Uji Yuya, Taniguchi Shiduku, Tamaoki Daisuke, Shishido Hodaka, Akimitsu Kazuya, Gomi Kenji
Plant Genome and Resource Research Center, Faculty of Agriculture, Kagawa University, Miki, Kagawa, 761-0795 Japan.
Plant Genome and Resource Research Center, Faculty of Agriculture, Kagawa University, Miki, Kagawa, 761-0795 Japan
Plant Cell Physiol. 2016 Sep;57(9):1814-27. doi: 10.1093/pcp/pcw101. Epub 2016 May 19.
JASMONATE ZIM-domain (JAZ) proteins act as transcriptional repressors of jasmonic acid (JA) responses and play a crucial role in the regulation of host immunity in plants. Here, we report that OsMYC2, a JAZ-interacting transcription factor in rice (Oryza sativa L.), plays an important role in the resistance response against rice bacterial blight, which is one of the most serious diseases in rice, caused by Xanthomonas oryzae pv. oryzae (Xoo). The results showed that OsMYC2 interacted with some OsJAZ proteins in a JAZ-interacting domain (JID)-dependent manner. The up-regulation of OsMYC2 in response to JA was regulated by OsJAZ8. Transgenic rice plants overexpressing OsMYC2 exhibited a JA-hypersensitive phenotype and were more resistant to Xoo. A large-scale microarray analysis revealed that OsMYC2 up-regulated OsJAZ10 as well as many other defense-related genes. OsMYC2 selectively bound to the G-box-like motif of the OsJAZ10 promoter in vivo and regulated the expression of early JA-responsive genes, but not of late JA-responsive genes. The nuclear localization of OsMYC2 depended on a nuclear localization signal within JID. Overall, we conclude that OsMYC2 acts as a positive regulator of early JA signals in the JA-induced resistance against Xoo in rice.
茉莉酸ZIM结构域（JAZ）蛋白作为茉莉酸（JA）应答的转录抑制因子，在植物宿主免疫调节中起关键作用。在此，我们报道水稻（Oryza sativa L.）中与JAZ相互作用的转录因子OsMYC2在水稻白叶枯病抗性反应中起重要作用，水稻白叶枯病是由稻黄单胞菌水稻致病变种（Xoo）引起的水稻最严重病害之一。结果表明，OsMYC2以依赖于JAZ相互作用结构域（JID）的方式与一些OsJAZ蛋白相互作用。OsJAZ8调控了JA诱导的OsMYC2上调。过表达OsMYC2的转基因水稻植株表现出JA超敏表型，且对Xoo更具抗性。大规模微阵列分析表明，OsMYC2上调了OsJAZ10以及许多其他防御相关基因。OsMYC2在体内选择性地结合到OsJAZ10启动子的G-box样基序上，并调控早期JA应答基因的表达，但不调控晚期JA应答基因的表达。OsMYC2的核定位依赖于JID内的核定位信号。总体而言，我们得出结论，OsMYC2在JA诱导的水稻抗Xoo抗性中作为早期JA信号的正调控因子发挥作用。
