低濃度酸素環境がモモとバナナ果実のエチレン生合成に及ぼす影響

Abstract

The rates of C2H4 production in peach and banana fruits stored under 3 % O2 decreased by approximately 60% and 50% respectively compared to those stored in air. 1-aminocyclo-propane-1-carboxylic acid (ACC) oxidase activity in both fruits did not change during low O2 and subsequent air storage, when measured in the disks incubated under air condition. Low O2 treatment increased slightly ACC contents in both fruits. However, the increase in ACC content in peaches was much less compared to the calculated increase based on the result of the inhibition in C2H4 production, on the assumption that low O2 atmosphere would not affect the conversion of s-adenosylmethionine (SAM) to ACC. When ACC oxidase activity in excised flesh tissues from peach, banana, cucumber, and eggplant was measured under various O2 concentrations, the activity was distinctly O2-dependent. Our results suggest that inhibition of C2H4 production by shortterm low O2 treatment is mainly due to inhibition of ACC oxidase activity, not due to decrease in amount of the enzyme. The inhibitory effect of low O2 on C2H4 production in peach fruit might be partly due to inhibition of the conversion of SAM to ACC.