Ectopic Expression ofOsSta2Enhances Salt Stress Tolerance in Rice.
Salt stress can severely reduce crop yields. To understand how rice (Oryza sativa) plants respond to this environmental challenge, we investigated the genes involved in conferring salt tolerance by screening T-DNA tagging lines and identifiedOsSta2-D(Oryza sativa Salttoleranceactivation2-Dominant). In that line, expression ofOsSta2was enhanced by approximately eightfold when compared with the non-transformed wild type (WT). This gene was highly expressed in the callus, roots, and panicles. To confirm its role in stress tolerance, we generated transgenic rice that over-expressesOsSta2under a maizeubiquitinpromoter. TheOsSta2-Ox plants were salt-tolerant at the vegetative stage, based on our calculations of chlorophyll fluorescence (Fv/Fm), fresh and dry weights, chlorophyll concentrations, and survival rates. Under normal paddy field conditions, the Ox plants were somewhat shorter than the WT control but had improved agronomic traits such as higher total grain yield. They were also more tolerant to osmotic stress and hypersensitive to abscisic acid. Based on all of these results, we suggest thatOsSta2has important roles in determining yields as well as in conferring tolerance to salt stresses.
Department of Life Science, Sogang University Seoul, South Korea.
Manu
M
Kumar
Department of Life Science, Sogang University Seoul, South Korea.
Juyoung
J
Choi
Department of Plant Molecular Systems Biotechnology, Kyung Hee University Yongin, South Korea.
Gynheung
G
An
Department of Life Science, Sogang University Seoul, South Korea.
Seong-Ryong
SR
Kim
ABA; abiotic stress; agronomic trait; drought stress; osmotic stress; rice; salt stress; tiller number