Objective Expression of antioxidant enzyme genes of rice in response to drought-stress was studied.
Method Simulated drought conditions using PEG6000 on Indica rice Hang 2 were used for the experimentation. The plants at 3-leaf stage were initially treated with 0% (CK), 18%, 20%, 22%, 24% or 26% PEG6000 to determine the appropriate concentration for the subsequent test. Under the selected PEG6000 treatment level, plant samples were collected at 0, 2, 4, 8, 12, 24, 48 and 72 h for analysis. The expressions of antioxidant enzyme genes (i.e., CATA, CATB and CATC), peroxidase genes (i.e., POX5.1 and POX1), superoxide dismutase genes (i.e., plastidic Cu/Zn-SOD and cytosolic Cu/Zn-SOD), ascorbate peroxidase gene (i.e., APX), and glutathione reductase gene (i.e., GR) of the rice plants were determined by qRT-PCR.
Result Based on the phenotype and survival rate of the rice plants in the preliminary test, 22% PEG6000 was chosen for the simulation experiment. The results of qRT-PCR showed that all 9 genes were upregulated initially under the treatment but downregulated afterward. Most of the genes significantly upregulated 4 h after treatment showing a response of the genes to the stress. In particular, CATA exhibited a most significant change at 8 h which was 28 times of that at 0 h.
Conclusion The expression of antioxidant enzyme genes significantly reacted to the PEG6000 treatment.
DownLoad: