Hydrogen peroxide reduced ATPase activity and the levels of ATP, ADP, and energy charge and its association with pulp breakdown occurrence of longan fruit during storage

The effects of hydrogen peroxide (H2O2) on the contents of adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP), the level of energy charge, and the activity of adenosine triphosphatase (ATPase) in pulp of harvested longan fruit, and its association with longan pulp breakdown occurrence were studied. The results showed that, compared to the control longans, H2O2-treated longans exhibited a higher index of pulp breakdown, a higher amount of AMP, but lower levels of ATP, ADP and energy charge. H2O2-treated longans also exhibited lower activities of Mg2+-ATPase, Ca2+-ATPase, and H+-ATPase in mitochondrial membrane, vacuolar membrane, and plasma membrane as compared to the control longans. Above findings demonstrated that H2O2 caused longan pulp breakdown by depleting energy and lowering the ATPase activity, indicating H2O2-induced pulp breakdown in harvested longan fruit was due to energy deficit.