小麦类受体蛋白基因TaRLP19 cDNA序列克隆及分析

为筛选小麦叶锈病抗病相关基因,以从小麦近等基因系TcLr19中获得的特异表达的168 bp cDNA-AFLP片段为靶序列,通过cDNA末端快速扩增(RACE)的方法获得2545 bp的cDNA序列,并在接菌的TcLr19叶片中进行RT-PCR验证,测序结果与RACE结果一致.tBLASTn比对发现该序列与预测的二穗短柄草的Receptor-like protein 2-like (LOC100825532)有67％的一致性(Expect=0.0).该基因包含一个2136 bp的开放阅读框,编码711个氨基酸；SMART分析表明其含有6个LRR结构域,属LRR-TM类型,推测其为假定的富含亮氨酸的类受体蛋白基因,暂命名为TaRLP19,GenBank登录号为(JN872563).半定量RT-PCR分析表明,该基因属组成型特异表达类型.为进一步研究叶锈菌与小麦TcLr19非亲和反应中类受体蛋白TaRLP19的功能及其表达调控机制等奠定基础.

Cloning and characterization of receptor-like protein TaRLP19 cDNA from wheat

To investigate the resistance-related gene of wheat leaf rust,the cDNA sequence of the aimed gene was cloned from TcLr19 carrying the Lr19 gene by using RACE technique based on the target fragment 168 bp amplified by cDNA-AFLP.It was verified further in TcLr19 leaves induced by Puccinia triticina with RT-PCR.The sequence cloned in wheat TcLr19 had a high identity with the sequence obtained from RACE clone.The sequence named TaRLP19 has a length of 2 545 bp,including a 2 136 bp ORF(open reading frame) which encodes 711 amino acids,and showed 67% identity with Brachypodium distachyon receptor-like protein 2-like(LOC100825532),Expect = 0.0;SMART analysis showed that the deduced protein contained six leucine-rich repeats(LRR) domains and one transmembrane domain,which was identical to the conserved domains of many plant resistance genes.The gene was constitutive specific expression gene in the TcLr19 wheat leaf by semi-quantitative RT-PCR.In this study,we obtained one resistance-related sequence which provided the short cut for understanding the mechanism between the near isogenic line TcLr19 and leaf rust pathogen.