National Key Laboratory for Germplasm Innovation & Utilization of Horticultural Crops, Huazhong Agricultural University (HZAU), Wuhan, China.
Hubei Hongshan Laboratory (HZAU), Wuhan, China.
Physiol Plant. 2024 Nov-Dec;176(6):e14594. doi: 10.1111/ppl.14594.
Blue light enhances the susceptibility of Nicotiana benthamiana to Phytophthora infestans, a causative agent of late blight disease. Investigating how blue light affects potato late blight resistance is an interesting aspect of exploring new ways to control late blight disease. Blue light photoreceptor phototropins (phot1, phot2) and their downstream interact protein StNRL1 have been shown to negatively regulate late blight resistance. In order to investigate whether other potato NPH3/RPT2-Like (NRL) family members are involved in regulating late blight resistance, this study focused on the potato NRL proteins containing RxSxS motif at the C-terminus. Another potato NRL protein StNRL-9, containing RxSxS motifs, was found to negatively regulate P. infestans resistance in potato and N. benthamiana. Overexpression of StNRL-9 in potato and N. benthamiana suppresses the accumulation of reactive oxygen species (ROS) and expression of the PTI marker genes NbWRKY7 and NbWRKY8. Similar to StNRL1, StNRL-9 interacts with the blue light receptors Stphot1 and Stphot2 on the cell membrane and could promote the degradation of a positive immune regulator StSWAP70. However StNRL-9 does not inhibit INF1-mediated cell death (ICD), which is different from the StNRL1 that inhibits ICD, indicating that both StNRL1 and StNRL-9 inhibit plant immunity in diverse ways. This study provides valuable information for further exploration of how plant phototropins and NRL family proteins regulate plant immunity.
蓝光增强了拟南芥对晚疫病病原菌的易感性。研究蓝光如何影响马铃薯晚疫病抗性是探索控制晚疫病新方法的一个有趣方面。蓝光光受体光敏色素（phot1、phot2）及其下游互作蛋白 StNRL1 已被证明负调控晚疫病抗性。为了研究其他马铃薯 NPH3/RPT2-Like（NRL）家族成员是否参与调节晚疫病抗性，本研究聚焦于含有 C 端 RxSxS 基序的马铃薯 NRL 蛋白。另一种含有 RxSxS 基序的马铃薯 NRL 蛋白 StNRL-9 被发现负调控马铃薯和拟南芥对 P. infestans 的抗性。StNRL-9 在马铃薯和拟南芥中的过表达抑制活性氧（ROS）的积累和 PTI 标记基因 NbWRKY7 和 NbWRKY8 的表达。与 StNRL1 相似，StNRL-9 与细胞膜上的蓝光受体 Stphot1 和 Stphot2 相互作用，并能促进正免疫调节因子 StSWAP70 的降解。然而，StNRL-9 不抑制 INF1 介导的细胞死亡（ICD），这与抑制 ICD 的 StNRL1 不同，表明 StNRL1 和 StNRL-9 以不同的方式抑制植物免疫。本研究为进一步探索植物光敏色素和 NRL 家族蛋白如何调节植物免疫提供了有价值的信息。
