番茄(Solanumlycopersum)是全球茄科中最重要的蔬菜和水果作物。许多害虫和病原体,尤其是病毒,严重影响番茄生产,造成不可估量的市场损失。在台湾,番茄作物的种植主要受到昆虫传播病毒的威胁,其中辣椒脉斑驳病毒(PVMV)是最流行的病毒之一。PVMV是Potyviridae家族Potyvirus属的成员,并且由蚜虫非持续传播。其侵染显著降低番茄果实产量和品质。到目前为止,没有抗PVMV的番茄品系可用。在这项研究中,我们对PVMV番茄分离物Tn进行亚硝酸盐诱导的诱变以产生减毒的PVMV突变体。PVMVTn在藜麦叶片中引起坏死病变,在烟草植物中引起严重的马赛克和枯萎。亚硝酸盐处理后,三个减毒PVMV突变体,选择m4-8、m10-1和m10-11,同时诱导在番茄植物中具有较低积累的对藜麦和N.benthamiana的较温和反应。在温室测试中,三个突变体对野生型PVMVTn表现出不同程度的交叉保护。m4-8在N.benthamiana和番茄植物中显示出对PVMVTn的最高保护效力,100%和97.9%,分别。PVMVTn和m4-8的全基因组序列比较显示,m4-8基因组中发生了20个核苷酸取代,导致18个氨基酸的变化。我们的结果表明,m4-8具有保护番茄作物免受PVMV侵害的极好潜力。M4-8在其他茄科作物保护中的应用,比如辣椒,将在未来研究。
Tomato (Solanum lycopersicum) is the most important vegetable and fruit crop in the family Solanaceae worldwide. Numerous pests and pathogens, especially viruses, severely affect tomato production, causing immeasurable market losses. In Taiwan, the cultivation of tomato crops is mainly threatened by insect-borne viruses, among which pepper veinal mottle virus (PVMV) is one of the most prevalent. PVMV is a member of the genus
Potyvirus of the family Potyviridae and is non-persistently transmitted by aphids. Its infection significantly reduces tomato fruit yield and quality. So far, no PVMV-resistant tomato lines are available. In this study, we performed nitrite-induced mutagenesis of the PVMV tomato isolate Tn to generate attenuated PVMV mutants. PVMV Tn causes necrotic lesions in Chenopodium quinoa leaves and severe mosaic and wilting in Nicotiana benthamiana plants. After nitrite treatment, three attenuated PVMV mutants, m4-8, m10-1, and m10-11, were selected while inducing milder responses to C. quinoa and N. benthamiana with lower accumulation in tomato plants. In greenhouse tests, the three mutants showed different degrees of cross-protection against wild-type PVMV Tn. m4-8 showed the highest protective efficacy against PVMV Tn in N. benthamiana and tomato plants, 100% and 97.9%, respectively. A whole-genome sequence comparison of PVMV Tn and m4-8 revealed that 20 nucleotide substitutions occurred in the m4-8 genome, resulting in 18 amino acid changes. Our results suggest that m4-8 has excellent potential to protect tomato crops from PVMV. The application of m4-8 in protecting other Solanaceae crops, such as peppers, will be studied in the future.