Isolation and molecular characterization of an ethylene response factor NtERF1-1 in Nicotiana tabacum cv. Xanthi

Apetala2/Ethylene Response Factors (AP2/ERF) play important roles in regulating gene expression under abiotic and biotic stress in the plant kingdom. Here, we isolated a member of the AP2/ERF transcription factors, NtERF1-1, from Nicotiana tabcum cv. Xanthi NN carrying the N gene, which is resistant to Tobacco mosaic virus (TMV). NtERF1-1 encoded a putative protein of 229 amino acids with a predicted molecular mass of 24.58 kDa. Nucleotide sequence analysis showed that NtERF1-1 contained a conserved DNA-binding domain at the N-terminal. Comparison of amino acid sequences revealed that NtERF1-1 possessed high similarities to ERFs from diverse plants. Semi-quantitative and real-time quantitative RT-PCR analyses indicated that NtERF1-1 was up-regulated following TMV infection. In addition, we speculated that NtERF1-1 might participate in the signal transduction pathway of defence response inducted by the interaction between the N gene and TMV.