Changes in soluble proteins in callus cells of hypersensitive tobacco inoculated with tobacco mosaic virus.

Protein changes occurred in callus cells of hypersensitive tobacco (Nicotiana tabacum var. Xanthi-nc) 72 hr after inoculation with tobacco mosaic virus and incubation on a minimal growth medium. Two protein bands, serologically related to viral coat protein, were obtained from extracts of infected cells following electrophoresis on 7% and 10% polyacrylamide gels. An additional, slower migrating protein, perhaps due to virus-induced stimulation of a host protein, also was detected. Although local lesions appeared on callus after 40 hr of incubation, four proteins previously reported in lesion-bearing hypersensitive tobacco leaves were not found. The possible significance of this and the usefulness of a callus-TMV system as a tool to study virus-induced protein changes are discussed.