Isolation and characterization of an AP2/ERF-type drought stress inducible transcription factor encoding gene from rice

A genomic DNA fragment of 964 bp corresponding to AP2/ERF family transcription factor was isolated from drought tolerant Oryza sativa L. cv. 'N-22' (AP2/ERF-'N-22') and Oryza sativa L. cv. 'Teipei 309' (AP2/ERF-jap). The cDNA sequence of AP2/ERF-'N-22' (732 bp) was amplified using gene specific primers. The gene contains two exons and a single intron. The deduced protein of the AP2/ERF-'N-22' contains a potential nuclear localization signal, a possible regulation domain and an AP2 DNA binding domain of 60 amino acids. Northern and RT-PCR analysis showed that transcript of AP2/ERF-'N-22' accumulates in response to WDS and the Southern analysis indicated the presence of single copy of AP2/ERF-'N-22' gene in Oryza sativa genome. Phylogenetic analysis of AP2/ERF family revealed that AP2/ERF-'N-22' belongs to group Va along with SHN clade of AP2/ERF protein which activates wax biosynthesis. A higher epicuticular wax content was observed at decreased RWC and positively correlated with AP2/ERF-'N-22' expression.