AN INHIBITOR OF EXTENSIN PEROXIDASE IN CULTURED TOMATO CELLS

Incubation of intact washed rapidly growing tomato (hybrid of Lycopers icon esculentum and L. peruvianum) suspension cells with 0.2 M phospha te buffer pH 7.0 for 23 hr at 25-degrees liberated a significant amoun t of oxidizing agent and a selective inhibitor of peroxidase-mediated cross-linking of extensin precursor in vitro. Further studies revealed that an endogenous heat-stable oxdizing agent and heat-labile inhibit or are two separate low molecular weight components (M(r) < 5000) and that the oxidizing agent is not H2O2.