Genetic transformation of the Nicotiana protein kinase (NPK1) gene confers osmotic tolerance in Egyptian maize.

Abstract

2 Abstract: Maize is an economically important food crop. Environmental stresses, such as water deficit, increased salinity of soil, and extreme temperature, are major factors limiting maize productivity. Biotechnology and especially genetic engineering could offer great benefits by developing inherent engineered tolerance to drought and salt stresses. In recent years, Agrobacterium-mediated transformation has been successfully applied in important gramineae species, especially maize. In the present work, we introduced the NPK1 gene (for drought and salt tolerance) in combination with bar gene (for herbicide resistance, as a selectable marker) into elite maize inbred lines using the Agrobacterium-mediated transformation, the transformation frequency ranged between 2.7% and 5.2% for the genotypes used. Molecular analysis revealed the presence and integration of the transgenes in the genome of transgenic plants. R1 progeny of transgenic plants were tested in vitro for tolerance to osmotic (mannitol) stresses as compared to non-transgenic control plants. Transgenic plants maintained a higher growth and showed increased tolerance to stress conditions compared to non- transgenic plants. Thus, providing strong evidence that the NPK1 may play an important role in the protection of maize against possible water-deficiency stress conditions.