Using β-ocimene to increase the artemisinin content in juvenile plants of Artemisia annua L.

Objective The anti-malarial drug, artemisinin, is harvested from the leaves of adult Artemisia annua L. plants. As its concentration in juvenile plants is very low, the present study aimed to assess if the airborne signaling molecule, beta-ocimene, could be used to enhance artemisinin accumulation in juvenile A. annua plants. Results Application of exogenous beta-ocimene increased artemisinin accumulation in A. annua. Treatment with 10 mu M beta-ocimene for 4 days resulted in juvenile plants accumulating artemisinin contents of up to 25 mg/g (2.5%) of dry weight. The expression levels of key genes encoding enzymes involved in both precursor biosynthetic pathways and artemisinin biosynthetic pathways induced by beta-ocimene were upregulated. Glandular secretory trichome (GST) size and density increased by 49.2% and 38.2%, respectively, along with the upregulation of genes associated with GST development. Conclusion beta-ocimene enhances artemisinin accumulation in juvenile A. annua plants by modulating artemisinin biosynthetic pathways and GST development.