College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China.
Key Laboratory of Mass Spectrometry Imaging and Metabolomics (Minzu University of China), State Ethnic Affairs Commission, Beijing 100081, China.
Anal Chem. 2024 Jul 23;96(29):11809-11822. doi: 10.1021/acs.analchem.4c01407. Epub 2024 Jul 8.
Plant samples with irregular morphology are challenging for longitudinal tissue sectioning. This has restricted the ability to gain insight into some plants using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). Herein, we develop a novel technique termed electromagnetic field-assisted frozen tissue planarization (EMFAFTP). This technique involves using a pair of adjustable electromagnets on both sides of a plant tissue. Under an optimized electromagnetic field strength, nondestructive planarization and regularization of the frozen tissue is induced, allowing the longitudinal tissue sectioning that favors subsequent molecular profiling by MALDI-MSI. As a proof of concept, flowers, leaves and roots with irregular morphology from six plant species are chosen to evaluate the performance of EMFAFTP for MALDI-MSI of secondary metabolites, amino acids, lipids, and proteins among others in the plant samples. The significantly enhanced MALDI-MSI capabilities of these endogenous molecules demonstrate the robustness of EMFAFTP and suggest it has the potential to become a standard technique for advancing MALDI-MSI into a new era of plant spatial omics.
形态不规则的植物样本进行纵向组织切片具有挑战性。这限制了利用基质辅助激光解吸/电离质谱成像（MALDI-MSI）深入研究某些植物的能力。在此，我们开发了一种称为电磁场辅助冷冻组织平面化（EMFAFTP）的新技术。该技术涉及在植物组织的两侧使用一对可调节的电磁铁。在优化的电磁场强度下，诱导冷冻组织的非破坏性平面化和规则化，从而实现有利于随后通过 MALDI-MSI 进行分子分析的纵向组织切片。作为概念验证，选择来自六种植物物种的形态不规则的花朵、叶子和根，以评估 EMFAFTP 对植物样本中次生代谢物、氨基酸、脂质和蛋白质等其他物质的 MALDI-MSI 的性能。这些内源性分子的 MALDI-MSI 能力显著增强，证明了 EMFAFTP 的稳健性，并表明它有可能成为推进 MALDI-MSI 进入植物空间组学新时代的标准技术。
