20 research outputs found
WRKY45-dependent priming of diterpenoid phytoalexin biosynthesis in rice and the role of cytokinin in triggering the reaction
Solanum venturii, a suitable model system for virus-induced gene silencing studies in potato reveals StMKK6 as an important player in plant immunity
Overexpression of Phosphomimic Mutated OsWRKY53 Leads to Enhanced Blast Resistance in Rice
WRKY transcription factors and mitogen-activated protein kinase (MAPK) cascades have been shown to play pivotal roles in the regulation of plant defense responses. We previously reported that OsWRKY53-overexpressing rice plants showed enhanced resistance to the rice blast fungus. In this study, we identified OsWRKY53 as a substrate of OsMPK3/OsMPK6, components of a fungal PAMP-responsive MAPK cascade in rice, and analyzed the effect of OsWRKY53 phosphorylation on the regulation of basal defense responses to a virulence race of rice blast fungus Magnaporthe oryzae strain Ina86-137. An in vitro phosphorylation assay revealed that the OsMPK3/OsMPK6 activated by OsMKK4 phosphorylated OsWRKY53 recombinant protein at its multiple clustered serine-proline residues (SP cluster). When OsWRKY53 was coexpressed with a constitutively active mutant of OsMKK4 in a transient reporter gene assay, the enhanced transactivation activity of OsWRKY53 was found to be dependent on phosphorylation of the SP cluster. Transgenic rice plants overexpressing a phospho-mimic mutant of OsWRKY53 (OsWRKY53SD) showed further-enhanced disease resistance to the blast fungus compared to native OsWRKY53-overexpressing rice plants, and a substantial number of defense-related genes, including pathogenesis-related protein genes, were more upregulated in the OsWRKY53SD-overexpressing plants compared to the OsWRKY53-overexpressing plants. These results strongly suggest that the OsMKK4-OsMPK3/OsMPK6 cascade regulates transactivation activity of OsWRKY53, and overexpression of the phospho-mimic mutant of OsWRKY53 results in a major change to the rice transcriptome at steady state that leads to activation of a defense response against the blast fungus in rice plants.UTokyo Research掲載「イネの耐病性向上に成功」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/enhanced-disease-resistance-in-rice-plants/UTokyo Research "Enhanced disease resistance in rice plants" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/enhanced-disease-resistance-in-rice-plants