Dilara Kaynar

Aquaporins (AQPs) are integral membrane proteins that facilitate water and solute transport, playing crucial roles in stress adaptation in both plants and animals. In mammals, aquaglyceroporins such as AQP3 and AQP7 are well characterized, whereas their plant counterparts remain less understood, particularly at the protein level. In this study, alfalfa (Medicago sativa) was grown in Hoagland’s medium supplemented with 0, 50, 100, 200, or 400 mM NaCl for 21 days. Protein extracts were analyzed by SDS-PAGE and Western blotting using antibodies against human - mouse - rat AQP3 and mouse - human AQP7. Two distinct cross-reactive protein bands were identified. Their expression was weak at 200 mM NaCl but strongly induced under severe salt stress at 400 mM NaCl. These results suggest a threshold-dependent regulation of aquaporin-like proteins in alfalfa. Unlike transcriptomic analyses, our protein-level approach highlights stress-specific expression dynamics and points to potential functional similarities with mammalian aquaglyceroporins, particularly in osmolyte transport and osmotic adjustment. This study underscores the importance of direct protein analysis for understanding stress physiology and provides new insights into salt stress adaptation mechanisms in forage legumes.

Salinity and alkaline conditions are among the most important abiotic stress factors that limit plant growth and development, especially in arid and semi-arid areas. Indeed, approximately 30,000 hectares of plain land located in the Dumlu region of Erzurum cannot be adequately utilized due to high groundwater levels, salinity, and alkalinity. Reclaiming this type of soil is quite costly, and one of the prominent alternatives is to identify plant species and varieties that are tolerant to high soil salinity and ensure their cultivation in such areas. For this purpose, in our study, along with the halophyte plant Puccinellia distans, silicon dioxide (SiO2) and potassium nitrate (KNO3) fertilizers were used. The research was conducted in greenhouses at Atatürk University Faculty of Agriculture, using soil samples appropriately taken from four different sections of the affected region with varying salt content, according to a completely randomized experimental design. For this purpose, a total of 144 pots (4×1×4×3×3=144) were used across 4 different locations, with 1 halophyte plant Puccinellia distans, 4 different silicon (SiO2) doses (0, 1, 2, and 4 mM), 3 different potassium nitrate (KNO3) doses (0, 20, and 40 mM) with 3 replications. Plant height, number of main stems, number of leaves, fresh forage yield and dry matter yield, crude protein content and yield, and ADF and NDF contents were examined in the plants obtained at the end of the trial. As a result, a decrease in all yield and yield components was observed in plants grown under saline-alkali conditions compared to plants grown in normal soil. However, in saline-alkaline conditions, the application of silicon and potassium generally reduced the negative effects of salinity stress on the plant. The highest dry matter yield, crude protein content, and yield value were obtained from the application of 40 mM KNO3 fertilizer without the addition of silicon. Based on these results, we can say that the plant Puccinella distans is promising for the evaluation of saline-alkali areas with similar conditions, and that potassium fertilization in particular is effective in increasing its yield.

In recent years, the development of nanotechnology and the results of many researches in this field have shown that it contributes significantly to germination, growth, development and product yield of plants. In addition, nanoparticle applications have been shown to positively affect cell structure and cell function on physiological and biochemical mechanisms in the regulation of adverse effects caused by various environmental stresses. In this study, zinc oxide (ZnO) and copper oxide (CuO) nanoparticle were applied to the seeds of sugar beet (Bernache) variety and the effects of changes in germination, weight and length measurements in radicle and plumule were investigated. It was determined that the seeds responded differently to both nanoparticle. In our study, copper oxide pretreatment caused an increase in radicle and plumula length. In terms of weights, it was observed that copper oxide 1800 mg/l application caused a significant increase in shoot and root wet weight. As a result, it was determined that copper oxide 1800 mg/l pretreatment had a positive effect on all parameters examined.

Phosphorus is considered one of the essential elements for legumes as it increases nitrogen fixation due to nodulation. Hence, for high productivity in legumes, it should be added as inorganic or organic fertilizer to soils containing insufficient phosphorus. Especially in recent years, using inorganic and organic fertilizers together has gained importance in terms of sustainable agriculture, considering plant growth and soil and environmental health together. The effects of three different doses of phosphorus fertilizer (0, 50, 100 kg P2O5 ha-1), and two different doses of poultry manure (0, 3 t ha-1) applications with two different doses (B0 or B1) of phosphorus solubilizing bacteria (Bacillus megaterium M-3) inoculation on hay yield and yield components of common vetch were examined in this study. In fact, while the highest hay yield and crude protein rate were obtained by bacterial inoculation together with phosphorus fertilizer application, the effect of poultry manure application on yield and yield parameters was variable. Instead, the applications had no significant effect on the number of main branches, ADF and NDF rates. Consequently, the application of 100 kg P2O5 ha-1 together with Bacillus megaterium inoculation can be recommended for high hay yield in common vetch under irrigated conditions in areas with poor or medium soils in terms of phosphorus.