Transcriptome analysis reveals mechanisms involved in the enhanced antagonistic efficacy of Sporidiobolus pararoseus Y16 treated by γ-aminobutyric acid

• GABA increased the activities of CAT and CHI in S. pararoseus Y16. • GABA decreased the MDA content of S. pararoseus Y16. • GABA increased the expression of stress resistance-related genes in S. pararoseus Y16. • The expression levels of CAT and CHI in S. pararoseus Y16 were increased. Our previous study showed that γ-aminobutyric acid (GABA) can significantly enhance the biological control efficacy of Sporidiobolus pararoseus Y16 on postharvest diseases of grapes. The possible physiological biocontrol mechanisms of the yeast have been reported previously, however, the associated molecular mechanisms were unclear. This study aimed to investigate the possible molecular mechanisms behind the enhanced biological control efficacy of S. pararoseus Y16 cultured with GABA based on transcriptome analysis. In addition, the activities of catalase (CAT) and chitinase (CHI) and the content of malondialdehyde (MDA) in S. pararoseus Y16 were investigated. The results showed that after the addition of 4 mg/mL GABA, the activities of CAT and CHI in S. pararoseus Y16 were significantly increased, and the content of MDA accumulation was decreased. Transcriptome analysis found that GABA-treated S. pararoseus Y16 can improve the ability of yeast ion transport, cell wall remodeling, antioxidants, growth and reproduction, resistance to stress, amino acid synthesis, etc., resulting in increased antagonistic efficacy of S. pararoseus Y16. These results provide a reference for future research on the use of antagonistic yeasts to prevent and control postharvest diseases of fruits and vegetables, and provide a theoretical basis for the practical application of antagonistic yeasts.