Genetic engineering of drought resistant potato plants by introduction of the trehalose-6-phosphate synthase (TPS1) gene from Saccharomyces cerevisiae

In yeast, trehalose-6-phosphate synthase is a key enzyme for trehalose bios ynthesis, encoded by the structural gene TPS1, Trehalose affects sugar meta bolism as well as osmoprotection against several environmental stresses, su ch as heat and desiccation, The TPS1 gene of Saccharomyces cerevisiae was e ngineered under the control of the CaMV 35S promoter for constitutive expre ssion in transgenic potato plants by Ti-plasmid of Agrobacterium-mediated t ransformation. The resulting TPS1 transgenic potato plants exhibited variou s morphological phenotypes in culture tubes, ranging from normal to severel y retarded growth, including dwarfish growth, yellowish lancet-shaped leave s, and aberrant root development. However, the plants recovered from these negative growth effects when grown in a soil mixture. The TPS1 transgenic p otato plants showed significantly increased drought resistance. These resul ts suggest that the production of trehalose not only affects plant developm ent but also improves drought tolerance.