水稻类受体激酶基因OsBAK1L调控细胞坏死机制

Mechanism of Receptor-like Kinases Gene OsBAK1L Involved in Regulating Cell Death Response of Rice

拟南芥类受体激酶BAK1(BRI1-associated kinase 1)在调控生长发育和免疫信号中有十分重要的作用。本研究选择水稻中BAK1的同源基因LOC_Os03g49620.4,将它暂命名为OsBAK1L并探索其结构和功能。结果表明,OsBAK1L定位于细胞膜,是SERKL(Somatic embryogenesis receptor kinase like)家族成员。OsBAK1L-RNAi转基因水稻中OsBAK1L下调表达。接种细菌性条斑病菌(Xanthomonas oryzae pv.oryzicola)菌株Rs105后,转基因苗与受体9804-Rxo1都表现过敏性反应(hypersensibility response,HR),但转基因苗HR推迟。此外,HR相关基因OsMPK13(Mitogen activated protein kinase 13)表达模式与HR变化趋势一致,在转基因苗中皆出现推迟现象。上述结果表明:OsBAK1L可能通过调节OsMPK13表达而推迟9804-Rxo1对细菌性条斑病菌的HR反应。

Plant receptor-like kinase BAK1 （BRIl-associated kinase 1） plays an important role in Arabidopsis in regulating diverse physiological processes, including development and signals in innate immunity. In this study, we choose a homologous gene LOC_Os03g49620.4 in rice and tentatively name it as OsBAKIL for structural and functional study. The result indicates that the OsBAK1L protein is a member of SERKL （Somatic embryogenesis receptor kinase Like） protein family and located in cell membrane. OsBAKIL was down regulated in OsBAKIL-RNAi transgenic rice plants. When the rice plants were inoculated with Xanthomonas oryzae pv. oryzicola Rsl05, hypersensibility response （HR） was triggered in both the OsBAKIL-RNAi transgenic plants and the resistant 9804-Rxol plants, while it was postponed only in OsBAK1L-RNAi transgenic rice plants. The expression pattern of HR associated gene, OsMPK13 （Mitogen activated protein kinase 13）, and HR were also delayed in transgenic plants and had the the same changing trends. These results indicate that OsBAKIL might control HR by regulating the expression of OsMPK13.