Laboratory of Plant Resistance and Genetics, College of Resources and Environmental Sciences, South China Agricultural University, Guangzhou, China.
Theor Appl Genet. 2011 Mar;122(5):1017-28. doi: 10.1007/s00122-010-1506-3. Epub 2010 Dec 12.
The blast resistance gene Pik-p, mapping to the Pik locus on the long arm of rice chromosome 11, was isolated by map-based in silico cloning. Four NBS-LRR genes are present in the target region of cv. Nipponbare, and a presence/absence analysis in the Pik-p carrier cv. K60 excluded two of these as candidates for Pik-p. The other two candidates (KP3 and KP4) were expressed in cv. K60. A loss-of-function experiment by RNAi showed that both KP3 and KP4 are required for Pik-p function, while a gain-of-function experiment by complementation test revealed that neither KP3 nor KP4 on their own can impart resistance, but that resistance was expressed when both were introduced simultaneously. Both Pikp-1 (KP3) and Pikp-2 (KP4) encode coiled-coil NBS-LRR proteins and share, respectively, 95 and 99% peptide identity with the two alleles, Pikm1-TS and Pikm2-TS. The Pikp-1 and Pikp-2 sequences share only limited homology. Their sequence allowed Pik-p to be distinguished from Pik, Pik-s, Pik-m and Pik-h. Both Pikp-1 and Pikp-2 were constitutively expressed in cv. K60 and only marginally induced by blast infection.
抗稻瘟病基因 Pik-p 被定位在水稻 11 号染色体长臂上的 Pik 位点，是通过基于图谱的计算机虚拟克隆方法分离得到的。在日本晴品种的目标区域存在 4 个 NBS-LRR 基因，而在 Pik-p 载体品种 K60 中进行的存在/缺失分析排除了其中两个候选基因 Pik-p。另外两个候选基因（KP3 和 KP4）在 K60 中表达。通过 RNAi 进行的功能丧失实验表明，KP3 和 KP4 都对 Pik-p 功能是必需的，而通过互补测试进行的功能获得实验表明，单独的 KP3 和 KP4 本身都不能赋予抗性，但同时引入这两个基因时则会表达抗性。Pikp-1（KP3）和 Pikp-2（KP4）分别编码卷曲螺旋 NBS-LRR 蛋白，与两个等位基因 Pikm1-TS 和 Pikm2-TS 分别具有 95%和 99%的肽序列同一性。Pikp-1 和 Pikp-2 序列仅具有有限的同源性。它们的序列使 Pik-p 能够与 Pik、Pik-s、Pik-m 和 Pik-h 区分开来。Pikp-1 和 Pikp-2 在 K60 中均持续表达，仅在受到稻瘟病感染时略有诱导。
