Plant growth regulator studies and emerging biotechnological approaches in Artemisia annua L.: A comprehensive overview

Artemisia annua L., a prominent Chinese medicinal plant, serves as the primary commercial source of artemisinin, a potent anti-plasmodial compound critical in malaria treatment. However, global artemisinin demand significantly exceeds supply due to the plant's low natural yield (0.1–0.9 % dry weight). Plant growth regulators (PGRs) are a versatile class of agrochemicals capable of modulating plant growth, physiology, and metabolism. Acting individually or through cross-talk in complex signaling cascades, PGRs elicit specific responses that enhance biomass and secondary metabolite production. In A. annua, strategic PGR applications have shown great potential to improve both in vivo and in vitro growth dynamics, stress resilience, and biosynthesis of bioactive compounds like artemisinin.

Recent advancements in biotechnological strategies, including in vitro culture systems, metabolic engineering, and bioprocess optimization, have demonstrated the potential of PGRs to maximize artemisinin production. These strategies leverage rapid micropropagation, molecular approaches (including transgenics), and cell-based culture techniques to enhance crop yield and secondary metabolite content. Furthermore, omics-driven research has provided detailed insights into the molecular mechanisms underpinning PGR-mediated artemisinin biosynthesis, enabling precise and targeted applications and thus offering sustainable solutions to meet rising global demands.

This review presents a comprehensive analysis of the biotechnological applications of PGRs in A. annua. It highlights the fundamental roles of plant hormones and their interactions in regulating responses to biotic and abiotic stresses. The review also emphasizes the targeted exogenous application of PGRs in plant regeneration through tissue culture, secondary metabolite elicitation, and the optimization of the artemisinin biosynthetic pathway. Furthermore, this work highlights the need to integrate PGRs and transgenic plant applications in A. annua as part of an innovative and scalable strategy that combines biotechnological tools, omics insights, and field validation. This review offers valuable insights for researchers and students in plant biotechnology, providing practical knowledge to advance the cultivation and metabolic optimization of A. annua for enhanced artemisinin production.