Low storage temperature affects quality and volatile compounds in fresh tomatoes

To investigate the impact of low temperature on the quality and flavor of ripe red tomatoes, we analyzed transcriptomes and volatile metabolomes of ripe red fruits stored at 0 °C and 20 °C for 8 days. The results showed that 0 °C maintained the sugar content by increasing the expression of sucrose synthetase (SUS) and sucrose transporter (SUT). Low expression of aroma synthesis-related genes, such as alcohol dehydrogenase 1 (ADH1), amino acid decarboxylase 1 A (AADC1A), and branched-chain amino acid aminotransferase 2 (BCAT2), were associated with reduced levels of pentanal, hexanal, 3-methylbutanal, 2-methylbutanal, and 2-phenylethanol. Additionally, the expression of pectinesterase (PE), beta-galactosidase (β-GAL), and beta-glucosidase (β-Glu), as well as phytoene synthase1 (PSY1) involved in carotenoid synthesis, was inhibited, thereby maintaining fruits texture and color. Furthermore, storage at 0 °C induced the expression of numerous genes regulating antioxidant and heat shock proteins, which further preserved the postharvest quality of tomatoes.