Low storage temperature affects quality and volatile compounds in fresh tomatoes.

Area of Science:

• Plant Science
• Food Science
• Molecular Biology

Background:

• Postharvest storage significantly impacts fruit quality and flavor.
• Low-temperature storage is a common method to extend the shelf life of produce.
• Understanding the molecular mechanisms behind low-temperature effects on tomatoes is crucial for quality preservation.

Purpose of the Study:

• To investigate the effects of low temperature (0°C) on the quality and flavor of ripe red tomatoes compared to standard storage (20°C).
• To analyze the transcriptomic and volatile metabolomic changes in tomatoes under different temperature conditions.
• To identify key genes and metabolic pathways involved in maintaining tomato quality during cold storage.

Main Methods:

• Transcriptome analysis to assess gene expression profiles.
• Volatile metabolome analysis to quantify aroma compounds.
• Comparison of gene expression and metabolite levels between tomatoes stored at 0°C and 20°C for 8 days.

Main Results:

• 0°C storage maintained sugar content by upregulating sucrose synthetase (SUS) and sucrose transporter (SUT) genes.
• Reduced expression of aroma synthesis genes (e.g., ADH1, AADC1A, BCAT2) at 0°C correlated with lower levels of key volatile compounds.
• Inhibition of genes involved in cell wall degradation (PE, β-GAL, β-Glu) and carotenoid synthesis (PSY1) at 0°C helped preserve tomato texture and color.
• Upregulation of antioxidant and heat shock protein genes was observed at 0°C, contributing to overall quality preservation.

Conclusions:

• Low-temperature storage (0°C) effectively preserves the quality attributes of ripe red tomatoes, including sugar content, texture, and color.
• Transcriptomic and metabolomic analyses reveal specific molecular mechanisms, such as modulation of sugar metabolism, aroma synthesis, cell wall integrity, and antioxidant pathways, responsible for these preservation effects.
• Cold storage induces protective mechanisms, including antioxidant and heat shock responses, further enhancing the postharvest quality and shelf life of tomatoes.