Insights into long non-coding RNA regulation of anthocyanin carrot root pigmentation

Abstract

Carrot (Daucus carota L.) is one of the most cultivated vegetable in the world and of great importance in the human diet. Its storage organs can accumulate large quantities of anthocyanins, metabolites that confer the purple pigmentation to carrot tissues and whose biosynthesis is well characterized. Long non-coding RNAs (lncRNAs) play critical roles in regulating gene expression of various biological processes in plants. In this study, we used a high throughput stranded RNA-seq to identify and analyze the expression profiles of lncRNAs in phloem and xylem root samples using two genotypes with a strong difference in anthocyanin production. We identified 639 differentially expressed lncRNAs between genotypes, and certain were specifically associated with a particular tissue. We then established regulatory correlations between lncRNAs and anthocyanin biosynthesis genes in order to identify a molecular framework for the differential expression of the pathway between genotypes. A specific natural antisense transcript (NAT) linked to the DcMYB7 key anthocyanin biosynthetic transcription factor suggested how the regulation of this pathway may have evolved between genotypes.