Transcriptomic Data Integration Inferring the Dominance of Starch Biosynthesis in Carbon Utilization of Developing Cassava Roots

Abstract

Carbon metabolism, which is an important process underlying the plant development, has been extensively studied in model plant Arabidopsis, however the understanding in this process for cassava root crop is very little. To enhance our understanding into the process, we studied carbon partitioning during cassava root development at the transcriptional level via transciptomic data integration into the metabolic pathways. The transcriptome data of three different developmental stages of cassava roots—fibrous root (FR), developing storage root (DR), and mature storage root (MR) from Yang et al.[1]—was integrated into the key carbon metabolism pathways reconstructed following the protocol of Rongsirikul et al.[2]. According to the 43 differentially expressed genes (56 proteins IDs) mapped into the pathways, we found that the genes involved in starch biosynthesis are more up-regulated, in contrast to the expression of genes in the cell wall biosynthesis and respiration. The results may imply the significance of starch biosynthesis among the carbon utilization processes in the developing cassava roots. In other words, the carbon source from α-D-glucose-1-phosphate (G1P) might be mostly used for starch biosynthesis rather than cell wall biosynthesis and respiration pathways during cassava root development.