Identification of

Abstract

AP2/ERF transcription factors (TF) are widely involved in the biological process of Ginkgo biloba , here, the ERF gene family may regulate plant stress responses through mediating secondary metabolism. To understand the regulation mechanisms of ERF gene family during this process, two transcriptome databases of ginkgo leaves under UV-B and drought stress were constructed respectively. The conserved domains, physicochemical properties and gene family homology of AP2/ERF TFs were analyzed using online bioinformatics tools, the expression of ERF gene family under these two adversity stresses were predicted and five ERF genes involved in flavonoid pathway were selected for qRT - PCR validation analysis. The results showed that 61 AP2/ERF TFs were identified from G. biloba , and which were classified into 28 GbERF, 23 GbDREB, 5 GbAP2, and 5 GbRAV, according to their conserved domains and motifs. The Amino acid numbers, isoelectric point (pI) and some other physicochemical properties varied greatly between different members. Sequence homology analysis with Arabidopsis thaliana and Glycine max  showed that the members in the same AP2/ERF subfamily were closely related. In G. biloba , the GbERF and GbDREB subfamily together constitute the ERF gene family, transcriptome prediction analysis showed that the expression of most members of ERF gene family were increased under UV-B and drought stress. From the validation analysis, we concluded that the changes of the expression levels of these five genes were consistent with the prediction results. This study provided scientific basis for the function analysis of ERF gene family in G. biloba .