Functional and Evolutionary Genomics of Protein Disulphide Isomerase (PDI) Geneb Family in Wheat and Its Wild relatives: A Review.

Mature wheat grain contain 8-20% proteins. The storage proteins of wheat determine the characteristics and unique properties of its flour in the process of pasta and bread-making and eventually the quality of the finished products obtained. The storage proteins play an integral role in determining the visco-elastic properties of wheat dough, a feature of high quality wheat. The genes, encoding storage proteins as well as factors that may affect their deposition, such as molecular chaperones and foldase enzymes, are of particular interest to wheat industry. Genomic, cDNA and promoter sequences of the three homoeologous gene encoding the “typical” PDI has been already cloned and characterized. Recently, eight new non-homoeologous wheat genes were cloned and characterized in bread wheat. Study characterizing the variability in a 700 bp region comprising 600 bp of 5’ upstream putative promoter region and 100 bp of the first exon of the typical PDI gene in 15 accessions of Triticum urartu (AA), Aegilops speltoides (BB) and Aegilops taushcii (DD), from diverse origin and Triticum aestivum cv Chinese Spring (AABBDD) has also been completed recently. This review explains how functional and evolutionary genomics tools aid in the study of a gene family and its promoter.