CROSS-REACTIVE ANTIGENS BETWEEN XANTHOMONAS-CAMPESTRIS PV CITRI PATHOTYPES AND CITRUS SPECIES

Cross-reactive antigens were detected in crude and semi-purified prepa rations from acetone powder of Citrus aurantifolia and Citrus sinensis leaves with antisera to Xanthomonas campestris pv. citri pathotypes A and C by DAS-ELISA. Antiserum to X. campestris pv. citri pathotype C revealed an antigenic disparity between C. aurantifolia (susceptible h ost to pathotype C) and C. sinensis (resistant host to pathotype C) wh ereas antiserum to X. campestris pv. citri pathotype A did not reveal any antigenic disparity between these hosts, both susceptible to patho type A. The occurrence of ''key'' cross-reactive antigens in Citrus sp ecies and X. campestris pv. citri and their possible involvement in su ch interaction are discussed.