Effect of Ethylene on the Increase in Catalase Activity through Microbody Development in Wounded Sweet Potato Root Tissue

摘要

Catalase activity increases when slices of sweet potato root tissue are incubated in air. The increase is due to de novo synthesis of the enzyme protein and probably also to activation of a precursor protein Esaka et al. (1983)PlantCell Physiol. 24: 615. The activity-increase was partly depressed when tissue slices were incubated in ethylenecontaining air, while the immunologically determined amount of catalase protein did not increase, rather it decreased, under the same conditions. We propose that ethylene inhibits the de novo synthesis of catalase protein but not the activation of precursor protein. Catalase from tissue slices incubated in ethylene-containing air migrated faster on a polyacrylamide gel than that from intact tissue or tissue slices incubated in air. When either polyacrylamide or an SDS-polyacrylamide gel applied with crude extract from tissue slices incubated in ethylene-containing air underwent immunological blotting, the blots were much fainter than those for intact tissue. In addition, microbody membrane fraction from incubated tissue slices contained a significant amount of catalase which was sedimented at the bottom of a sucrose density gradient (20–70) and was not solubilized by high concentrations of lubrol PX. The fraction showed an exceptionally high catalase activity per unit amount of immunoreactive protein to anti-catalase antibody. We propose that ethylene causes some modification of catalase protein which facilitates the formation of aggregates or core