Descripción
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The heterotrimeric G protein complex is an essential regulator of Arabidopsis immune responses. Genetic ablation of G protein function, as it occurs in the agb1-2 mutant, which lacks the ? subunit protein (AGB1) of this complex, confers defective activation of Microbe-Associated Molecular Pattern (MAMP)-triggered immunity resulting in susceptibility to different pathogens, including the necrotrophic fungus Plectosphaerella cucumerina BMM (PcBMM). A mutant screen for suppressors of agb1-2 susceptibility (sgb mutants) to PcBMM identified the sgb10 mutant, which harbours a null allele (mkp1-2) of the mitogen-activated protein kinase (MAPK) phosphatase 1 gene (MKP1). MKP1 is a negative regulator of the activity of MAPKs during MAMP-triggering immunity and the salicylic acid (SA) signalling pathway. We found that the SA pathway is constitutively active in the mkp1-2 agb1-2 double mutant and that the enhanced susceptibility of agb1-2 to the bacterium Pseudomonas syringae pv. tomato DC3000 and the oomycete Hyaloperonospora arbidopsidis is restored to wild-type levels by the mkp1-2 allele. The production of reactive oxygen species (ROS) is enhanced upon MAMP treatment in mkp1 mutants compared to wild-type plants, indicating that MKP1 negatively balances the production of ROS triggered by MAMPs. This MKP1 function takes place through the transcriptional modulation of the NADPH oxidase gene RbohD, which is enhanced in mkp1 plants upon MAMP treatment or pathogen infection. Moreover, MKP1 regulates ROS production by modulating RBOHD activity, since mkp1 plants constitutively overexpressing RbohD (35S::RbohD mkp1) display elevated ROS levels upon MAMP treatment. In addition, a significant reprograming of the metabolic profile occurs in mkp1 plants, with more than 200 metabolites (including antimicrobial metabolites) showing differential accumulation in comparison to wild-type plants. These results indicate that MKP1 functions downstream of the heterotrimeric G protein during MAMP-triggered immunity, directly regulating the activity of RboHD, as well as other immune responses required for disease resistance. | |
Internacional
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Si |
Nombre congreso
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When development meets stress: Understanding developmental reprogramming upon pathogenesis in plants |
Tipo de participación
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970 |
Lugar del congreso
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Barcelona |
Revisores
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Si |
ISBN o ISSN
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000-00-0000-000-0 |
DOI
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Fecha inicio congreso
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03/09/2018 |
Fecha fin congreso
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04/09/2018 |
Desde la página
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20 |
Hasta la página
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20 |
Título de las actas
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B-Debate |