Magnesium and manganese interactively modulate parthenolide accumulation and the antioxidant defense system in the leaves of Tanacetum parthenium

A balanced nutrient supply is a critical factor affecting accumulation of terpenoids in plants, yet data related to the interactive effects of two essential nutrients for the biosynthesis of sesquiterpenes are scarce. Here, the interactional effects between magnesium (Mg) and manganese (Mn) on plant growth, oxidative status, parthenolide accumulation and expression of key genes involved in parthenolide biosynthesis including 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate reductase (HDR), 3-hydroxy-3-methylglutarylcoenzyme A reductase (HMGR), germacrene A synthase (GAS), germacrene A oxidase (GAO), costunolide synthase (COS) and parthenolide synthase (PTS) in the leaves of feverfew plants grown at different Mn and Mn levels were assessed. Plant growth and leaf pigment concentrations were associated with the amount of applied Mg but could be modified by the Mn level. Deprivation and the addition of both Mg and Mn induce oxidative stress. Mg supply also alleviated the adverse effects of Mn excess on plant growth and oxidative status. In addition, parthenolide biosynthesis decreased under deprivation of Mg or Mn, but the addition of Mn up to 50μM under 2mM Mg supply considerably increased its accumulation. The parthenolide accumulation trend might reflect the up-regulation of terpenoid-related genes and enzyme activities as well as the oxidative status of feverfew leaves. Our data suggest a profound effect of the combined supply of Mg and Mn on parthenolide biosynthesis through the activation of terpene synthases, which concomitantly modulate by oxidative status.

Biosynthesis and localization of parthenolide in glandular trichomes of feverfew (Tanacetum parthenium L. Schulz Bip.)

Feverfew (Tanacetum parthenium) is a perennial medicinal herb and is a rich source of sesquiterpene lactones. Parthenolide is the main sesquiterpene lactone in feverfew and has attracted attention because of its medicinal potential for treatment of migraine and cancer. In the present work the parthenolide content in different tissues and developmental stages of feverfew was analyzed to study the timing and localization of parthenolide biosynthesis. The strongest accumulating tissue was subsequently used to isolate sesquiterpene synthases with the goal to isolate the gene encoding the first dedicated step in parthenolide biosynthesis. This led to the isolation and charachterization of a germacrene A synthase (TpGAS) and an (E)-β-caryophyllene synthase (TpCarS). Transcript level patterns of both sesquiterpene synthases were analyzed in different tissues and glandular trichomes. Although TpGAS was expressed in all aerial tissues, the highest expression was observed in tissues that contain high concentrations of parthenolide and in flowers the highest expression was observed in the biosynthetically most active stages of flower development. The high expression of TpGAS in glandular trichomes which also contain the highest concentration of parthenolide, suggests that glandular trichomes are the secretory tissues where parthenolide biosynthesis and accumulation occur.

Chemical composition, antibacterial activity and cytotoxicity of essential oils of Tanacetum parthenium in different developmental stages

CONTEXT

Tanacetum parthenium Schultz Bip. (Asteraceae) is an aromatic perennial plant, widely distributed in the northern hemisphere. This species traditionally has been used in insecticides, cosmetics, balsams, dyes, medicines and preservatives.

MATERIAL AND METHODS

The essential oil of T. parthenium was obtained by hydrodistillation in three developmental stages and analyzed by gas chromatography-mass spectrometry. The antibacterial activity of the oils was investigated against four Gram-positive and four Gram-negative bacteria. The oil was tested for cytotoxicity against THP-1 cells using the Trypan blue assay.

RESULTS

Twenty-nine components were identified in the essential oil; the highest amount was extracted at the flowering stage. The main component, in the flowering stage, was camphor (18.94%) and other major components were bornyl acetate (18.35%), camphene (13.74%), bornyl isovalerate (3.15%), borneol (10.93%), juniper camphor (6.23%) and β-eudesmol (2.65%). Minimum inhibitory concentration of essential oil was evaluated from 4 µL mL(-1) against Staphylococcus subtilis to 38 µL mL(-1) against Entrobacter aerogenes. Toxicity assay showed that the oil has no significant toxicity at 5-15% v/v concentrations on THP-1 cells.

DISCUSSION AND CONCLUSION

This study demonstrates the occurrence of camphor/bornyl acetate chemotype of T. parthenium in western regions of Iran. The finding showed also the studied oils have relatively good antibacterial activity without significant toxicity, thus have great potentiality to be used as natural health product.