Environmental Research and Innovation Department, Luxembourg Institute of Science and Technology, Esch-sur-Alzette, Luxembourg.
Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium.
Plant Biol (Stuttg). 2018 Nov;20(6):1023-1035. doi: 10.1111/plb.12865. Epub 2018 Jul 24.
Cadmium (Cd) is a non-essential, toxic heavy metal that poses serious threats to both ecosystems and human health. Plants employ various cellular and molecular mechanisms to minimise the impact of Cd toxicity and cell walls function as a defensive barrier during Cd exposure. In this study, we adopted a quantitative gel-based proteomic approach (two-dimensional difference gel electrophoresis) to investigate changes in the abundance of cell wall and soluble proteins in stems of Medicago sativa L. upon long-term exposure to Cd (10 mg·Cd·kg soil as CdSO ). Obtained protein data were complemented with targeted gene expression analyses. Plants were affected by Cd exposure at an early growth stage but seemed to recover at a more mature stage as no difference in biomass was observed. The accumulation of Cd was highest in roots followed by stems and leaves. Quantitative proteomics revealed a changed abundance for 179 cell wall proteins and 30 proteins in the soluble fraction upon long-term Cd exposure. These proteins are involved in cell wall remodelling, defence response, carbohydrate metabolism and promotion of the lignification process. The data indicate that Cd exposure alters the cell wall proteome and underline the role of cell wall proteins in defence against Cd stress. The identified proteins are linked to alterations in cell wall structure and lignification process in stems of M. sativa, underpinning the function of the cell wall as an effective barrier against Cd stress.
镉（Cd）是一种非必需的有毒重金属，对生态系统和人类健康构成严重威胁。植物采用各种细胞和分子机制来最小化 Cd 毒性的影响，细胞壁在 Cd 暴露时充当防御屏障。在这项研究中，我们采用了一种基于凝胶的定量蛋白质组学方法（二维差异凝胶电泳）来研究长期暴露于 Cd（以 CdSO 的形式存在于 10 mg·Cd·kg 土壤中）对紫花苜蓿茎中细胞壁和可溶性蛋白质丰度的影响。获得的蛋白质数据补充了靶向基因表达分析。植物在早期生长阶段受到 Cd 暴露的影响，但在更成熟的阶段似乎恢复了，因为生物量没有差异。Cd 在根中积累最多，其次是茎和叶。定量蛋白质组学揭示，长期 Cd 暴露后，细胞壁蛋白的丰度发生了变化，有 179 种，可溶性部分的蛋白质有 30 种。这些蛋白质参与细胞壁重塑、防御反应、碳水化合物代谢和木质化过程的促进。这些数据表明，Cd 暴露改变了细胞壁蛋白质组，并强调了细胞壁蛋白在抵御 Cd 胁迫中的作用。鉴定出的蛋白质与 Cd 胁迫下紫花苜蓿茎细胞壁结构和木质化过程的改变有关，这为细胞壁作为 Cd 胁迫的有效屏障的功能提供了依据。
