Iranian Medicinal Plants Society Journal of Medicinal plants and By-products 2322-1399 15 6 2026 11 01 Investigation of the Expression Pattern of Key Genes in the BiosyntheticPathway of Pinene and Limonene Metabolites in Different Juniperus L. Species from North Khorasan, Iran 649 658 135258 10.22034/jmpb.2026.371957.2130 EN Toktam Moradian Department of Horticultural Sciences, Shir.C., Islamic Azad University, Shirvan, Iran Ahmad Asgharzadeh Department of Horticultural Sciences, Shir.C., Islamic Azad University, Shirvan, Iran Maryam Tatari Department of Agriculture Science, Shir.C., Islamic Azad University, Shirvan, Iran Journal Article 2026 01 02 Medicinal plants play a crucial role in the biodiversity of many countries and are rich sources of secondary metabolites, forming the basis for numerous valuable pharmaceuticals. Although the biosynthesis of these compounds is under genetic control, it is profoundly influenced by environmental factors. In this study, the expression of key genes involved in the monoterpene biosynthetic pathway, including limonene synthase (lim), pinene synthase (pin), and ARM repeat proteins (arm), was investigated in three Juniperus species (Juniperus sabina, J. polycarpos, and J. communis) across two tissues (leaf and fruit). Field samples were collected from the Salouk region in North Khorasan province. Genes involved in the biosynthesis of the main metabolites were identified, and specific primers were designed. Subsequently, RNA extraction, cDNA synthesis, and PCR optimization were performed, and finally, gene expression was evaluated using the qRT-PCR method. The results showed that gene expression was significantly affected by both tissue type and plant species. Specifically, pin gene expression in fruit ranged from 0.0399 in J. communis to 0.152 in J. sabina, and in leaf from 0.0023 to 0.0093, indicating a substantial increase in expression in fruit compared to leaf. Furthermore, lim gene expression in fruit ranged from 0.0149 in J. communis to 0.0285 in J. sabina, and in leaf from 0.0019 to 0.0202, demonstrating increased expression in fruit across all species. Regarding the arm gene, expression in fruit was higher in J. communis and J. sabina compared to J. polycarpos, with expression values of approximately 0.0334 in J. communis fruit and 0.0324 in J. sabina fruit, while in leaf, values were similar to or lower than these amounts in other species. These results indicate that pin and lim genes exhibit the highest expression levels in fruit, and the arm gene displays differential expression patterns depending on the species and plant tissue.

https://jmpb.areeo.ac.ir/article_135258_aedea190f39c41a52005efb3509a541c.pdf