Regulatory Mechanism of Melon Fruit Morphology Based on Transcriptomic and Metabolomic Analysis

Melon is a globally popular fruit, renowned for its sweet taste and rich aroma.The shape of melon fruits significantly influences both consumer purchasing decisions and mechanized processing efficiency.However, the regulatory mechanisms governing melon fruit shape remain largely elusive.In this study, we conducted comprehensive transcriptome and metabolome analyses of the fruit pulp of two distinct melon varieties, T78 and T144.The transcriptomic analysis revealed 1,975 up-regulated genes and 1,660 down-regulated genes.Through GO and KEGG enrichment analyses of differentially expressed genes, we found that hormone synthesis and metabolism pathways were associated with melon fruit elongation and growth.Metabolomic profiling identified 550 metabolites, and machine learning algorithms determined that 20 metabolites, including phosphatidylcholine and myristic acid, were significantly correlated with fruit length.Notably, our findings suggest a potential association between CmTOR expression and melon fruit length.Furthermore, by integrating expression data from genes involved in cytokinin and auxin biosynthesis and signaling pathways, we found that the fruit pulp of the melon variety T144 exhibited enhanced cell division and elongation, which may be associated with fruit elongation., providing a molecular foundation for elucidating the regulatory mechanisms of melon fruit shape.