Blast disease is a devastating fungal disease of rice, one of the world's staple foods. Race-specific resistance to blast disease has usually not been durable. Here, we report the cloning of a previously unknown type of gene that confers non–race-specific resistance and its successful use in breeding. Pi21 encodes a proline-rich protein that includes a putative heavy metal–binding domain and putative protein-protein interaction motifs. Wild-type Pi21 appears to slow the plant's defense responses, which may support optimization of defense mechanisms. Deletions in its proline-rich motif inhibit this slowing. Pi21 is separable from a closely linked gene conferring poor flavor. The resistant pi21 allele, which is found in some strains of japonica rice, could improve blast resistance of rice worldwide.
稻瘟病是世界主要糧食作物水稻的一種破壞性很大的真菌性病害。稻瘟病的種屬專一性抗性通常持續(xù)的時間不長。本文我們報道了一個之前未知的具有非種屬專一性抗性的基因，并將其成功應(yīng)用于育種。Pi21 編碼一個富含脯氨酸的蛋白，該蛋白包含一個可能的重金屬結(jié)合結(jié)構(gòu)域和可能的蛋白互作結(jié)構(gòu)域。野生型的Pi21 可以減緩植物的抗病反應(yīng)，這可能有利于優(yōu)化抗病反應(yīng)機(jī)制。將該蛋白的富含脯氨酸基序去除后抑制了對抗病反應(yīng)的減緩作用。Pi21 基因是從一個與之緊密連鎖的影響稻米口味的基因分離出來?？共〉?em>pi21 等位基因在一些粳稻品種也有，該抗病的pi21 等位基因可以在世界范圍內(nèi)提高水稻對稻瘟病的抗性。