Time-Series Transcriptome of Cucumis melo Reveals Extensive Transcriptomic Differences with Different Maturity.

As the most important melon cultivar grown in the north-western provinces of China, Hami melon ( Cucumis melo ) produces large edible fruits that serve as an important dietary component in the world. In general, as a climacteric plant, melon harvested at 60% maturity results in a product with bad quality, while the highest-quality product can be guaranteed when harvesting at 90% maturity. In order to clarify the genetic basis of their distinct profiles of metabolite accumulation, we performed systematic transcriptome analyses between 60% and 90% maturity melons. A total of 36 samples were sequenced and over 1.7 billion reads were generated. Differentially expressed genes in 60% and 90% maturity melons were detected. Hundreds of these genes were functionally enriched in the sucrose and citric acid accumulation process of C. melo . We also detected a number of distinct splicing events between 60% and 90% maturity melons. Many genes associated with sucrose and citric acid accumulation displayed as differentially expressed or differentially spliced between different degrees of maturity of Hami melons, including CmCIN2 , CmSPS2 , CmBGAL3 , and CmSPS2 . These results demonstrate that the phenotype pattern differences between 60% and 90% maturity melons may be largely resulted from the significant transcriptome regulation.