Characterization of a drought-responsive gene, OsTPS1, identified by the T-DNA gene-trap system in rice

Trehalose-6-phosphate synthase (TPS) is a key enzyme for trehalose biosynthesis. To understand the function of the TPS gene, we identified the T-DNA insertion in a TPS gene of rice. Line 1C-071-05 had T-DNA inserted at the second intron of OsTPS1. its deduced OsTPS1 protein shared 52% homology with Arabidopsis TPS. Reverse transcriptase-PCR analysis of OsTPS1 showed that OsTPS1 is inducible by drought, salt, cold, and ABA. Leaves of OsTPS1 knockout (KO) plants were more sensitive to drought or cold stress than were the wild types. Furthermore, transgenic rice of UBI::CBF1 had high expression OsTPS1 mRNA, suggesting that OsTPS1 is regulated by the CBF/DREB transcription factor. Therefore, we propose that OsTPS1 plays an important role during the abiotic stress response.