Purification of a phospholipase from Botrytis and its effects on plant tissues

A phospholipase from Botrytis cinerea, grown in pure culture, was purified more than 1000-fold. Whilst it possessed no acyl hydrolase activity toward a variety of p-nitrophenyl fatty acyl derivatives, phosphatidyl choline (lecithin) acted as a substrate; the enzyme being of either type ‘A’ or ‘B’ specificity. When the purified enzyme was applied to washed beetroot discs, betacyanin leakage was induced. Loss of substances which absorb at 260 nm also occurred when washed potato tuber discs were incubated with the enzyme. Incubation with a lysosome-enriched fraction from potato sprout tissues resulted in increased acid phosphatase activity in the incubation supernatant. The phospholipase had no macerating effect on a variety of plant tissues, nor did it cause disruption of isolated protoplasts from these tissues. Studies with mitochondria from mung beans revealed no effects of the enzyme upon the respiratory activity of these organelles. The result suggested that a major site of action of the B.cinerea phospholipase was the lysosomes.