Metal nanoparticles Synthesis of engineered nanoparticles is usually done by the interaction of microorganisms, algae or plant extracts. It is quite obvious that nanomaterials may be useful or harmful in living system depending on their shape, size and above all the nature of specific metal ion. The effect of engineered metal nanoparticles of varying size and concentration on different parts of a variety of SHP099 solubility dmso plants is given in Table 1. Table 1 Effects

of engineered metal nanoparticles on plants Nanoparticle Size (nm) Plant Concentration Effect References Aluminium   Corn, cucumber, lettuce, radish, rapeseed 2,000 mg L-1 No effect selleck compound on germination [44] 1 to 100 Red kidney beans, ryegrass 10, 100, 1,000 and 10,000 mg L-1 No toxicity [45]   Radish, rapeseed 2,000 mg L-1 Improved root growth [44]   Ryegrass 2,000 mg L-1 Decreased root length [44]   Ryegrass 2,000 mg L-1 Reduced germination selleckchem [44]   Corn, lettuce 2,000 mg L-1 Reduced root length [44] Copper   Lettuce 0.013% (w/w) No effect on germination, improved shoot/root ratio [13]   Mung bean <200 mg L-1 Reduced seedling growth [30]   Mung bean 800 mg L-1

Reduced shoot growth [30]   Wheat <200 mg L-1 Reduced root and seedling growth [30] 50 Zucchini 1,000 mg L-1 Reduced biomass

[46] 50 Zucchini 1,000 mg L-1 Reduced root growth [46] Dodecanethiol-functionalized gold   Lettuce 0.013% (w/w) No effect on germination, improved shoot/root ratio [13] Gold 10 Cucumber, lettuce 62, 100 and 116 mg L-1 Positive effect on germination index [47] Iron   Flax, meadow fescue, red clover, white clover 100, 250 and 500 mg L-1 No effect on germination [48]   Barley, ryegrass 100 and 250 mg L-1 No effect on germination [48]   Barley, flax, ryegrass 2,000 and 5,000 mg L-1 Completely inhibited germination [48]   Barley 300 mg L-1 Reduced Mirabegron germination [48]   Flax, barley, ryegrass >1,500 mg L-1 No germination [48] Mixture of gold/copper   Lettuce 0.013% (w/w) No effect on germination, improved shoot/root ratio [13] Palladium entrapped in Al(OH)2 matrix   Lettuce 0.013% to 0.066% (w/w) No effect on germination, improved shoot/root ratio [13] Silicon 10 Zucchini 1,000 mg L-1 Completely inhibited germination [46] Silver 20 Flax 20, 40, 60, 80 and 100 mg L-1 No effect on germination [48] 2 Cucumber, lettuce 62, 100 and 116 mg L-1 Low to zero toxicity [47] 20.6 ± 3.1 Clover 0.01 mg kg-1 Reduced aboveground biomass [49] 0.1 mg kg-1 No effect on biomass [49] 1 mg kg-1 No effect on biomass [49] 10 Wheat 0.5, 1.5, 2.5, 3.5 and 5.