A promising application of drought stress for increasing product quality of Iranian endemic Satureja sahendica Bornm medicinal plant

Sahendian savory (Satureja sahendica Bornm.) is an Iranian endemic species from Lamiaceae family. This plant has been used in the food industry, cosmetics and medical preparations. In the current study, drought stress was induced at flowering stage based on a completely randomized design (CRD) with three replications in green house. Treatments were considered as five sampling times (control, 3, 6, 9 and 12 days) with three interval days that imposed after stopping irrigation. Soil volumetric moisture, and several physiological traits were measured, including leaf water potential, relative water content, pigments, soluble sugars, and proline. Metabolite profiling revealed that metabolites, such as rosmarinic acid, caffeic acid, ursolic acid, carnosic acid, soluble sugars and proline affected by drought stress and significantly increased by drought stress. The oil yield and thymol as the most valuable compound in the oil of Sahandian savory, was significantly increased, although, the quantitative content of some compounds in oil such as Carvacrole, γ-Terpinene and p- Cymene were decreased in response to drought stress. It can be concluded that in addition to osmoprotectant accumulation, savory plant improved its drought tolerance by changing in its secondary metabolites’ components in essential oil and in extract. In conclusion, the combination of metabolite profiling and physiological parameters contributed to a greater understanding of the mechanisms of savory plant’s response at metabolomics level.