Solid-state NMR investigations of cellulose structure and interactions with matrix polysaccharides in plant primary cell walls

• Main Authors: Wang, Tuo (Contributor), Hong, Mei (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Chemistry (Contributor)
• Format: Article
• Language: English
• Published: Oxford University Press, 2017-04-06T16:10:21Z.
• Subjects: Article
• Online Access: Get fulltext

Until recently, the 3D architecture of plant cell walls was poorly understood due to the lack of high-resolution techniques for characterizing the molecular structure, dynamics, and intermolecular interactions of the wall polysaccharides in these insoluble biomolecular mixtures. We introduced multidimensional solid-state NMR (SSNMR) spectroscopy, coupled with [superscript 13]C labelling of whole plants, to determine the spatial arrangements of macromolecules in near-native plant cell walls. Here we review key evidence from 2D and 3D correlation NMR spectra that show relatively few cellulose-hemicellulose cross peaks but many cellulose-pectin cross peaks, indicating that cellulose microfibrils are not extensively coated by hemicellulose and all three major polysaccharides exist in a single network rather than two separate networks as previously proposed. The number of glucan chains in the primary-wall cellulose microfibrils has been under active debate recently. We show detailed analysis of quantitative [superscript 13]C SSNMR spectra of cellulose in various wild-type (WT) and mutant Arabidopsis and Brachypodium primary cell walls, which consistently indicate that primary-wall cellulose microfibrils contain at least 24 glucan chains.
United States. Dept. of Energy. Office of Basic Energy Sciences (Center for Lignocellulose Structure and Formation Award # DE-SC0001090)