GsERF1 enhances Arabidopsis thaliana aluminum tolerance through an ethylene-mediated pathway

Ethylene response factor (ERF) transcription factors constitute a subfamily of the AP2/ERF superfamily in plants and play multiple roles in plant growth and development as well as in stress responses. In this study, theGsERF1gene from the wild soybean BW69 line (an Al-resistantGlycine sojaline) was rapidly induced in response to aluminum stress. Quantitative real-time PCR (qRT–PCR) analysis showed that theGsERF1gene maintained a constitutive expression pattern and was induced in soybean in response to aluminum stress, with increased amounts of transcripts detected in the roots. The putative GsERF1 protein, which contains an AP2 domain, was located in the nucleus and maintained transactivation activity. In addition, under AlCl3 treatment, GsERF1 overexpression increased the relative growth rate of the roots of Arabidopsis and weakened the hematoxylin staining of hairy roots. Ethylene synthesis-related genes such asACS4,ACS5andACS6were upregulated inGsERF1transgenic lines compared with the wild type under AlCl3treatment. Furthermore, the expression levels of stress/ABA-responsive marker genes, includingABI1, ABI2, ABI4, ABI5andRD29B, in theGsERF1transgenic lines were affected by AlCl3treatment, unlike those in the wild type. Taken together, the results indicated that overexpression ofGsERF1may enhance aluminum tolerance ofArabidopsisthrough an ethylene-mediated pathway and/or ABA signaling pathway, the findings of which lay a foundation for breeding soybean plants tolerant to aluminum stress.