Expression analysis of low-temperature and warming treated Chiifu and Kenshin inbred lines to identify high-temperature adaptation-related gene in Brassica rapa.

Methionine sulfoxide reductases catalyze the reduction of MetSO back to the correct Met residue. Previously, the gene of Capsicum annuum methionine sulfoxide reductase B2 was isolated and CaMSRB2-overexpressing tomato shows enhanced growth, which may trigger increased resistance to the pathogens. To assess the role of this enzyme in rice, we generated transgenic lines under the control of the rice Rab21 (responsive to ABA protein 21) promoter with/without Bar marker gene. Several physiological tests such as MV and Fv/Fm, indicators of an oxidative stress-inducing agent and a potential maximal PSII quantum yield, respectively strongly suggested CaMSRB2 confers drought tolerance to rice. Using 3′-tiling microarray covering the whole rice genes, we carried out genome-wide expression analyses with CaMsrB2-transformed rice (Oryza sativa L. cv. ILMI). Rice was grown in port for six weeks and treated with drought by water withholding for two days. A total of 6 chips were used for the microarray experiment. RNA was extracted from plants just before and 2 days after the duration of water withdrawl for the control and the comparison, respectively. Experiments were performed with three or two biological replicates.