Relationship between ethylene production and ripening in cv. Hayward fruits at harvest and during storage.
Sfakiotakis, E.; Antunes, M. D.; Stavroulakis, G.; Niklis, N.;
Rivista di Frutticoltura e di Ortofloricoltura Year: 1999 Vol: 61 Issue: 12 Pages: 59-65 Ref: 16 ref.
1999
บทคัดย่อ
The role of ethylene in postharvest physiology of kiwifruits is reviewed. Kiwifruits differ from other climacteric fruits in that they show no increase in ethylene production on the vine nor produce ethylene during cold storage. The fruits show a typical climacteric of respiration and ethylene production at moderate temperatures (17-34 deg C), while at low temperatures (>11-14.5 deg C) they behave as non-climacteric fruits. The fruits show thermoregulation of ethylene production separate from the ripening process. Ethylene production can be induced autocatalytically by exogenous ethylene or propylene, exposure to chilling temperatures, wounding and Botrytis infection. Propylene stimulates ethylene and ACC production at warm temperatures by inducing ACC synthase and ACC oxidase activities. Although the propylene-treated fruits do not produce ethylene at cold storage temperatures, ripening proceeds independently of autocatalytic ethylene production. There is an inhibition of propylene-induced ethy
lene production in kiwifruits below a critical temperature range of 11-14.5 deg C. This inhibition of ethylene production at low temperatures is attributed primarily to the inhibition of the expression of the propylene-induced ACC synthase gene and to the possible post-transcriptional modification of ACC oxidase. Increased CO2 concentrations (10%) in the storage atmosphere drastically reduce the rate of propylene-induced ethylene production, while reduced O2 concentrations (1-5%) inhibit propylene-induced ethylene production at the ACC synthesis level. Exposure of fruits to chilling temperatures for at least 12 days stimulates ethylene production upon rewarming by inducing ACC synthase and ACC oxidase activity. However, fruits removed from prolonged storage at 0 deg C in conventional or controlled atmosphere storage show reduced capacity to produce ethylene, due to reduced ACC production and ACC synthase and ACC oxidase activities. Ultra-low oxygen (ULO) storage inhibits more drastically the induction of eth
ylene production by chilling, mainly by destroying the system that converts ACC to ethylene. Wounding and Botrytis infection induce the fruits to produce ethylene even at low temperatures. Accumulation of ethylene from wounding or Botrytis infection can cause excessive softening of the fruits in storage. It is suggested that the above findings can be used to draw up guidelines for an integrated handling system to prolong the storage life and improve the edible quality of kiwifruits.