Nitrogen-modified atmosphere with re-aeration storage triggers deterioration in paddy rice by disrupting central carbon metabolism.

Nitrogen-modified atmosphere (NMA) storage is extensively adopted for the postharvest preservation of paddy rice for pest control, yet its quality tends to deteriorate at an accelerated rate during subsequent re-aeration storage (RS). This study explored the central carbon metabolic changes in indica and japonica paddy rice under conventional storage (CS), 99%-N₂ re-aeration storage (HCN-RS), and 95%-N₂ re-aeration storage (LCN-RS). Results showed that post re-aeration, HCN-RS and LCN-RS significantly reduced rice freshness, germination rate, energy charge, and activities of key metabolic enzymes (e.g., G-6-PDH, ATP synthase) relative to CS, despite better performance during modified storage. Targeted metabolomics revealed perturbed carbon metabolic pathways (glycolysis, the pentose phosphate pathway, the tricarboxylic acid cycle, and amino acid and nucleotide metabolism), with differential metabolites (fructose-6-phosphate, AMP, GMP, cytosine, and homogentisic acid) identified between treatments. This study characterized the central carbon metabolic changes associated with quality deterioration under NMA-RS, providing theoretical support for optimized rice storage.