An AP2/EREBP-type transcription-factor gene from rice is cold-inducible and encodes a nuclear-localized protein

We cloned an AP2/EREBP gene by dot blotting and named it OsDREBL. Analysis of its deduced amino-acid sequence indicated that this protein had a potential nuclear-localization signal, a possible acidic-activation domain and an AP2 DNA binding domain. Northern analysis showed that the transcripts of OsDREBL accumulated rapidly (within 30 min) in response to low temperature, but not in response to ABA, NaCl and dehydration treatments. Southern analysis indicated the presence of a single-copy of the OsDREBL gene in the Oryza sativa genome. Our research also demonstrated that OsDREBL was localized to the nucleus but did not bind effectively to the C-repeat/dehydration responsive element (CRT/DRE). These results suggested that OsDREBL may function as a transcription factor in the cold-stress response, independent of the DREB signal-transduction pathway.