Changes in Ethylene Production and Activities of Related Enzymes in Peach Seeds Excised at Different Growth Stages

摘要

Peach seeds started to evolve a burst of ethylene shortly after removal from the pits. The ethylene production was very high at early and middle stages of growth and declined at late stage. The 1-aminocyclopropane-l-carboxylate (ACC) content increasedsharply in parallel with ethylene production at the early stage but slightly at the middle and late growth stages. The initial ACC synthase activity after removal from the pits was greatest at the early stage and increased greatly during incubation at 24°C up to 12 hrs and then declined, whereas only slight increases were observed at the middle and late stages. On the other hand, the initial ACC oxidase activity was lowest at the early stage and only slightly increased during incubation at this stage.However, the initial ACC oxidase activity at the middle and late stages was greater than at the early stage and increased during incubation at the middle stage, but only slightly increased up to 12 hrs, then declined at the late stage. Therefore, it seems that the burst of ethylene in peach seeds after removal from the pits is regulated differently at different growth stages.