of soil bacteria, dehydrogenase activity, and fluoranthene removal in T2, T3, and T4 treatments compared to T1. At the highest concentration of fluoranthene, as a result of simultaneous application of salicylic acid and mycorrhizal fungi (T4), the fluoranthene removal increased by 63, 21, 13, and 16% in comparison with T0, T1, T2, and T3, respectively. Based on the results, salicylic acid and mycorrhizal fungi, either alone or in combination, have a significant effect on the improvement of phytoremediation potential in tall fescue.


Assuntos
Biodegradação Ambiental , Festuca/metabolismo , Micorrizas/fisiologia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Ácido Salicílico/metabolismo , Poluentes do Solo/metabolismo , Biomassa , Festuca/microbiologia , Fluorenos , Reguladores de Crescimento de Planta , Raízes de Plantas/crescimento & desenvolvimento , Solo , Microbiologia do Solo , Simbiose
4.
Int J Mol Sci ; 20(12)2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31216620

RESUMO

Salicylic acid (SA), as an enigmatic signalling molecule in plants, has been intensively studied to elucidate its role in defence against biotic and abiotic stresses. This review focuses on recent research on the role of the SA signalling pathway in regulating cadmium (Cd) tolerance in plants under various SA exposure methods, including pre-soaking, hydroponic exposure, and spraying. Pretreatment with appropriate levels of SA showed a mitigating effect on Cd damage, whereas an excessive dose of exogenous SA aggravated the toxic effects of Cd. SA signalling mechanisms are mainly associated with modification of reactive oxygen species (ROS) levels in plant tissues. Then, ROS, as second messengers, regulate a series of physiological and genetic adaptive responses, including remodelling cell wall construction, balancing the uptake of Cd and other ions, refining the antioxidant defence system, and regulating photosynthesis, glutathione synthesis and senescence. These findings together elucidate the expanding role of SA in phytotoxicology.


Assuntos
Cádmio/toxicidade , Resistência à Doença , Doenças das Plantas/etiologia , Plantas/efeitos dos fármacos , Plantas/metabolismo , Ácido Salicílico/metabolismo , Transdução de Sinais , Adaptação Biológica , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Cádmio/metabolismo , Fotossíntese/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Espécies Reativas de Oxigênio/metabolismo , Ácido Salicílico/farmacologia , Estresse Fisiológico
5.
J Agric Food Chem ; 67(24): 6716-6724, 2019 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-31135151

RESUMO

Insect attack is known to induce a high accumulation of volatile metabolites in tea ( Camellia sinensis). However, little information is available concerning the effect of insect attack on tea quality-related nonvolatile specialized metabolites. This study aimed to investigate the formation of characteristic nonvolatile specialized metabolites in tea leaves in response to attack by major tea insects, namely, tea green leafhoppers and tea geometrids, and determine the possible involvement of phytohormones in metabolite formation resulting from insect attack. Both tea green leafhopper and tea geometrid attacks increased the jasmonic acid and salicylic acid contents. The abscisic acid content was only increased under tea green leafhopper attack, perhaps due to special continuous piercing-sucking wounding. Tea green leafhopper attack induced the formation of theaflavins from catechins under the action of polyphenol oxidase, while tea geometrid attack increased the l-theanine content. Exogenous phytohormone treatments can affect the caffeine and catechin contents. These results will help to determine the influence of major tea pest insects on important tea quality-related metabolites and enhance understanding of the relationship of phytohormones and quality-related nonvolatile metabolite formation in tea exposed to tea pest insect attacks.


