VIEW ARTICLE

Resistance

Protection of Transgenic Plants Expressing the Coat Protein Gene of Watermelon Mosaic Virus II or Zucchini Yellow Mosaic Virus Against Six Potyviruses. Shigetou Namba, Department of Plant Pathology, Cornell University, Geneva, NY 14456, Permanent address: Laboratory of Plant Pathology, Faculty of Agriculture, University of Tokyo, Bunkyo-Ku, Tokyo, Japan; Kaishu Ling(2), Carol Gonsalves(3), Jerry L. Slightom(4), and Dennis Gonsalves(5). (2)(3)(5)Department of Plant Pathology, Cornell University, Geneva, NY 14456; (4)Molecular Biology Unit 7242, The Upjohn Company, Kalamazoo, MI 49007. Phytopathology 82:940-946. Accepted for publication 22 May 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/Phyto-82-940.

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.