Differential Subcellular Distribution and Physiological Responses of Artemisia argyi to Pb, Cu, and Zn Stress

Artemisia argyi is recognized as a promising phytoremediation crop due to its high economic value. A 90-day greenhouse pot experiment was conducted to assess the effects of different doses of lead (Pb), copper (Cu), and zinc (Zn) on the growth, heavy metal accumulation, and physiological responses of A. argyi cultivated in alkaline soil. The results indicated that exposure to Pb, Cu, or Zn significantly decreased photosynthetic pigment content and induced substantial reactive oxygen species generation, consequently elevating glutathione and malondialdehyde levels. Biomass and heavy metal accumulation data demonstrated that A. argyi possesses high tolerance to Pb stress, characterized by low translocation rates and predominant accumulation in roots and cell walls. This retention mechanism supports its potential as a lead-enriching plant while maintaining economic value. In contrast, Zn exhibited the highest translocation rate among the metals tested. Although the proportion of Zn in organelles decreased with increasing stress intensity, its enrichment in organelles remained notably higher than that under Pb or Cu stress. Copper exhibited intermediate mobility, with limited accumulation in organelles, thereby inducing relatively minor cellular damage. These findings elucidate the metal-specific accumulation patterns in A. argyi and underscore its potential as a phytoremediation crop for heavy metal-contaminated soils.