Assuntos
Camellia sinensis/metabolismo , Hemípteros/fisiologia , Folhas de Planta/química , Folhas de Planta/parasitologia , Animais , Biflavonoides/análise , Biflavonoides/metabolismo , Camellia sinensis/química , Camellia sinensis/parasitologia , Catequina/análise , Catequina/metabolismo , Ciclopentanos/análise , Ciclopentanos/metabolismo , Glutamatos/análise , Glutamatos/metabolismo , Oxilipinas/análise , Oxilipinas/metabolismo , Reguladores de Crescimento de Planta/química , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/metabolismo , Ácido Salicílico/análise , Ácido Salicílico/metabolismo
6.
J Plant Physiol ; 238: 40-52, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31129470

RESUMO

Plant viral infections alter gene expression and metabolism in infected host. To study the molecular responses of Mexican lime to CTV infection, an analysis of plant metabolome in response to infection with severe (T318) or mild (T385) isolates of CTV was performed. Healthy plants and those infected with any of the two virus strains showed different metabolite profiles, at different stages of new sprout development. Proline content increased in plants infected with CTV, proportionally to the virulence of the virus strain. Abscisic acid content decreased after virus infection whereas jasmonic and salicylic acid levels increased. CTV infection had an impact on plant secondary metabolism, by stimulating the synthesis of different metabolites such as l-methylhistidine, phenylpropanoid derivatives. These metabolites are common responses of different organisms, including higher mammals, to viral diseases, and its presence in this system points to the existence of universal responses to virus infection among different kingdoms.


Assuntos
Citrus aurantiifolia/virologia , Closterovirus , Doenças das Plantas/virologia , Reguladores de Crescimento de Planta/metabolismo , Citrus aurantiifolia/metabolismo , Citrus aurantiifolia/fisiologia , Ciclopentanos/metabolismo , Espectrometria de Massas , Metabolômica , Oxilipinas/metabolismo , Prolina/metabolismo , Ácido Salicílico/metabolismo
7.
Ecotoxicol Environ Saf ; 180: 374-383, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31102845

RESUMO

Ozone (O3) can cause oxidative stress in plants and humans. Catechin is an antioxidant that enriches tea and can probably increase O3 tolerance in plants. To investigate the mechanism of catechin to alleviate O3 stress in plants, Zamiocalcus zamiifolia (an efficient plant for O3 phytoremediation) was sprayed with 5 mM catechin and was used to expose O3 (150-250) under long-term operation (10 cycles). We investigated whether exogenous catechin could enhance O3 removal and alleviate O3 stress through a balanced redox state in plants. Z. zamiifolia sprayed with catechin exhibited higher O3 removal (80.27±3.12%), than Z. zamiifolia without catechin (50.03±2.68%). O3 in the range of 150-250 ppb led to stress in plants, as shown by an increased malondialdehyde content (MDA) and salicylic acid (SA). Whereas under the presence of O3, exogenous catechin could maintain the MDA content and inhibit SA accumulation. Under Z. zamiifolia+catechin+O3 conditions, catechin reacted with O3, which led to the formation of catechin-quinone. The formation of catechin-quinone was confirmed by the depletion of reduced glutathione content (GSH). This catechin-quinone could induce GST and APX genes that are up-regulated approximately 35- and 5-fold, respectively. Hence, Z. zamiifolia+catechin+O3 conditions had higher performance for coping with oxidative stress than did Z. zamiifolia+O3 conditions. This evidence demonstrates that catechin could enhance O3 removal through a balanced redox state in plant cells. Finally, the application of tea extract for enhanced O3 removal is also shown in this study.


Assuntos
Poluentes Atmosféricos/toxicidade , Antioxidantes/metabolismo , Araceae/efeitos dos fármacos , Catequina/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ozônio/toxicidade , Araceae/enzimologia , Araceae/metabolismo , Benzoquinonas/metabolismo , Biodegradação Ambiental , Clorofila/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Malondialdeído/metabolismo , Oxirredução , Ácido Salicílico/metabolismo
8.
Int J Mol Sci ; 20(10)2019 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-31108845

