Changes in respiration and ethylene production rates by young soybean and cherry tomato fruits exposed to an abrupt decrease in oxygen concentration

"Responses of respiration and C2H4 production in young soybean and cherry tomato fruits to an abrupt decrease in O2 concentration was investigated. The rates of O2 consumption, CO2 evolution and C2H4 production under ambient atmosphere and when O2 concentration was abruptly decreased from21% to 3.5% were compared. A mathematical model, which assumes the exponential gas exchange with the time after the completion of O2 gas replacement, fitted well with the experimental data. The response rate constant K, which was newly defined, enabled the Quantitative evaluation of the response to low O2 atmosphere. K values for O2 consumption, CO2 evolution and C2H4 production differed: CO2evolution had the lowest K value among gases. Moreover, K value for CO2 evolution depended on the species and maturity. These results may be attributed to the differences in 02 metabolism and physical properties, such as gas solubility, skin permeability and tissue structure."