Tomato abiotic stress enhanced tolerance by trehalose biosynthesis

Trehalose is a nonreducing disaccharide of glucose that has been correlated with tolerance to different stress conditions. Transgenic tomato plants were generated by the introduction of the yeast trehalose-6-phosphate synthase (TPS1) gene, under the control of the cauliflower mosaic virus regulatory sequences (CaMV35S) for expression in plants. Using Agrobacterium-mediated transfer, the gene was incorporated into the genomic DNA and constitutively expressed in Lycopersicon esculentum cv. UC82B plants. TPS1 transgenic tomato plants exhibited pleiotropic changes Such as thick shoots, rigid dark-green leaves, erected branches and an aberrant root development. Additionally, leaves of transgenic TPS1 tomato plants showed a chlorophyll and starch content higher to wild-type plants. Under drought, salt and oxidative stress TPS1 tomato plants improved tolerance than wild type, suggesting that carbohydrate alterations produced by trehalose biosynthesis be linked to the stress response. These results indicate the feasibility of engineering tomato for increased tolerance of abiotic stress, without decreasing productivity, under both stress and nonstress conditions through trehalose biosynthesis. (c) 2005 Elsevier Ireland Ltd. All rights reserved.