RESUMO

Anthracnose is a major leaf disease in tea plant induced by Colletotrichum, which has led to substantial losses in yield and quality of tea. The molecular mechanism with regards to responses or resistance to anthracnose in tea remains unclear. A de novo transcriptome assembly dataset was generated from healthy and anthracnose-infected leaves on tea cultivars "Longjing-43" (LJ43) and "Zhenong-139" (ZN139), with 381.52 million pair-end reads, encompassing 47.78 billion bases. The unigenes were annotated versus Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), National Center for Biotechnology Information (NCBI) non-redundant protein sequences (Nr), evolutionary genealogy of genes: Non-supervised Orthologous Groups (eggNOG) and Swiss-prot. The number of differential expression genes (DEGs) detected between healthy and infected leaves was 1621 in LJ43 and 3089 in ZN139. The GO and KEGG enrichment analysis revealed that the DEGs were highly enriched in catalytic activity, oxidation-reduction, cell-wall reinforcement, plant hormone signal transduction and plant-pathogen interaction. Further studies by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and high-performance liquid chromatography (HPLC) showed that expression of genes involved in endogenous salicylic acid biosynthesis and also accumulation of foliar salicylic acid are involved in the response of tea plant to anthracnose infection. This study firstly provided novel insight in salicylic acid acting as a key compound in the responses of tea plant to anthracnose disease. The transcriptome dataset in this study will facilitate to profile gene expression and metabolic networks associated with tea plant immunity against anthracnose.


Assuntos
Camellia sinensis/genética , Colletotrichum/patogenicidade , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Camellia sinensis/metabolismo , Camellia sinensis/microbiologia , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Sequenciamento de Nucleotídeos em Larga Escala , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Proteínas de Plantas/genética , Ácido Salicílico/metabolismo
9.
Int J Mol Sci ; 20(10)2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31126102

RESUMO

The RNA silencing pathways modulate responses to certain stresses, and can be partially tuned by several hormones such as salicylic acid (SA) and abscisic acid (ABA). Although SA and ABA are often antagonistic and often modulate different stress responses, they have similar effects on virus resistance, which are partially achieved through the antiviral RNA silencing pathway. Whether they play similar roles in regulating the RNA silencing pathway is unclear. By employing coexpression and promoter analyses, we found that some ABA- and SA-related transcription factors (TFs) are coexpressed with several AGO, DCL, and RDR genes, and have multiple binding sites for the identified TFs in the queried promoters. ABA and SA are antagonistic with respect to the expression of AGO1 and RDRs because ABA was able to induce these genes only in the SA mutant. Nevertheless, both hormones showed similarities in the regulation of other genes, for example, the induction of AGO2 by ABA was SA-dependent, indicating that ABA acts upstream of SA in this regulation. We inferred that the similar effects of ABA and SA on some genes resulted in the redundancy of their roles in resistance to bamboo mosaic virus, but that the two hormones are antagonistic with respect to other genes unrelated to their biosynthesis pathways.


Assuntos
Ácido Abscísico/metabolismo , Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/genética , Ácido Salicílico/metabolismo , Arabidopsis/virologia , Doenças das Plantas/virologia , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Potexvirus/genética , Interferência de RNA , RNA Viral/genética , Fatores de Transcrição/genética
10.
Plant Mol Biol ; 101(1-2): 21-40, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31049793

RESUMO

KEY MESSAGE: Arabidopsis thaliana mlo3 mutant plants are not affected in pathogen infection phenotypes but-reminiscent of mlo2 mutant plants-exhibit spontaneous callose deposition and signs of early leaf senescence. The family of Mildew resistance Locus O (MLO) proteins is best known for its profound effect on the outcome of powdery mildew infections: when the appropriate MLO protein is absent, the plant is fully resistant to otherwise virulent powdery mildew fungi. However, most members of the MLO protein family remain functionally unexplored. Here, we investigate Arabidopsis thaliana MLO3, the closest relative of AtMLO2, AtMLO6 and AtMLO12, which are the Arabidopsis MLO genes implicated in the powdery mildew interaction. The co-expression network of AtMLO3 suggests association of the gene with plant defense-related processes such as salicylic acid homeostasis. Our extensive analysis shows that mlo3 mutants are unaffected regarding their infection phenotype upon challenge with the powdery mildew fungi Golovinomyces orontii and Erysiphe pisi, the oomycete Hyaloperonospora arabidopsidis, and the bacterial pathogen Pseudomonas syringae (the latter both in terms of basal and systemic acquired resistance), indicating that the protein does not play a major role in the response to any of these pathogens. However, mlo3 genotypes display spontaneous callose deposition as well as signs of early senescence in 6- or 7-week-old rosette leaves in the absence of any pathogen challenge, a phenotype that is reminiscent of mlo2 mutant plants. We hypothesize that de-regulated callose deposition in mlo3 genotypes might be the result of a subtle transient aberration of salicylic acid-jasmonic acid homeostasis during development.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Ligação a Calmodulina/metabolismo , Resistência à Doença/genética , Glucanos/metabolismo , Doenças das Plantas/imunologia , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Ascomicetos/fisiologia , Proteínas de Ligação a Calmodulina/genética , Ciclopentanos/metabolismo , Genótipo , Homeostase , Mutação , Oomicetos/fisiologia , Oxilipinas/metabolismo , Fenótipo , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/genética , Folhas de Planta/fisiologia , Pseudomonas syringae/fisiologia , Ácido Salicílico/metabolismo
11.
Plant Physiol Biochem ; 141: 83-94, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31136934

