Relationship of fruit color and anthocyanin content with related gene expression differ in strawberry cultivars during shelf life

Strawberry fruit is highly perishable after harvest, as the fruit quality rapidly deteriorates during shelf life. Fruit color also dramatically changes during this period. The objective of this study was to elucidate the comparative responses of fruit quality, anthocyanin content, and expression of genes (including transcription factors and structural genes related to the biosynthesis of anthocyanin) in fruits of the 'Seolhyang' and 'Jukhyang' strawberry cultivars at different fruit maturity stages and during postharvest shelf life. Fruit dimensions increased as fruits matured and then decreased during shelf life in both cultivars. Soluble solids content and titratable acidity were higher in 'Jukhyang' than in 'Seolhyang' fruits. Fruit color variables were not different in both strawberry cultivars as fruit matured, but peel chroma and a* values were higher in 'Jukhyang' than in 'Seolhyang' cultivar during shelf life. Total phenolic compounds and anthocyanins, total antioxidant activity, pelargonidin-3-O- glucoside, and pelargonidin-3-O-(6 "-malonyl)-glucoside contents were higher in 'Seolhyang' than in 'Jukhyang' fruits. In contrast, the contents of cyanidin-3-O-glucoside and pelargonidin-3-O-rutinoside were lower in 'Seolhyang' than in 'Jukhyang' during shelf life. The expression of genes related to the anthocyanin biosynthetic pathway differentially responded to fruit maturity and shelf life. The collective results indicated that the phenotypic response of fruit color was differentially associated with individual anthocyanins, anthocyanin transcription factors, and biosynthesis-related gene expression in strawberry cultivars during shelf life.