CLONING AND EXPRESSION OF THE CUTINASE-A GENE OF BOTRYTIS-CINEREA

Cutinase of Botrytis cinerea has been suggested to play an important r ole in penetration of host tissues. A protein fraction with cutin hydr olyzing activity was purified from culture filtrates of B. cinerea ind uced for cutinase activity. An 18-kDa protein in this fraction was ide ntified as cutinase and the corresponding gene cutA was cloned. The ge ne is present in a single copy in the genome of B. cinerea strain SAS5 6 and its predicted amino acid sequence shows significant homology (31 to 35% identity) to other fungal cutinases. RNA blot analysis showed that cutA mRNA is induced in vitro by the cutin monomer 16-hydroxyhexa decanoic acid and repressed by glucose. The expression of cutA during infection of tomato leaves is low during early phases of infection, bu t high when the fungus has colonized the leaf and starts to sporulate.