RESUMO

Fusarium wilt caused by Fusarium oxysporum f. sp. cubense (Foc), is one of the most devastating diseases in bananas resulting in significant loss of Cavendish bananas production worldwide. Here we show the agronomic traits and the resistance of 'Guijiao 9' in the field trials from 2012 to 2017. And then we dissect and compare the transcriptome response from these two cultivars (cv. 'Guijiao 9' and cv. Williams) in an attempt to understand the molecular basis that contribute to the enhanced Foc tropical race 4 (Foc-TR4) resistance. 'Guijiao 9' is a Cavendish cultivar with strong resistance to Foc-TR4, which was reflected in a lower disease severity and incidence in glasshouse and field trails, when compared to the susceptible cultivar Williams. Gene expression profiles of 'Guijiao 9' and Williams were captured by performing RNA-Seq analysis on 16 biological samples collected over a six day period post inoculation with Foc-TR4. Transcriptional reprogramming in response to Foc-TR4 was detected in both genotypes but the response was more drastic in 'Guijiao 9' than in Williams. Specific genes involved in plant-pathogen interaction and defense signaling including MAPK, calcium, salicylic acid, jasmonic acid and ethylene pathways were analyzed and compared between 'Guijiao 9' and Williams. Genes associated with defense-related metabolites synthesis such as NB-LRR proteins, calmodulin-binding protein and phenylpropanoids biosynthesis genes were significantly up-regulated in 'Guijiao 9' resistant to Foc-TR4 infection. Taken together, this study highlights the important roles of plant hormone regulation and defense gene activation in mediating resistance in 'Guijiao 9'.


Assuntos
Resistência à Doença/genética , Fusarium/patogenicidade , Regulação da Expressão Gênica de Plantas , Musa/genética , Doenças das Plantas/genética , DNA Complementar/genética , Bases de Dados Genéticas , Perfilação da Expressão Gênica , Biblioteca Gênica , Genes de Plantas , Musa/microbiologia , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Raízes de Plantas/genética , Ácido Salicílico/metabolismo , Metabolismo Secundário , Especificidade da Espécie , Transcrição Genética , Transcriptoma , Regulação para Cima
12.
Phytopathology ; 109(6): 942-951, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31066346

RESUMO

Cri-9402 was identified as a protein effector from Cronartium ribicola, based on the effect of its expression on growth of Pseudomonas syringae Psm ES4326 introduced into transiently transformed tobacco leaves and stably transformed Arabidopsis seedlings. In tobacco leaves transiently expressing its coding sequence, growth of P. syringae Psm ES4326 was inhibited. Expression of pathogenesis-related (PR) protein 2 (PR2), PR4a, endochitinase B, hypersensitive-related 201 (HSR201), HSR203J, and proteinase inhibitor 1 was upregulated but expression of PR1, coronatine insensitive 1, and abscisic acid 1 was significantly suppressed. In transformed Arabidopsis seedlings, the effector stimulated growth of P. syringae Psm ES4326; significantly suppressed expression of PR1, PR2, nonexpresser of pathogenesis-related genes 1 (NPR1), NPR3, NPR4, phytoalexin deficient 4, and salicylic acid induction deficient 2; and enhanced expression of plant defensin 1.2 (PDF1.2). The above results showed that the majority of responses to this effector in tobacco leaves were converse to those in transformed Arabidopsis. We could conclude that Cri-9402 promoted disease resistance in tobacco leaves and disease susceptibility in Arabidopsis seedlings. Its transcript was mainly expressed in aeciospores of C. ribicola and was probably involved in production or germination of aeciospores, and it was an effector potentially functioning in white pine-blister rust interactions.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Basidiomycota , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/microbiologia , Proteínas de Plantas/genética , Pseudomonas syringae , Ácido Salicílico/metabolismo
13.
Plant Sci ; 283: 266-277, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31128697

