Increase in alpha-linolenic acid content by simultaneous expression of fatty acid metabolism genes in Sesame (Sesamum indicum L.)

Sesame is considered one of India’s important sources of edible oil and an excellent dietary source for its nutritional and medicinal value. Sesame DGAT1 and PDAT1 genes were co-expressed with omega 3 FAD genes. Systemic isolation of sesame DGAT1 , PDAT1 , ER type FAD3 , and chloroplast type FAD7/8 genes were performed. Their sequence was analyzed for genomic organization, amino acid characterization, organ specificity, and phylogenetic relationships. The insilico analysis revealed the unique features of DGAT1, PDAT1 , and FAD3 gene sequences, whereas FAD7 and FAD8 sequences had the same protein characters and were grouped in phylogeny analysis, only variation was found in their mRNA UTR regions. Functional expression of sesame TAG synthesis genes and omega-3 FAD genes was studied in yeast mutant H1246 deficient for TAG synthesis. Functional analyses in yeast with the presence of ALA confirmed the identity of sesame FAD3 , FAD7 and FAD8 genes. Recombinant expression of pESC + DGAT1 + FAD3 vector in yeast mutant resulted in lipid accumulation with 10% higher ALA content. Thus this gene combination can be co-expressed in sesame and other plant systems to increase the lipid accumulation with high omega-3 fatty acid (ALA) content.