近年, 我国学者在水稻(Oryza sativa)广谱抗病机制、抗性与产量协调机制等方向的研究取得了一系列突破性进展。最近, 何祖华和杨卫兵团队在水稻抗病性研究中再次取得突破, 发现1个以钙感应蛋白ROD1和过氧化氢酶CatB为核心的信号轴, 通过负调控水稻免疫反应, 保证正常生长条件下维持低水平的免疫反应, 促进水稻正常生长发育, 而在病原菌侵染时下调ROD1蛋白, 诱导免疫反应。ROD1缺失突变体高抗稻瘟病、纹枯病和白叶枯病, 但因免疫过强抑制生殖生长。需要指出的是, 在热带和亚热带栽培籼稻中, ROD1富集了1个独特的变异SNP1^A。SNP1^A对免疫的抑制作用较小, 因此具有较好的抗病性, 这可能对水稻在热带和亚热带的适应性具有重要意义。SNP1^A对水稻生长发育和产量无明显影响, 表明这一变异在抗病改良育种中可能具有重要价值。有意思的是, 某些稻瘟菌携带的效应蛋白AvrPiz-t, 通过模拟ROD1的结构和功能干扰水稻的抗病性。因此, ROD1-CatB信号轴在水稻与病原微生物适应性演化中具有独特意义。

Chinese scientists have made multiple breakthroughs in recent years in rice disease resistance studies, particularly in the areas of durable resistance and resistance-yield coordination. Most recently, a team led by Zuhua He and Weibing Yang at the CAS Center for Excellence in Molecular Plant Sciences made another major advance in our understanding of disease resistance and host-pathogen co-evolution in rice. They showed that the calcium sensor protein ROD1 directly enhances the activity of catalase protein CatB to remove reactive oxygen species during immune responses, preventing excessive immune responses and ensuring optimum rice plant growth. Remarkably, they also illustrated that a functionally attenuated variant of ROD1 is enriched in wild and domesticated Indica rice from tropical and subtropical regions and that this variant allows elevated resistance against sheath blight disease. Importantly, this variant is likely useful for breeding as it does not compromise rice growth and yield. Interestingly, they further demonstrated that an effector protein from the rice blast fungus structurally and functionally mimics ROD1 to suppress rice immunity. Thus, this study uncovers an immune regulatory axis defined by ROD1 and CatB that is at the center of rice-pathogen co-evolution.