Pepper gene encoding a basic beta-1,3-glucanase is differentially expressed in pepper tissues upon pathogen infection and ethephon or methyl jasmonate treatment

A basic beta-1,3-glucanase cDNA clone (CABGLU) was isolated from the cDNA l ibrary constructed from hypersensitive response lesions of pepper leaves in fected with avirulent strain of Xanthomonas campestris pv. vesicatoria. The deduced polypeptide of CABGLU which contains a C-terminal extension N-glyc osylated at a single site characterized as typical structure of class I bet a-1,3-glucanase has a high level of identity with tobacco basic beta-1,3-gl ucanase (77.4%), but only a moderate level of identity with tomato acidic b eta-1,3-glucanase (42.6%). Genomic DNA gel blot analysis indicates that the pepper genome contains one or two beta-1,3-glucanase copy genes. Transcrip ts of the CABGLU gene were more induced in incompatible interactions than i n compatible interactions, when inoculated with X. campestris pv. vesicator ia or Phytophthora capsici. Accumulation of CABGLU mRNA was strongly induce d in pepper leaves by both ethephon and methyl jasmonate. The CABGLU mRNA w as constitutively expressed only in the roots of all the plant organs. Thes e data indicate that the basic beta-1,3-glucanase gene may be induced by pa thogen attack and abiotic stresses. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.