Abstract:

The effect of exogenous ethylene on respiration rate, ethylene production, cytochrome C oxidase (COX) activity
and the gene expression levels of mitochondrial DNA-encoded subunits Ⅰ, Ⅱ and Ⅲ of cytochrome C oxidase in fruits of
the stony-hard peach (Prumus persica) cultivar ‘Jianayan’ was determined during postharvest storage. The results showed
that exogenous ethylene accelerated the decline of firmness and promoted the respiration rate and ethylene production of
peach fruits during postharvest storage and resulted in earlier appearance of the peaks of respiration and ethylene production.
Meanwhile, exogenous ethylene inhibited COX activity and the expression level of COX Ⅲ gene throughout the storage
process and suppressed the expression of COXⅠ and COXⅡ genes in the later stage of the storage period. Exogenous
ethylene inhibited the respiration via COX pathway and accelerated the softening and senescence of fruit.

Key words: peach, ethylene, mitochondria, respiration rate, cytochrome C oxidase