Induction and expression of cutinase activity during saprophytic growth of the fungal plant pathogen, Glomerella cingulata

The fungus Glomerella cingulata damages a wide range of crops in the tropics and subtropics. This fungus produces an extracellular enzyme, cutinase, which has been implicated in the plant disease process. A cutin monomer, 16hydroxyhexadecanoic acid was used to induce cutinolytic esterase activity during saprophytic growth of G. cingulata. Cutinolytic esterase was induced in cultures grown in cutin monomer but was repressed by glucose. The pattern of cutinolytic activity obtained from the induction and enzyme assays correlates with the results of the Northern blot analyses. The cutinolytic activity and expression from this study demonstrates that the enzyme is tightly regulated by the cutin monomer, 16hydroxyhexadecanoic acid.