Molecular Characterization of Anthocyanin and Betulinic Acid Biosynthesis in the Fruit of the Red and White Mulberry using High-Throughput Sequencing
Background : Mulberry (Morus alba L.), renowned for their medicine benefits and the leave as the sole food for silkworm (Bombyx mori). To understanding the molecular mechanism of color formation and nutritive value in different mulberry fruit varieties, we use high-throughput transcriptome sequencing technique to investigated the anthocyanin and betulinic biosynthesis pathway related functional genes. In addition, the total antosyanin and betuinic acid contend were also measured. Methods and Results : The resulting cDNA library was then sequenced using an Illumina HiSeq™ 2000 system. The clean reads were assembled using Trinity software, Then perform gene family clustering to get final unigenes. The pH differential method was used to determine the total anthocyanin content (TAC) of methanol extract from the red and white mulberry, and High-performance liquid chromatography (HPLC) analysis was used to quantify the triterpenes content. In this study, total 50,149 unigenes with an average length of 1,125 nt and N50 equaling 1,861 nt were generated. Using these transcriptome sequecing, cDNAs encoding anthocyanin biosynthetic genes and triterpene biosynthetic genes were isolated. In addition, total anthocyanins and betulinic acid content were analyzed. A great amount of total anthocyanins (59.16 mg/g) were found in fully ripe fruit of Cheongil. Accumulation of betulin and betulinic acid were also detected in all stages of Cheongil and Turkey fruits with small amount. Conclusion : The results of transcriptome sequencing provide useful information at molecular lever in mulberry research, such as interesting gene discovering, marker assisted molecular breeding, and interesting metabolic pathway investigate. The gene expression results could help us understanding of the molecular mechanisms of different fruit color determining factor.