Isolation and characterisation of a gene for a DREB transcription factor from Phyllostachys edulis induced by drought

Abstract

SummaryWe have cloned a novel drought-induced gene PeDREB2 from Phyllostachys edulis using the RACE method and demonstrated that the deduced protein sequence contained a conserved AP2 DNA-binding domain that belonged to the EREBP/AP2 family. PeDREB2 gene expression peaked at 12 h under conditions of drought stress, and transcripts accumulated rapidly by 6 h under salt stress, but expression was not affected by abscisic acid or cold stress treatments. In onion epidermal cells, the recombinant protein, PeDREB2-163GFP, was localised to the nucleus. In yeast, the PeDREB2 protein bound specifically to dehydration-response elements to activate transcription of the His3 and LacZ reporter genes. When fused to a sequence encoding the LexA DNA-binding domain, the PeDREB2 protein was an effective trans-activator in the yeast one-hybrid assay. Therefore, PeDREB2 represents a novel transcription factor and, like other EREBP/AP2 regulons, is activated in response to environmental stress factors in tropical plants such as Phyllostachys edulis (bamboo).