Increased root elongationno effect on germination, evapotranspiration, and plant biomass
Larue et al. (2012a)
14, 25
Brassica napus, Triticum estivum 1 week
n.a.
100 mg/L
n.a.
Increased root elongationno effect on germination, evapotranspiration, and plant biomass
Larue et al. (2012b)
27
Cucumis sativus, 15 days
n.a.
100, 250, 500, 1000, 4000 mg/L
n.a.
promotion of root elongationhigher nitrogen accumulation in roots
Servin et al. (2012)
27
Solanum lycopersicum, 15 days
50, 100, 1000, 2500, 5000 mg/L
n.a.
n.a.
No effect on root elongation
Song et al. (2013)
21, 50
Allium cepa 18 h
10, 100 mg/L (21 nm)
n.a.
10, 100, 1000 mg/L (50 nm), 1000 mg/L (21 nm)
Increase in genotoxicity with concentration
Demir et al. (2014)
35
Pisum sativum, 24 hours
n.a.
n.a.
100, 250, 500, 750 mg/L
No effect on root length, stem length, and leave surface areaDiminished secondary lateral roots, diminished nutrient transportdisrupted Rhizobium–legume symbiosis system and nitrogen fixation
Fan et al. (2014)
90–98
Allium cepa, 4 h
n.a.
n.a.
12.5, 25, 50, 100 mg/L
Increased damage from reactive oxygen speciesIncrease in genotoxicity with concentration
Pakrashi et al. (2014)
4
Lactuca sativa, 7 days
10–1000 mg/L
n.a.
n.a.
Higher accumulation of Fe, P, S, and Ca in the root epidermisDecreased concentrations of Fe, P, S, and Ca in both the parenchyma and vascular cylinder
Larue et al. (2016)
29, 92
Trifolium pratense, 7‐day old plants for 28 days
n.a.
n.a.
12.5, 25 mg/L
Decrease in nodule formationDecrease in growth
Moll et al. (2016)
10–30
Hydrilla verticillata, 24 h
0.01, 0.1, 1 mg/L
n.a.
10 mg/L
Increase in catalase and glutathione reductase activityIncrease in H2O2 at 10 mg/L
Okupnik and Pflugmacher (2016)
25, 33, 41, 40
Oryza sativa, 35‐day old plants for 7 days
n.a.
10, 1000 mg/L
n.a.
Reduced concentration of Pb in plantNo negative effect on plants
Cai et al. (2017)
8
Hordeum vulgare, 7 days
100 mg/L
n.a.
150–1000 mg/L
Decrease in root length
Kořenková et al. (2017)
21
Triticum aestivum, 20 days
n.a.
n.a.
5, 50, 150 mg/L
Impaired light‐dependent and ‐independent phases of photosynthesisDecreased chlorophyll a content, maximal and effective efficiency of PSII, net photosynthetic rateDecreased transpiration rate, stomatal conductance, intercellular CO2 concentration, and starch content
Dias et al. (2019)
The experiments performed with plants grown in soil contaminated with nanoparticles, either in pots in laboratory, greenhouse, or in field conditions represent the realistic scenarios of exposure to nanoparticles in the environment to a greater degree. From these experiments, the right concentration of TiO2NPs can be more objectively selected and later used to enhance plant growth in agriculture. Most of these experiments need to be performed for a longer duration than that of hydroponic growth and hence, it can help to get a better understanding of the effects of long‐term exposure of nanomaterials in plants (Table 2.3). Usually, two modes of nanoparticle application were preferred, (1) contamination of soil where plants were growing and (2) foliar application at the important stages of development of plants (Servin et al. 2013; Raliya et al. 2015b; Rezaei et al. 2015; Marchiol et al. 2016; Pošćić et al. 2016; Moll et al. 2017; Rafique et al. 2018; Giorgetti et al. 2019; Zahra et al. 2019; Bellani et al. 2020). In case of soil contamination, it was observed that the higher concentrations of TiO2NPs in soil may have negative effects on the growth of plants