RESUMO

Hormones play an important role in fruit ripening and in response to biotic stress. Nevertheless, analyses of hormonal profiling during plant development and defense are scarce. In this work, changes in hormonal metabolism in grapevine (Vitis vinifera) were compared between a susceptible (Trincadeira) and a tolerant (Syrah) variety during grape ripening and upon infection with Botrytis cinerea. Infection of grapes with the necrotrophic pathogen Botrytis cinerea leads to significant economic losses worldwide. Peppercorn-sized fruits were infected in the field and mock-treated and infected berries were collected at green, veraison and harvest stages for hormone analysis and targeted qPCR analysis of genes involved in hormonal metabolism and signaling. Results indicate a substantial reprogramming of hormonal metabolism during grape ripening and in response to fungal attack. Syrah and Trincadeira presented differences in the metabolism of abscisic acid (ABA), indole-3-acetic acid (IAA) and jasmonates during grape ripening that may be connected to fruit quality. On the other hand, high basal levels of salicylic acid (SA), jasmonates and IAA at an early stage of ripening, together with activated SA, jasmonates and IAA signaling, likely enable a fast defense response leading to grape resistance/ tolerance towards B. cinerea. The balance among the different phytohormones seems to depend on the ripening stage and on the intra-specific genetic background and may be fundamental in providing resistance or susceptibility. In addition, this study indicated the involvement of SA and IAA in defense against necrotrophic pathogens and gains insights into possible strategies for conventional breeding and/or gene editing aiming at improving grape quality and grape resistance against Botrytis cinerea.


Assuntos
Ácido Abscísico/metabolismo , Botrytis/metabolismo , Ciclopentanos/metabolismo , Ácidos Indolacéticos/metabolismo , Oxilipinas/metabolismo , Doenças das Plantas/microbiologia , Reguladores de Crescimento de Planta/metabolismo , Ácido Salicílico/metabolismo , Vitis/metabolismo , Ácido Abscísico/fisiologia , Antocianinas/metabolismo , Reguladores de Crescimento de Planta/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Especificidade da Espécie , Vitis/crescimento & desenvolvimento , Vitis/microbiologia
14.
Plant Sci ; 284: 127-134, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31084865

RESUMO

Avr9/Cf-9-INDUCED F-BOX1 (ACIF1) was first identified during screening of Avr9/Cf-9-elicited genes in tobacco. Further analysis revealed that ACIF1 was required for hypersensitive responses triggered by various elicitors in tobacco and tomato, indicating that it may be involved in various disease resistance. Here, we cloned its cotton (Gossypium hirsutum) homolog GhACIF1, which encodes an F-box protein. We show that GhACIF1 interacts with the putative SKP1-like protein, named GhSKP1. Disease resistance assays show that GhACIF1 enhances resistance to Verticillium dahliae in Arabidopsis plants, while silencing of GhACIF1 confers sensitivity to V. dahliae in cotton. Further analysis show that PevD1 elicitor activates hypersensitive and acquired immune response mediated by GhACIF1. Collectively, these results indicate that GhACIF1 contributes to protection against V. dahliae infection.


