Investigation of L-Phe induced biocontrol efficiency of Yarrowia lipolytica against postharvest blue mold of pears and its underlying mechanisms.

Abstract

In this study, Yarrowia lipolytica was cultured with L-Phenylalanine (L-Phe) as an inducer to investigate its effect on the biocontrol efficacy of Y. lipolytica against postharvest diseases in pears. This investigation also clarifies the physiological mechanisms by which L-Phe induces the biocontrol efficacy of Y. lipolytica. Experimental results confirmed that L-Phe could trigger and enhance the effectiveness of Y. lipolytica in controlling postharvest blue mold in pears. Furthermore, Y. lipolytica inhibited the spore germination rate and germ tube length of Penicillium expansum in a liquid medium and decreased the colony diameter of P. expansum on a solid medium. Cultivating Y. lipolytica with the inducer (L-Phe) improved its growth, reproduction, and biofilm-forming efficiency on pear surfaces. Moreover, Y. lipolytica induced by L-Phe increased the activities of defense-related enzymes in pears, promoted the accumulation of antimicrobial secondary metabolites, and upregulated the genes encoding defense-related enzymes compared to Y. lipolytica alone. These changes collectively enhance the disease resistance of pears. Therefore L-Phe can improve the biocontrol efficacy of Y. lipolytica against postharvest blue mold in pears.