OsTPS8 CONTROLS SALT STRESS TOLERANCE AND AGRONOMIC TRAITS IN RICE

Abstract

Two homozygous single-copy-Ds-insertion mutants were selected out of twelve rice mutants. One of them showed dwarf phenotype compared to WT, where Ds was inserted in OsPS1F gene. Basic characterization of this mutant was carried out using complementation and overexpression transgenic lines of OsPSIF. Another mutant (Ds insertion in OsTPS8, trehalose-6-phosphate synthase 8) showed salt-sensitivity as well as plant architecture defects compared to WT. The mutant phenotype was rescued by complementing the mutant with gDNA of OsTPS8 and OsTPS8 overexpression lead to salt tolerance. Additionally, OsTPS8 dsRNAi line mimicked the ostps8 phenotype. In ostps8, soluble sugar concentrations were lower than in the WT. Members of OsPP2C, SAPKs and ABA responsive genes showed significant downregulation in ostps8 compared to WT which indicates their possible involvement in TPS downstream pathways. These findings will help to elucidate the role of trehalose biosynthetic genes in growth, development and salt stress response in plants.