CELL-WALL BOUND AND SOLUBLE PEROXIDASES IN NORMAL AND DWARF TOMATO

Normal and dwarf tomato shoots were analyzed for their peroxidase isoenzyme content and total peroxidase activity. Both plant types were shown by electrophoresis to contain three isoenzymes that moved toward the anode and one that moved toward the cathode. Both types contained a cell wall bound peroxidase that was electrophoretically different from the four soluble isoenzymes. Cell wall bound peroxidase was separated from soluble peroxidase isoenzymes in crude extracts by using purified cell walls. With this method, accurate measurements of the total cell wall bound and soluble peroxidase activities were obtained. Cell wall bound peroxidase accounted for 30% and 56% of the activity in etude extracts of normal and dwarf plants, respectively. Total peroxidase activity in the normal plant was 74% cell wall bound and 81% in the dwarf plant. Cell wall bound peroxidase activity was 5.2 times greater in the dwarf when compared to the normal plant. © 1990, American Chemical Society. All rights reserved.