小麦类受体蛋白激酶基因TaPK3A的克隆与抗纹枯病功能初步分析

Cloning and functional analysis of wheat receptor-like kinase gene TaPK3A

小麦纹枯病已成为我国小麦生产的重要限制因素。研究小麦防御反应分子基础,发掘有效的抗病基因是小麦抗纹枯病育种突破的前提。本研究从抗纹枯病小麦品系CI12633中克隆出一个类受体蛋白激酶(receptor-like protein kinase, RLK)基因TaPK3A,并对其表达特性及抗纹枯病功能进行了分析和验证。TaPK3A基因的开放阅读框长度为1983 bp,编码660个氨基酸组成的类受体蛋白激酶。TaPK3A在抗纹枯病小麦品系 CI12633中的表达受禾谷丝核菌的诱导而显著上调;TaPK3A在根、茎、叶、穗中都有表达,以叶中的表达量最高;TaPK3A的表达受植物激素水杨酸诱导最为显著。利用大麦条形花叶病毒(barley stripe mosaic virus, BSMV)诱导的基因沉默(virus-induced gene silencing,VIGS)技术,降低抗纹枯病小麦CI12633中TaPK3A的转录水平,再接种禾谷丝核菌 WK207 进行纹枯病抗性鉴定。结果显示,与对照植株相比, TaPK3A转录量下降的CI12633植株对纹枯病的抗性显著降低,说明TaPK3A是小麦防御纹枯病反应所需的。

Wheat sharp eyespot has become an important limiting factor of wheat production in China. The precondition for wheat sharp eyespot resistant breeding is to study the molecular basis of wheat defense response and to identify effective resistance genes. In this study, a wheat receptor-like kinase (RLK) gene, named TaPK3A, was cloned from sharp eyespot-resistant wheat line CI12633, and the expression and function of the TaPK3A gene were analyzed. TaPK3A contains an open reading frame with 1983 bp length. It encodes a protein kinase that is consisted of 660 amino acids. RT-qPCR analysis showed that the expression of TaPK3A in sharp eyespot-resistant wheat line CI12633 was significantly induced by the pathogen of sharp eyespot (Rhizoctonia cerealis). The TaPK3A gene was expressed in all the tissues, with the highest expression level in the leaves. The expression of TaPK3A was significantly up-regulated by salicylic acid. By means of barley stripe mosaic virus (BSMV) based virus-induced gene-silencing (VIGS), TaPK3A was silenced in CI12633 plants. After R. cerealis (WK207) inoculation, TaPK3A-silenced CI12633 plants displayed a significant decrease in resistance to R. cerealis infection compared with BSMV: GFP-infected CI12633 plants (control). These results suggested that TaPK3A is required for wheat defense response to sharp eyespot.