biologia plantarum

Biologia plantarum 59:497-506, 2015 | DOI: 10.1007/s10535-015-0533-y

Overexpression of TsApx1 from Thellungiella salsuginea improves abiotic stress tolerance in transgenic Arabidopsis thaliana

Z. Q. Li¹, J. X. Li¹, H. J. Li², Z. H. Shi¹, G. F. Zhang^1,*

¹ Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, P.R. China

² The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, P.R. China

The halophyte Thellungiella salsuginea is a new model plants due to its small genome size, short life cycle, and copious seed production. Although T. salsuginea shares a high sequence identity with its close relative Arabidopsis thaliana, it shows a greater tolerance to salinity, drought, freezing, heat, and cold. To elucidate the mechanism of abiotic stress resistance in T. salsuginea, we characterized its cytosolic Apx1 gene (TsApx1) and established A. thaliana transgenic lines overexpressing TsApx1. Under 300 mM NaCl, the content of H₂O₂, malondialdehyde, and proline were lower and the activities of superoxide dismutase, catalase, glutathione peroxidase, and ascorbate peroxidase were all higher in the transgenic plants overexpressing TsApx1 (35S:TsApx1-GFP) than in the wild-type plants. The atapx1 mutant plants of A. thaliana had a NaCl/mannitol-sensitive phenotype. The ectopic expression of TsApx1 in the atapx1 mutant effectively remedied the phenotype. These results suggest that TsApx1 plays an important role in scavenging reactive oxygen species in the cytoplasm under salinity or drought. Although TsApx1 in T. salsuginea was constantly expressed at a high level, this gene was clearly inducible. In summary, the high constitutive expression and rapid induction of TsApx1 may contribute to the tolerance to abiotic stresses in T. salsuginea.

Keywords: antioxidative enzymes; ascorbate peroxidase; ectopic expression; reactive oxygen species

Subjects: transgenic plants; ectopic expression; reactive oxygen specied; salinity; proline; malondialdehyde; ascorbate peroxidase; catalase; guaiacol peroxidase; superoxide dismutase; water content; drought

Received: October 15, 2014; Revised: February 9, 2015; Accepted: February 16, 2015; Published: September 1, 2015Show citation