Table 2.
Impact of nanoparticles on germination, morphological physio-biochemical and molecular parameters of monocot plants under drought stress
| Nanoparticles (NPs) | Concentration of NPs | Name of crop /family | Mode of treatment | Response/tolerance mechanism | References |
|---|---|---|---|---|---|
| Cu NPs and Zn NPs | 1% | Winter wheat (Triticum aestivum, Poaceae) | Seed treatment | Decreased Thiobarbituric acid reactive substances (TBARS). Increased antioxidative enzyme (SOD and catalase) activity. Increased carotenoids | Taran et al. (2017) |
| Nanoceria- Cerium oxide nanoparticles | 10 mg/L | Sorghum (Sorghum bicolor, Poaceae) | Foliar Treatment | Decreased ROS, hydrogen peroxide and MDA. Increased the activities of CAT (Catalase), SOD (superoxide dismutase) and POD (peroxidase). Decreased photosynthetic rates and stomatal conductance | Djanaguiraman et al. (2018) |
| Chitosan nanoparticles containing GSNO | 100 µM | Sugarcane (Saccharum officinarum, Poaceae) | Hydroponics treatment | Increased Leaf CO2 assimilation. Enhanced stomatal conductance and increased relative water content | Silveira et al. (2019) |
| ZnO NPs | 2.17 mg/kg | Wheat (Triticum aestivum, Poaceae) | Soil treatment | Increased uptake of Zn, N and P | Dimpka et al. (2020) |
| TiO2 NPs | 500, 1000, and 2000 mg/kg | Wheat (Triticum aestivum, Poaceae) | Soil treatment | Increased seedling length (SL), superoxide dismutase (SOD) activity, total soluble proteins, net photosynthetic rate and intercellular CO2 concentration (Ci) | Faraji and Sepehri (2020) |
| Selenium nanoparticles | 10, 20, 30, and 40 mg/L | Wheat (Triticum aestivum, Poaceae) | Foliar treatment | Enhanced morphological traits such as root/shoot length, leaf number and area, fresh/dry weight of root and shoot | Ikram et al. (2020) |
| Silver and copper nanoparticles | 0, 3, 5 and 7 mg/L Cu NPS and 0, 10, 20 and 30 mg/L Ag NPS | Wheat (Triticum aestivum, Poaceae) | Hydroponic treatment | Enhanced morphological traits, stomatal conductance and chlorophyll stability index, leaf succulence and leaf K content | Ahmed et al. (2021a, b) |
| Iron oxide nanoparticles | 0, 25, 50, and 100 mg/kg | Rice (Oryza sativa, Poaceae) | Soil treatment | Increased biomass, photosynthetic efficiency, antioxidant enzymes, uptake of nutrients. Decreased ROS | Ahmed et al. (2021a, b) |
| Titanium oxide nanoparticles | 20 and 40 ppm | Wheat (Triticum aestivum, Poaceae) | Soil treatment | Increased biomass, chlorophyll content, RWC, MSI, antioxidant enzymes, and osmolyte content | Mustafa et al. (2021) |
| Zinc oxide nanoparticles + biochar | 100 mg/L | Wheat (Triticum aestivum, Poaceae) | Soil treatment | Improved wheat growth and biomass, chlorophylls contents, antioxidant enzyme and reduced activities by scavenging ROS | Bashir et al. (2021) |
| Zinc oxide nanoparticles | 100 mg/L | Maize (Zea mays, Poaceae) | Soil treatment | Reduced photosynthetic pigment degradation and regulated the stomatal movement, maintained a higher net photosynthetic rate, and enhanced water use efficiency. Enhanced activities of UDP-glucose pyrophosphorylase, phosphoglucoisomerase and cytoplasmic invertase which enhanced the biosynthesis of starch and sucrose and regulated glycolysis | Sun et al. (2021) |
