CHITOSAN INDUCES RESISTANCE COMPONENTS IN ARACHIS-HYPOGAEA AGAINST LEAF RUST CAUSED BY PUCCINIA-ARACHIDIS SPEG

Chitosan (1000 ppm) reduced germination of uredospores of Puccinia ara chidis, the incitant of groundnut leaf rust disease. Chitosan treatmen t of groundnut leaves before inoculation reduced the number of lesions , lesion diameter and sporulation of P. arachidis. Chitosan-treated le aves showed an increase in endogenous salicylic acid, intercellular ch itinase and glucanase activity. These compounds had been previously as sociated with induced resistance responses. Enzyme activity staining s howed new isoforms of chitinase and glucanase in treated groundnut lea ves. Western blot analysis of treated groundnut leaves also showed new isoforms of chitinase and glucanase. (C) 1998 Elsevier Science Ltd. A ll rights reserved.