谷子抗病基因同源序列的克隆与分析

谷子锈病是谷子上的一种流行性强、毁灭性大的病害,严重影响谷子生产.种植抗病品种是防治锈病最经济有效的方法,但谷子抗锈病种质资源非 常贫乏,而且高抗锈病的材料其农艺性状又很差.很难通过传统育种方法培育抗锈病品种,因此克隆谷子抗锈病基因尤为重要.目前克隆到的许多植 物抗病基因编码的氨基酸序列都有一定的保守结构域.根据抗病基因保守结构域,已克隆的抗病基因主要分为5类,其中最主要的是NBS-LRR(nu- leotide-binding site leucine-rich epeat)和STK(Se-rine／Threonine protein kinase)类.因而根据抗病基因保守结构域设计引物,从植物的DNA中扩增植物的抗病基因同源序列RGA(resistance geneanalogs)更加快捷有效,目前通过RGA方法克隆植物抗病基因已有报道1,2].

Cloning and sequencing of disease resistance gene analogs in foxtail millet

Cloning approach of resistance gene analogs (RGA) is simple and practical method in finding plant resistant gene. In order to clone RGA from the foxtail millet cultivar Shilixiang resistant to rust , PCR method was carried out with degenerate primers based on conserved regions of NBS domain and STK domain. 25 NBS-LRR RGAs and 11 STK RGAs were isolated. The cloned NBS-LRR RGA had the conservative motifs P-loop, Kinase 2a, Kinase 3a and hydrophobic domain and the cloned STK RGA had eight catalytic domain. Tryptophan as the last residue of Kinase-2a motif and phylogenetic analysis showed that the cloned NBS-LRR RGAs were non-TIR NBS-LRR family. The further study of such RGA was useful for breeding of rust resis-tant foxtail millet cultivars and cloning rust resistant gene.