Table 4.
Biochemical activities of some metal/metalloid-based NPs to combat abiotic stress effects.
| Nanoparticles (NPs) | Abiotic Stresses | Impact on Plants to Mitigate Stress/to Enhance Tolerability | Plant Species | References |
|---|---|---|---|---|
| Si NPs (SiO2) | Mercury | Enhanced growth, chlorophyll levels, and decreased Hg accumulation in both roots and shoots | Glycine max L. | [201] |
| Drought and salinity | Increased leaves’ growth and chlorophyll levels maintained an equilibrium between Na+ and K+ ions, promoted photosynthesis process | Musa acuminata | [202] | |
| Salinity | Increased growth, relative water content (RWC), proline contents, chlorophyll contents | Fragaria sp. | [127] | |
| Salinity | Regulation of salt toxicity-associated genes, elevated seed germination efficiency, root growth and weight | Solanum lycopersicum L. | [126] | |
| Drought | Increased biomass contents, photosynthetic pigment levels, and upregulated photosynthesis process by improving rate of net photosynthesis and conductance of stomata | Crataegus sp. | [117] | |
| Chromium [Cr(VI)] | Enhanced growth, nutrient uptake, and antioxidant enzymes’ activities reduced Cr(VI) accumulation | Pisum sativum L. | [50] | |
| Salinity | Increased RWC, crop yield, and the activities of enzymatic antioxidants | Vicia faba L. | [203,204] | |
| Cold | Inhibited seed dormancy, increased seed germination, and weight of seedlings | Agropyron elongatum L. | [205] | |
| Salinity | Enhanced growth parameters, proline levels, and pigment contents | Ocimum basilicum | [206] | |
| Salinity | Inhibited seed dormancy, increased seed germination, and fresh weight | Lens culinaris Medik. | [207] | |
| Salinity | Increased the rate of seed germination, growth; alleviated the levels of H2O2, MDA, electrolyte leakage; improved pigment contents and antioxidant defense system | Cucurbita pepo L. | [122] | |
| Salinity | Increased fresh weight, RWC, chlorophyll contents, and rate of photosynthesis | Solanum lycopersicum L. | [208] | |
| Salinity | Increased root growth, weight, seed germination | Lycopersicum esculentum | [209] | |
| Ti NPs (TiO2) | Salinity | Enhanced germination, growth parameters of seedlings, fresh weight and dry weight, RWC, K+ ion, proline and total phenolic contents; also upregulated the activities of antioxidant enzymes and alleviated Na+ ion, MDA levels, and electrolyte leakage | Zea mays L. | [163] |
| Drought | Elevated the dry weight of seedlings, RWC, chlorophyll, and carotenoid contents; also promoted transpiration rate and stomatal conductance | Triticum aestivum | [6] | |
| Arsenic (As) | Improved growth and biomass contents, reduced MDA contents, and induced the regulation of antioxidant properties | Vigna radiata L. | [210] | |
| Salinity | Positive impact on agronomically important attributes by inducing antioxidant properties | Dracocephalum moldavica | [211] | |
| Drought | Enhanced chlorophyll and carotenoid levels, reduced the accumulation of H2O2 and MDA | Linum usitatissimum | [212] | |
| Cadmium (Cd) | Inhibited the toxic effects of Cd, enhanced RWC, growth parameters, chlorophyll contents, rate of net photosynthesis; restricted lipid peroxidation and proline levels | Glycine max L. | [213] | |
| Cold | Upregulated the activities of RubisCo and phosphoenolpyruvate carboxylase, downregulated H2O2 content | Cicer arietinum L. | [214] | |
| Drought | Modulated toxic effects, improved biomass accumulation, and RWC | Ocimum basilicum L. | [215] | |
| Drought | Increased growth and starch contents | Triticum aestivum L. | [107] | |
| Cold | Reduced electrolyte leakage index and MDA contents | Cicer arietinum L. | [216] | |
| Ag NPs | Salinity | Enhanced germination rate and no. of germinated seeds, downregulated the levels of oxidative stress, and induced the activities of antioxidant enzymes viz., APX, GR, GPX | Triticum aestivum L. cv. Pusa Kiran. | [217] |
| Heat | Induced growth, area, and numbers of leaves | Triticumaestivum L. | [132] | |
| Salinity | Promoted growth and enhanced the synthesis of NAA, IBA contents, alleviated ABA level | Triticumaestivum L. | [102] | |
| Salinity | Increased seed germination rate, fresh weight, and dry weight | Trigonella foenum-graecum | [218] | |
| Salinity | Enhanced proline and carbohydrate levels | Triticumaestivum L. | [129] | |
| Cold | Upregulated the genes responsible for the activities of antioxidants | Arabidopsis. thaliana | [219] | |
| Flooding | Upregulated protein levels, growth parameters, and downregulated the production of toxic products in the process of glycolysis | Glycine max | [220] | |
| Dark | Enhanced pigments levels, activities of enzymatic antioxidants, reduced MDA level | Pelargonium zonale | [221,222] | |
| Post-harvest | Enhanced fresh weight and decreased bacterial colony formation in stem | Chrysanthemum morifolium L. | [223] | |
| ZnO | Drought | Enhanced growth, RWC, and nutrient uptake | Solanum melongena L. | [162] |
| Drought and cadmium (Cd) | Enhanced growth, chlorophyll contents, and SOD and POX activities | Triticumaestivum L. | [224] | |
| Salinity | Enhanced growth of both roots and shoots, biomass contents, chlorophyll contents, protein levels, photosynthetic parameters, and then, activities of CAT, SOD and POX | Lycopersicon esculentum | [225] | |
