Increase in Catalase mRNA in Wounded Sweet Potato Tuberous Root Tissue

Abstract

Catalase protein, as well as its activity, increases in wounded sweet potato tuberous root tissue [Esaka et al. (1983) Plant Cell Physiol. 24: 615]. Whether catalase mRNA increases in wounded tissue was examined with a hybridization probe of a cDNA for sweet potato catalase mRNA. The content of catalase mRNA in the tissue increased after a lag phase of 10 h to reach a maximum at 30 h after wounding, whereas total RNA content increased without a lag phase. The increase in the mRNA content after the lag phase preceded that in catalase activity. In the early stages after wounding, catalase mRNA in polysomes increased in spite of no increase in the total content of mRNA in the tissue. We propose that an increase in catalase mRNA is responsible for the increase in catalase protein in wounded sweet potato tuberous root tissue. In the early stage after wounding, however, the translation of catalase mRNA seems to be activated through increased availability of ribosomes.