Identification and characterization of potato anthocyanin synthesis and regulatory miRNA based on comparative transcriptome [miRNA-seq]

The anthocyanin glycosides in potato tubers not only provide the plant with bright color and high nutritional value, but also have pharmacological effects such as antioxidant, hypotensive, lipid-lowering and immunity-boosting. However, the regulatory mechanism of anthocyanin in potato tubers is still unclear. In this study, twelve miRNA libraries, three of which are from the Red beauty (R-1, R-2 and R-3), three of which are from the Black kingkong (B-1, B-2 and B-3), three of which are from the Longshu No.7 (Y-1, Y-2 and Y-3) and three of which are from the LK77 (W-1, W-2 and W-3), were constructed and analyzed by high-throughput sequencing. A total of 167.3 M of clean reads were obtained. After the raw reads were subjected to quality control and filtering, 151,010,820 clean tags were obtained from the twelve libraries. The filtered reads were subsequently compared with the updated potato reference genome, and the vast majority of effective reads were successfully mapped. The mapped reads from the twelve libraries covered 77.10-84.48% of the potato genome, therefore, the analysis based on the genome was considered reliable. The lengths of the obtained miRNAs were further analysed to find that 64% of the miRNAs were concentrated at 21bp in length, followed by a higher number of miRNAs at 22bp and 24bp in length. Overall design: Four kinds of potatoes (Black kingkong, Red beauty, Longshu No.7 and LK99) were planted at Yuzhong Experimental Station of Lanzhou County, Gansu Academy of Agricultural Sciences. They were planted on 22 April 2019 and harvested on 28 September. All conditions during planting were kept consistent for all four varieties, such as irrigation, light, temperature, etc. At harvest, the materials of each variety were randomly sampled, with 3 replicates for each sample, for anthocyanin determination and transcriptome sequencing.