Abstract
Tea leaf galloyl - catechins, (-) -epicatechin gallate ((-) ECg) and (-) -epigallocatechin gallate ((-) EGCg) inhibited local lesion formation by tobacco mosaic virus (TMV) on Nicotiana glutinosa. In the present report, the amount of catechins necessary for inhibiting TMV infectivity and recovery of the infectivity after catechin removal by gelatin were investigated. When 0.1 and 0.2% (w/v) of (-) ECg were added to TMV solution (ca. 32μg/ml), the inhibition was estimated to be 90 and 99%, respectively. The same concentrations of (-) EGCg inhibited by 98 and 99%, respectively. When a definite concentration of gelatin was added to the mixture of (-) ECg and infected tobacco leaf extract, the number of local lesions increased as the period of incubation was prolonged. The addition of gelatin, however, did not cause any change in the inhibitory activity of (-) EGCg even after aprolonged incubation. The mode of inhibition by catechin of the local lesion formation was discussed in connection with the action of tannic acid.
