Isolation of a cultivar-specific gene to soybean stunt virus

宿主对植物病毒的抗性具体观察取决于宿主-病毒组合。利用黄瓜花叶病毒（CMV）及其大豆淀粉（SSV），分析了两种寄主-病毒组合（寄主种-CMV和大豆品种-SSV）对黄瓜花叶病毒的抗性表型。在后一种组合中，我们确定了抗性机制的作用位置，并提出存在两个互补的显性宿主因子来控制大豆品种对SSV的抗性。在黄瓜- cmv和大豆-SSV组合中，系统感染的主要决定因素是包括3a基因的结构域，根据品种的不同，品种对SSV的抗性需要额外的病毒基因（CP基因），RNA3的S区（主要是5'非翻译区）和包括整个2b基因的区域一起是系统运动所必需的。因此，这与有两个宿主因素影响病毒全身性感染的观察是一致的。

Host resistance to plant viruses is specifically observed depending on host-virus combination. Using Cucumber mosaic virus(CMV) and its soybean starain (SSV), we analyzed the resistant phenotype that a virus does not systemicaily spread but it it is localized in the inoculated leaves in two host-virus combinations (host species-CMVs and soybean cultivars-SSVs). In the latter combination, we determined where the resistance mechanism operates and suggested existence of two complementary dominant host factors to control the sobybean cultivar resistance to SSV. Both in cucumber-CMV and in soybean-SSV combinations, the primary determinant for systemic infection is the domain including the 3a gene and depending on cultivars, an additional viral gene (the CP gene) was required in the cultivar resistance to SSV, the S region of RNA3 (mainly the 5' non-translated region) and the region including the entire 2b gene were together necessary for the systemic movement. It is therefore consistant with the observation that there are two host factors to affect the viral sysmtemic infection.