Differential expression analysis of genes involved in starch biosynthesis and metabolism in different tissues of taro

【Objective】Transcriptome experiments were performed on different tissues of taro(Colocasia esculenta) to provide genetic resources for the study of molecular mechanisms of taro gene function and metabolic regulatory networks. 【Method】Taro corms,leaves,petioles and roots of Lipu taro 1 were collected 90 d after sowing for physiological testing and transcriptome sequencing. GO and KEGG functional enrichment analysis was performed for differentially expressed genes(DEGs) in different tissues,and starch biosynthesis and metabolism related genes were identified and their expression patterns were analyzed. 【Result】The starch and soluble sugar contents of taro corms were 134.85 and 23.92mg/g respectively,which were the highest among the four tissues. A total of 85.41 Gb Clean data were obtained for the transcriptome sequencing,with the efficiency of comparison with the reference genome ranging from 90.30% to 92.56%,and a total of 33828 genes were functionally annotated. The number of DEGs between the different tissues ranged from 5625 to 10562. In the comparison groups between corms and roots,leaves,petioles,GO functional enrichment analysis showed enrichment of 2,5 and 5 GO terms related to starch biosynthesis and metabolism in biological processes respectively; KEGG enrichment analysis showed enrichment of 146,161 and 126 DEGs in starch and sucrose metabolism pathways respectively. Enrichment analysis identified 82 DEGs involved in starch biosynthesis and metabolism,which showed different expression patterns in the four tissues,among them,ADP-glucose pyrophosphorylase genes(AGPase gene)(Taro_004018 and Taro_026553),the granule-bound starch synthetase gene(GBSS gene)(Taro_033806),and the starch branching enzyme gene(SBE gene)(Taro_009230) expressed significantly higher in the corm than in the other tissues(P<0.05). 【Conclusion】GO and KEGG functional enrichment analysis reveals differences in metabolic functions among the four taro tissues,with the corm showing higher expression of genes related to starch content as well as key enzymes for starch biosynthesis than the other tissues,and being a storage organ for starch.