Abstract
Inhibitory effects on the local lesion formation of some proteinaceous inhibitors of plant viral infection such as trypsin, pancreatin, pancreatic ribonuclease (NBC, 5X cryst.) and Chenopodium sap were studied using suitable virus-host combinations as shown in Fig. 1 and 2, cucumber mosaic virus (CMV), tobacco mosaic virus (TMV), TMV-RNA, and daikon mosaic virus (DMV) being used as the test inocula.
Both Chenopodium sap and pancreatic ribonuclease (0.5mg/ml) showed remarkable inhibition of lesion formation in all virus-host combinations when applied within 30 to 60 minutes after inoculation. This was also the case when they were applied to Nicotiana glutionsa one day before inoculation with TMV, suggesting that the inhibition is probably attributed to their injurious effects on cytoplasm of the host cell. Both trypsin and pancreatin were also inhibitory to the lesion formation in all virus-host combinations when applied within 30 to 60 minutes after inoculation, whereas they showed little effect when applied to N. glutinosa one day before inoculation with TMV. The results led us to an interpretation that the effect of trypsion and pancreatin is attributable to interference in the formation of virus-receptor complex at the susceptible site.
