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Plant Biotechnology Journal：水稻GWAS鉴定了一个新的NLR基因作用于稻瘟病抗性

已有 3241 次阅读 2019-11-21 16:44 |个人分类:每日摘要|系统分类:论文交流

Genome‐wide association study identifies an NLR gene that confers partial resistance to Magnaporthe oryzae in rice

First author: Ming‐Hao Liu; Affiliations: Institute of Plant Protection, Chinese Academy of Agricultural Sciences (中国农科院植物保护研究所): Beijing, China

Corresponding author: Guo‐Liang Wang

Because of the frequent breakdown of major resistance (R) genes, identification of new partial R genes against rice blast disease is an important goal of rice breeding. In this study, we used a core collection of the Rice Diversity Panel II (C‐RDP‐II), which contains 584 rice accessions and are genotyped with 700,000 single‐nucleotide polymorphism (SNP) markers. The C‐RDP‐II accessions were inoculated with three blast strains collected from different rice‐growing regions in China. Genome‐wide association study identified 27 loci associated with rice blast resistance (LABRs). Among them, 22 LABRs were not associated with any known blast R genes or QTLs. Interestingly, a nucleotide‐binding site leucine‐rich repeat (NLR) gene cluster exists in the LABR12 region on chromosome 4. One of the NLR genes is highly conserved in multiple partially resistant rice cultivars, and its expression is significantly up‐regulated at the early stages of rice blast infection. Knockout of this gene via CRISPR‐Cas9 in transgenic plants partially reduced blast resistance to four blast strains. The identification of this new non‐strain specific partial R gene, tentatively named rice blast Partial Resistance gene 1 (PiPR1), provides genetic material that will be useful for understanding the partial resistance mechanism and for breeding durably resistant cultivars against blast disease of rice.

由于主要抗性（R）基因的频繁失效，鉴定新的能够作用于水稻稻瘟病抗性的R基因是水稻育种的一个重要目标。本文中，作者利用了一个包含584份水稻材料的资源库C‐RDP‐II，这些材料已经用700,000个SNP标记做了基因分型。作者收集了来自中国三个不同水稻生长地区的稻瘟病病原菌，与C‐RDP‐II库中的材料共培养。全基因组关联分析鉴定了27个与水稻的稻瘟病抗性相关的位点LABR。其中，22个LABR与任何已知的R基因或QTL无关联。有趣的是，4号染色体上LABR12区域存在一个核苷酸结合位点富含亮氨酸的重复序列NLR基因簇。这个基因簇中有一个基因在多个部分抗性水稻栽培种中高度保守，并且在稻瘟病病菌侵染的早期阶段，该基因的表达显著上调。通过CRISPR‐Cas9技术敲除该基因会导致转基因株系对于四个稻瘟病菌株的抗性部分减弱。本文鉴定了一个新的非菌株特异性的部分抗性R基因，命名为PiPR1，这对于R基因作用机制的研究以及抗水稻稻瘟病的抗性育种都具有非常重要的作用。