The Copper Metal and Magnetite Nanoparticles Conjugated with Salicylic Acid Composite Stimulated Wheat Defense Mechanism and Affected Cellular Components under Heat Stress

Aims: This study aimed to examine the effect of magnetite coating of salicylic acid and Cu metal nanoparticles on yield, cellular contents, and some biochemical constituents of wheat subjected to heat stress. Background: An applied experiment was conducted over two seasons at the Agricultural Experimental Station of Desert Research Center (DRC), which was supervised by the El Wadi El Gadeed Governorate in Egypt. The grains of wheat cultivars Sids1 (tolerant) and Gimmeza7 (sensitive) were treated with copper metal as NPs (Cu NPs) (0.25, 0.50, 0.75, 1.0, and 10 ppm) and magnetite NPs (0.25, 0.50, 0.75, 1.0 and 10 ppm) coated with salicylic acid at 100ppm (Fe NPs+SA). Objective: The objective of this study was to examine wheat tolerance to heat stress and subsequently yield by comparing two wheat cultivars under the same conditions. Methods: The chemically formulated nanoparticles were well characterized and applied in two wheat cultivars subjected to heat stress. Results: The results showed that all NPs treatments had a positive impact on all physiological parameters and grain yield. Sids1 surpassed Gemmeiza7 in the quality of wheat grains (essential, nonessential amino acids). However, Gimmeza7 exceeded Sids1 in yield quantity, especially with the application of SA+Fe NPs at 0.50 ppm. These effects were associated with heat tolerance and the best survival in wheat cultivars. There was an increase in glutathione content, antioxidant enzymes (Glutathione -S- Transferase), and/or a decline in malondialdehyde content. Conclusion: Fe NPs+SA (0.5ppm) helped the Gimmeza7 cultivar to mitigate the effects of heat stress through activating growth, glutathione, and glutathione S transferase, enhancing yield quantity in two wheat cultivars (Misr1 and Gimmeza11), and decreasing their MDA content.