The Effect of Titanium Dioxide Nanoparticles on the Relative Expression of Catalase, P450, SOD, Ditds and WRKY Genes of Vitex Agnus-Castus L.

Each environmental factor is able to change the way genes are expressed. Application of nanoparticles also affects the expression of different genes in plants. The aim of this study was to investigate the effect of three different concentration of titanium dioxide nanoparticles, TiO2 (zero, 200 and 800 micrograms per milliliter) on the relative expression of catalase, P450, SOD, diTDS and WRKY genes in Vitex plant leaf tissue using qRT- PCR. Plant cultivation was carried out in 2018 in the greenhouse of Islamic Azad University of Mashhad. The experiment was arranged as completely random design with 5 replications. XRD measurements showed that applied TiO2 nanoparticles were in the form of anatase. Statistical analysis of gene expression in treated leaves of Vitex plant with TiO2 nanoparticles showed that this nanoparticle significantly affected the expression of catalase, P450, SOD, diTPS and WRKY genes. A concentration of 800 micrograms per milliliter of TiO2 nanoparticle increased the expression of catalase, P450, SOD and WRKY genes and decreased the expression of diTPS gene. In contrast, concentrations of 200 micrograms per milliliter only increased the expression of catalase and WRKY genes. The expression of the diTPS gene under treatments of 200 and 800 micrograms per liter of TiO2, compared with control, decreased by 2.1 and 0.46, respectively. Overall, the nanoparticle was able to influence the expression of genes in the biosynthetic pathway of terpenoids, as well as the plant's antioxidant enzymes, depending on the concentration of nanoparticles.