Citral exerts its antifungal activity against Penicillium digitatum by affecting the mitochondrial morphology and function.

This work investigated the effect of citral on the mitochondrial morphology and function of Penicillium digitatum. Citral at concentrations of 2.0 or 4.0 μL/mL strongly damaged mitochondria of test pathogen by causing the loss of matrix and increase of irregular mitochondria. The deformation extent of the mitochondria of P. digitatum enhanced with increasing concentrations of citral, as evidenced by a decrease in intracellular ATP content and an increase in extracellular ATP content of P. digitatum cells. Oxygen consumption showed that citral resulted in an inhibition in the tricarboxylic acid cycle (TCA) pathway of P. digitatum cells, induced a decrease in activities of citrate synthetase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, succinodehydrogenase and the content of citric acid, while enhancing the activity of malic dehydrogenase in P. digitatum cells. Our present results indicated that citral could damage the mitochondrial membrane permeability and disrupt the TCA pathway of P. digitatum.