Yu Wen, Cheng Yazhi, Jiang Jiale, Li Zhijie, Li Qingyun, Wang Weifeng, Yang Zhixiao, Wu Shengxin, Ding Anming
Tobacco-Rice Synergistic Development Industrial Technology Engineering Center, Fujian Research Institute of Tobacco Science, Fuzhou, 350003, China.
Chinese Academy of Agricultural Sciences Institute of Tobacco Research, Qingdao, 266101, China.
Plant Cell Rep. 2025 Nov 21;44(12):278. doi: 10.1007/s00299-025-03667-8.
NtRPP13, a CNL-type gene suppressed by Ralstonia solanacearum, mediates a positive regulation of hypersensitive response and phytohormone-related defense genes for bacterial wilt resistance in tobacco. Bacterial wilt, caused by Ralstonia solanacearum, is a devastating soil-borne disease that infects hundreds of plant species worldwide. To date, while effective control strategies for this pathogen remain limited, exploring resistant genes is particularly important in disease-resistant breeding. Nucleotide-binding site-leucine-rich repeat (NBS-LRR) proteins are key participants in effector-triggered immunity in plants. This study identified a novel NBS-LRR resistance gene, NtRPP13, in tobacco, which exhibited downregulation in roots of a susceptible tobacco cultivar upon R. solanacearum infection. The NtRPP13 protein contained a typical coiled-coil (CC) domain at its N-terminus and was classified into the CC-NBS-LRR category. Subcellular localization analysis revealed that NtRPP13 localizes to the plasma membrane. Additionally, exposure to phytohormones-including abscisic acid, auxin and gibberellic acid, and abiotic stressors such as drought and cold altered NtRPP13 expression. This could be attribute to the corresponding cis-acting elements in the NtRPP13 promoter. Transient overexpression of NtRPP13 triggered a hypersensitive response (HR) in Nicotiana benthamiana, while stable overexpression in transgenic tobacco plants significantly enhanced resistance to R. solanacearum, with varying resistance levels observed between different transgenic lines. Moreover, following inoculation with R. solanacearum, the transgenic plants exhibited marked upregulation of some key defense-related marker genes associated with the HR, salicylic acid (SA), jasmonic acid (JA), and ethylene signaling pathways, along with significantly elevated levels of JA and SA, compared to wild-type controls. These findings suggest that NtRPP13 contributes to tobacco defense against R. solanacearum by mediating crosstalk between multiple signaling pathways.
NtRPP13是一个受青枯雷尔氏菌抑制的CNL型基因，它介导了烟草对青枯病抗性的过敏反应和植物激素相关防御基因的正向调控。由青枯雷尔氏菌引起的青枯病是一种毁灭性的土传病害，感染全球数百种植物。迄今为止，针对这种病原菌的有效防治策略仍然有限，因此在抗病育种中探索抗性基因尤为重要。核苷酸结合位点富含亮氨酸重复序列（NBS-LRR）蛋白是植物中效应物触发免疫的关键参与者。本研究在烟草中鉴定出一个新的NBS-LRR抗性基因NtRPP13，在青枯雷尔氏菌感染后，该基因在感病烟草品种的根中表达下调。NtRPP13蛋白在其N端含有一个典型的卷曲螺旋（CC）结构域，属于CC-NBS-LRR类别。亚细胞定位分析表明，NtRPP13定位于质膜。此外，暴露于包括脱落酸、生长素和赤霉素在内的植物激素以及干旱和寒冷等非生物胁迫下会改变NtRPP13的表达。这可能归因于NtRPP13启动子中的相应顺式作用元件。NtRPP13的瞬时过表达在本氏烟草中引发了过敏反应（HR），而在转基因烟草植株中的稳定过表达显著增强了对青枯雷尔氏菌的抗性，不同转基因株系之间观察到不同的抗性水平。此外，与野生型对照相比，接种青枯雷尔氏菌后，转基因植株中一些与HR、水杨酸（SA）、茉莉酸（JA）和乙烯信号通路相关的关键防御相关标记基因显著上调，同时JA和SA水平也显著升高。这些发现表明，NtRPP13通过介导多种信号通路之间的相互作用，有助于烟草抵御青枯雷尔氏菌。
