Isolation of a basic 34 kiloDalton b-1,3-glucanase with inhibitory activity against Phytophthora capsici from pepper stems

A basic b-1,3-glucanase (34 kDa, pI 9±3)induced in pepper (Capsicum annuum L., cv. Hanbyul)stems by mercuric chloride treatment was puri®ed using CM-cellulose cation exchange chromatography, Bio-gel P-60 gel ®ltration, and FPLC cation exchange and gel ®ltration chromatography. A close serological relationship was found between the pepper 34 kDa b-1,3- glucanse and tomato b-1,3-glucanase. The 34 kDa b-1,3-glucanase inhibited hyphal growth of the chitin-negative fungus Phytophthora capsici, but did not show antifungal activity against the chitincontaining fungi Alternaria mali, Colletotrichum gloeosporioides, Magnaporthe grisea, and Fusarium oxysporum f.sp. cucumerinum. Treatment with higher amounts of the b-1,3-glucanase caused lysis of the hyphal and zoospore cells of P. capsici. Moreover, the 34 kDA b-1,3-glucanase acted synergistically with a pepper basic 32 kDa chitinase in inhibiting hyphal growth of F. oxysporum f.sp. cucumerinum and P. capsici.