Deng Changhui, Hu Weiyao, Shen Wentao, Li Fangfang, Dai Zhaoji, Cui Hongguang
Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests (Ministry of Education) and School of Tropical Agriculture and Forestry, Hainan University, Haikou, China.
Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
Plant Dis. 2025 Jul;109(7):1459-1469. doi: 10.1094/PDIS-09-24-1949-RE. Epub 2025 Jul 10.
A total of 164 viruses have been identified in peppers worldwide. To combat viruses, pathogen-derived resistance (PDR) has been employed by expressing a viral genomic segment or a viral protein in host plants. Unfortunately, peppers are recalcitrant to genetic transformation and regeneration. An alternative strategy is to generate PDR in pepper plants by using an attenuated virus-based expression vector. In a previous study on the function of pepper veinal mottle virus (PVMV) 6K1 protein, we mutated a conserved Ala with Arg (A15R), and a second mutation (R15G) was observed in virus progeny. In this study, we demonstrated that mutating Ala to Gly (A15G) in the 6K1 yields a stable attenuated strain (named PVMV-G-A15G). PVMV-G-A15G can cross-protect pepper plants against a severe strain of PVMV and its close relative, chilli veinal mottle virus. We then engineered PVMV-G-A15G into a viral expression vector that has the Golden Gate cloning feature. To examine if the PVMV vector can be used to mediate PDR, we inserted the complete sequence of potato virus X (PVX) into the engineered PVMV-G-A15G. Preinoculated plants with the recombinant PVMV-G-A15G that carries the PVX sequence are resistant to PVX infection. Taken together, our research demonstrates that the attenuated PVMV can be employed for delivering the target virus sequence to mediate PDR.
全球范围内已在辣椒中鉴定出总共164种病毒。为了对抗病毒，通过在宿主植物中表达病毒基因组片段或病毒蛋白来采用病原体衍生抗性（PDR）。不幸的是，辣椒对遗传转化和再生具有抗性。一种替代策略是通过使用基于弱化病毒的表达载体在辣椒植株中产生PDR。在先前关于辣椒脉斑驳病毒（PVMV）6K1蛋白功能的研究中，我们将一个保守的丙氨酸突变为精氨酸（A15R），并且在病毒后代中观察到了第二个突变（R15G）。在本研究中，我们证明将6K1中的丙氨酸突变为甘氨酸（A15G）可产生一种稳定的弱化菌株（命名为PVMV-G-A15G）。PVMV-G-A15G可以交叉保护辣椒植株免受PVMV的强毒株及其近亲辣椒脉斑驳病毒的侵害。然后，我们将PVMV-G-A15G改造为具有金门克隆特性的病毒表达载体。为了检验PVMV载体是否可用于介导PDR，我们将马铃薯X病毒（PVX）的完整序列插入到改造后的PVMV-G-A15G中。用携带PVX序列的重组PVMV-G-A15G预先接种的植株对PVX感染具有抗性。综上所述，我们的研究表明弱化的PVMV可用于递送目标病毒序列以介导PDR。
