Аннотация
Abstract This study investigates the impact of high-temperature stress on the biosynthesis of two major bioactive compounds—hypericin and hyperforin—in Hypericum species. Temperature is one of the most critical environmental factors influencing the secondary metabolism and pharmacological quality of medicinal plants. Under heat stress, the balance between reactive oxygen species (ROS) production and antioxidant defense mechanisms alters significantly, affecting gene expression related to the biosynthetic pathways of hypericin and hyperforin. Using quantitative PCR and biochemical assays, the expression levels of key genes such as Hyp-1, PKS, and AS were analyzed under controlled temperature regimes. The results revealed that elevated temperature leads to oxidative stress, causing variations in ROS accumulation and the downregulation of specific biosynthetic genes, ultimately reducing the concentration of hypericin and hyperforin in plant tissues. These findings provide valuable insights into the molecular and physiological mechanisms underlying temperature-induced changes in the pharmacological quality of Hypericum and can guide future strategies for improving stress tolerance and metabolite production in medicinal plants.