College of Plant Protection, Shenyang Agricultural University, Shenyang 110866, China.
Rice Research Institute, Shenyang Agricultural University, Shenyang 110866, China.
Int J Mol Sci. 2022 Jul 26;23(15):8214. doi: 10.3390/ijms23158214.
Sheath blight (ShB) caused by is a major disease of rice, seriously affecting yield; however, the molecular defense mechanism against ShB remains unclear. A previous transcriptome analysis of rice identified that inoculation significantly induced . Genetic studies using and overexpressing plants identified that positively regulates ShB resistance. This MDPK protein was found localized in the endoplasmic reticulum (ER) and Golgi apparatus. Yeast one-hybrid assay, electrophoresis mobility shift assay (EMSA), and chromatin immunoprecipitation (ChIP) showed that the intermediate domain proteins IDD12, IDD13, and IDD14 bind to the promoter. Moreover, IDD14 was found to interact with IDD12 and IDD13 to form a transcription complex to activate expression. The three IDDs demonstrated an additive effect on activation. Further genetic studies showed that the and single mutants were more susceptible to ShB but not , while , , and overexpressing plants were less susceptible than the wild-type plants. The , , and mutants also proved the additive effect of the three on expression, which regulates ShB resistance in rice. Notably, overexpression maintained normal yield levels in rice. Thus, our study proves that IDD12, IDD13, and IDD14 activate to enhance ShB resistance in rice. These results improve our knowledge of rice defense mechanisms and provide a valuable marker for resistance breeding.
鞘腐病（ShB）是由 引起的一种主要的水稻病害，严重影响产量；然而，对 ShB 的分子防御机制仍不清楚。先前对水稻的转录组分析表明， 接种显著诱导了 。利用 和过表达植物进行的遗传研究表明， 正向调节 ShB 抗性。这种 MDPK 蛋白被发现定位于内质网（ER）和高尔基体。酵母单杂交分析、电泳迁移率变动分析（EMSA）和染色质免疫沉淀（ChIP）表明，中间域蛋白 IDD12、IDD13 和 IDD14 与 启动子结合。此外，发现 IDD14 与 IDD12 和 IDD13 相互作用形成转录复合物，激活 表达。这三个 IDD 对 激活表现出累加效应。进一步的遗传研究表明， 和 单突变体对 ShB 更敏感，但对 不敏感，而 、 、和 过表达植物比野生型植物更不敏感。 、 、和 突变体也证明了这三个 对 表达的累加效应，这调节了水稻中对 ShB 的抗性。值得注意的是， 过表达在水稻中保持了正常的产量水平。因此，我们的研究证明了 IDD12、IDD13 和 IDD14 激活 来增强水稻对 ShB 的抗性。这些结果提高了我们对水稻防御机制的认识，并为抗性育种提供了有价值的标记。
