Protection against detrimental effects of potyvirus infection in transgenic tobacco plants expressing the papaya ringspot virus coat protein gene.

We obtained transgenic tobacco plants expressing the papaya ringspot virus (PRV) coat protein (CP) gene by transformation via Agrobacterium tumefaciens. Expression was effectively monitored by enzyme-linked immunosorbent assays (ELISA) of crude tissue extracts. Subcloned plants derived from eight original Ro transformants were inoculated with potyviruses: tobacco etch (TEV), potato virus Y (PVY), and pepper mottle (PeMV). Plants that accumulated detectable levels of the PRV CP showed significant delay in symptom development and the symptoms were attenuated. Similar results were obtained with inoculated R1 plants. We conclude that the expression of the PRV CP-gene imparts protection against infection by a broad spectrum of potyviruses.