Gene cloning, subcellular localization and expression analysis of the AsERF1 gene from Aquilaria sinensis / 药学学报

ABSTRACT

Ethylene-response factors, which are a subfamily of the AP2/ERF family, play an important role in ethylene signal transduction, plant growth and plant resistant. In this study, a full-length cDNA of the AsERF1 gene was cloned from Aquilaria sinensis. Sequence analysis, prokaryotic expression and purification, subcellular localization, tissue-specific analysis and expression analysis under different abiotic stresses was performed. The open reading frame (ORF) of the AsERF1 gene was 691 bp, encoding a protein of 229 amino acids with a predicted molecular mass of 25.36 kD. The AsERF1 protein contained the conserved AP2 sequence of ERF protein. A phylogenetic analysis indicated that the AsERF1 protein showed greatest sequence similarity with ERF2 from Populus trichocarpa. The recombinant AsERF1 protein was expressed in Escherichia coli BL21(DE3) cells using the prokaryotic expression vector pET28a-AsERF1 and the recombinant AsERF1 protein was purified. Agrobacterium-mediated protein expression experiments demonstrated that AsERF1 mainly localized to the nucleus. Expression analysis indicated that AsERF1 was primarily observed in leaves. The AsERF1 expression level was induced by salt, drought, low temperature and CdCl2 treatment, while the abundance of AsERF1 was most significantly induced by drought stress. These results provide valuable insights into the role of AsERF1 in plant defense and the mechanism of agarwood formation.