水稻小种特异性抗稻瘟病基因的等位性变异研究进展

Allelic variation in thee race-specific blast resistance genes in rice

稻瘟病是制约水稻安全生产的主要病害之一,稻瘟病抗性基因的发掘与利用一直是理论研究和育种应用的热点。从1999年克隆Pib开始,已经从17个位点克隆了50多个小种特异性抗稻瘟病基因,不均匀地分布在水稻染色体上。绝大多数抗稻瘟病基因编码NLR(nucleotide-binding and leucine-rich repeat)结构域蛋白,单独或成对介导抗性。在抗稻瘟病基因位点中,存在丰富的等位性变异,这些变异常常发生在识别效应因子的关键结构域中,从而识别同源或序列无相似性的效应因子,使变异的基因具备新的小种特异性抗性。本文综述了水稻小种特异性抗稻瘟病基因的研究进展,讨论了等位性变异在抗稻瘟病基因的应用中的潜力。

Rice blast is one of destruction disease in rice and threaten the rice production and food security in China.Therefore,it is always the hotspot for exploring and utilizing rice blast resistance genes in study and breeding.Since the first resistance gene Pib was reported in 1999,it has been identified more than 50 race-spe-cific resistance genes against Magnaporthe oryzae.These genes were cloned from 17 loci in eight of the twelve chromosomes of rice unevenly.Most of them encode nucleotide-binding and leucine-rich repeat proteins,which mediate the rice blast disease resistance as monogenic or paired genes.Among the 50 resistance genes,most of them are allelic or paralog genes of ones in 17 loci.Natural variations mainly occur in the domains that function to recognize effector,and confer the capability of resistance protein to recognize new effectors,generating new race-specific resistance in rice.We reviewed the progress in the study of rice blast resistance genes and discussed the potential application of their allelic variations in rice breeding.