Antifungal mechanisms of γ-aminobutyric acid against the postharvest pathogen Alternaria alternata

Abstract

γ-Aminobutyric acid (GABA) is a plant resistance elicitor essential in preventing and controlling postharvest disease in fruits and vegetables. However, limited information is available involving the inhibitory effect of exogenous GABA on postharvest pathogens. This study found that GABA inhibited the postharvest pathogenic fungus, Alternaria alternata (A. alternata). Transcriptome analysis revealed that the genes related to sporulation, toxin synthesis, and cell wall degradation enzymes are downregulated in A. alternata after GABA treatment. Moreover, the effect of GABA on A. alternata was verified using electron microscopy and by determining the activity of the cell wall degradation enzyme. These findings provided information about the underlying antifungal mechanism about GABA against A. alternata and suggested that GABA could be a potential alternative for controlling A. alternata in fruit and vegetable preservation.