To elaborate the biological function of PEPC which encodes phosphoenolpyruvate carboxylase from C₄ halophyte Suaeda aralocaspica,we investigated the performance of recombinant PEPC in Escherichia coli Transetta (DE3) under various abiotic stresses.The full-length cDNA of PEPC (GenBank accession No.KP985714) was obtained by 5′-RACE technique and its procaryotic expression vector pGEX-4T-1-PEPC was constructed.The content and enzyme activity of PEPC were measured by the spectrophotometric method and enzyme linked immunosorbent assay (ELISA).Meantime,the tolerance of the recombinant E.coli Transetta::pGEX-4T-1-PEPC to different abiotic stresses was also investigated.Bioinformatics analyses showed that PEPC contained 2 901 bp nucleotides and encoded 966 amino acids,which possesses the typical conserved domains of PEPC (e.g.active sites VlTAHPTQsiRR and VMIGYSDSgKDAG),and shares 90% amino acid similarity to PEPC from Beta vulgaris;our PEPC was a non-secretory PEPC-1 type hydrophilic protein without signal peptide sequence,and the molecular weight of the recombinant PEPC was approximately 130-140 kD,which was confirmed by western blot analysis.The recombinant PEPC presented relatively higher enzymatic activity when induced by 0.8 mmol/L IPTG at 37 ℃.Compared with the control strain,the recombinant E.coli Transetta::pGEX-4T-1-PEPC showed better growth performance under various abiotic stresses ［i.e.200-800 mmol/L NaCl,5%-20% PEG 6 000,25 ℃-52 ℃,50-400 μmol/L methyl viologen,and the wide acid and base range (pH 3.0-11.0)］.The results showed that overexpression of PEPC gene from S.aralocaspica in E.coli enhanced the tolerance under various abiotic stresses,which suggests that PEPC may confer stress tolerance to E.coli.Our work can provide more evidence for revealing the biological function of PEPC from S.aralocaspica.