Environmental Stress Response of a Dehydroascorbate Reductase Gene from Tomato, and Its Protective Role in Escherichia coli

We investigated the role of a dehydroascorbate reductase (SlHDAR1) gene from Solanum lycopersicum leaves in response to abiotic stresses, and the effect of the gene was assessed in transgenic Escherichia coli against oxidative stress. Coding sequence of SlDHAR1 was subcloned into pET-28a(+) expression vector, and transformed it into E. coli BL21 (DE3). The SlDHAR1 gene was induced in tomato leaves in response to cold and wounding, not to absicic acid (ABA). Effective induction of SlDHAR1 protein was observed in E. coli by Isopropyl-β-D-thiogalactopyranoside (IPTG). Increased mRNA level was noted in the E. coli cells transformed with SlDHAR1. The growth of the transgenic E. coli cells expressing SlDHAR1 was evidenced to be faster than control strain in the both solid and liquid growth media supplemented with H₂O₂. Taken together, the SlDHAR1 gene could play a role in cold and wound stress responses of tomato plants and the gene may be protective to E. coli to oxidative stress.