The effects of some nanoparticles on the amount of hyperisin compounds of Hypericum perforatum L. and Hypericum retusum Aucher grown under in vitro medium

In this study, the effect of 4 different nanoparticle applications on hypericin and its derivatives, and on the expression of HpPKS1 and HpPKS2 genes were investigated in the shoots of Hypericum retusum Aucher and H. perforatum L. grown under in vitro conditions. For this purpose, the seeds of H. retusum and H. perforatum were germinated in Murashige and Skoog (MS) nutrient medium lacking plant growth regulator. The shoots obtained from germination medium were taken into subculture and replicated periodically in MS nutrient medium containing 0.5 mg-1 BA, and were used in nanoparticle experiments. In the first experiments conducted within the scope of the thesis proposal, iron (III) oxide (Fe2O3), titanium dioxide (TiO2), zinc oxide (ZnO) and aluminum oxide (Al2O3) nanoparticles in different concentrations (25, 75 and 200 mgL-1) were applied to shoots grown under in vitro medium. An increase was observed in the amount of hypericin and derivative compounds in H. perforatum shoots grown in nutrient medium containing 200 mgL-1 ZnO or 75 mgL-1 Al2O3, Fe2O3 and TiO2. Also, in H. retusum shoots; increased hypericin and its derivatives were observed in nutrient medium containing 200 mgL-1 ZnO or 25 mgL-1 Al2O3, Fe2O3 and TiO2. After the first experiments, the H. retusum shoots were grown in nutrient medium containing Al2O3, ZnO, Fe2O3 and TiO2 nanoparticles at 10, 15 and 25 mgL-1 ratio. H. perforatum shoots were cultured in nutrient medium containing 200, 250 and 300 mgL-1 ZnO, Fe2O3 and Al2O3 or 15, 25 and 75 mgL-1 TiO2. The amount of hypericin and derivative compounds in the leaves of H. perforatum increased in medium containing 250 mgL-1 Al2O3 or Fe2O3, 200 mgL-1 ZnO or 75 mgL-1 TiO2 nanoparticles, compared to the control group. The rate of hypericin and derivative compounds in H. perforatum bodies also increased in medium containing 300 mgL-1 Fe2O3 and ZnO nanoparticles. In H. retusum leaves, while Al2O3 and ZnO nanoparticles did not have a positive effect on the concentration of related compounds, the amount of hypericin and derivative compounds increased in the nutrient medium containing 15 mgL-1 Fe2O3 or 10 mgL-1 TiO2. In addition, in H. retusum shoots, the amount of hypericin and derivative compounds increased in the presence of 25 mgL-1 Al2O3 or Fe2O3 or 10 mgL-1 ZnO and TiO2. It has been determined that the application of Al2O3 and TiO2 nanoparticles in leaf tissue by qPCR analysis of H. perforatum had no detectable effect on HpPKS1 gene expression; on the other hand, it indicated parallel increase with increase in nanoparticle concentration for Fe2O3 nanoparticle application. In shoot tissue, different nanoparticle applications had an effect on HpPKS2 gene expression but it was determined that gene expression was lower in different experiment groups compared to control group. It has been observed that aluminum nanoparticles affect expression of HpPKS2 gene in leaf tissue in inversely proportional to nanoparticle concentration. It was determined that the amount of HpPKS2 gene expression in the body tissue was not within detectable limits. In H. retusum Aucher, HpPKS2 gene expression analysis was detected in all samples except Fe2O3 200 mgL-1 experimental group due to different nanoparticle applications. Among these experimental groups, application of 300 mgL-1 ZnO increased HpPKS2 gene expression in the stem. For HpPKS1 gene expression in the leaf control sample is not within measurable limits. Al2O3, Fe2O3, ZnO and TiO2 nanoparticles applied to H. perforatum and H. retusum species have been successful in increasing the amount of hypericin and derivative compounds. The TiO2 nanoparticle having the smallest size among the tested nanoarticles has given more successful results than the other three nanoparticles. The obtained results have affected the type, size, and concentration of the nanoparticle tested.