THE ROLE OF GROWTH HORMONES DURING USTILAGO MAYDIS (DC) CORDA PATHOGENSIS IN MAIZE PLANTS

Abstract

The endogenous hormonal changes after U. maydis inoculation resulted in early and slight activation of gibberellin like substances in the vegetative tissues of inoculated plants 2 and 4 days after ino- culation, thereafter the inhibitors were more active. Such behaviour was confirmed well in the acidic Gibberellin like fraction measured by GLC technique. substances appeared to be significant in fungal cul- ture filtrate at the end of the incubation period only. Auxins were more active in vegetative tissues of ino- culated plants as a result of fungal inoculation. Such activities were more at tumer development (last samples). Auxins appeared with significant values in culture Results for filtrates through experimental period. auxins also were confirmed well in the acidic fraction measured by GLC. Inoculated plants showed clear acti- vity in cytokinins 4 days after inoculation only and then decreased. A decrease in cytokinin was observed in other samples. Cytokinin appeared as fungal meta- bolite and its amounts decreased by increasing incuba- tion period.