Cell wall plant polysaccharide-degrading enzymes in autolysis of Botrytis cinerea

Abstract

The mycelium of Botrytis cinerea undergoes a loss of 80% of its dry weight during the autolytic phase of growth in culture. The activities of lytic enzymes (polygalacturonase, endo-polygalacturonase, polymethylgalacturonase, endo-polymethylgalacturonase, pectin lyase, endo-pectin lyase, pectin esterase, xylanase, exo-cellulase and endo-cellulase) directly implicated in the degradation of plant cell walls were always higher in the culture liquid than in the mycelial extracts. Enzyme activities in the culture liquid increased during autolysis then decreased slightly at the end of this period, except for pectin esterase and polymethylgalacturonase which disappeared. With the exception of endopectin lyase, activities in the mycelial extract decreased and eventually disappeared during or at the end of the autolysis. Pectate lyase and endo-pectate lyase were not evident. The enzymatic complex obtained from autolyzed cultures of B. cinerea produced maceration of tissues, death of the cells and attack on bean plants.