<i>Populus alba</i> (white poplar) thiol-peptide compounds allow intracellular and extracellular cadmium detoxification

Cadmium (Cd) is a toxic heavy metal introduced into the environment through natural and human activities. <i>Populus alba</i> is a promising species for phytoremediation due to its ability to synthesize thiol-peptides like glutathione (GSH) and phytochelatins (PCn), which play a crucial role in heavy metal detoxification. In this study, we developed an HPLC-ESI-MS/MS method to quantify intracellular and extracellular thiol-peptides in <i>P. alba</i> ‘Villafranca’ clone exposed to different Cd concentrations over short- and long-term periods. We also evaluated functional responses, including biometric traits and photosynthetic efficiency. Despite prolonged Cd exposure, plants showed high resistance, with no effects on growth or PSII performance. Cd treatment significantly increased PCn levels, particularly in roots, with PC2, PC3, and PC4 contributing to detoxification. Notably, GSH and PCn were detected extracellularly, suggesting a plasma membrane efflux mechanism. Sodium orthovanadate, an inhibitor of plasma membrane transporters, strongly reduced extracellular GSH and only partially affected PCn efflux. These results suggest that GSH and PCn may not share the same transport pathways. This study underscores the dual role of thiol-peptides in Cd detoxification, through intracellular sequestration and extracellular extrusion, and highlights <i>P. alba</i> as a model for studying Cd toxicity mitigation in plants.镉（Cadmium, Cd）是一种通过自然活动与人类活动进入环境的有毒重金属。银白杨（Populus alba）因可合成谷胱甘肽（GSH）、植物螯合肽（PCn）等巯基肽而成为极具应用潜力的植物修复物种，这类肽类在重金属解毒过程中发挥关键作用。本研究建立了高效液相色谱-电喷雾串联质谱（HPLC-ESI-MS/MS）方法，对短期与长期暴露于不同镉浓度的银白杨‘Villafranca’无性系的细胞内、外巯基肽进行定量分析；同时评估了植株的生物学性状与光合效率等生理响应。尽管经历长期镉暴露，该无性系仍表现出极强的耐受性，未出现生长或光系统II（PSII）性能受抑制的情况。镉处理显著提升了PCn的含量，尤以根系最为明显，其中PC2、PC3与PC4在解毒过程中贡献突出。值得注意的是，研究在细胞外也检测到了GSH与PCn，这表明植株存在质膜外排机制。质膜转运蛋白抑制剂原钒酸钠可强烈抑制细胞外GSH的分泌，但仅对PCn的外排产生部分影响。上述结果提示，GSH与PCn可能并非共享同一转运途径。本研究阐明了巯基肽在镉解毒过程中通过细胞内螯合与细胞外排出共同发挥的双重作用，并凸显银白杨可作为研究植物镉毒性缓解机制的模式物种。

搜集汇总

背景与挑战

背景概述

该数据集聚焦于白杨（Populus alba）中硫肽化合物（如谷胱甘肽和植物螯合肽）在镉解毒中的作用机制。研究通过HPLC-ESI-MS/MS方法量化了细胞内外的硫肽化合物，发现白杨在镉暴露下表现出高抗性，植物螯合肽水平显著增加，且硫肽化合物通过细胞内螯合和细胞外排双重途径实现镉解毒。这突出了白杨作为植物修复模型在重金属污染治理中的潜力。