Christoph Sperisen

The Primary Structure of Plant Pathogenesis-related Glucanohydrolases and Their Genes

The endo-type glucanohydrolases s-1,3-glucanase (E.C. 3.2.1.39) and chitinase (E.C. 3.2.1.14) are abundant proteins widely distributed in seedplant species (Clarke and Stone, 1962; Ballance and Manners, 1978; Powning and Irzykiewicz, 1965). The physiological functions of s-1,3- glucanase and chitinase are not known. Based on the distribution of the enzyme and its putative substrates such as callose, it has been proposed that s-1,3-glucanases may have a role in fruit ripening (Hinton and Pressey, 1980), pollen tube growth (Roggen and Stanley, 1969; Ori et al., 1990), coleoptile growth (Masuda and Wada, 1967), regulation of transport through vascular tissues (Clarke and Stone, 1962), cellulose biosynthesis (Meier et al., 1981) and cell division (Waterkeyn, 1967; Fulcher et al., 1976). Although the existence of other substrates has not been ruled out, chitin, the known substrate of chitinase, is not found in higher plants.