TiO2 nanoparticles alleviates the effects of drought stress in tomato seedlings

: Nanoparticles have been widely used in recent years, to increase plant tolerance under stress conditions. In this study, TiO 2 nanoparticles (NPs) (100 ppm) were applied to tomato plants exposed to drought, and the changes were investigated by physiological, biochemical and proteomic methods. It was determined that TiO 2 NPs treatment increased the relative water content and decreased the proline and malondialdehyde content under drought conditions. As a result of proteomic analysis, it was revealed that the expression of a total of 132 proteins changed as a result of the comparison of the treatment groups (drought vs . control, control-100 vs . control, and drought-100 vs . drought). One of the most striking results of the study was the increase of the amounts of photosynthesis-related proteins and plasmamembrane intrinsic protein in both drought and control groups with TiO 2 NP-treatmtent. The up-regulation of plasmamembrane intrinsic protein is very important for preserving the water potential under drought conditions. Taken together, it was observed that the water potential of the plant was preserved, lipid peroxidation decreased under drought conditions with the application of TiO 2 nanoparticles, and the expression of proteins related to photosynthesis, energy and antioxidant system increased. This study provided clues to the molecular mechanism of the results of many studies available in the literature about nanoparticle treatment under stress condition and showed that TiO 2 nanoparticles have a great potential to be used to increase the stress tolerance of tomato plants under drought conditions.