The relationship between mitochondrial respiration metabolism, energy efficiency and ultraweak luminescence in...

Ultraweak luminescence (UWL) is a natural phenomenon characterized by extremely low light emission in living organisms. Although it has attracted scientific attention for decades, its underlying mechanisms remain unclear.

This study aimed to elucidate the relationship between mitochondrial respiratory metabolism and UWL in strawberry fruit mitochondria, focusing on how electron transport and oxidative phosphorylation affect UWL intensity.

Mitochondria from the strawberry variety 'Hongyan' were treated with activators adenosine diphosphate (ADP) and sodium succinate (C₄H₄Na₂O₄) or inhibitors 2,4-Dinitrophenol (DNP) and sodium vanadate (NaVO₄) during ATP synthesis. Comparative analyses assessed mitochondrial respiration, energy parameters, and UWL changes under these treatments.

Activator treatments significantly increased respiratory enzyme activities of succinate dehydrogenase (SDH), cytochrome c oxidase (COX) and H⁺-ATPase, respiration rate, respiratory pathway contributions, ATP, ADP, energy charge, and UWL intensity at higher concentrations (P < 0.05). In contrast, inhibitor treatments caused progressive reductions in these indicators and UWL intensity, also reaching significance at higher concentrations. Correlation analysis showed UWL intensity was positively associated with respiration metrics, especially respiration rate and cytochrome pathway contribution (P < 0.05), and strongly correlated with ATP, ADP, and energy charge (P < 0.05 or P < 0.01), while negatively correlated with AMP (P < 0.05). Principal component analysis indicated that energy parameters contributed most to UWL variation, followed by respiration rate and enzyme activities.

UWL intensity reflects mitochondrial respiratory metabolism and ATP production, suggesting mitochondria are key organelles in UWL generation. UWL could serve as a potential indicator of mitochondrial function and cellular energy status.