Transcription factor TERF1 regulates nuclear genes expression through miRNAs in tobacco under drought stress condition

Ethylene is an important phytohormone that regulates plant response to drought stress. ETHYLENE RESPONSE FACTOR 1 (ERF1), a transcription factor of ERF/AP2 family, plays an important role in activating ethylene signaling pathway through binding the GCC box in the promoters of ethylene responsive genes. Although we know some protein-coding genes regulated by ERF1, we know nothing about how ERF1 regulates the expression of miRNAs. We utilized the tobacco overexpressing TOMATO ETHYLENE RESPONSE FACTOR1 (TERF1), an ERF1 transcription factor isolated from tomato, to investigate the miRNAs expression profile under natural dehydration condition by method of qRT-PCR. Results show that 25 miRNAs are significantly induced and only 10 miRNAs are significantly repressed by TERF1. Binding sites for ERF transcription factors are observed in six upregulated miRNAs and the core genes involved in the processing of pre-miRNA are also significantly induced by TERF1. We predicted the target genes regulated by the differentially expressed miRNAs by the on-line programme of psRNATarget. Gene ontology (GO) analysis shows that the significantly enriched biological processes for the target genes regulated by the downregulated miRNAs are located in chloroplast. We also predicted the important regulatory genes regulated by the differentially expressed miRNAs, including transcription factors, kinases and phosphatases. Our research provides novel mechanism for regulation of nuclear genes expression by TERF1 at posttranscriptional level under drought stress condition.