Exogenously applied proline with silicon and zinc nanoparticles to mitigate salt stress in wheat plants grown on saline soil

There is a growing interest in utilizing exogenous osmolality compounds that can improve plants' performance under salt-stress conditions. Proline and nanoparticles exogenously applied are thought to play a role in reaching this goal, in particular by increasing the plants' ability to withstand several abiotic stresses, including salinity. To mitigate salt stress in wheat plants, exogenously applied proline and nanoparticles of silicon and zinc have been suggested. A field trial was laid out in a randomized complete block design with three replicates of each treatment. Exogenously applied treatments were set as follows: control water spraying (CK), proline (Pro), SiO2 NPs (Si), ZnO NPs (Zn), SiO2-ZnO NPs (Si + Zn), and proline and SiO2-ZnO NPs (Pro + Si + Zn). Proline and SiO2-ZnO NPs alleviated salt stress and significantly improved wheat's growth, yield, and nutrient content. Leaf-chlorophyll, proline, potassium (K), silicon (Si), zinc (Zn), and the K/Na ratio were all increased in leaves with exogenous application of proline and SiO2-ZnO NPs. Furthermore, sodium (Na) levels decreased. Nutrient contents in grain and straw, as well as crude protein in wheat grains, were significantly increased by the exogenous application of proline and SiO2-ZnO NPs. Furthermore, the greatest biological, grain, and straw yields were achieved with exogenously applied proline and SiO2-ZnO NPs. Our findings concluded that exogenously applying proline and SiO2-ZnO NPs successfully mitigated salt stress. Likewise, significantly increased all parameters investigated, with the exception of the Na content in wheat plant leaves, thereby increasing growth and yield in wheat plants grown in salinity soils.