Mechanism of improving the quality of table grapes (Vitis. spp.) by exogenous eugenol based on transcriptome

Summary Grape is widely consumed all over the world for its rich nutritious and health‐promoting effects. While grape berries are prone to quality deterioration after harvest. This study aimed to investigate the effect of eugenol treatment on the quality of grape berries based on the transcriptome. Harvested grape berries were treated with eugenol, and then collected for nutrient component determination and transcriptomics analyses. As a results, treatment with eugenol enhanced the berries firmness, increased the contents of soluble sugars, organic acids and phenolic compounds, improved the antioxidant capacity, and altered gene expression levels of related pathways. Transcriptome analysis revealed 699 differentially expressed genes by 100 mmol L −1 eugenol‐treated berries. Among these DEGs, the transcriptional levels involved in the cell wall, sugar and acid metabolism, phenylpropane metabolism, antioxidant enzymes, and WRKY, MYB family transcription factors were significantly regulated. This study will help to promote the application of eugenol for quality improvements in grape berries.