INHIBITION OF ETHYLENE PRODUCTION BY TROPOLONE COMPOUNDS IN YOUNG EXCISED PEACH SEEDS

The effect of tropolone, hinokitiol, purpurogallin, and colchicine on ethylene production and ACC content in young excised peach seeds was i nvestigated. Application of aqueous solution or suspension of these co mpounds inhibited ethylene production and suppressed the increase of A CC. Tropolone and hinokitiol at 250 ppm inhibited ethylene production by 95%, whereas pur purogallin and colchicine were less effective. Tro polone and hinokitiol are readily volatilized so that when the effect of their gaseous phase on ethylene production was examined, we found t heir inhibitory effects were proportionate to their concentrations. Th e inhibition by low gaseous hinokitiol concentration was released when the seeds were transferred to air, but it was irreversible when the c oncentration was high. Mechanisms of inhibition of ethylene biosynthes is by tropolones are briefly discussed.