Hydrolyzes chitin and plays a role in defense against fungal pathogens containing chitin. Inhibits the growth of T.reesei fungus on plate assay. Random endo-hydrolysis of N-acetyl-beta-D-glucosaminide (1->4)-beta-linkages in chitin and chitodextrins. Expressed at low levels in roots, leaves, sheaths and meristems. Belongs to the glycosyl hydrolase 19 family. Chitinase class I subfamily.