Expression characteristics of GFP driven by NAC1 promoter and its responses to auxin and gibberellin

A 1050 by fragment upstream transcription start site of a transcription factor gene NAC1 in Arabidopsis thaliana was amplified and cloned into plasmid pRD420 to construct a green fluorescent protein(GFP) fusion system under the control of NACl promoter. Plasmids were introduced into tobacco by Agrobacterium-mediated method to regenerate plants with NACl-GFP gene, and expression pattern of NACl-GFP and its responses to auxin and gibberellin (GA) were observed. GFP was found to accumulate specifically in root, and was detected after treatment of auxin, N-1-Naphthylphthalamic acid (NPA, an auxin antagonist) or GA(3). It was indicated that the expression of GFP driven by NAC1 promoter was induced not only by auxin but also by GAs, suggesting that NACl mediated both the auxin signaling and the GAs signaling involved in lateral roots development.