Effect of nanoparticle treatment on expression of a key gene involved in thymoquinone biosynthetic pathway in <i>Nigella sativa</i> L.

<p>Thymoquinone is the most important secondary metabolite in black Cumin, which has several pharmaceutical applications. In this study, effect of TiO<sub>2</sub> and SiO<sub>2</sub> nanoparticles as new elicitors, on expression of <i>Geranyl diphosphate synthase</i> gene (GPPS gene), as a key gene involved in thymoquione biosynthesis pathway was investigated in two Iranian accessions. Plants were treatment in the early flowering stage and after 24 h of 50 and 100 mg/L of each nanoparticle, separately. After RNA extraction, GPPS gene expression was analysed by qRT-PCR method. The results showed that the TiO<sub>2</sub> and SiO<sub>2</sub> nanoparticles, generally stimulates the GPPS expression. The TiO<sub>2</sub> nanoparticles were more effective than SiO<sub>2</sub> for the induction of GPPS expression. Also, 100 mg/L treatment of nanoparticles raised gene expression more than 50 mg/L concentration. It can be concluded these nanoparticles can be used as robust elicitors to enhance the production of Thymoquinone in black cumin through up-regulation of related metabolic pathway genes.</p>