Proteins Associated with Citrus Blight. K. S. Derrick, University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850. R. F. Lee, R. H. Brlansky, L. W. Timmer, B. G. Hewitt, and G. A. Barthe. University of Florida, Institute of Food and Agricultural Sciences, Citrus Research and Education Center, 700 Experiment Station Road, Lake Alfred 33850. Plant Dis. 74:168-170. Accepted for publication 19 September 1989. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0168.

Proteins in crude extracts from healthy and blight-affected citrus trees were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Complex patterns of proteins from healthy and diseased trees were observed in extracts prepared by pulling buffers through sections of roots under vacuum. Several proteins present in extracts from diseased trees were either absent or present in much lower concentrations in healthy trees. The additional proteins observed from trees with blight appeared to be diagnostic for the disease. Protein patterns characteristic of trees with blight were observed in assays of 17 blight-symptomatic trees that had been infected by root grafting.