Control efficiency and potential mechanisms of chlorogenic acid against postharvest gray mold caused by Botrytis cinerea on peach fruit

Abstract

Botrytis cinerea (B. cinerea) is characterized by its wide dissemination and high rotting ability, making peach fruit (Prunus persica L.) highly susceptible to gray mold infection. This study investigated the antifungal effects of the plant-derived phenolic substance chlorogenic acid (CGA) against gray mold on peach fruit and explored its potential inhibitory mechanisms. The results showed that 5 g L−1 CGA inhibited the growth of B. cinerea mycelium, and effectively reduced the lesion diameter and spore production of B. cinerea on peach fruit stored at 25 ℃. In vitro experiments demonstrated that CGA inhibited fungal spore germination, germ tube elongation, cell viability, and mycelial penetration. In addition, CGA decreased ergosterol content and induced malondialdehyde (MDA) accumulation, ultimately disrupting the membrane integrity. Furthermore, the gene expression of two crucial enzymes in the ergosterol biosynthesis pathway, namely sterol C-24 reductase (ERG4) and sterol C-24 methyltransferase (ERG6), was down-regulated by CGA. Additionally, CGA competitively inhibited the protein activities of ERG4 and ERG6 in B. cinerea, thereby blocking the biosynthesis of ergosterol. CGA treatment also reduced the natural rotting rate, delayed fruit ripening and senescence, and maintained the storage quality of peach fruit. This study provides new insights for the development of plant-derived antimicrobial agents and offers references for the potential application of CGA treatment in the postharvest management of gray mold on peach fruit.