Defense against chitin-containing fungal pathogens. Seems particularly implicated in resistance to jasmonate-inducing pathogens such as A.brassicicola. In vitro antifungal activity against T.reesei, but not against A.solani, F.oxysporum, S.sclerotiorum, G.graminis and P.megasperma. Random endo-hydrolysis of N-acetyl-beta-D-glucosaminide (1->4)-beta-linkages in chitin and chitodextrins. High constitutive level in roots with lower levels in leaves and flowering shoots. Ethylene induces high levels of systemic expression of basic chitinase with expression increasing with plant age. Locally and systemically induced by jasmonic acid (JA) and pathogens such as A.brassicicola and P.syringae, particularly in case of hypersensitive responses (HR). Not induced by wounding. Belongs to the glycosyl hydrolase 19 family. Chitinase class I subfamily. Truncated N-terminus. Truncated N-terminus.