Table 1.
Effects of nTiO2 on plants under drought conditions.
| Stress Conditions | nTiO2 Crystalline Phase; Concentrations; Primary (PS) or Hydrodynamic Size (HS) | Plant Species | Application Method | Ameliorative Effects | Ref. |
|---|---|---|---|---|---|
| After seed-filling maintained at 50% FC | Anatase; 10, 100, and 500 mg L−1; PS 10–25 nm. |
Linum usitatissimum L. | Three foliar applications at the initial seed-filling | Increased leaf carotenoids and seed protein | [88] |
| PEG-6000 solutions at −0.4 and −0.8 MPa | Not stated; 500 and 2000 mg L−1 PS 10–25 nm. |
Triticum aestivum L. | Seed priming for 7 days | Increased shoot and root length, as well as fresh weight | [83] |
| 75% and 50% FC for 6 weeks | Not stated; 500, 1000 and 2000 mg kg−1 soil; PS 10–25 nm. |
Triticum aestivum L. | Soil amended | Increased leaf RWC, chlorophylls and carotenoids levels, and antioxidant enzymes (APX, CAT). Decreased lipid peroxidation and H2O2 production | [82] |
| 45% FC for 15 days | Not stated; 20 and 40 mg kg−1 soil; PS 347–447 nm. |
Triticum aestivum L. | Soil amended | Increased root length, hormone level (IAA and GA), proline and sugars. Improvement of the antioxidant enzymes (SOD, POD and CAT) and nutrient uptake (K and P) | [81] |
| 105 and 140 mm evaporation from the class A evaporation pan (mm day−1) | Anatase; 50 and 100 mg L−1 PS 10–25 nm. |
Zea mays L. | Foliar spray twice with an interval of 2 weeks (at the 4–6 leaf stage and 2 weeks after that) | Increased leaf relative water content, Fv/Fm, carotenoids, chlorophylls, proline, soluble protein and grain yield. Improvement of the activity of the antioxidant enzymes (SOD, APX and CAT) | [84] |