Yang Dewei, He Niqing, Huang Fenghuang, Chen Jialin, Yu Minxiang, Jin Yidan, Lin Shaojun, Li Shengping
Institute of Rice, Fujian Academy of Agricultural Sciences, Fuzhou 350018, China.
College of Agriculture and Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
Plants (Basel). 2025 Jan 14;14(2):217. doi: 10.3390/plants14020217.
In rice, leucine-rich repeat nucleotide-binding site (NLR) proteins are pivotal immune receptors in combating -triggered rice blast. However, the precise molecular mechanism underlying how NLR proteins regulate downstream signalling remains elusive due to the lack of knowledge regarding their direct downstream targets. The NLR protein Pigm-1 was cloned from Shuangkang 77009 in our laboratory. This study shows that the nucleotide-binding site (NBS) domain of Pigm-1 facilitates its binding to and activation of OsRac1 while the coiled-coil (CC) domain enables its binding to and activation of RAI1, ultimately inducing cell death. At the same time, after knocking out in the background of Shuangkang 77009 containing , two knockout lines showed susceptibility to rice blast. This study reveals OsRac1, a GTPase, as a signalling molecule involved in Pigm-1-mediated blast resistance, suggesting its potential as a common downstream effector of rice NLR proteins. Additionally, a transcriptional activator, RAI1, acts as an essential Pigm-1 interactor for blast resistance. Furthermore, a novel material 9311() was prepared by using two-line restorer line 9311 as receptor and Shuangkang 77009 as donor with molecular marker-assisted technology, which improved blast resistance and yield. This research demonstrates that molecular marker-assisted selection technology enhances both resistance and yield in the crucial two-line restorer 9311(). This study offers crucial insights into how Pigm-1 protein activates downstream molecules and serves as a valuable reference for the molecular breeding of rice blast resistance genes, particularly .
在水稻中，富含亮氨酸重复序列的核苷酸结合位点（NLR）蛋白是对抗稻瘟病菌引发的稻瘟病的关键免疫受体。然而，由于缺乏关于其直接下游靶点的知识，NLR蛋白如何调节下游信号传导的精确分子机制仍不清楚。NLR蛋白Pigm-1是我们实验室从双抗77009中克隆出来的。本研究表明，Pigm-1的核苷酸结合位点（NBS）结构域促进其与OsRac1的结合并激活OsRac1，而卷曲螺旋（CC）结构域使其能够与RAI1结合并激活RAI1，最终诱导细胞死亡。同时，在含有Pigm-1的双抗77009背景下敲除Pigm-1后，两个敲除株系对稻瘟病表现出易感性。本研究揭示了一种小G蛋白OsRac1作为参与Pigm-1介导的抗稻瘟病的信号分子，表明其作为水稻NLR蛋白常见下游效应物的潜力。此外，一种转录激活因子RAI1是Pigm-1介导抗稻瘟病必不可少的相互作用蛋白。此外，利用分子标记辅助技术，以两系恢复系9311为受体、双抗77009为供体，创制了新型材料9311（Pigm-1），提高了稻瘟病抗性和产量。本研究表明分子标记辅助选择技术提高了关键两系恢复系9311（Pigm-1）的抗性和产量。本研究为Pigm-1蛋白如何激活下游分子提供了重要见解，为水稻抗稻瘟病基因尤其是Pigm-1的分子育种提供了有价值的参考。
