Efficient in vitro regeneration of the endangered species Artemisia arborescens L. through direct organogenesis and impact on secondary metabolites production

Tree wormwood (Artemisia arborescens L.; family Asteraceae) is an endangered medicinal and ornamental plant with industrial and ecological potentials. Here, we report an efficient micropropagation method for the in vitro regeneration of this species. Initiation culture was established from nodal segments in basic Murashige and Skoog (MS) medium. Shoot induction and elongation were assessed in MS medium supplemented with different concentrations of 6-benzylaminopurine (BAP; 0-1.5 mg/L) in combination with indole 3-acetic acid (IAA; 0-0.4 mg/L). The growth regulators combination of 0.5 mg/L BAP + 0.1 mg/L IAA gave the best result with a 100% shoot induction rate and morphologically stable vitroplants without callogenesis. The half-strength MS medium supplemented with 1 mg/L indole 3-butyric acid (IBA) resulted in the highest rooting rate, the maximum root number, and the highest root length. Rooted plantlets were successfully acclimatized with a 70% survival rate. The phytochemical analyses revealed enhanced total phenolic and flavonoid contents in the micropropagated plants compared to the mother plant. However, no significant fluctuations were recorded for the condensed tannins and essential oil contents between the micropropagated plants and the mother plant. The GC-MS analysis revealed that, except for some minor compounds which showed significant variation between the in vitro regenerated plants and the mother plant, contents of the main essential oil components were unchanged. This simple and rapid in vitro regeneration protocol through direct organogenesis could be applied both for ex situ and in situ conservation programs and for the sustainable production of tree wormwood bioactive phytochemicals.

Automated summary

An efficient micropropagation method for tree wormwood was developed. Direct organogenesis was the most effective method for regeneration. This method can be used for conservation and sustainable production in various projects.