Abstract
Arabidopsis DREB2A is a transcription factor that binds the DRE/CRT cis-acting element and controls the expression of many stress-inducible genes. Posttranscriptional modification of DREB2A seems to be necessary for its activation in plants. In this study, we isolated a cDNA for a DREB2 ortholog, ZmDREB2A and identified 2 types of the ZmDREB2A cDNA. One contains an intron in the N-terminal region and the other was a mature-type cDNA. We analyzed accumulation of these 2-type mRNAs in maize using RT-PCR analysis and found that the mature mRNA was detected only under stress condition. These results suggest that the level of the ZmDREB2A protein is regulated by the splicing of the DREB2A mRNA. To compare the function of ZmDREB2A and DREB2A we generated transgenic Arabidopsis plants overexpressing ZmDREB2A. Currently, we are analyzing stress tolerance of these transgenic plants and upregulated genes in the plants using microarray and northern blot analysis.
