Transcriptome analysis of maca () root at different developmental stages.

PREMISE OF THE STUDY

Maca (; Brassicaceae) has been cultivated by Andeans for thousands of years as a food source and has been used for medicinal purposes. However, little is known about the mechanism underlying material accumulation during plant growth.

METHODS

RNA-Seq technology was used to compare the transcriptome of black maca root at three developmental stages. Gene Ontology term enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were applied for the identification of pathways in which differentially expressed genes were significantly enriched.

RESULTS

Trinity was used to de novo assemble the reads, and 120,664 unigenes were assembled. Of these, 71.53% of the unigenes were annotated based on BLAST. A total of 18,321 differentially expressed genes were observed. Gene Ontology term enrichment analysis found that the most highly represented pathway among the differentially expressed genes was for genes involved in starch and sucrose metabolism. We also found that genes involved in secondary metabolite biosynthesis, such as glucosinolate biosynthesis, were significantly enriched.

DISCUSSION

The genes that were differentially expressed between developmental time points likely reflect both developmental pathways and responses to changes in the environment. As such, the transcriptome data in this study serve as a reference for subsequent mining of genes that are involved in the synthesis of important bioactive components in maca.