Obtaining Wheat (Triticum aestivum L.) Lines with Yeast Genes for Trehalose Biosynthesis

Yeast ( Saccharomyces cerevisiae ) genes for trehalose biosynthesis ( TPS1 a nd TPS2 ) were transferred into genomes of several common wheat cultivars using two methods of Agrobacterium -mediated transformation (in vitro and in planta) to enhance drought tolerance. For this purpose, vectors pBract214-TPS1 and pBract214-TPS2 were constructed using the Gateway-cloning technique. Both the vectors contained TPS1 and TPS2 genes under control of the constitutive maize ubiquitin promoter ( PUbi ) and selectable marker hygromycin-phosphotransferase ( hpt ) gene. Three- to five-day-old calluses obtained from immature wheat embryos were used as explants for the transformation in vitro. Selection of transgenic plants was carried out on nutrient medium supplemented with 30 mg/L hygromycin (as a selectable agent). Seeds of wheat (transgenic generation T1) were obtained by the in planta method of transformation. Integration and the presence of yeast genes in wheat genomic DNA isolated from transgenic plants were confirmed by PCR analysis using primers specific to TPS1 and TPS2 genes.