Cinnamaldehyde Inhibits Postharvest Gray Mold on Pepper Fruits via Inhibiting Fungal Growth and Triggering Fruit Defense

Abstract

Gray mold infected with Botrytis cinerea frequently appears on fruits and vegetables throughout the supply chain after harvest, leading to economic losses. Biological control of postharvest disease with phytochemicals is a promising approach. CA (cinnamaldehyde) is a natural phytochemical with medicinal and antimicrobial activity. This study evaluated the effect of CA in controlling B. cinerea on fresh pepper fruit. CA inhibited B. cinerea growth in vitro significantly in a dose- (0.1–0.8 mM) and time-dependent (6–48 h) manner, with an EC50 (median effective concentration) of 0.5 mM. CA induced the collapse and breakdown of the mycelia. CA induced lipid peroxidation resulting from ROS (reactive oxygen species) accumulation in mycelia, further leading to cell leakage, evidenced by increased conductivity in mycelia. CA induced mycelial glycerol accumulation, resulting in osmotic stress possibly. CA inhibited sporulation and spore germination resulting from ROS accumulation and cell death observed in spores. Spraying CA at 0.5 mM induced a defense response in fresh pepper fruits, such as the accumulation of defense metabolites (flavonoid and total phenols) and an increase in the activity of defense enzymes (PAL, phenylalanine ammonia lyase; PPO, polyphenol oxidase; POD, peroxidase). As CA is a type of environmentally friendly compound, this study provides significant data on the activity of CA in the biocontrol of postharvest gray mold in peppers.

Cinnamon and clove aqueous extracts promote in vitro and postharvest control of Alternaria alternata in tomato fruit

“…Huang et al (2019) evaluated the antifungal mechanism of trans-cinnamaldehyde against Penicillium italicum and observed that the plasma membrane of the mold had been severely destroyed and the cell wall collapsed. The antifungal activity of cinnamaldehyde against Botrytis cinerea was closely related to reactive oxygen species (ROS) accumulation and oxidative injury in both mycelia and spores (Yang et al, 2023). Wang et al ( 2023) demonstrated that the clove extract exhibited inhibitory activities against Botryosphaeria dothidea causing damage in cell membrane integrity and biological function via downregulating the genes involved in the membrane component and transmembrane transport.…”

Preparation of Azoxystrobin-Zinc Metal–Organic Framework/Biomass Charcoal Composite Materials and Application in the Prevention and Control of Gray Mold in Tomato

“…It poses a significant threat to the productivity of tomato crops by infiltrating multiple plant components, including stems, leaves, and fruits, thereby compromising food safety [5]. Botrytis cinerea has a strong environmental adaptability and produces spores that can easily infect nearby plants [6].After harvest, this pathogen can persist as mycelium, with or without conidia and sclerotia, in crop wastes [7]. Unfortunately, to date, there are still no reports on resistant tomato varieties [8].…”