Abstract Culture filtrates of virulent and avirulent forms of Fusarium solani differ in pisatin-inducing potential. This difference appears to be in part due to quantitative rather than qualitative differences in the multiple pisatin-eliciting components of the fungal cultures. The patterns of pisatin-inducing activity for both virulent and avirulent forms were similar when filtrates were fractionated on ion exchange or DEAE agarose columns. Gel filtration separations indicate that the elicitors are heterogeneous in size. These eliciting components are stable to freezing and are fairly heat stable. The inducing activity is stable to DNase and RNase digestion but considerably reduced by pronase digestion. As with other pisatin inducers, induction by the culture filtrates is completely blocked by the addition of cycloheximide or cordycepin. In addition to inducing components, both forms of the fungus appear to also produce an inhibitor of pisatin production which is detectable in high concentrations of the culture filtrates.
D. Daniels, L. Hadwiger
Physiologial Plant Pathology