Lead (Pb) toxicity is a growing serious environmental pollution that threatens human health and crop productivity. Poplar, as an important economic and ecological forest species, has the characteristics of fasting growth and accumulating heavy metals, which is a powerful model plant for phytoremediation. Here, a novel label-free quantitative proteomic platform of SWATH-MS was applied to detect proteome changes in poplar seedling roots following Pb treatment. In total 4388 unique proteins were identified and quantified, among which 542 proteins showed significant abundance changes upon Pb(II) exposure. Functional categorizations revealed that differentially expressed proteins (DEPs) primarily distributed in specialized biological processes. Particularly, lignin and flavonoid biosynthesis pathway were strongly activated upon Pb exposure, implicating their potential roles for Pb detoxification in poplar. Furthermore, hemicellulose and pectin related cell wall proteins exhibited increased abundances, where may function as a sequestration reservoir to reduce Pb toxicity in cytoplasm. Simultaneously, up-regulation of glutathione metabolism may serve as a protective role for Pb-induced oxidative damages in poplar. Further correlation investigation revealed an extra layer of post-transcriptional regulation during Pb response in poplar. Overall, our work represents multiply potential regulators in mediating Pb tolerance in poplar, providing molecular targets and strategies for phytoremediation.

铅 (Pb) 毒性是一种日益严重的环境污染，威胁着人类健康和作物生产力。杨树作为重要的经济生态林树种，具有生长快、重金属积累的特点，是植物修复的有力模式植物。在这里，一种新型的 SWATH-MS 无标记定量蛋白质组学平台被应用于检测铅处理后杨树幼苗根部的蛋白质组变化。总共鉴定和量化了 4388 种独特的蛋白质，其中 542 种蛋白质在 Pb(II) 暴露后显示出显着的丰度变化。功能分类显示差异表达蛋白 (DEP) 主要分布在专门的生物过程中。特别是，木质素和黄酮类生物合成途径在铅暴露后被强烈激活，暗示它们对杨树铅解毒的潜在作用。此外，半纤维素和果胶相关的细胞壁蛋白表现出增加的丰度，其可作为螯合库以减少细胞质中的铅毒性。同时，谷胱甘肽代谢的上调可能对铅引起的杨树氧化损伤起到保护作用。进一步的相关研究揭示了杨树铅响应过程中的额外转录后调控层。总的来说，我们的工作代表了介导杨树铅耐受性的多种潜在调节剂，为植物修复提供了分子靶点和策略。其中可用作螯合库以减少细胞质中的 Pb 毒性。同时，谷胱甘肽代谢的上调可能对铅引起的杨树氧化损伤起到保护作用。进一步的相关研究揭示了杨树铅响应过程中的额外转录后调控层。总的来说，我们的工作代表了介导杨树铅耐受性的多种潜在调节剂，为植物修复提供了分子靶点和策略。其中可用作螯合库以减少细胞质中的 Pb 毒性。同时，谷胱甘肽代谢的上调可能对铅引起的杨树氧化损伤起到保护作用。进一步的相关研究揭示了杨树铅响应过程中的额外转录后调控层。总的来说，我们的工作代表了介导杨树铅耐受性的多种潜在调节剂，为植物修复提供了分子靶点和策略。