Table 2.

Effects of nTiO₂ on plants under salinity conditions.

Stress Conditions	nTiO2 Crystalline Phase; Concentrations; Primary (PS) or Hydrodynamic Size (HS)	Plant Species	Application Method	Ameliorative Effects	Ref.
180 mM NaCl for 28 days	Not stated; 160, 320 and 480 mg L−1; PS 20–78 nm.	Vicia faba L.	Two foliar applications, 3 and 10 days after NaCl treatments	Increased root and shoot length and dry weight. Improvement of the levels of proline, sugars, chlorophylls and carotenoids. Increased antioxidant enzyme activities (SOD, POD, APX and CAT). Decreased lipid peroxidation and H2O2 production	[42]
100 and 200 mM NaCl for 40 days	Anatase; 500, 1000 and 2000 mg kg−1; PS 10–25 nm.	Hordeum vulgare L.	Soil amended	Increased root length, leaf RWC, net CO2 assimilation rate, stomatal conductance, transpiration rate, chlorophyll and proline. Improvement of the antioxidant enzyme activities (APX and CAT). Decreased lipid peroxidation	[87]
50 and 100 mM NaCl for 2 weeks	Anatase; 100 and 200 mg L−1; PS 25 nm.	Stevia rebaudiana Bertoni.	Foliar spray for 3 times (during the growth period)	Increased root and shoot height, fresh and dry weight, leaf RWC, chlorophylls, carotenoids contents. Improvement of the net CO2 assimilation rate and Fv/Fm. Increased antioxidant enzyme activities (SOD, POD, APX and CAT). Decreased lipid peroxidation and H2O2 production	[86]