| Graphene oxide nanosheet + PGPB | 0.52 mg/g | Maize (Zea mays, Poaceae) | Soil treatment | Increased shoot biomass. Increased proline, activities of SOD and CAT. Increased ABA. Enhanced photosynthetic parameters | Lopes et al. (2021) |
| Selenium nanoparticles | 100 µg/mL | Wheat (Triticum aestivum, Poaceae) | Soil treatment | Enhanced plant growth, grain quantity and quality. photosynthetic pigments and gas exchange parameters | El-Saadony et al. (2021) |
| Silicon nanoparticles + PGPR | 150 mg/kg | Wheat (Triticum aestivum, Poaceae) | Seed and soil treatment | Improved biomass, & chlorophyll-a, & b. Improved relative water content, gas exchange attributes, nutrients uptake, and osmolytes production. Increased the antioxidant enzymes activities such as, SOD, POD, & CAT | Akhtar et al. (2021) |
| Zinc oxide nanoparticles and bulk zinc sulphate | 15 mg/L | Wheat (Triticum aestivum, Poaceae) | Seed treatment | Prevented chlorophyll degradation, improved photosynthetic parameters and plant growth. Decreased the activity of antioxidant enzymes- CAT), POD, SOD, & GR as well as MDA content. Upregulated H2O2 signalling pathway | Rai-Kalal and Jajoo (2021) |
| Copper nanoparticles | 52, 69.4, and 86.8 µM | Maize (Zea mays, Poaceae) | Seed treatment | Increased leaf water content and plant biomass. Increased anthocyanin, chlorophyll and carotenoid content and reduced ROS | Van Nguyen et al. (2022) |
| Iron oxide nanoparticles | 0.3, 0.6, 0.9, and 1.2 mM | Wheat (Triticum aestivum, Poaceae) | Seed treatment | Increased in chlorophyll a and b, carotene. Increased in free proline, antioxidant levels (SOD and APX) and total protein content. Decreased in lipid peroxidation and electron leakage | Noor et al. (2022) |
| Zinc oxide nanoparticles | 10 ppm | Wheat (Triticum aestivum, Poaceae) | Seed treatment | Increased biomass, photosynthetic pigments, nutrients, soluble sugars, proteins, ABA and indole acetic acid content. Increased proline, antioxidant enzymes (SOD, CAT, APX, GSH & DHAR). Reduced electrolyte leakage, MDA and H2O2 | Azmat et al. (2022) |
| Iron nanoparticles | 5, 10, and 15 mg/L | Wheat (Triticum aestivum, Poaceae) | Seed treatment | Increased rhizosphere colonization level, water use efficiency and photosynthetic rate. Increased biomass | Naseer et al. (2022) |
| Silicon dioxide nanoparticles | 150 mg/L | Wheat (Triticum aestivum, Poaceae) | Seed treatment | Increased germination percentage, germination index, and germination vigour index. shoot length and root length. Increased photosynthetic pigments, osmolytes content, relative water content, membrane stability index, phenol, flavonoid content, indole acetic acid and cytokinin. Increased in activity of CAT, POD, & SOD | Akhtar and Ilyas (2022) |
| Titanium dioxide and zinc oxide nanoparticles | 5 and 10 mg/L | Wheat (Triticum aestivum, Poaceae) | Seed treatment | Increased morphological parameters, grain yield, and crop water productivity. Increased in photosynthetic pigments. Increased in IAA content, proline, total soluble sugars and amino acids. Regulation of protein synthesis | El-Bassiouny et al. (2022) |
| Zinc oxide nanoparticles | 5, 10, 15, 25, and 50 ppm | Rice (Oryza sativa, Poaceae) | Seed treatment | Increase in plant height, total chlorophyll contents, plant fresh and dry weights. Increased panicle length, number of tillers, paddy yield and straw yield. Reduced MDA. Increased proline content, activities of SOD, CAT, & POD | Waqas Mazhar et al. (2022) |