Isolation and characterization of two temperature-sensitive mutants of cowpea mosaic virus

Two temperature-sensitive mutants of cowpea mosaic virus have been isolated following nitrous acid mutagenesis. One mutant, 8-14, was shown to have a temperature-sensitive defect in the B component RNA. The location of the temperature-sensitive defect of the other mutant, 8-10, was not unambiguously determined. No virus-specific proteins were detected in leaves inoculated with the mutants and grown at the restrictive temperature. Dot blot analysis and infectivity assays indicated that reduced amounts of viral RNA were synthesized in leaves inoculated with 8-10 or 8-14 under restrictive conditions and the RNA was not encapsidated.