Sahendian savory (Satureja sahendica Bornm) is a medicinal plant species which produces valuable secondary metabolites including thymol, p-cymene and γ-terpinene. In this study, optimization of hairy roots culture in S. sahendica using Agrobacterium rhizogenes was efficiently established. High frequency of genetic transformation was obtained using node and internode explants and three bacterial strains (ATCC 15834, A4, and LBA 9402). However, leaf explants showed no susceptibility to induce hairy roots with the A. rhizogenes strains. The node explants and LBA 9402 strain were the best combination for root induction. Infection time of 20 min caused greater transformation occurrence compared to 10 and 30 min, respectively. Node explants infected with LBA 9402 were found to produce more transformants upon co-cultivation for 2 days. The maximum induction of hairy roots was obtained from bacterial infection at a density of OD600 = 0.8. Polymerase chain reaction by gene-specific primers from rol B gene confirmed the positive transformation events. S. sahendica efficiently provided and produced a large number of hairy roots which could be used for the production of secondary metabolites or other molecular and biotechnological applications. Production of thymol an important secondary metabolite of S. sahendica from hairy root cultures was confirmed by TLC and GC analysis. Elicitor-treated hairy root cultures with methyl jasmonate and ammonium nitrate produced more amount of thymol compared to untreated roots. These results demonstrate that secondary metabolite production such as thymol in hairy root culture of Sahendian savory could be used to increase low secondary metabolite production in this valuable medicinal plant.
