水稻OsRPK2基因的克隆及功能初步鉴定

类受体蛋白激酶基因OsRPK1在水稻的抗逆信号传导中起着重要作用。本研究扩增获得与OsRPK1高度同源的OsRPK2基因,构建p1300:35S:OsRPK2过表达载体后转化拟南芥。对35S:OsRPK2纯合体拟南芥进行抗逆性分析表明,在盐、ABA、PEG胁迫下,OsRPK2过表达拟南芥萌发率都明显低于野生型拟南芥,其幼苗的根长生长和成株生长状况方面比野生型拟南芥表现出更为明显的受抑现象。生理检测表明,盐胁迫处理后,与野生型拟南芥相比,35S:OsRPK2转基因拟南芥中叶绿素含量下降更为明显,脯氨酸上升量较小,丙二醛含量上升更为明显,这些内在生理机制使得OsRPK2过表达拟南芥抗逆性明显下降。通过对35S:OsRPK2拟南芥的qRTPCR检测发现,OsRPK2的过量表达使拟南芥抗逆信号通路下游的SAD、SOS3和FRY基因表达明显受到抑制,OsRPK2基因可能通过SOS和CDPK信号通路影响拟南芥的抗逆性。

Cloning and Functional Analysis of Rice Gene OsRPK2

Receptor-like protein kinase gene OsRPK1 plays an important role in the resistance signal transduction of rice.OsRPK2 gene,which is highly homologous to OsRPK1,was amplified and transformed into Arabidopsis thaliana by the overexpression vector p1300:35S:OsRPK2.The stress resistance analysis of 35S:OsRPK2 Arabidopsis homozygous showed that the germination rate of OsRPK2 overexpressed Arabidopsis was significantly lower than that of the wild-type under salt,ABA and PEG stress.The root and plant growth of the OsRPK2 overexpressed Arabidopsis seedlings showed more obvious inhibition than that of wild-type.Physiological detection of 35S:OsRPK2 Arabidopsis showed that the chlorophyll content decreased more significantly,proline increased less and malondialdehyde content increased more significantly than the wildtype after salt treatment.These physiological mechanisms of OsRPK2 overexpression Arabidopsis significantly reduce the stress resistance.Through qRT-PCR detection of the OsRPK2 overexpressed Arabidopsis,the overexpression of OsRPK2 inhibited the expression of SAD,SOS3 and FRY genes significantly.Therefore,OsRPK2 gene may affect Arabidopsis resistance through SOS and CDPK signaling pathway.