Seed-Based Compromises and Adaptations in Drought-Resistant Plants Facing Extreme Metal Contamination

Industrial and mining activities have significantly contaminated soils worldwide, making areas unfit for reuse or habitation. Mine tailings often have acidic pH, poor nutrient content, and low microbial biomass, with elevated metal levels toxic to many plants, challenging growth, and development. Phytoremediation, utilizing metal-tolerant or accumulating plants for metal(loid) stabilization, transformation, or extraction from contaminated sites, is gaining industrial traction. Therefore, understanding plant physiological and biochemical adaptation processes to stress is crucial. This study focuses on the halophyte Atriplex lentiformis, which tolerates high metal levels (Zn, Cd, As, and Pb). We investigated its reproductive strategies and metal homeostasis mechanisms in seeds using Synchrotron X-ray Fluorescence Microscopy (XFM) and tomography. Our findings show toxic metals mainly located in maternal tissues surrounding the seeds, with high zinc levels in embryos from polluted areas, indicating unique adaptation mechanisms. This research deepens our understanding of plant trace element cycling in disturbed ecosystems.