Yang Jing-Ting, Tan Zhi-Min, Jiang Yu-Tong, Bai Yu-Xuan, Zhang Yan-Jie, Xue Hong-Wei, Xu Tong-Da, Dong Tao, Lin Wen-Hui
School of Life Sciences and Biotechnology, Joint International Research Laboratory of Metabolic and Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China.
Department of Immunology and Microbiology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518055, Guangdong, China.
Sci Adv. 2025 Jan 10;11(2):eads7738. doi: 10.1126/sciadv.ads7738. Epub 2025 Jan 8.
Environmental stressors, including pathogens, substantially affect the growth of host plants. However, how non-adapted bacteria influence nonhost plants has not been reported. Here, we reveal that infection of flowers by pv. PXO99A, a bacterial pathogen causing rice blight disease, suppresses ovule initiation and reduces seed number without causing visible disease symptoms. TleB, secreted by the type VI secretion system (T6SS), interacts with plant E3 ligase PUB14 and disrupts the function of the PUB14-BZR1 module, leading to decreased ovule initiation and seed yield. On the other site, PUB14 concurrently promotes TleB's degradation. Our findings indicate that bacterial infections in nonhost plants directly repress offspring production. The regulatory mechanism by effectors PUB14-BZR1 is widely present, suggesting that plants may balance reproduction and defense and produce fewer offspring to conserve resources, thus enabling them to remain in a standby mode prepared for enhanced resistance.
包括病原体在内的环境应激源会对宿主植物的生长产生重大影响。然而，非适应性细菌如何影响非宿主植物尚未见报道。在此，我们发现引起水稻白叶枯病的细菌病原体稻瘟病菌小种PXO99A对花朵的侵染会抑制胚珠起始并减少种子数量，且不会引发明显的病害症状。VI型分泌系统（T6SS）分泌的TleB与植物E3连接酶PUB14相互作用，破坏PUB14-BZR1模块的功能，导致胚珠起始减少和种子产量降低。另一方面，PUB14同时促进TleB的降解。我们的研究结果表明，非宿主植物中的细菌感染会直接抑制后代的产生。效应物PUB14-BZR1的调控机制广泛存在，这表明植物可能会平衡繁殖和防御，通过减少后代数量来保存资源，从而使其能够保持一种为增强抗性做好准备的待命模式。
