Identification of GeERF transcription factors in Gelsmium elegans and their expression under low temperature stress

Abstract

With prominent medicinal value, Gelsemium elegans has been overexploited, resulting in the reduction of the wild resource. As a result, artificial cultivation turns out to be a solution. However, this medicinal species is intolerant to low temperature, and thus genes responding to the low temperature are important for the cultivation of this species. Based on the transcriptome database of G. elegans at 4 ℃, 29 differentially expressed GeERF genes were identified. Bioinformatics analysis of 21 GeERF gene sequences with intact open reading frames showed that 12 and 9 of the GeERF proteins respectively clustered in DREB subgroup and ERF subgroup. GeDREB1 A-1-GeERF6 B-1, with molecular weight of 23.78-50.96 kDa and length of 212-459 aa, were all predicted to be hydrophilic and in nucleus. Furthermore, the full-length cDNA sequence of GeERF2B-1 was cloned from the leaves of G. elegans. Subcellular localization suggested that GeERF2B-1 was located in the nucleus. According to the quantitative reverse-transcription PCR(qRT-PCR), GeERF2B-1 showed constitutive expression in roots, stems, and leaves of G. elegans, and the expression was the highest in roots. In terms of the response to 4 ℃ treatment, the expression of GeERF2B-1 was significantly higher than that in the control and peaked at 12 h, suggesting a positive response to low temperature. This study lays a scientific basis for the functional study of GeERF transcription factors and provides gene resources for the improvement of stress resistance of G. elegans.