Modifications of the Coat Protein Gene of Tobacco Mosaic Virus Resulting in the Induction of Necrosis

Abstract

We are examining the interaction of tobacco mosaic virus (TMV) with Nicotiana species relative to the induction of necrosis. A number of point mutations in the coat protein gene have been found to induce a hypersensitive reaction (HR) in plants with the N’N’ genotype. Several of these coat protein point mutations also induce a systemic necrosis on nn genotype plants. Partial deletions of the coat protein gene have been found to induce a generalized necrosis that appears not to be specific to any one host gene. Removal of the entire TMV coat protein gene does not effect the induction of HR in NN genotype plants. Thus, a viral component other than the coat protein gene can elicit HR in NN genotype plants.