Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Wood cellulose microfibrils have a 24-chain core–shell nanostructure in seed plants

Matters Arising to this article was published on 20 May 2024

Abstract

Wood cellulose microfibril (CMF) is the most abundant organic substance on Earth but its nanostructure remains poorly understood. There are controversies regarding the glucan chain number (N) of CMFs during initial synthesis and whether they become fused afterward. Here, we combined small-angle X-ray scattering, solid-state nuclear magnetic resonance and X-ray diffraction analyses to resolve CMF nanostructures in native wood. We developed small-angle X-ray scattering measurement methods for the cross-section aspect ratio and area of the crystalline-ordered CMF core, which has a higher scattering length density than the semidisordered shell zone. The 1:1 aspect ratio suggested that CMFs remain mostly segregated, not fused. The area measurement reflected the chain number in the core zone (Ncore). To measure the ratio of ordered cellulose over total cellulose (Roc) by solid-state nuclear magnetic resonance, we developed a method termed global iterative fitting of T1ρ-edited decay (GIFTED), in addition to the conventional proton spin relaxation editing method. Using the formula N = Ncore/Roc, most wood CMFs were found to contain 24 glucan chains, conserved between gymnosperm and angiosperm trees. The average CMF has a crystalline-ordered core of ~2.2 nm diameter and a semidisordered shell of ~0.5 nm thickness. In naturally and artificially aged wood, we observed only CMF aggregation (contact without crystalline continuity) but not fusion (forming a conjoined crystalline unit). This further argued against the existence of partially fused CMFs in new wood, overturning the recently proposed 18-chain fusion hypothesis. Our findings are important for advancing wood structural knowledge and more efficient use of wood resources in sustainable bio-economies.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Proposed CMF structural models.
Fig. 2: SAXS analyses of intact wood.
Fig. 3: Wood analyses by ssNMR.
Fig. 4: Extrapolation of cellulose NMR spectra by GIFTED experiments.
Fig. 5: XRD analyses of intact wood.
Fig. 6: SAXS analyses of aged wood.

Similar content being viewed by others

Data availability

The datasets generated during and/or analysed during the current study are available from the corresponding authors on reasonable request. Source data are provided with this paper.

Code availability

The computer source code for GIFTED global fitting analysis is given in the Supplementary Code.

References

  1. Guo, M., Song, W. & Buhain, J. Bioenergy and biofuels: history, status, and perspective. Renew. Sust. Energ. Rev. 42, 712–725 (2015).

    Article  CAS  Google Scholar 

  2. Keijsers, E. R., Yılmaz, G. & van Dam, J. E. The cellulose resource matrix. Carbohydr. Polym. 93, 9–21 (2013).

    Article  CAS  PubMed  Google Scholar 

  3. Bar-On, Y. M., Phillips, R. & Milo, R. The biomass distribution on Earth. Proc. Natl Acad. Sci. USA 115, 6506–6511 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Spawn, S. A., Sullivan, C. C., Lark, T. J. & Gibbs, H. K. Harmonized global maps of above and belowground biomass carbon density in the year 2010. Sci. Data 7, 112 (2020).

  5. Rowell, R. M. Handbook of Wood Chemistry and Wood Composites (CRC Press, 2012).

  6. Moshkelani, M., Marinova, M., Perrier, M. & Paris, J. The forest biorefinery and its implementation in the pulp and paper industry: energy overview. Appl. Therm. Eng. 50, 1427–1436 (2013).

    Article  CAS  Google Scholar 

  7. Pu, Y., Kosa, M., Kalluri, U. C., Tuskan, G. A. & Ragauskas, A. J. Challenges of the utilization of wood polymers: how can they be overcome? Appl. Microbiol. Biotechnol. 91, 1525–1536 (2011).

