Inhibition of the mevalonate pathway enhances carvacrol biosynthesis and DXR gene expression in shoot cultures of Satureja khuzistanica Jamzad.

Carvacrol is a major component of Satureja khuzistanica Jamzad (≤90%) that has significant antimicrobial and antioxidant properties. Considering the specific capabilities of S. khuzistanica to produce highly pure carvacrol, this plant is an important potential source of carvacrol that could address the abundant consumption and increasing demand for this monoterpene in current world markets. This research was performed to better understand the process of biosynthesis and accumulation of carvacrol in S. khuzistanica. Tests were performed on shoot cultures of S. khuzistanica in Linsmaier-Skoog (LS) medium treated with different concentrations of fosmidomycin (an inhibitor of the non-mevalonate pathway) and mevinolin (an inhibitor of the mevalonate pathway) for 21 days at the following concentrations: 0, 10, 25, 50, 75 and 100 µM. The present study demonstrated that the MEP pathway is the major pathway that provides IPP for the biosynthesis of carvacrol, and the expression and activity levels of the DXR enzyme have a critical effect on carvacrol biosynthesis. Surprisingly, Mevinolin at concentrations of 75 and 100 µM increased the carvacrol content and the DXR activity and gene expression in S. khuzistanica plantlets.

Evaluation of seed and seedling emergence enhancement of some population of Sahandy savory (Satureja sahendica) by gibberlic acid, potasium nitrate, pre-cooling, physical and chemical scarification treatment.

In greenhouse experiment, the seed samples of 3 populations were treated with treatments including: cold stratification, Gibberlic Acid (50 ppm and 100 ppm), Potassium nitrate (0.2%, 0.4%), physical scarification (sand paper), chemical scarification (Ethylic alcohol 70%) and distilled water (control), then these treated seed samples were sown in pots as randomize design with three replication. The germination characteristics including: germination percentage, speed of germination, length of root and shoot, seedling length, ratio of root length by shoot length, vigor index, fresh weight arid dry weight, ratio of dry weight by fresh weight were evaluated during 45 days of experiment. Comparing between three populations of Sahandy savory, seed germination characteristics of the Ghazvin population was higher than the other two populations. According to effect of treatment on germination seed characteristics, the species of savory and their population, it was concluded that effect of Gibberlic Acid and Potassium nitrate was higher than physical scarification and chemical scarification comparing with control. With more effective of gibberlic acid and KNO3 and cold treatment on seed germination enhancement of the population, it was clarified that the type of dormancy of some population of Sahandy savory was physiological dormancy.

Production and optimisation of rosmarinic acid by Satureja hortensis L. callus cultures.

In this study, production and optimisation of rosmarinic acid, a phenolic acid and an economically important metabolite, was investigated in the callus cultures established from the mature seeds of Satureja hortensis L. (summer savory) plant. Gamborg's B5 basal medium, supplemented with indol butyric acid (IBA) (1.00 mg L(-1)), N6-benzyl aminopurine (6-BA) (1.00 mg L(-1)) and sucrose (2.5%, w/v), was employed for the establishment and maintenance of the callus cultures. Applications were individually prepared by preparing the media containing different IBA/6-BA combinations and sucrose concentrations. All of the applications were carried out in the continuous dark. In the applications, where the effects of IBA/6-BA combinations on the growth and rosmarinic acid accumulation were assayed (1-15 applications), the highest biomass yield was obtained from the medium supplemented with 1.00 mg L(-1) IBA and 5.00 mg L(-1) 6-BA. In the case of the rosmarinic acid accumulation, an opposite relationship was determined between the growth and rosmarinic acid production. While the highest biomass yield was obtained from the medium containing 1.00 mg L(-1) IBA and 5.00 mg L(-1) 6-BA, the highest rosmarinic acid accumulation was obtained from the medium supported with 1.00 mg L(-1) IBA and 1.00 mg L(-1) 6-BA. In the applications where the effects of sucrose concentrations on the growth and rosmarinic acid accumulation were examined, the highest biomass yield was obtained from the medium which is supplemented with 5.0% (w/v) sucrose. In this category, the highest rosmarinic acid accumulation was obtained from the medium which is supported with 3.0% (w/v) sucrose. According to the experiments carried out with the wild S. hortensis, it is found to have 25.02+/-1.21 mg g(-1) rosmarinic acid. No differentiation was observed in any callus during the course of this study.