Lu Hong, Ge Panpan, Ma Yonghuan, Lin Feng, Jing Dedao, Zhou Tong, Cui Feng
State Key Laboratory of Animal Biodiversity Conservation and Integrated Pest Management, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
University of Chinese Academy of Sciences, Beijing, China.
Mol Plant Pathol. 2025 Jul;26(7):e70121. doi: 10.1111/mpp.70121.
Plant viruses usually exploit plasmodesmata (PDs) to achieve cellular infection in host plants. Although PD-associated proteins are commonly implicated in the regulation of PD pore size, a few limited cases demonstrate their roles as viral targets suitable for resistance breeding. Here we screened the importin α protein family of rice to identify the PD-associated members and explored their effects on the infection of rice stripe virus (RSV), one of the most notorious pathogens threatening rice yields. Both Importin α1b and α4 were found to be localised on the plasma membrane and PD. Only importin α4 knockout mutant rice exhibited resistance to RSV infection while the role of importin α1b in RSV infection was negligible. The absence of importin α4 enhanced callose deposition at PDs, which impeded viral intercellular movement. Flotillin 1 is another PD-associated protein in rice and was previously reported to facilitate RSV infection. When flotillin1 and importin α4 were simultaneously knocked out, the double-knockout mutant exhibited a synergically higher resistance level to RSV not only in the greenhouse but also in natural fields without affecting agronomic traits. This study proposed the potential of the two PD-associated proteins as targets for engineering virus resistance in future.
植物病毒通常利用胞间连丝（PDs）在宿主植物中实现细胞感染。尽管与PD相关的蛋白质通常参与调节PD孔径，但少数有限的案例表明它们作为适合抗性育种的病毒靶标的作用。在这里，我们筛选了水稻的输入蛋白α蛋白家族，以鉴定与PD相关的成员，并探索它们对水稻条纹病毒（RSV）感染的影响，RSV是威胁水稻产量的最臭名昭著的病原体之一。发现输入蛋白α1b和α4都定位于质膜和PD上。只有输入蛋白α4敲除突变体水稻对RSV感染表现出抗性，而输入蛋白α1b在RSV感染中的作用可忽略不计。输入蛋白α4的缺失增强了PD处胼胝质的沉积，这阻碍了病毒的细胞间移动。Flotillin 1是水稻中另一种与PD相关的蛋白质，先前报道它促进RSV感染。当Flotillin1和输入蛋白α4同时被敲除时，双敲除突变体不仅在温室中而且在自然田间对RSV都表现出协同更高的抗性水平，且不影响农艺性状。本研究提出了这两种与PD相关的蛋白质作为未来工程化病毒抗性靶标的潜力。
