Involvement of G-Alpha Protein GNA3 in Production of Cell wall-Degrading Enzymes by Trichoderma reesei (Hypocrea jecorina During Mycoparasitism Against Pythium ultimum

The involvement of G-alpha protein GNA3 in production of cell wall-degrading enzymes by Trichoderma reesei (Hypocrea jecorina) during mycoparasitism against Pythium ultimum was analyzed. Cellulase activity was measured as filter paper activity. Endochitinase activity was determined by the colorimetric method using colloidal chitin as substrate. Protease activity was assayed using azocasein (Sigma) as substrate. Intracellular cAMP levels were also determined using a direct cAMP enzyme in imunoassay kit (Sigma). The results showed that there was evidence that typical morphological changes associated with mycoparasitism (such as attachment) could be mediated by G-alpha protein activity level and not by direct increases in cAMP production.