探索早期陆地植物中有机碳的地球化学分布:一种新方法。
Exploring the geochemical distribution of organic carbon in early land plants: a novel approach.
机构信息
School of Natural and Environmental Sciences, Newcastle University, Drummond Building, Newcastle upon Tyne NE1 7RU, UK
National EPSRC XPS Users' Service (NEXUS), School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
出版信息
Philos Trans R Soc Lond B Biol Sci. 2018 Feb 5;373(1739). doi: 10.1098/rstb.2016.0499.
Terrestrialization depended on the evolution of biosynthetic pathways for biopolymers including lignin, cutin and suberin, which were concentrated in specific tissues, layers or organs such as the xylem, cuticle and roots on the submillimetre scale. However, it is often difficult, or even impossible especially for individual cells, to resolve the biomolecular composition of the different components of fossil plants on such a scale using the well-established coupled techniques of gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry. Here, we report the application of techniques for surface analysis to investigate the composition of X-ray photoelectron spectroscopy of two different spots (both 300 µm × 600 µm) confirmed the presence of carbon. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealed 'chemical maps' (imaging mode with 300 nm resolution) of aliphatic and aromatic carbon in the intact fossil that correlate with the vascular structures observed in high-resolution optical images. This study shows that imaging ToF-SIMS has value for determining the location of the molecular components of fossil embryophytes while retaining structural information that will help elucidate how terrestrialization shaped the early evolution of land plant cell wall biochemistry.This article is part of a discussion meeting issue 'The Rhynie cherts: our earliest terrestrial ecosystem revisited'.
陆地化依赖于生物聚合物生物合成途径的进化,包括木质素、角质和栓质,它们在亚毫米尺度上集中在特定的组织、层或器官中,如木质部、表皮和根。然而,使用已建立的气相色谱/质谱和液相色谱/质谱耦合技术,通常很难(甚至不可能)在如此小的尺度上解析化石植物不同成分的生物分子组成,尤其是对于单个细胞而言。在这里,我们报告了表面分析技术在研究两个不同点(均为 300 µm×600 µm)的 X 射线光电子能谱的组成中的应用。这两个点证实了碳的存在。飞行时间二次离子质谱(ToF-SIMS)揭示了完整化石中脂肪族和芳香族碳的“化学图谱”(成像模式,分辨率为 300nm),与在高分辨率光学图像中观察到的脉管结构相关。这项研究表明,成像 ToF-SIMS 具有确定化石胚胎植物分子成分位置的价值,同时保留有助于阐明陆地化如何塑造陆地植物细胞壁生物化学早期进化的结构信息。本文是关于“Rhynie 燧石:重新审视我们最早的陆地生态系统”的讨论会议的一部分。