Shi Feifei, Wang Ying, Zhang Fang, Yuan Xingxing, Chen Huatao, Chen Xuehao, Chen Xin, Cui Xiaoyan
Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences/Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement, Nanjing, China.
Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing, China.
Front Genet. 2020 Sep 15;11:536771. doi: 10.3389/fgene.2020.536771. eCollection 2020.
(SMV), a member of the genus , is a prevalent and devastating viral pathogen in soybean-growing regions worldwide. Potyvirus-encoded P3 protein is reported to participate in virus replication, movements, and pathogenesis. This study provides evidence that the soybean () endo-1,3-beta-glucanase protein (designated as GmGLU) interacts with SMV-P3 by using a yeast two-hybrid system to screen a soybean cDNA library. A bimolecular fluorescence complementation assay further confirmed the interaction, which occurred on the cytomembrane in cells. Subcellular localization experiment indicated that GmGLU localized in cytomembrane and could co-localized at PD with PD marker. The transient expression of GmGLU promoted the coupling of Turnip mosaic virus replication and cell-to-cell movement in . Meanwhile, qRT-PCR experiment demonstrated that the expression of GmGLU which involved in callose regulation increased under SMV infection. Under SMV infection, callose deposition at PD was observed obviously by staining with aniline blue, which raise a physical barrier restricting cell-to-cell movement of SMV. When overexpression the GmGLU into the leaves under SMV infection, the callose induced by SMV was degraded. Coexpression the GmGLU and SMV in soybean leaves, callose was not found, whereas a large amount of callose deposition on soybean leaves which were only under SMV infection. The results show that GmGLU can degrade the callose induced by SMV infection and indicate that GmGLU may be an essential host factor involvement in potyvirus infection.
大豆花叶病毒（SMV）是该属的一个成员，是全球大豆种植区普遍存在且具有破坏性的病毒病原体。据报道，马铃薯Y病毒编码的P3蛋白参与病毒复制、移动和发病机制。本研究提供了证据，表明大豆（）内切-1,3-β-葡聚糖酶蛋白（命名为GmGLU）通过酵母双杂交系统筛选大豆cDNA文库与SMV-P3相互作用。双分子荧光互补试验进一步证实了这种相互作用，其发生在细胞的细胞膜上。亚细胞定位实验表明，GmGLU定位于细胞膜，并可与胞间连丝标记物在胞间连丝处共定位。GmGLU的瞬时表达促进了芜菁花叶病毒在中的复制与细胞间移动的偶联。同时，qRT-PCR实验表明，参与胼胝质调控的GmGLU的表达在SMV感染下增加。在SMV感染下，用苯胺蓝染色明显观察到胞间连丝处有胼胝质沉积，这形成了一个物理屏障，限制了SMV的细胞间移动。当在SMV感染下将GmGLU过表达到叶片中时，SMV诱导的胼胝质被降解。在大豆叶片中共表达GmGLU和SMV时，未发现胼胝质，而仅在SMV感染的大豆叶片上有大量胼胝质沉积。结果表明，GmGLU可以降解SMV感染诱导的胼胝质，并表明GmGLU可能是参与马铃薯Y病毒感染的一个重要宿主因子。