| Salinity | Upregulated protein and proline levels, enhanced the activities of antioxidants, reduced H2O2 and MDA levels | Trigonella foenum-graecum | [226] | |
| Arsenic (As) | Promoted growth and phytochelatin contents, decreased As uptake in the seedlings | Oryza sativa L. | [227] | |
| Salinity | Enhanced pigment contents, the activities of CAT and SOD; alleviated the levels of total soluble sugar and proline | Abelmoschus esculentus L. | [124] | |
| Arsenic (As) | Enhanced growth, reduced As uptake, increased photosynthetic activities, induced the activities of antioxidant enzymes | Glycine max | [228] | |
| Drought | Enhanced yield of grains and Zn accumulation | Triticumaestivum L. | [229] | |
| Salinity | Increased proline contents, total sugars, and the activities of CAT, SOD, and POX | Mangifera indica L. | [125] | |
| Drought | Enhanced antioxidant defense system and the synthesis of melatonin | Zea mays L. cv. Jidan 27 | [57] | |
| Cadmium (Cd) | Enhanced growth, biomass contents, pigment contents, photosynthetic attributes, and the activities of antioxidant enzymes; alleviated Cd accumulation in shoots and roots | Zea mays L. | [230] | |
| Cadmium (Cd) | Enhanced growth, reduced Cd uptake and electrolyte leakage, induced the activities of POX and SOD | Triticumaestivum L. | [231] | |
| Cadmium (Cd) and lead (Pb) | Enhanced growth, pigment contents, protein levels, and antioxidant enzyme activities; reduced lipid peroxidation | Lycopersicon leucocephala | [232] | |
| Salinity | Enhanced growth, Zn levels, chlorophyll levels, rate of CO2 assimilation; reduced Na+ contents | Helianthus annuus L. | [233] | |
| Drought | Enhanced germination rate and reduced dry weight | Glycine max | [119] | |
| Cu NPs | Drought | Enhanced biomass levels and productivity of grains, elevated chlorophyll, carotenoid and anthocyanin contents; reduced oxidative stress by upregulating antioxidant defense system | Zea mays L. | [103] |
| Cadmium (Cd) | Enhanced growth and weight, decreased Cd accumulation, elevated ion contents and antioxidative properties | Triticum aestivum L. | [234] | |
| Chromium (Cr) | Enhanced growth and biomass contents, reduced Cr uptake, increased nutrient uptake and antioxidative properties | Triticum aestivum L. | [235] | |
| Fe NPs | Drought and cadmium (Cd) | Enhanced growth parameters, photosynthetic activities, uptake of Fe; decreased Cd accumulation | Triticum aestivum L. | [236] |
| Drought | Promoted H+-ATPase activity, maintained opening and closing of stomata; elevated biomass, pigment contents and internal CO2 | Arabidopsis thaliana | [237] | |
| Chromium (Cr) | Restricted the conversion of Cr (VI) to Cr (III) and Cr (VI) accumulation | Brassica juncea | [238] | |
| Fe2O3 | Salinity | Decreased MDA and proline contents, subdued antioxidant properties | Mentha piperita L. | [99] |
| Drought and cadmium (Cd) | Enhanced growth, biomass contents, nutrient uptake; upregulated antioxidant enzymes, photosynthetic attributes; reduced uptake and translocation of Cd | Oryza sativa L. | [239] | |
| Salinity and cadmium (Cd) | Promoted growth, plant weight, biomass and NPK contents; deceased Cd accumulation; elevated pigment contents and antioxidant enzyme activities | Triticum aestivum L. | [240] | |
| Drought | Enhanced growth and chlorophyll levels, decreased H2O2 and MDA levels | Brassica napus | [69] | |
| Fe3O3 | Salinity | Induced the production of flavonoid, phenolic compounds, and anthocyanin; enhanced the activities of APX, GR, CAT, and GPX | Dracocephalum moldavica L. | [241] |
| Fe3O4 | Salinity | Promoted growth, pigment contents, RWC, total soluble sugar; enhanced membrane stability | Fragaria x ananassa Duch. | [104] |
| Cadmium (Cd), lead (Pb), copper (Cu) and zinc (Zn) | Restricted the toxic effects of heavy metals, enhanced the activities of SOD and POX | Triticum aestivum L. | [135] | |
| FeSO4 | Salinity | Enhanced weight, pigment levels, photosynthetic attributes viz., net photosynthesis, stomatal conductance, assimilation of CO2, Fe concentration; decreased Na levels | Helianthus annuus L. | [242] |
| Al2O3 | Flooding | Enhanced growth and induced biochemical activities | Glycine max L. cv. Enrei | [115] |
| Flooding | Enhanced growth of hypocotyl, promoted protein levels in mitochondrial membrane, and glycolysis process | Glycine max L. | [112] | |
| CeO | Salinity | Maintained ionic equilibrium, enhanced root growth, reduced the generation of ROS | Gossypium hirsutum L. | [80] |
| Light, dark chilling and temperature | Enhanced internal CO2, quantum yield of PS-II, RuBisCo activity, and reduced ROS levels | Arabidopsis thaliana | [78] | |
| CeO2 | UV-B | Absorbed UV radiation and alleviated oxidative stress levels | Chlorella vulgaris | [243] |
| Chitosan NPs | Drought | Enhanced crop productivity, biomass contents, RWC, chlorophyll contents; promoted the rate of photosynthesis, and induced the activities of SOD and CAT | Triticum aestivum L. | [244] |
| Drought | Enhanced RWC, weight and protein in grains, proline levels, and induced the activities of SOD and CAT | Hordeum vulgare L. | [245] |