Over-expression of Potentilla superoxide dismutase improves salt stress tolerance during germination and growth in Arabidopsis thaliana

A novel autoclavable copper-zinc superoxide dismutase gene was cloned from a high altitude plant Potentilla atrosanguinea which is a critical enzyme in eliminating reactive oxygen species (ROS) from plant cells under different abiotic stresses. Transgenic plants of Arabidopsis were developed by over-expressing cytosolic Cu/Zn-SOD from Potentilla atrosanguinea (PaSOD) under CaMV35S promoter via Agrobacterium tumefaciens mediated transformation. Homozygous T3 lines were analyzed for stress tolerance. Transgenic Arabidopsis plants showed enhanced tolerance to salt stress during germination, seedling establishment and growth in terms of larger root length, larger rosette area and the higher number of leaves besides the high levels of SOD, as compared to the wild type (WT) under NaCl stress. Increased stress tolerance was possibly due to the increased levels of PaSOD transcripts, as evidenced by the semi quantitative RT-PCR