Ectopic expression of the LoERF017 transcription factor from Larix olgensis Henry enhances salt and osmotic-stress tolerance in Arabidopsis thaliana

Dehydration-responsive element binding (DREB) transcription factors (TFs) play a significant role in the response to many abiotic stresses, and they can regulate the downstream expression of some defense genes. In this study, a novel DREB TF gene, designated as LoERF017, was identified from Larix olgensis. The ORF of the LoERF017 gene is 624 bp and it contains an AP2/EREBP domain belonging to a typical DREB TF. Sub-cellular location analysis showed that LoERF017 was located in the nucleus. QRT-PCR analysis indicated that LoERF017 could be induced by NaCl, PEG6000, sodium nitroprusside (SNP), and ABA treatment. Moreover, an analysis of the survival rate and the development of transgenic plants under mannitol and NaCl revealed that the overexpression of LoERF017 in Arabidopsis could improve tolerance to osmotic and salt stress. Compared with wild-type (WT) plants, the overexpression of LoERF017 resulted in higher superoxide dismutase (SOD) and peroxidase (POD) activities and lower malondialdehyde (MDA) and reactive oxygen species (ROS) levels under osmotic stress. Downstream stress-responsive genes, including COR, rd29A, and ERD10, were also activated in transgenic plants overexpressing LoERF017. In brief, the overexpression of the LoERF017 gene may directly or indirectly induce antioxidant enzyme systems and downstream stress-response genes to enhance osmotic resistance capacity in plants.