Abstract
Background: Hami melon (Cucumis melo var. saccharinus) is a popular fruit in China noted for its excellent taste, which is largely determined by its physical and chemical characteristics, including flesh texture, sugar content, aroma, and nutrient composition. However, the mechanisms through which the associated with these characteristics are regulated have not yet been sufficiently determined. In this study, we monitored changes in the fruits of two germplasms differing in physical and chemical characteristics throughout the period of fruit development. Results: Ripe fruit of the bred variety ‘Guimi’ had significantly higher soluble sugar contents than the fruit of the common variety ‘Yaolong’, whereas differences in fruit shape and color between these two germplasms were observed during the course of development. Comparative transcriptome analysis, conducted to identify regulators and pathways underlying the observed differences at corresponding stages of development, revealed a higher number of differentially expressed genes (DEGs) in Guimi than in Yaolong. Moreover, most of the DEGs detected during early fruit development of Guimi were associated with cell wall biogenesis. Temporal analysis of the identified DEGs revealed similar trends in the enrichment of downregulated genes in both germplasms, although there were certain differences in the enrichment trends of upregulated genes. Further analyses revealed trends in the differential changes of multiple genes involved in cell wall biogenesis and sugar metabolism during fruit ripening.Conclusions: We were thus able to identify a number of genes associated with the ripening of Hami melon, which will accordingly provide novel insights into the molecular mechanisms underlying the development of fruit characteristics in these melons.
Comparative Transcriptomic Analysis of Two Cucumis Melo Var. Saccharinus Germplasms Differing in Fruit Physical and Chemical Characteristics
