抗稻瘟病主效QTL rbr2是Pib的等位基因

The Major Blast Resistance QTL rbr2 is an Allele of Pib Gene

稻瘟病是世界范围内水稻的重要病害之一。本研究通过对来自水稻品种明恢63的一个抗稻瘟病主效数量性状位点(QTL)rbr2的精细定位、序列测定和表达分析,证实这个主效抗病QTL基因是一个新的抗稻瘟病基因,它编码NBS(nucleotide-binding site)-LRR(leucine-rich repeat)类蛋白,是已经分离克隆的抗稻瘟病基因Pib的等位基因。这两个等位基因编码产物的主要差异存在于LRR结构域,它可能是造成二者介导的抗病反应的抗谱不同的主要原因。rbr2基因可以作为一个新抗源用于水稻抗性改良。

Blast is one of the most devastating diseases office worldwide. Here we show that the gene underlying the major quantitative trait locus （QTL）, rbr2, for blast resistance in rice variety Minghui 63 is a new blast resistance gene by fining mapping, sequence analysis, and expression analysis of rbr2. The rbr2 encodes a nu- cleotide-binding site （NBS）-leucine-fich repeat （LRR） type protein and is an allele of blast resistance gene P/b. The amino acid differences of the predicted encoding products of rbr2 and Pib occur mainly in LRR domain, which may be the major cause that the resistance spectrums mediated by the two genes are different. The rbr2, as a new resistance gene, can be used in rice breeding programs.