AU - Tavakoli, Farahnaz AU - Rafieiolhossaini, Mohammad AU - Ravash, Rudabeh AU - Ebrahimi, Morteza TI - Effect of low temperature elicitor at different times on adventitious root culture of Hypericum perforatum PT - JOURNAL ARTICLE TA - jispp JN - jispp VO - 10 VI - 44 IP - 44 4099 - http://jispp.iut.ac.ir/article-1-1491-en.html 4100 - http://jispp.iut.ac.ir/article-1-1491-en.pdf SO - jispp 44 ABĀ  - The use of Abiotic elicitors is very important in biosynthetic pathways that lead to the formation and regulation of secondary metabolites. The aim of this study was to investigate the effect of Low temperature elicitors on the amount of hypericin, flavonoids, phenol, antioxidant capacity and dry weight of ).Seeds of Topaz cultivar, Pharmasat Germany, with 99% purity and 85% potency, were prepared for the ability to produce secondary metabolites. Seeds were grown in MS medium in sterile containers and stored in a growth chamber at 25±1 ° C with light rotation for 8 hours in the dark and 16 hours of light with fluorescent light. This study was performed as a factorial study in a completely randomized design with three replications and the effect of temperatures of 4, 8, 16 and 25 ° C for 24 hours, 72 hours and one week. The highest amount of hypericin at 4 ° C for one week and 72 hours with 0.59 and 0.55 μg / g dry matter, respectively, and the highest antioxidant capacity at 4 ° C for one week at 0.87% was observed. With increasing temperature to 16 degrees (for 24 hours) the lowest amount of hypericin and antioxidant capacity was observed. Applying a temperature of 4 degrees for a week increased the amount of flavonoids. The highest amount of phenol was obtained in the samples treated at 4 ° C for one week and 72 hours with the amount of 5.65 and 5.03 mg / g dry matter, respectively. Applying 4 ° C for one week had the greatest effect on the dry weight of the plant. Due to the increase in secondary metabolites of hypericin, phenol, flavonoids and antioxidant capacity of H. perforatum after application of 4 ° C treatment (for one week and 72 hours), the use of this elicitor to increase secondary metabolites of H. perforatum Recommended. CP - IRAN IN - Plant Breeding and Biotechnology Department, Faculty of Agriculture LG - eng PB - jispp PG - 33 PT - Research YR - 2021