Changes in indole-3-acetic acid,indole-3-acetic acid oxidase,and peroxidase isoenzymes in the seeds of developing peach fruits

Changes in indole-3-acetic acid (IAA) content of peach (Prunus persica L. Batsch cv. Merry) seeds were followed during fruit development. The highest concentration of IAA, 2.7 g/g fresh weight, was found at the beginning of Stage III of fruit development, approximately 50–60 days after anthesis. The IAA-decarboxylating capacity of crude extracts of seeds was also greatest at 55–60 days after anthesis. Four soluble peroxidase isoenzymes were found on anionic electrophoresis. There were no marked changes in two isoenzymes (R_f 0.23 and 0.51), which were present in all three stages of fruit growth. There was a marked increase in a band atR_f 0.59 between Stages II and III, and a decrease in a band atR_f 0.68 from Stages II to III. Neither band (R_f 0.59 and 0.68) was present at Stage I.