Transformation of tobacco with an Arabidopsis thaliana gene involved in trehalose biosynthesis as a model to increase drought resistance in crop plants

摘要

Trehalose plays an important role in desiccation stress protection and its accumulation is an effective way of increasing drought tolerance in both model and important crops using genes of bacterial origin. In this work we aimed to improve desiccationtolerance in tobacco by increasing trehalose accumulation through transformation with the Arabidopsis thaliana trehalose phosphate synthase gene (AtTPSl) that is involved in trehalose biosynthesis. A cassette harboring the AtTPSl gene under the controlof the CaMV35S promoter and the bialaphos resistance gene Bar as a selective agent was inserted in the plasmid vector pGreen0229 and used for Agrobacterium-mediated transformation of tobacco. Several T_0 plants were obtained and analyzed by PCR for the presence of the AtTPSl gene. Thirty lines were positive and their seeds were germinated in media with 6 mg 1~(-1) PPT to obtain T_i plants that were grown in the greenhouse to obtain T_2 seeds. T_2 seeds were germinated in selective media (6 mg l~(-1) PPT) and those lines which seeds showed 100 % survival rate were considered homozygous transgenic T_i lines. Three lines were selected and T_2 seeds were germinated on media with different concentrations of mannitol to score their resistance to osmotic stress. Transgenic plants showed higher germination rates at higher levels of mannitol than did wild type plants.