Advanced Mechanisms and Comparative Efficiency of Aquatic Macrophytes in Heavy Metal Remediation: A 2025 Systematic Review

Abstract Heavy metal (HM) contamination in aquatic ecosystems remains a significant environmental threat due to the non-biodegradable nature and bioaccumulation potential of metals like Cd, Pb, and Cr. This review synthesizes cutting-edge research from 2024-2025, focusing on the genomic and transcriptomic pathways of aquatic hyperaccumulators. Specifically, we analyze the recently published 1.11 Gbp genome of Eichhornia crassipes and its whole-genome duplication (WGD) events that facilitate metal sequestration. Comparative data between Pistia stratiotes and Lemna minor reveal significant removal efficiencies (up to 99.7% for Pb at low concentrations). The study concludes by identifying the regulatory role of ABC transporters and ZIP family genes as primary targets for bioengineering the next generation of phytoremediation systems. Keywords: Phytoremediation, Heavy Metals, Eichhornia crassipes, Transcriptomics, Wastewater Treatment, Bioaccumulation Factor (BCF).