Production of RNA and Coat Protein of a Wild-type Isolate and a Temperature-sensitive Mutant of Cowpea Chlorotic Mottle Virus in Cowpea Leaves and Tobacco Protoplasts

Summary The multiplication of a temperature-sensitive (ts) mutant of cowpea chlorotic mottle virus (CCMV) in tobacco protoplasts has been examined. The results were similar to those obtained with intact cowpea plants. No intact virus was produced above 33.5 °C, and no coat protein, either soluble or insoluble was detected in the absence of intact virus. Ribonucleic acid (RNA) of the ts mutant, however, was synthesized at 35 °C. Virus particles made at 25 °C were degraded in vivo when the infected protoplasts were subsequently cultured at 35 °C. RNA-3 of ts CCMV was apparently encapsidated much more often than RNA-3 of wild-type (wt) CCMV in doubly infected protoplasts cultured at either 25 or 35 °C.