Comparative transcriptome analysis, identification and expression analysis of sucrose phosphate synthasegenes in high and low starch cassava (Manihot esculentaCrantz) genotypes

The identification and characterization of the sucrose phosphate synthase(SPS) genes family have been carried out in several plant species; nevertheless, studies on the analysis of SPSgenes in cassava are limited. We report the study of four SPSgenes; (sucrose phosphate synthase3 F, sucrose phosphate synthase1F, sucrose phosphate synthasefamily protein and sucrose phosphate synthase2 F) identified from transcriptome analysis (NCBI Bio project ID: PRJNA998707) of the total RNA isolated from storage roots of TME-419 and H-165 cassava varieties. The sequence analysis revealed that the expression of SPSgenes was mainly between the third and sixth months of storage root development in the two cassava varieties. However, TME-419 variety recorded 3.4-fold higher in expression of SPSthan H-165 variety. Variations observed in the level of expression of the SPSgenes and the reliability of the selected differentially expressed genes was validated via reverse transcription-polymerase chain reaction. The chromosome position of the SPSgenes were located on Chr 18, Chr 15, Chr 14 and Chr 16 for sucrose phosphate synthasefamily protein, Sucrose phosphate synthase3 F, Sucrose phosphate synthase1F and Sucrose phosphate synthase2 F respectively. The correlation analysis showed that the expression of SPSgenes is positively correlated with the level of sucrose and starch contents in the cassava storage roots. This implies that high expression of SPSgenes in cassava storage roots has the ability to expedite the rate of starch accumulation, which is important for the cassava industry, food security, and breeding of elite cassava and related starch-producing crops.