**2.6 Titanium dioxide nanoparticles (TiO2 NPs)**

Titanium is a transition element and the 9th most abundant element that contributes 0.33% of the earth's outer layer [43]. It improves photosynthesis and chlorophyll pigments in plants by altering antioxidant enzyme activities [44]. Titanium has an integral role in plants' tolerance under stressful conditions [45]. *Dracocephalum moldavica* plants were treated with TiO2 NPs improved plant growth, and proline content and increased enzymatic activities, soluble sugars, and amino acids under salinity stress [46].



*Improvement of Abiotic Stress Tolerance in Plants with the Application of Nanoparticles DOI: http://dx.doi.org/10.5772/intechopen.110201*

**Table 1.**

*Effect of nanoparticles on plants under salinity stress.*
