callose

views updated

callose An insoluble glucan that is found in higher plants, in which glycosidic (see GLYCOSIDE) linkages join the first and third carbon atoms of neighbouring beta-glucose units. Structurally it is similar to the protozoal storage carbohydrates, paramylon and leucosin, and also to the algal product laminarin. In angiosperms it is formed in response to injury, especially in phloem and in germinating pollen tubes.