Synergistic action of antioxidative systems contributes to the alleviation of senescence in kiwifruit

• Controlled atmosphere maintains the activity of antioxidative systems in kiwifruit.
• Controlled atmosphere suppresses ROS levels and alleviates oxidative damage.
• Controlled atmosphere promotes the expression of antioxidative genes.

Fruit senescence has been reported to be initiated by reactive oxygen species (ROS) and directly affects the quality of post-harvest fruit. Antioxidative systems protecting fruits against ROS-induced damages have been studied, but it remains poorly understood whether antioxidative systems are involved in the regulation of kiwifruit senescence. This study shows that senescence of kiwifruit was accompanied by elevation in ROS levels and subsequent oxidative damage in membranes and proteins. Controlled atmosphere storage (CA, 1% O2 plus 5% CO2), which maintained the activity of antioxidative systems, effectively suppressed the accumulation of ROS, alleviated oxidative damage and finally delayed fruit senescence, suggesting the regulatory effect of antioxidative systems on kiwifruit senescence. To further determine the underlying molecular mechanisms, expression profiles of 25 oxidative stress-related genes were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in kiwifruit stored in air and CA, respectively. Gene-expression patterns revealed that upregulated expression of SOD3, CAT1, APX1, APX2 and GR3 in the CA may predominantly contribute to the maintenance of antioxidative systems. Additionally, the synergistic action of antioxidative components is one of the determinants for the competence of the antioxidative systems. These findings may broaden understanding of the multifaceted mechanism of fruit senescence and underscore the positive effect of controlled atmosphere storage on the antioxidative systems in this process.