Assuntos
Resistência à Doença , Proteínas F-Box/fisiologia , Gossypium/imunologia , Doenças das Plantas/microbiologia , Proteínas de Plantas/fisiologia , Verticillium , Resistência à Doença/fisiologia , Proteínas F-Box/genética , Inativação Gênica , Gossypium/genética , Gossypium/microbiologia , Doenças das Plantas/imunologia , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/genética , Ácido Salicílico/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Técnicas do Sistema de Duplo-Híbrido , Verticillium/metabolismo
15.
BMC Plant Biol ; 19(1): 173, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-31046667

RESUMO

BACKGROUND: In higher plants, salicylic acid (SA) plays important roles in inducing resistance to biotic and abiotic stresses. Tomato yellow leaf curl virus (TYLCV) causes a highly devastating viral disease in plants, particularly in tomato. However, the roles of SA in inducing tomato plant resistance to TYLCV remain unclear. RESULTS: In this study, we investigated whether the exogenous application of SA can improve the resistance of tomato plants to TYLCV in two tomato cultivars, resistant 'Zhefen-702' and susceptible 'Jinpeng-1'. The impacts of SA on the accumulation of ascorbic acid (AsA) and biosynthetic gene expression, the activity of some important reactive oxygen species (ROS)-scavenging enzymes, and the expression patterns of stress-related genes were also determined. Results indicated that SA can effectively regulate the accumulation of AsA, especially in 'Jinpeng-1'. Similarly, the expression patterns of most of the AsA biosynthetic genes showed a negative relationship with AsA accumulation in the resistant and susceptible tomato cultivars. In the two tomato cultivars, the activities of ascorbate peroxidase (APX) and peroxidase (POD) in the SA + TYLCV treated plants were increased during the experiment period except at 14 days (APX in 'Jinpeng-1' was also at 4 days) post infected (dpi) with TYLCV. Simultaneously, the activity of SOD was reduced in 'Jinpeng-1' and increased in 'Zhefen-702' after treatment with SA + TYLCV. SA can substantially induce the expression of ROS-scavenging genes at different extents. From 2 to 10 dpi, the virus content in the SA + TYLCV treated plants was remarkably lower than those in the TYLCV treated plants in 'Jinpeng-1'and Zhefen-702'. CONCLUSIONS: The above results suggest that SA can enhance tomato plant resistance by modulating the expression of genes encoding for ROS-scavenging players, altering the activity of resistance-related enzymes, and inducing the expression of pathogenesis-related genes to produce systemic acquired resistance. Simultaneously, these results confirm that SA is a resistance-inducing factor against TYLCV infection that can be effectively applied in tomato plants.


Assuntos
Begomovirus , Doenças das Plantas/virologia , Ácido Salicílico/metabolismo , Resistência à Doença , Suscetibilidade a Doenças , Doenças das Plantas/genética
16.
Environ Sci Pollut Res Int ; 26(19): 19705-19718, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31089999

RESUMO

Leaf blast is the main rice disease in the world causing significant losses in productivity. Blast integrate management (BIM) requires the use of genetic resistance, cultural practices, and chemical control, although for sustainable BIM, the insertion of biological agents may be the fourth component for. The objective of this work was to test three formulations of Burkholderia pyrrocinia (BRM32113) previously selected and to verify the effectiveness in resistance induction and blast control in rice. Two experiments were carried out, in a completely randomized design with three replications, in the greenhouse (E1 and E2). E1 aimed to select the best treatment for suppressing leaf blast severity and activating plant defense mechanisms. It was composed of 8 treatments: (1) formulated 11+ B. pyrrocina × Magnaporthe oryzae; (2) formulated 17+ B. pyrrocina × M. oryzae; (3) formulated 32+ B. pyrrocina × M. oryzae; (4) formulated 11 × M. oryzae; (5) B. pyrrocinia 17 × M. oryzae; (6) formulated 32 × M. oryzae; (7) B. pyrrocina × M. oryzae; (8) M. oryzae; (9) control (water). E2 aimed to investigate the effect of the best treatments, for the promotion of plant growth and suppression of leaf blast by calculating AUDPC. It was composed of 6 treatments: (1) formulated 11+ B. pyrrocina × M. oryzae; (2) formulated 32+ B. pyrrocina × M. oryzae; (3) formulated 11 × M. oryzae; (4) formulated 32 × M. oryzae; (5) B. pyrrocina × M. oryzae; (6) water. And after, we did two assays aimed to localize this biological agent after application at seed, soil, and rice plant. In E1, formulated 11+ B. pyrrocinia and 32+ formulated and B. pyrrocina were the best, suppressing leaf blast by up to 97% and providing the significant increase of the enzymes ß-1,3-glucanase, chitinase, phenylalanine ammonia lyase, lipoxygenase, and salicylic acid at 24 h and 48 h after inoculation with M. oryzae. In E2, treatments formulated 11+ B. pyrrocinia, formulated 32+ B. pyrrocinia, and B. pyrrocina provided more significant increases in growth promotion and reduced area under disease progress curve. B. pyrrocinia was detected in the rice plant for 18 days, predominantly in the root system (internal and external). The use of B. pyrrocinia formulations based on sugarcane molasses and glycerol can be an essential strategy for sustainable management. Although all the benefits come from these sustainable formulations, the adoption by commercial biological segment depends on an established formulation process. It seems that all the results showed here by this research will be readily assimilated by startups of the organic segment.


