Abstract
Infrared and Raman spectra of sequentially extracted primary cell walls and their pectic polymers were obtained from five angiosperm plants. Fourier-transform Raman spectrometry was shown to be a powerful tool for the investigation of primary cell-wall architecture at a molecular level, providing complementary information to that obtained by Fourier-transform infrared microspectroscopy. The use of an extraction procedure using imidazole instead of cyclohexane trans-1,2-N,N,N[prime],N[prime]-diaminotetraacetate allows the extension of the infrared spectral window for data interpretation from 1300 to 800 cm-1, to 2000 to 800 cm-1, and allows us to obtain Raman spectra from extracted cell-wall material. Wall constituents such as pectins, proteins, aromatic phenolics, cellulose, and hemicellulose have characteristic spectral features that can be used to identify and/or fingerprint these polymers without, in most cases, the need for any physical separation. The Gramineae (rice [Oryza sativa], polypogon [Polypogon fugax steud], and sweet corn [Zea mays]) are spectroscopically very different from the nongraminaceous monocotyledon (onion [Allium cepa]) and the dicotyledon (carrot [Daucus carota]); this reflects differences in chemical composition and cross-linking of the walls. The possibility of a taxonomic classification of plant cell walls based on infrared and Raman spectroscopies and the use of spectral fingerprinting for authentication and detection of adulteration of products rich in cell-wall materials are discussed.
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Selected References
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- Kim J. B., Carpita N. C. Changes in Esterification of the Uronic Acid Groups of Cell Wall Polysaccharides during Elongation of Maize Coleoptiles. Plant Physiol. 1992 Feb;98(2):646–653. doi: 10.1104/pp.98.2.646. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McCann M. C., Hammouri M., Wilson R., Belton P., Roberts K. Fourier transform infrared microspectroscopy is a new way to look at plant cell walls. Plant Physiol. 1992 Dec;100(4):1940–1947. doi: 10.1104/pp.100.4.1940. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McNeil M., Darvill A. G., Albersheim P. Structure of Plant Cell Walls: X. RHAMNOGALACTURONAN I, A STRUCTURALLY COMPLEX PECTIC POLYSACCHARIDE IN THE WALLS OF SUSPENSION-CULTURED SYCAMORE CELLS. Plant Physiol. 1980 Dec;66(6):1128–1134. doi: 10.1104/pp.66.6.1128. [DOI] [PMC free article] [PubMed] [Google Scholar]