Terpinen-4-ol treatment maintains quality of strawberry fruit during storage by regulating sucrose-induced anthocyanin accumulation

Terpinen-4-ol, the main component of tea tree oil, controls postharvest decay of strawberry fruit. In this study, nuclear magnetic resonance (NMR)-based metabolomics was used to investigate global metabolic profiles in strawberries treated with terpinen-4-ol and stored at 20 °C for 3 d. Measurements showed higher levels of sucrose and fructose, and lower levels of α-d-glucose, β-d-glucose, and citric acid in terpinen-4-ol-treated fruit. Treatment also increased expression of FaSS and FaSPS mRNAs and decreased expression of FaAI. Terpinen-4-ol treatment maintained higher anthocyanin levels accompanied by increasing the expression of genes in the pentose phosphate, phenylpropanoid, and flavonoid pathways, and transcription factor MYB10. In addition, expression of FaSnRK1 was also increased in terpinen-4-ol-treated fruit. We conclude that terpinen-4-ol maintains strawberry fruit quality by regulating sucrose metabolism and anthocyanin biosynthesis, and that FaSnRK1 perceives the higher sucrose levels to induce anthocyanin accumulation in treated fruit.