PROTECTION OF TRANSGENIC PLANTS EXPRESSING THE COAT PROTEIN GENE OF WATERMELON MOSAIC VIRUS-II OR ZUCCHINI YELLOW MOSAIC-VIRUS AGAINST 6 POTYVIRUSES

The coat protein (CP) genes of watermelon mosaic virus II (WMV II) and zucchini yellow mosaic virus (ZYMV) were engineered for expression in plant tissues and subsequently transferred into Nicotiana benthamiana by Agrobacterium tumefaciens. Transgenic N. benthamiana plants expressing the CP gene of WMV II or ZYMV showed protection against symptom development when inoculated with WMV II and six other potyviruses: bean yellow mosaic (BYMV), potato Y (PVY), pea mosaic (PeaMV), clover yellow vein (CYVV), pepper mottle (PeMV), and tobacco etch (TEV). The level of protection depended on the challenge virus and the inoculum strength, with the best protection being against the lower inoculum dose. Overall, transgenic plants that expressed WMV II or ZYMV CP genes showed highest resistance to WMV II, followed by CYVV; then the group of BYMV, TEV and PeMV; and then PVY and PeaMV. Transgenic plants expressing the WMV II CP gene generally showed better protection against these potyviruses than those expressing the ZYMV CP gene. Given this and other reports, it appears that transgenic plants that express a potyvirus CP gene will show at least a noticeable level of protection against symptom development when challenged by other potyviruses.