INVOLVEMENT OF PLANT CHITINASE IN SEXUAL REPRODUCTION OF HIGHER-PLANTS

Higher plants do not contain chitin but chitin-hydrolytic enzyme or chitinase activity is present in extracts of seeds, roots or leaves. Large increases of the enzyme activity have been found in the latter two organs following attack by chitin-containing phytopathogens or pests. This has led to the widespread notion that plant chitinase is a defence protein. However, the present study reports that active chitinase enzyme is present in the extracts of healthy and non-senescent petunia flower tissues. Furthermore, almost all the flower chitinase activity is localized in the stigma and increases about five-fold therein following anther dehiscence. This strongly suggests the plant chitinase has a heretofore unrecognized specific function in the sexual reproduction of higher plants.