Methyl salicylate treatment alleviates peel spotting of ‘Sucrier’ banana by improving mitochondrial physiological properties and functions

Abstract

The stage of mitochondrial health is of important in instigating senescence and physiological disorder. The aim of this study was to investigate the effect of methyl salicylate (MeSA) on preserving mitochondrial properties and functions related to senescent spotting of ‘Sucrier’ banana. Ripen banana fruit (color index 4) treated with 2 mM MeSA for 30 min, were examined for physiological and biochemical changes during 6 d of storage 25 °C. It was found that the treatment effectively hindered the occurrence of senescence spotting during storage. At the same time, both mitochondrial superoxide and hydrogen peroxide production were found to be reduced. This reduction of reactive oxygen species coincided with enhanced activity of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, ascorbate peroxidase and alternative oxidase. The treatment lowered overall permeability of mitochondria, as demonstrated by delaying the opening of mitochondrial permeability transition pores and preventing the loss of mitochondrial membrane potential and mitochondrial cytochrome c content. Moreover, the activity of NADH dehydrogenase, succinate dehydrogenase and cytochrome c oxidase activities as well as ATP content remained higher under the treatment. These findings suggested that MeSA treatment delayed the appearance of peel spotting through strengthening mitochondrial antioxidant defense mechanisms. This, in turn, preserves the health and function of the organelle which ultimately leads to postponing the onset of peel spotting.