Enhance salinity resistance in Arabidopsis thaliana by overexpression of phosphoethanolamine N-methyltransferase gene from spinach (Spinacia oleracea, Iranian landrace)

One of the plant resistant mechanisms to abiotic stresses is production of a compatible solute named glycine betaine. Choline is the precursor of this important metabolite and it is also essential compound for the structural integrity and signaling of cell membrane. In plants, the most important step of choline production is catalyzed by cytoplasmic phosphoethanolamine N-methyltransferase (PEAMT ; EC 2.1.1.103) enzyme. In this study, PEAMT gene from spinach (Spinacia oleracea Iranian landrace) was amplified using specific primers and cloned into an intermediate cloning vector (pJET). In order to overexpression of PEAMT gene, the construct of PBI121GUS-9:PEAMT was made and finally was transferred to the Agrobacterium tumefaciens GV3101 (PMP90). Floral dip method was used for transformation and initial analysis of putative transgenic plants was tested in selective medium containing kanamycin. Then resistant seedlings at the molecular level were evaluated using PCR and RT-PCR methods. Results confirmed plant transformation in the level of transcription. Subsequently, The phenotypic analysis under salt stress showed that the main root length of transgenic plants was significantly longer than control nontransgenics. In adition, glycinebetaine contents and peroxidase activity were significantly higher in transgenic compare to non-transgenics control plants.