Purification of an elicitor-inducible antifungal chitinase from suspension-cultured rice cells

Suspension-cultured rice cells showed an appreciable amount of chitinase activity when the cultured cells were treated with an elicitor isolated from Rhizoctonia solani, the rice sheath blight pathogen. A fivefold increase in chitinase activity was observed 24 h after elicitor treatment. The elicitor-inducible chitinase was purified by ammonium sulfate fractionation, chitin affinity chromatography and gel filtration. Its molecular weight is 35 kDa and it has an isoelectric point of 8.3. The 35 kDa basic chitinase inhibited mycelial growth of R. solani in vitro. Morphological changes appeared within 1 h following exposure of mycelium to the chitinase. The hyphal tip showed marked swelling and subsequently lysis was also observed.