Assuntos
Agentes de Controle Biológico/farmacologia , Burkholderia , Resistência à Doença/efeitos dos fármacos , Magnaporthe , Oryza/microbiologia , Doenças das Plantas/prevenção & controle , Agentes de Controle Biológico/isolamento & purificação , Burkholderia/metabolismo , Magnaporthe/crescimento & desenvolvimento , Oryza/enzimologia , Doenças das Plantas/microbiologia , Folhas de Planta/enzimologia , Folhas de Planta/microbiologia , Distribuição Aleatória , Ácido Salicílico/metabolismo
17.
Phytopathology ; 109(8): 1367-1377, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30990377

RESUMO

Polyamines (PAs) are ubiquitous aliphatic amines that play important roles in growth, development, and environmental stress responses in plants. In this study, we report that exogenous application of spermine (Spm) is effective in the induction of resistance to gray mold disease, which is caused by the necrotrophic fungal pathogen Botrytis cinerea, on tomato (Solanum lycopersicum), bean (Phaseolus vulgaris), and Arabidopsis thaliana. High throughput transcriptome analysis revealed a priming role for the Spm molecule in the genus Arabidopsis, resulting in strong upregulation of several important defense-associated genes, particularly those involved in systemic-acquired resistance. Microscopic analysis confirmed that Spm application potentiates endogenous defense responses in tomato leaves through the generation of reactive oxygen species and the hypersensitive response, which effectively contained B. cinerea growth within the inoculated area. Moreover, co-application of Spm and salicylic acid resulted in a synergistic effect against the pathogen, leading to higher levels of resistance than those induced by separate applications of the two compounds. The Spm plus salicylic acid treatment also reduced infection in systemic nontreated leaves of tomato plants. Our findings suggest that Spm, particularly when applied in combination with salicylic acid, functions as a potent plant defense activator that leads to effective local and systemic resistance against B. cinerea.


Assuntos
Arabidopsis , Botrytis/patogenicidade , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lycopersicon esculentum , Phaseolus , Espermina/farmacologia , Resistência à Doença , Lycopersicon esculentum/microbiologia , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo
18.
Mol Plant Microbe Interact ; 32(9): 1243-1255, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31025899

RESUMO

Plants encounter beneficial and detrimental microorganisms both above- and belowground and the health status of the plant depends on the composition of this pan-microbiome. Beneficial microorganisms contribute to plant nutrition or systemically or locally protect plants against pathogens, thus facilitating adaptation to a variety of environments. Induced systemic resistance, caused by root-associated microbes, manifests as aboveground resistance against necrotrophic pathogens and is mediated by jasmonic acid/ethylene-dependent signaling. By contrast, systemic acquired resistance relies on salicylic acid (SA) signaling and confers resistance against secondary infection by (hemi)biotrophic pathogens. To investigate whether symbiotic rhizobia that are ubiquitously found in natural ecosystems are able to modulate resistance against biotrophs, we tested the impact of preestablished nodulation of Medicago truncatula and pea (Pisum sativum) plants against infection by the powdery mildew fungus Erysiphe pisi. We found that root symbiosis interfered with fungal penetration of M. truncatula and reduced asexual spore formation on pea leaves independently of symbiotic nitrogen fixation. Improved resistance of nodulated plants correlated with elevated levels of free SA and SA-dependent marker gene expression upon powdery mildew infection. Our results suggest that nodulation primes the plants systemically for E. pisi-triggered SA accumulation and defense gene expression, resulting in increased resistance.


