CHANGES IN ASCORBATE PEROXIDASE-ACTIVITIES DURING FRUIT RIPENING IN CAPSICUM-ANNUUM

The ascorbate peroxidase (APX) system was studied in Capsicum annuum d uring fruit ripening. A large increase in organelle APX activity was f ound during chloroplast-chromoplast transition whereas only a slight d ifference was detected in total fruit extracts. On native gels, four d ifferent isoforms were found in total fruit extracts but the patterns for red and green fruit were quite different. In isolated organelles, six isozymes were found and a comparison of the patterns showed signif icant differences. A cDNA encoding a cytosolic APX was cloned and sequ enced. The corresponding transcript was shown to increase 3-4-fold dur ing fruit ripening.