PATHOGENESIS-RELATED PROTEINS IN SOLANUM-DULCAMARA L RESISTANT TO THE GALL MITE ACERIA-CLADOPHTHIRUS (NALEPA) (SYN ERIOPHYES-CLADOPHTHIRUS NAL)

Feeding by the gall mite Aceria cladophthirus on resistant varieties of Solanum dulcamara leads to the development of small necrotic local lesions. This hypersensitive response in infested leaves is accompanied by the accumulation of several novel proteins referred to as pathogenesis-related proteins (PR proteins). This report expands the range of stimuli triggering PR protein synthesis and confirms that these proteins are markers of the hypersensitive response of plants. Simultaneously, chitinase and β-1,3-glucanase activities are induced during the development of A. cladophthirus-induced lesions. This suggests that some PR proteins of S. dulcamara have chitinase and β-1,3-glucanase activities. These enzymes may contribute to the defense responses of plants against mites. © 1991 Academic Press Limited.