Raman Imaging of Plant Cell Walls in Sections of Cucumis sativus

Abstract

Raman microspectra combine information on chemical composition of plant tissues with spatial information. The contributions from the building blocks of the cell walls in the Raman spectra of plant tissues can vary in the microscopic sub-structures of the tissue. Here, we discuss the analysis of 55 Raman maps of root, stem, and leaf tissues of Cucumis sativus, using different spectral contributions from cellulose and lignin in both univariate and multivariate imaging methods. Imaging based on hierarchical cluster analysis (HCA) and principal component analysis (PCA) indicates different substructures in the xylem cell walls of the different tissues. Using specific signals from the cell wall spectra, analysis of the whole set of different tissue sections based on the Raman images reveals differences in xylem tissue morphology. Due to the specifics of excitation of the Raman spectra in the visible wavelength range (532 nm), which is, e.g., in resonance with carotenoid species, effects of photobleaching and the possibility of exploiting depletion difference spectra for molecular characterization in Raman imaging of plants are discussed. The reported results provide both, specific information on the molecular composition of cucumber tissue Raman spectra, and general directions for future imaging studies in plant tissues.

Plant phenotyping relevance

ラマンイメージングを用いて植物組織の細胞壁組成と木部形態を抽出・比較しており、画像取得・解析手法が研究の中心であるため。

Code and data availability

The article describes Raman imaging of Cucumis sativus tissue sections with HCA/PCA analysis, but contains no data availability statement, no public repository deposit, no author code release, and no supplementary asset URL. Only the CC BY license link is present, which is not a paper-specific asset.

No evidence-backed public reproduction asset is currently recorded.