Dihydroartemisinin induces a two-step transcriptional response and stage-specific developmental shifts in malaria parasites, Plasmodium falciparum

The parasite Plasmodium falciparum causes malaria, the deadliest human parasitic disease, which remains fatal when not promptly treated. Evolving parasite resistance to frontline artemisinin-based therapies threatens vulnerable populations and decades of progress toward malaria elimination. Yet the mode of action of dihydroartemisinin (DHA), the active metabolite of these treatments, remains incompletely understood. Here we applied dose-response transcriptomics across the three intraerythrocytic stages - rings, trophozoites, and schizonts, revealing a two-tier transcriptional response to DHA, with low- and high-dose programs consistent with specific drug action and cytotoxic damage. The trophozoite stage mounts the strongest and most coordinated response, including a striking reversal of the developmental cascade in which protein synthesis machinery is broadly downregulated and a ring-like transcriptional profile is reactivated - reminiscent of drug-induced quiescence. Coordinated regulation of multiple protein complexes, most notably Kelch13 and its interacting partners (KIC), points to organized transcriptional control of the parasites drug response. This work provides a stage- and dose-resolved view of DHA action in P. falciparum and a template for future antimalarial mechanism-of-action studies.