Enhancing Drought Tolerance in Wheat Cultivars through Nano-ZnO Priming by Improving Leaf Pigments and Antioxidant Activity

Abstract

Climate change, global warming, stagnant productivity of wheat and food security concerns owing to frequent spells of drought stress (DS) have necessitated finding biologically viable drought-mitigation strategies. A trial was conducted to test two promising wheat cultivars (Ujala-16 and Zincol-16) that were subjected to pre-sowing priming treatments with different doses of ZnO nanoparticles (NPs = 40, 80, 120 and 160 ppm) under 50% and 100% field capacity (FC) conditions. The ZnO NPs were prepared with a co-precipitation method and characterized through X-ray diffraction (XRD) and with a scanning electron microscope (SEM). For comparison purposes, untreated seeds were sown as the control treatment. The response variables included botanical traits (lengths, fresh and dry wrights of root and shoot), chlorophyll (a, b and total) contents, antioxidant and proline contents and nutrients status of wheat cultivars. The results showed that DS significantly decreased all traits of wheat cultivars, while ZnO NPs, especially the 120 ppm dose, remained superior by increasing all botanical traits at 100% FC. In addition, ZnO NPs increased the chlorophyll a (1.73 mg/g FW in Ujala-16 and 1.75 mg/g FW in Zincole-16) b (0.70 mg/g FW in Ujala-16 and 0.71 mg/g FW in Zincole-16) and total chlorophyll content (2.43 mg/g FW in Ujala-16 and 2.46 mg/g FW in Zincole-16) by improving the activity of antioxidant and proline content. Moreover, plant nutrients such as Ca, Mg, Fe, N, P, K, and Zn contents were increased by ZnO NPs, especially in the Zincol-16 cultivar. To summarize, Zincol-16 remains superior to Ujala-16, while ZnO NPs (120 ppm dose under 100% FC) increases the growth and mineral contents of both wheat varieties. Thus, this combination might be recommended to wheat growers after testing further in-depth evaluation of more doses of ZnO NPs.

Seed Priming with Zinc Oxide Nanoparticles to Enhance Crop Tolerance to Environmental Stresses

“…Zinc has an important role in cereal growth; since it is an essential nutrient for normal homeostasis, it is actively involved in the metabolism of proteins, the synthesis of hormones and enzymes and it helps to alleviate oxidative damages, thus improving nutrient profiles [22,103]. Seed priming with ZnO NPs plays a role in alleviating drought-induced damages in cultivars grown in environments subjected to water shortage [81,82]. This was achieved, for instance, by Mazhar et al [81], who performed seed nano-priming by dipping the rice seeds in suspensions of ZnO NPs at different concentrations (0, 5, 10, 15, 25 and 50 ppm) for 24 h. Afterwards, primed seeds were planted in water shortage conditions, corresponding to 35% irrigation as compared to normal pots.…”

“…Priming of wheat seeds by ZnO NPs had different effects on the growth and well-being of plants depending on the dose. In an investigation by Abbas et al [82], wheat seeds were treated with commercial ZnO NPs for 12 h at 40, 80, 120 and 160 ppm, sowed, and grown in pots both under water stress and well-watered conditions. After 4 weeks, all primed plants displayed better biometric parameters than the un-primed counterparts, under both watering conditions.…”

Inulin-Coated ZnO Nanoparticles: A Correlation between Preparation and Properties for Biostimulation Purposes

“…Therefore, the synthetic strategy becomes crucial for the ensuing application. These combined properties, however, are often overlooked when dealing with plant administration, often relying on commercial nanoparticles that are not always fully characterized [ 75 , 92 , 93 , 94 , 95 , 96 , 97 , 98 ]. Engineered nanoparticles for biostimulation are usually lab prepared, although the implementation of the protocol is typically not discussed.…”

Proximal canopy sensing of twenty-two bread wheat genotypes for nutritional quality, yield attributes and grain yield under Mediterranean climate

“…Under changing climate and rapidly increasing human population, crop production has become immensely vital to ensure food and nutritional security globally (Siddiqui et al, 2019;Iqbal, 2020;Oakes et al, 2024). Among staple food crops, wheat (Triticum aestivum L.) constitutes of one of the most strategic crops by feeding over half of the world's human populace (Arısoy, 2011;Chowdhury et al, 2021;Iqbal et al, 2021;Yildirim et al, 2022;Abbas et al, 2023). There are many wheat species, however, bread wheat is the most produced among wheat species (Iqbal et al, 2018;Choudhary et al, 2021;Sorour et al, 2021).…”