Study on the inhibitory activity and mechanism of Mentha haplocalyx essential oils nanoemulsion against Fusarium oxysporum growth

Abstract

As a green and environmentally friendly natural product, Mentha haplocalyx essential oil (MEO) inhibits F. oxysporum, but its field application is limited by its poor water solubility. The nanoemulsion can improve bioavailability and provide a green way to prevent and control P. notoginseng root rot. In this study, Tween-80 and anhydrous ethanol were selected as carriers, and the ultrasonic method was adopted to prepare a nanoemulsion of MEO (MNEO) with an average particle size of 26.07 nm. Compared with traditional emulsion of MEO (MTEO, MEO dissolved in an aqueous solution of 2% DMSO and 0.1% Tween 80), MNEO was superior in inhibiting F. oxysporum in terms of spore germination, hyphal growth, and minimum inhibitory concentration (MIC). Through transcriptomic and metabolomic analyses, it was found that both MNEO and MTEO can inhibit the Glycolysis/Gluconeogenesis and Starch and Sucrose metabolism pathways of F. oxysporum. Nevertheless, MNEO can inhibit the expression of more genes and metabolites. In addition, some key genes in meiosis, ribosome, and ribosome biogenesis were also significantly downregulated only under MNEO treatment. These genes and metabolites provide valuable information for the later prevention and control of F. oxysporum and provide a theoretical basis for better utilization of MEO resources to develop plant-derived bacteriostatic agents and agricultural modernization and ecological development.