(E)-2-Octenal inhibits Neofusicoccum parvum growth by disrupting mitochondrial energy metabolism and is a potential preservative for postharvest mango.

Abstract

Stem-end rot caused by Neofusicoccum parvum is among the most detrimental diseases affecting postharvest mangoes. The present investigation utilized (E)-2-octenal to manage N. parvum infections, elucidating its mechanism of action. The findings revealed that (E)-2-octenal exhibited outstanding antimicrobial potency against N. parvum in vitro within the concentration range of 0.4-1.6 µL/mL. Additionally, (E)-2-octenal significantly compromised the cell membrane integrity and mitochondrial energy metabolism of N. parvum, evidenced by dramatically increased intracellular material leakage and ROS levels, along with reduced mitochondrial membrane potential, ATP, and energy charge. Further experiments showed noteworthy effects on the tricarboxylic acid cycle (TCA) cycle and the key enzyme activities of succinate dehydrogenase (SDH) and malate dehydrogenase (MDH). Molecular docking revealed hydrogen bonding between (E)-2-octenal's aldehyde group and SDH (Trp-307) and MDH (Gly-101), indicating direct targeting of these enzymes for inhibition. To enhance the practical application of (E)-2-octenal, we developed an aerogel-loaded (E)-2-octenal material (ALO) that exhibited superior antimicrobial efficacy in vitro. In vivo, ALO effectively controlled mango stem-end rot, with optimal efficacy at 20 µL/L. This concentration also delayed the natural disease of mango without degrading fruit quality. According to these findings, (E)-2-octenal is a promising preservative against postharvest mango infections, potentially by impeding cellular energy metabolism through direct interaction with SDH and MDH within the TCA pathway, culminating in mitochondrial dysfunction and cell membrane damage.