Transformation and Expression of HvDRF1 Drought Tolerant Gene in Two Medicago sativa Cultivars

Drought stress factors are the most dangerous issues for crop productivity and will be a more limiting factor in the future due to climate change. Genes for drought tolerance have been identified and isolated from barley to produce drought stress-tolerant cultivars in other plants with precise gene transfer. The main aim of the following study is to transfer the HvDRF1 gene from barley, known for its drought tolerance properties, into alfalfa cultivars using chitosan nanoparticles as a gene vector. The successful transformation of the HvDRF1 gene into the transformed alfalfa plants was confirmed using both PCR and RT-PCR techniques. The drought tolerance of the transformed alfalfa plants was assessed through various morphological and physiological measurements. These measurements demonstrated that the transformed alfalfa plants displayed a higher level of drought tolerance compared to non-transformed plants. The measurements of drought-responsive traits such as proline, plant biomass, photosynthetic pigments, phenolic compounds, and flavonoids as well as the RWC (relative water content), indicate that the transformed plants express more tolerance to drought compared to the control non-transformed plants. These results support the use of chitosan nanoparticles as a gene vector, proving to be an effective method for gene transfer to alfalfa and potentially other crop plants.