ISOLATION OF A BASIC 34-KILODALTON BETA-1,3-GLUCANASE WITH INHIBITORYACTIVITY AGAINST PHYTOPHTHORA-CAPSICI FROM PEPPER STEMS

A basic beta-1,3-glucanase (34 kDa, pi 9.3) induced in pepper (Capsicu m annuum L., cv. Hanbyul) stems by mercuric chloride treatment was pur ified using CM-cellulose cation exchange chromatography, Bio-gel P-60 gel filtration, and FPLC cation exchange and gel filtration chromatogr aphy. A close serological relationship was found between the pepper 34 kDa beta-1,3-glucanse and tomato beta-1,3-glucanase. The 34 kDa beta- 1,3-glucanase inhibited hyphal growth of the chitin-negative fungus Ph ytophthora capsici, but did not show antifungal activity against the c hitin-containing fungi Alternaria mall, Colletotrichum gloeosporioides , Magnaporthe grisea, and Fusarium oxysporum f.sp. cucumerinum. Treatm ent with higher amounts of the beta-1,3-glucanase caused lysis of the hyphal and zoospore cells of P. capsici. Moreover, the 34 kDA beta-1,3 -glucanase acted synergistically with a pepper basic 32 kDa chitinase in inhibiting hyphal growth off, oxysporum f.sp. cucumerinum and P. ca psici. (C) 1997 Academic Press Limited.