In vitro conservation, phytochemistry, and medicinal activity of Artemisia tridentata Nutt.: metabolomics as a hypothesis-generating tool for plant tissue culture

Abstract

Artemisia tridentata Nutt. and related species in the subgenus Tridentatae are ecologically important plants with a rich history of ceremonial and medicinal use by the indigenous people of North America. With the exception of antimicrobial and insecticidal bioassays, there is limited data to support the traditional uses of A. tridentata. Additionally, wild A. tridentata populations are declining and conservation of genetic resources is warranted. The current study was designed to (a) develop in vitro protocols to conserve A. tridentata in axenic culture and to provide plant tissues for phytochemical analysis, (b) to investigate the presence of neurologically-active phytochemicals in A. tridentata and (c) to develop metabolomics as a tool for understanding secondary metabolite biosynthesis under aseptic conditions. A collection of in vitro-grown germplasm lines was established from wild-harvested seeds of A. tridentata. Neurotransmitters acetylcholine, GABA, melatonin and serotonin were identified and quantified in the plant tissues. Crude extracts of A. tridentata inhibited acetylcholinesterase in a bioassay. A metabolomics analysis with chemometric statistics quantified changes in the phytochemical profiles of wild-harvested plants and plantlets in axenic culture. A total of 1,543 phytochemicals were found in all samples of A. tridentata including 52 significant ions putatively identified as monoterpene, phenolic or sesquiterpene compounds. Together, these data provide the foundation for further investigations of the phytochemical diversity and medicinal activity of A. tridentata and demonstrate a research approach for use of metabolomics as a tool for understanding secondary metabolite biosynthesis under aseptic conditions.