Antifungal activity of thymol and carvacrol against postharvest pathogens Botrytis cinerea

Abstract

Botrytis cinerea is a primary pathogen causing stem and fruit rot during pre-and post-harvest. In the present study, the main purpose was to inquire into the antifungal activity and potential mechanisms of thymol and carvacrol against B. cinerea. During the experiment, the effects of thymol and carvacrol on physical and biochemical parameters of B. cinerea were evaluated. Results indicated that thymol and carvacrol exhibited strong antifungal activity against the targeted pathogen, with minimum inhibitory concentration and minimum fungicidal concentration of 65 mg/L and 100 mg/L for thymol, and 120 lL/L and 140 lL/L for carvacrol. Thymol and carvacrol changed obviously the morphology of B. cinerea hyphae by disrupting and distorting the mycelia through scanning electron microscopy. The membrane permeability of B. cinerea hyphae was prompted with the increment of two chemical agents' concentration, as evidenced by extracellular conductivity increase, the release of cell constituent, and the decrease of extracellular pH. Furthermore, a marked decline in total lipid content of B. cinerea cells was induced by the two chemical agents, suggesting that the cell membrane structures were destructed. Therefore, present results indicated that thymol and carvacrol may be used as a good alternative to conventional fungicides against B. cinerea in controlling grey molds in horticultural products.

Effects of Origanum vulgare essential oil and its two main components, carvacrol and thymol, on the plant pathogen Botrytis cinerea

“…In this experiment, the destruction of cell membrane was confirmed by SEM and SYTOX Green fluorescence staining. Consistent with previous expectations and recent reports ( Zhang et al, 2019 ), the results of SEM showed that the normal morphology of B . cinerea mycelia were damaged.…”

Peer Review #2 of "Effects of Origanum vulgare essential oil and its two main components, carvacrol and thymol, on the plant pathogen Botrytis cinerea (v0.1)"

“…In this experiment, the destruction of cell membrane was confirmed by SEM and SYTOX Green fluorescence staining. Consistent with previous expectations and recent reports (Zhang et al 2019), the results of SEM showed that the normal form of B. cinerea mycelia were damaged. After carvacrol and thymol treatment, the hypha appeared shrinkage, collapse and disorganization compared with that in the control.…”

Composition, Antifungal, Phytotoxic, and Insecticidal Activities of Thymus kotschyanus Essential Oil

“…Particularly for thymol, a monoterpene phenolic compound, previous studies indicated an important effect against the growth of important fruit and food-spoiling fungi, such as A. niger, Alternaria alternata, B. cinerea, Fusarium oxysporum, and Rhizopus oryzae, that are [58][59][60][61][62]. In a similar way as the results obtained by us, other studies observed that thymol and carvacrol exhibit an important antifungal activity against postharvest pathogens Botrytis cinerea [63] and also against spoilage yeasts in wine [64]. Additionally, other research found that carvacrol inhibits the growth of Penicillium expansum spores, which agree with our results [65].…”