Artemisia annua , a traditional Chinese medicinal plant, is renowned for producing artemisinin, a potent antimalarial drug. However, cadmium pollution in the soil significantly inhibits the growth and metabolic processes of A. annua , jeopardizing safe and high-yield artemisinin production. Here, we explore the effects of hydrogen on the physiological responses of A. annua under cadmium stress, utilizing the hydrogen storage material MgH 2 . Our findings reveal that MgH 2 treatment alone has a limited impact on the growth and development of A. annua . However, when combined with cadmium stress, MgH 2 treatment restores approximately 10% of the biomass lost due to cadmium stress. MgH 2 treatment also significantly increases endogenous hydrogen in seedlings, reducing the expression of cadmium uptake and transport genes induced by heavy metal, leading to lower cadmium absorption and accumulation. Additionally, MgH 2 mitigates the adverse effects on leaf gas exchange and chlorophyll content, restoring about 15% of photosynthetic capacity compromised by cadmium exposure. Notably, MgH 2 also modifies the soil microbial community structure and enhances carbon cycling, suggesting its beneficial role in remediating cadmium damage in soil. Finally, our results demonstrate that MgH 2 can fully restore glandular-secreting trichome (GST) density and artemisinin production at high cadmium concentrations in A. annua . Given the primary use of A. annua for compound extraction, our findings provide a new safe and sustainable strategy for cultivation and production of traditional Chinese medicinal plants. • Applying MgH 2 to Artemisia annua under cadmium stress could promote plant growth and increase the biomass. • Hydrogen derived from MgH 2 inhibits the expression of transporters, thereby reducing cadmium uptake by cells. • Cadmium alters the rhizosphere microbial structure in soil and hydrogen produced by MgH 2 can reshape the structure. • Cadmium reduces the density of glandular secretory trichomes (GSTs) in A. annua , thereby lowering artemisinin production, but MgH 2 has potential to restore artemisinin production capacity.
Cao et al. (Thu,) studied this question.