Characterization of carotenoid biosynthesis pathway genes from wheat Triticum Aestivum L

Abstract

Wheat is one of the important staple crops being consumed worldwide. It provides considerable amounts of carbohydrate, protein and a significant source of carotenoids in the human diet. In the present study, the genes involved in the carotenoid biosynthesis pathway were identified from the wheat genome database, and their in-silico characterization was performed. In addition, total thirty wheat varieties were examined for carotenoid content and composition in their seeds. The analysis revealed a low level of and#946;-carotene in all the varieties and lutein being predominant carotenoid found in wheat grain. Three PSY (TaPSY1, TaPSY2¸ and TaPSY3) genes were identified in wheat, and each having three homoeologs located on A, B and D subgenomes. The promoter analysis revealed the presence of various cis-regulatory elements. It indicates the diverse role of these genes supported by the expression pattern in the developmental stages and stress conditions. The results from bacterial complementation assay indicated higher activity of TaPSY1 gene in the synthesis of and#946;-carotene. Similarly, over expression of TaPSY1 genes in Arabidopsis thaliana gave rise to maximum increase in and#946;-carotene content. This study revealed that TaPSY genes actively participates in the carotenoid biosynthesis and over expression of selected TaPSY gene enhanced the level of carotenoids in leaves and seeds of transgenic Arabidopsis lines. Overall this led us to conclude that TaPSY1 is the potential key gene of wheat, which can enhance the level of carotenoids, especially and#946;-carotene after it s over expression in plant system. newline