Table 1.
Examples of toxic effects of various AgNP on terrestrial plants, including decreased germination, inhibited growth, reduced root and shoot length.
| AgNP (resource, size, coating and [AgNP] in ppma) | Type of seeds | Main effect(s) of AgNP | Ref. |
|---|---|---|---|
| Synthesized using trisodium citrate, 0–50 in deionized water | Black eyed (Vigna unguiculata), Garbanzo (Cicer arietinum), Lentil bean (Lens culinaris) | Decrease in germination rate of Garbanzo, slow seedling growth. | This study |
| Nanosilver adsorbed on fumed silica, 0–10,000 in deionized water | Onion (Allium cepa L), radish (Raphanus sativus L.) | Induce root growth inhibition at a concentration as low as 0.001 ppm. | [5] |
| Purchased from Sigma Aldrich, <100 nm, 0–20 in deionized water | Lycopersicum esculentum, Zea mays | Inhibit root length and germination. | [8] |
| Purchased from NanoComposix®, 5–75 nm, PVP-coated, 0–100 in distilled water | Allium cepa | Reduce germination in a diameter-dependent manner. Smaller size had stronger inhibition. | [9] |
| Chemical synthesized, 50 nm, sodium citrate coated, 0–100 in water | Seven Varieties of tomato (Lycopersicon esculentum Mill) | Shorten sprout time, decrease germination percentage, vigor index, tolerance index, root and shoot length. | [10] |
| Different sizes, 20, 30–60, 70–120 and 150nm, 0–1000 in water | Jasmine rice (Oryza sativa L. cv. KDML 105) | Decrease seed germination and subsequent seedling growth. | [11] |
| Purchased from Natural Path/Silver Wings, 1–10nm, 0–500 in deionized water | Radish (Raphanus sativus) | Reduce the root and shoot lengths and the seedlings had less Ca, Mg, B, Cu, Mn, and Zn elements. | [12] |
| Purchased from Purest Colloids (MesoSilver, 0.6–2 nm) and Quantum Sphere (Ag-QSI, 20 nm); 0–100 in water with 0.1% (v/v) Tween 20 | Flax (Linum usitatissimum L., cv. Electra), ryegrass (Lolium perenne L, cv. Tove), two-rowed barley (Hordeum vulgare L, cv. Annabell) | Inhibit seed germination and never completely impede germination. Reduction in shoot growth. | [13] |
| Purchased from Sigma-Aldrich, PVP coated, 0–540 in distilled water | Wheat (Triticum aestivum) | A significant inhibitory effect on root and shoot length of seedlings. | [14] |
| Purchased from Shanghai Science & Technology, 30 nm and 70 nm, 100 in deionized water | Lettuce (Lactuca sativa L.) | Decrease seed germination and seedling development indices. Larger AgNP exerted stronger toxicity. | [15] |
| Purchased from RAS AG (Regensburg, Germany), 15 nm, contains Tagat Tween 20, 0–2000 in MES buffer (pH 6.0–6.1) | Zea mays L. | Affect seed germination and shoot length negatively in a dose-dependent manner. AgNP retarded root growth. | [16] |
| Microwave assisted reduction using Cassia auriculata leaf extract, 13nm, 0–50 in deionized water | Pearl millet (Pennisetum glaucum) | Higher concentration of AgNP decreased the root, shoot and total seedling length. | [17] |
| Provided by ABC Nanotech (Daejeon, Korea), Citrate-coated, 5–25 nm, 0–40 in deionized water | Phaseolus radiates, Sorghum bicolor | Seedling growth was adversely affected. | [18] |
| Biologically synthesized, 0–500 in sterile deionized water | Chinese cabbage (Brassica rapa ssp. pekinensis) | Reduce root, shoot growth, and fresh biomass. | [19] |
| Purchased from XFNANO Materials Technology (China), 17nm, PVP coated, 0–9.2 in medium with Ca(NO3)2, KNO3, MgSO4, KH2PO4 (pH 6.0) | Wheat (Triticum aestivum L.) | Decrease in relative root elongation and root weight, which could be alleviated by extracellular polymeric substances isolated from Pseudomonasputida. | [20] |
| Synthesized using leaf extract of Aloe vera plants, 22 nm, 0–324 in deionized water | Pea (Pisium sativum) | Decline growth parameters, photosynthetic pigments and chlorophyll fluorescence. | [21] |
| Obtained from Ted Pella Inc. (Reading, US), 20 nm, 0–50 in ½ MS agar medium | Mung bean (Vigna radiata L.) | Significant reduction in shoot length, root elongation and weight. | [22] |
| Synthesis from isolate B. marisflavi., 1–10 in deionized water | turnip (Brassica rapa ssp. rapa L.) | 5 and 10 ppm AgNP decreased the plant growth, biomass, and chlorophyll content. | [23] |
| Obtained from Biopure AG10, Nanocomposix (San Diego, USA), 10nm, PVP coated, 1–10 in deionized water with/without PVP | Wheat (Triticum aestivum) | Adversely affect the seedling growth and induced morphological modifications in root tip cells. | [24] |
| Reduced using sodium borohydride and coated by Tween-20, 1000 | Oryza sativa | Deposit inside the root cells by damaging the cell wall and vacuoles to enter. | [25] |
| Obtained from Attostat Inc. (West Jordan, UT, US), 10 nm, 0 – 5 in sand | Wheat (Triticum aestivum L.) | Reduce the length of shoots and roots in a dose-dependent manner. | [26] |
| Obtained from US Research Nanomaterials Inc (Texas, US), 20 nm diameter, 0–790 in soil | Bishop pine (Pinus muricata D. Don) | Reduce the root length but have a small effect on ground plant biomass. | [27] |
| Chemical synthesized, 5–50 nm sphere, 100–900 in soil | Faba bean (Vicia faba L.) | The germination declined by 40% when exposed to 800 ppm AgNP. | [28] |
| Purchased from U.S. Research Nanomaterials, 20 nm, 0–2500 | Corn (Zea mays L.) | Toxic effect on corn root elongation. | [29] |
a
Concentration range is converted to ppm for a better comparison. Density of all solutions is considered as 1.0 g/mL.
Abbreviations: DDAB, didecyldimethylammonium bromide; PVP, polyvinylpyrrolidine.