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The accumulation of compatible solutes during stress in plant cell is well documented. Proline is one of these solutes which accumulate in the cytosol in response to drought or salinity stress in plants. Proline has several functions during stress just like osmotic adjustment, osmoprotection, free radical scavenger and antioxidant. Ornithine δ-aminotransferase (δ-OAT) is an important enzyme in proline biosynthetic pathway. It catalyzes the transamination of ornithine to pyrroline-5-carboxylate which can be reduced into proline. Expression of ornithine δ-aminotransferase gene isolated from Vicia villosa(VvOAT) showed protein with a molecular mass of 63 KDa which is compatible with the predicted mass and after VvOAT gene delivery into E. colihost HB101, VvOAT gene enhanced its salt tolerance. Homology modeling of VvOAT was performed based on the crystal structure of the ornithine δ-aminotransferase from humans (PDB code 2OATA). With this model, a flexible docking study with the substrate and inhibitors was performed. The results indicated that PHE170 and ASN171 in VvOAT are the important determinant residues in binding as they have strong hydrogen bonding contacts with the substrate and inhibitors. All the obtained results indicated the efficiency of utilizing this gene in conferring salt tolerance.

Using pulsed laser ablation technique, graphene oxide (GO) nanoparticles were incorporated into a polymeric blend of polyvinyl chloride (PVC) and polyvinylidene fluoride (PVDF). The nanocomposites were fabricated in film shapes using the casting method. The obtained films were investigated upon their structure and morphology. The films showed a rough surface with moderate porosity. The maximum roughness peak height increased from 142.9 to 198.9 nm for PVC and GO@PVC/PVDF. The thermal stability of the fabricated films was studied and showed that polymers displayed high stability up to 200 °C then were deteriorated exponentially. The weight loss reached around 3.2 % in the first stage and reached about 93.4 % at the last stage, which was above 400 °C. Further, the contact angle plunged from 90.2±3.4° to 65.4±2.5° for PVC, and GO@PVC/PVDF, respectively. Moreover, the dielectric loss was measured upon the variation of applied frequency. It decreased exponentially, starting from 7.1, 12.7, and 21.8 for PVC, PVC/PVDF and GO@ PVC/PVDF, respectively. The cell viability of the nanocomposite films was measured through the human fibroblasts cell line and showed an improvement upon the additional PVDF and GO to be around 95.3 ± 4 ± 3.5% in the case of GO@PVC/PVDF film.