ABSTRACT
Several classes of proteins, called pathogenesis-related (PR) proteins, are induced in response to the infection of plants with microbial pathogens.
This chapter deals with the family of PR-2 proteins, which are
β
-1,3-glucanases (glucan endo-1,3-
β
-
glucosidases, E.C. 3.2.1.39) able to catalyze endo-type hydrolytic cleavage of the 1,3-
β
-D-glucosidic linkages in
β
-1,3-glucans. The
β
-1,3-glucanases are abundant, highly regulated enzymes widely distributed in seed-plant species.
