EFFECT OF CUCURBITACINS ON MESSENGER-RNA CODING FOR LACCASE IN BOTRYTIS-CINEREA

The effect of cucurbitacin and of Ecballium extract on the formation o f mRNA coding for laccase was examined in cultures of Botrytis cinerea grown with inducers of laccase formation, in the presence or absence of the inhibitory compounds. RNA was isolated from the cultures and pr obed with specific DNA probes for laccase. As an internal control, the RNA was probed for Botrytis beta-tubulin mRNA. From an analysis of th e results it is clear that cucurbitacin I and Ecballium extract specif ically repress the amount of mRNA coding for laccase. This could accou nt for the previously observed repression of laccase formation by cucu rbitacins.