胁迫相关蛋白激酶基因OsSAPK2调控水稻抗白叶枯病反应

水稻蔗糖非酵解型蛋白激酶Sn RK2,又称胁迫相关蛋白激酶(stress-activated protein kinase genes in rice,Os SAPKs),在调控水稻非生物胁迫信号传导中起着重要作用。本研究对Os SAPK2的结构及其在水稻抗白叶枯病反应中的功能进行了初步研究。结果表明Os SAPK2被定位于细胞核和细胞质内,与Os SAPK1、Os SAPK3同属于Kulik’s II组。Os SAPK2-RNAi转基因水稻中Os SAPK2下调表达,人工接种水稻白叶枯病菌后,转基因水稻比受体对照的病斑长度显著增长,抗病相关基因Os LRR1、Os HIR1表达水平下降,感病相关基因Os MAPK5表达水平升高。此外,Os SAPK2具有自激活活性,可能与Os MAPK5等胁迫相关蛋白互作。上述结果为进一步研究Os SAPK2调控水稻抗白叶枯病的分子机制提供了信息。

Stress-activated Protein Kinase OsSAPK2 Involved in Regulating Resistant Response to Xanthomonas oryzae pv. oryzae in Rice

Sucrose nonfermenting1-related protein kinase2 (SnRK2), also known as stress-activated protein kinase (OsSAPKs), plays an important role in signal transduction. In this study, we analyzed the structure and function of OsSAPK2 in response to Xanthomonas oryzae pv. oryzae (Xoo) infection. The result suggested that OsSAPK2 is a member of Kulik’s II group like OsSAPK1, OsSAPK3 and located in nucleus and cytoplasm. OsSAPK2 and disease-resistant genes OsLRR1, OsHIR1 were down regulated in OsSAPK2-RNAi transgenic rice, while disease-related gene OsMAPK5 was up regulated. Compared with non-transgenic plants, transgenic plants were more susceptible to Xoo infection. OsSAPK2 could activate itself and interact with several stress-related proteins. These results indicate that OsSAPK2 might be involved in the regulation of resistance response by regulating the expression of OsLRR1, OsHIR1, OsMAPK5 and interacting with stress-related proteins.