Salt stress obstructs plant’s growth by affecting metabolic processes, ion homeostasis and over-production of reactive oxygen species. In this regard silicon (Si) has been known to augment a plant’s antioxidant defense system to combat adverse effects of salinity stress. In order to quantify the Si-mediated salinity tolerance, we studied the role of Si (200 ppm) applied through rooting media on antioxidant battery system of barley genotypes; B-10008 (salt-tolerant) and B-14011 (salt-sensitive) subjected to salt stress (200 mM NaCl). A significant decline in the accumulation of shoot (35–74%) and root (30–85%) biomass was observed under salinity stress, while Si application through rooting media enhancing biomass accumulation of shoots (33–49%) and root (32–37%) under salinity stress. The over-accumulation reactive oxygen species i.e., hydrogen peroxide (H₂O₂) is an inevitable process resulting into lipid peroxidation, which was evident by enhanced malondialdehyde levels (13–67%) under salinity stress. These events activated a defense system, which was marked by higher levels of total soluble proteins and uplifted activities of antioxidants enzymatic (SOD, POD, CAT, GR and APX) and non-enzymatic (α-tocopherol, total phenolics, AsA, total glutathione, GSH, GSSG and proline) in roots and leaves under salinity stress. The Si application through rooting media further strengthened the salt stressed barley plant’s defense system by up-regulating the activities of enzymatic and non-enzymatic antioxidant in order to mitigate excessive H₂O₂ efficiently. The results revealed that although salt-tolerant genotype (B-10008) was best adopted to tolerate salt stress, comparably the response of salt-sensitive genotype (B-14011) was more prominent (accumulation of antioxidant) after application of Si through rooting media under salinity stress.

Zinc as a micronutrient is highly essential for animals and plants to attain optimum growth and development. Zinc-deficient soils result in stunted and abnormal growth of plants. Three wheat varieties, i.e., Zincol-2016 (biofortified), Galaxy-2013, and Punjab-2011 (both non-biofortified), were sown in pots containing fertile soil in a completely randomized design with four replicas. The seedlings were sprayed with four zinc solutions (Control, 0.03%, 0.06%, and 0.09% of Zn as ZnSO₄.7H₂O) 40 days after sowing. It was observed that the impact of 0.06% zinc spray was more pronounced on wheat plants as compared to that of 0.03% and 0.09%. More pronounced improvement in growth, chlorophyll content, total soluble proteins, and sugars was observed in cv. Zincol-2016 as compared to that in the other two varieties, Galaxy-2013 and Punjab-2011. Similarly, Zn foliar spray significantly enhanced root, straw, and grain K⁺, Cu²⁺, Zn²⁺, and Fe²⁺ contents in all three cultivars. In contrast, grain phytate contents were reduced with increased supplementation of Zn. Data revealed that grain yield was improved significantly by exogenous application of zinc, especially at 0.06% in all three wheat varieties, but being more promising in Zincol-2016. Furthermore, Zincol-2016 accumulated higher zinc contents in grains as compared to that in Galaxy-2013 and Punjab-2011. Foliar application of zinc resulted in higher uptake and accumulation of this element from soil to seeds, thereby resulting in improved vegetative growth.