Liu Jing, Hu Yaping, Lu Xiaoqing, Xu Jifen, Wang Hongyang, Tang Wei, Li Canhui
Yunnan Key Laboratory of Potato Biology, School of Life Science, Yunnan Normal University, Kunming 650500, China.
Yunnan Key Laboratory of Potato Biology, School of Life Science, Yunnan Normal University, Kunming 650500, China.
Plant Sci. 2025 Aug;357:112539. doi: 10.1016/j.plantsci.2025.112539. Epub 2025 May 3.
Potato late blight caused by Phytophthora infestans is a devastating disease in potato production. Effectors secreted by P. infestans can target plant proteins and disrupt plant immune responses. The research on plant target proteins has mainly focused on ubiquitination, immune-related proteases, MAPK signal transduction pathways, and transcription factors. The question of whether plants possess novel disease resistance-related proteins or pathways remains unanswered. In this study, we identified a potato ribosomal protein, StRPS5, as a target of the P. infestans RxLR effector, Pi16275. Subcellular co-localization of StRPS5 and Pi16275 was observed in the nucleus, cytoplasm and cell membrane of Nicotiana benthamiana. The expression of StRPS5 was induced and up-regulated in the early stage of P. infestans infection. Furthermore, transient overexpression of StRPS5 in tobacco leaves was observed to inhibit the infection. We also observed a significant accumulation of HO at the site of StRPS5 overexpression, indicating a role of StRPS5 in promoting the outbreak of reactive oxygen species (ROS) burst after pathogen infection. Silencing of StRPS5 in potato exhibited a marked increase in susceptibility towards P. infestans, whereas overexpression of the gene led to an enhancement of disease resistance. As ROS are key signaling molecules in plant immune responses against pathogens, we investigated flg22-triggered ROS accumulation in transgenic potatoes and the results showed that ROS accumulation in StRPS5-silenced leaves was significantly depressed, while the accumulation was increased in StRPS5-overexpressing leaves. Collectively, our findings demonstrate that potato ribosomal protein StRPS5 serves as a target for the P. infestans effector Pi16275 and that StRPS5 positively regulates potato resistance to P. infestans by increasing the accumulation of ROS.
由致病疫霉引起的马铃薯晚疫病是马铃薯生产中的一种毁灭性病害。致病疫霉分泌的效应蛋白可作用于植物蛋白并破坏植物免疫反应。对植物靶蛋白的研究主要集中在泛素化、免疫相关蛋白酶、丝裂原活化蛋白激酶（MAPK）信号转导途径和转录因子上。植物是否拥有新的抗病相关蛋白或途径这一问题仍未得到解答。在本研究中，我们鉴定出一种马铃薯核糖体蛋白StRPS5，它是致病疫霉RxLR效应蛋白Pi16275的作用靶点。在本氏烟草的细胞核、细胞质和细胞膜中观察到了StRPS5和Pi16275的亚细胞共定位。致病疫霉感染初期，StRPS5的表达被诱导并上调。此外，观察到烟草叶片中StRPS5的瞬时过表达抑制了感染。我们还观察到在StRPS5过表达位点有大量过氧化氢（HO）积累，这表明StRPS5在促进病原体感染后活性氧（ROS）爆发中发挥作用。马铃薯中StRPS5的沉默使其对致病疫霉的易感性显著增加，而该基因的过表达则导致抗病性增强。由于ROS是植物对病原体免疫反应中的关键信号分子，我们研究了flg22诱导的转基因马铃薯中ROS的积累，结果表明，StRPS5沉默叶片中的ROS积累显著降低，而在StRPS5过表达叶片中ROS积累增加。总的来说，我们的研究结果表明，马铃薯核糖体蛋白StRPS5是致病疫霉效应蛋白Pi16275的作用靶点，并且StRPS5通过增加ROS的积累来正向调节马铃薯对致病疫霉的抗性。