Assuntos
Ascomicetos , Resistência à Doença , Medicago truncatula , Ervilhas , Nodulação , Ácido Salicílico , Ascomicetos/fisiologia , Resistência à Doença/fisiologia , Medicago truncatula/microbiologia , Fixação de Nitrogênio , Ervilhas/microbiologia , Doenças das Plantas/microbiologia , Ácido Salicílico/metabolismo
19.
Plant Cell Physiol ; 60(7): 1536-1555, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30989238

RESUMO

INDETERMINATE DOMAIN (IDD)/BIRD proteins belong to a highly conserved plant-specific group of transcription factors with dedicated functions in plant physiology and development. Here, we took advantage of the chimeric repressor gene-silencing technology (CRES-T, SRDX) to widen our view on the role of IDD4/IMPERIAL EAGLE and IDD family members in plant immunity. The hypomorphic idd4SRDX lines are compromised in growth and show a robust autoimmune phenotype. Hormonal measurements revealed the concomitant accumulation of salicylic acid and jasmonic acid suggesting that IDDs are involved in regulating the metabolism of these biotic stress hormones. The analysis of immunity-pathways showed enhanced activation of immune MAP kinase-signaling pathways, the accumulation of hydrogen peroxide and spontaneous programmed cell death. The transcriptome of nonelicited idd4SRDX lines can be aligned to approximately 40% of differentially expressed genes (DEGs) in flg22-treated wild-type plants. The pattern of DEGs implies IDDs as pivotal repressors of flg22-dependent gene induction. Infection experiments showed the increased resistance of idd4SRDX lines to Pseudomonas syringae and Botrytis cinerea implying a function of IDDs in defense adaptation to hemibiotrophs and necrotrophs. Genome-wide IDD4 DNA-binding studies (DAP-SEQ) combined with DEG analysis of idd4SRDX lines identified IDD4-regulated functional gene clusters that contribute to plant growth and development. In summary, we discovered that the expression of idd4SRDX activates a wide range of defense-related traits opening up the possibility to apply idd4SRDX as a powerful tool to stimulate innate immunity in engineered crops.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/imunologia , Ciclopentanos/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Proteínas Repressoras/fisiologia , Ácido Salicílico/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Arabidopsis/genética , Botrytis , Resistência à Doença , Homeostase , Sistema de Sinalização das MAP Quinases , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Imunidade Vegetal/genética , Imunidade Vegetal/fisiologia , Pseudomonas syringae , Proteínas Repressoras/genética
20.
Int J Mol Sci ; 20(7)2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30935036

RESUMO

Systemic acquired resistance (SAR) induction is one of the primary defence mechanisms of plants against a broad range of pathogens. It can be induced by infectious agents or by synthetic molecules, such as benzo(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH). SAR induction is associated with increases in salicylic acid (SA) accumulation and expression of defence marker genes (e.g., phenylalanine ammonia-lyase (PAL), the pathogenesis-related (PR) protein family, and non-expressor of PR genes (NPR1)). Various types of pathogens and pests induce plant responses by activating signalling pathways associated with SA, jasmonic acid (JA) and ethylene (ET). This work presents an analysis of the influence of BTH and its derivatives as resistance inducers in healthy and virus-infected plants by determining the expression levels of selected resistance markers associated with the SA, JA, and ET pathways. The phytotoxic effects of these compounds and their influence on the course of viral infection were also studied. Based on the results obtained, the best-performing BTH derivatives and their optimal concentration for plant performance were selected, and their mode of action was suggested. It was shown that application of BTH and its derivatives induces increased expression of marker genes of both the SA- and JA-mediated pathways.


Assuntos
Resistência à Doença/efeitos dos fármacos , Tiadiazóis/farmacologia , Tabaco/imunologia , Ciclopentanos/metabolismo , Etilenos/metabolismo , Oxilipinas/metabolismo , Ácido Salicílico/metabolismo , Tabaco/efeitos dos fármacos , Tabaco/virologia , Tobamovirus/patogenicidade
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