Salt marshes are coastal ecosystems which are declining due to global warming and pollution, such as mercury (Hg) pollution. The extra- and intracellular mechanisms of tolerance to Hg in plants are identified but the involvement of the plasma membrane is poorly known. This study aims to identify the effects induced by Hg in plant membranes and to unravel their role on plants tolerance to Hg. Juncus maritimus was collected from a salt marsh historically contaminated with Hg. Two sites differing in Hg contamination were chosen. Hg concentration, membrane damage, antioxidant response and lipidomic analysis were performed in the different plant organs (roots, rhizome and leaves). The strategy of J. maritimus to tolerate environments contaminated by Hg seems to rely on restricting the entrance of Hg into the root cells, with a remodeling of root lipids contributing to the efficiency of this mechanism. The root lipids remodelling acts by protecting the cellular metabolism from Hg toxicity and thus reducing the effort of cells in counteracting Hg effects (e.g., antioxidant mechanisms). This knowledge can be used to develop strategies to preserve these important but vulnerable ecosystems, and can also be relevant for phytoremediation approaches.

盐沼是沿海生态系统，由于全球变暖和污染，例如汞 (Hg) 污染，它们正在衰退。确定了植物对 Hg 耐受的细胞外和细胞内机制，但对质膜的参与却知之甚少。本研究旨在确定 Hg 对植物膜中的影响，并阐明它们对植物对 Hg 耐受性的作用。Juncus maritimus是从历史上被汞污染的盐沼中收集的。选择了汞污染不同的两个地点。在不同的植物器官（根、根茎和叶）中进行汞浓度、膜损伤、抗氧化反应和脂质组学分析。J. maritimus的策略容忍被汞污染的环境似乎依赖于限制汞进入根细胞，根脂质的重塑有助于这种机制的效率。根脂质重塑通过保护细胞代谢免受汞毒性的影响，从而减少细胞对抗汞效应（例如抗氧化机制）的努力。这些知识可用于制定保护这些重要但脆弱的生态系统的策略，也可用于植物修复方法。