ABSTRACT “Mingzhu No. 5” melon is prized for its distinctive flavor; however, rapid postharvest quality deterioration severely limits its commercial potential. Here, we integrated physiological measurements with untargeted metabolomic and transcriptomic to elucidate quality changes and the underlying molecular mechanisms during room‐temperature storage. Sucrose content and flesh firmness declined markedly and were associated with downregulation of the sucrose synthesis gene CmSPS2 and coordinated expression changes in cell wall‐degrading genes, including polygalacturonase ( PG ), pectin methylesterase ( PME ), and PL . Essential and aroma‐related amino acids, particularly branched‐chain and sulfur‐containing amino acids, decreased substantially, consistent with the upregulation of amino acid catabolic genes CmBCAT1 and CmPDC1 . Volatile profiling revealed early accumulation of ester followed by increased sulfur‐containing and off‐odor volatiles at later stages, driven by dynamic regulation of the lipoxygenase pathway genes ( LOXs , hydroperoxidase HPL , alcohol dehydrogenases ADHs , and alcohol acyltransferases AATs ). Weighted gene co‐expression network analysis further suggested that transcription factors from the MYB, AP2/ERF, WRKY, bZIP, and bHLH families may coordinate sucrose metabolism, cell wall modification, and aroma biosynthesis during storage. These findings highlight a complex transcriptional regulatory network underlying postharvest flavor and texture deterioration and provide molecular targets for improving melon storability.
Li et al. (Sun,) studied this question.