Abstract: Ethylene response factor (ERF) proteins are important plant-specific transcription factors. Increasing evidences show that ERF proteins regulate plant pathogen resistance, abiotic stress response and plant development through interaction with different stress responsive pathways. Previously, we revealed that overexpression of TERF1 in tobacco activates a cluster gene expression through interacting with GCC box and DRE, resulting in enhanced sensitivity to ABA and tolerance to drought, and dark green leaves of mature plants, indicating that TERF1 participates in the integration of ethylene and osmotic responses. Here we further report that overexpression of TERF1 confers sugar response in tobacco. Analysis of the novel isolated tomato TERF1 promoter provides the information that there are many cis-acting elements, including sugar responsive elements SURE and W box, suggesting that TERF1 might be sugar inducible. This prediction is confirmed by RT-PCR amplification that transcripts of TERF1 are accumulated in tomato seedlings after application of glucose. Further investigation indicates that expression of TERF1 in tobacco enhances sensitivity to glucose during seed germination, root and seedling development, showing decrease of the fresh weight and root elongation under glucose treatment. Detailed investigations evidence that TERF1 interacts with sugar responsive cis-acting element SURE and activates the expression of sugar response genes, establishing the transcriptional regulation of TERF1 in sugar response. Therefore, our results deepen our understanding of glucose response mediated by ERF protein TERF1 in tobacco.

Key words: ERF protein TERF1, glucose, sugar responsive gene, tobacco