Comparison of some molecular, enzymatic and antifungal properties of chitinases from thorn-apple, tobacco and wheat

Abstract

Chitinases (E.C.3.2.1.14) were isolated from leaves of thorn-apple ( Datura stramonium), tobacco ( Nicotiana tabacum) and from embryos of wheat ( Triticum aestivum). All three chitinases exhibited similar physico-chemical, enzymatic and antifungal properties. However, the chitinase from wheat differed slightly from the other two in that it did not yield a line of identity upon immunodiffusion against Datura stramonium chitinase antiserum, and did not produce the same oligosaccharide pattern when used to hydrolyse chitin. All three chitinases inhibited germination of Trichoderma hamatum and Phycomyces blakesleeanus spores at concentrations as low as 8 and 32 μg ml −1 respectively. Hyphal growth of T. hamatum and P. blakesleeanus was inhibited by 50%, at chitinase concentrations of 2 and 20 μg ml −1 respectively. However, at this concentration and indeed at concentrations as high as 320 μg ml −1, spore germination and hyphal growth of Botrytis cinerea was not affected by the chitinases.