    Article  CAS  PubMed  Google Scholar 

  8. Chakrabarty, A. & Teramoto, Y. Recent advances in nanocellulose composites with polymers: a guide for choosing partners and how to incorporate them. Polymers 10, 517 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  9. Spörl, J. M. et al. Ionic liquid approach toward manufacture and full recycling of all‐cellulose composites. Macromol. Mater. Eng. 303, 1700335 (2018).

    Article  Google Scholar 

  10. Coleman, H. D., Yan, J. & Mansfield, S. D. Sucrose synthase affects carbon partitioning to increase cellulose production and altered cell wall ultrastructure. Proc. Natl Acad. Sci. USA 106, 13118–13123 (2009).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Myburg, A. A., Hussey, S. G., Wang, J. P., Street, N. R. & Mizrachi, E. Systems and synthetic biology of forest trees: a bioengineering paradigm for woody biomass feedstocks. Front. Plant Sci. 10, 775 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  12. Chen, C. et al. Structure–property–function relationships of natural and engineered wood. Nat. Rev. Mater. 5, 642–666 (2020).

    Article  CAS  Google Scholar 

  13. Cheng, G., Zhang, X., Simmons, B. & Singh, S. Theory, practice and prospects of X-ray and neutron scattering for lignocellulosic biomass characterization: towards understanding biomass pretreatment. Energy Environ. Sci. 8, 436–455 (2015).

    Article  CAS  Google Scholar 

  14. Rongpipi, S., Ye, D., Gomez, E. D. & Gomez, E. W. Progress and opportunities in the characterization of cellulose—an important regulator of cell wall growth and mechanics. Front. Plant Sci. 9, 1894 (2018).

    Article  PubMed  Google Scholar 

  15. Martinez-Sanz, M., Gidley, M. J. & Gilbert, E. P. Application of X-ray and neutron small angle scattering techniques to study the hierarchical structure of plant cell walls: a review. Carbohydr. Polym. 125, 120–134 (2015).

    Article  CAS  PubMed  Google Scholar 

  16. Fernandes, A. N. et al. Nanostructure of cellulose microfibrils in spruce wood. Proc. Natl Acad. Sci. USA 108, E1195–E1203 (2011).

    Article  PubMed  PubMed Central  Google Scholar 

  17. Newman, R. H. Estimation of the relative proportions of cellulose I alpha and I beta in wood by carbon-13 NMR spectroscopy. Holzforschung 53, 335–340 (1999).

    Article  CAS  Google Scholar 

  18. Nishiyama, Y., Langan, P. & Chanzy, H. Crystal structure and hydrogen-bonding system in cellulose Iβ from synchrotron X-ray and neutron fiber diffraction. J. Am. Chem. Soc. 124, 9074–9082 (2002).

    Article  CAS  PubMed  Google Scholar 

  19. Nishiyama, Y., Sugiyama, J., Chanzy, H. & Langan, P. Crystal structure and hydrogen bonding system in cellulose Iα from synchrotron X-ray and neutron fiber diffraction. J. Am. Chem. Soc. 125, 14300–14306 (2003).

    Article  CAS  PubMed  Google Scholar 

  20. Oehme, D. P., Yang, H. & Kubicki, J. D. An evaluation of the structures of cellulose generated by the CHARMM force field: comparisons to in planta cellulose. Cellulose 25, 3755–3777 (2018).

    Article  CAS  Google Scholar 

  21. Penttilä, P. A., Rautkari, L., Österberg, M. & Schweins, R. Small-angle scattering model for efficient characterization of wood nanostructure and moisture behaviour. J. Appl. Crystallogr. 52, 369–377 (2019).

    Article  PubMed  PubMed Central  Google Scholar 

  22. Wang, T., Yang, H., Kubicki, J. D. & Hong, M. Cellulose structural polymorphism in plant primary cell walls investigated by high-field 2D solid-state NMR spectroscopy and density functional theory calculations. Biomacromolecules 17, 2210–2222 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Vorokh, A. S. Scherrer formula: estimation of error in determining small nanoparticle size. Nanosyst. Phys. Chem. Math. 9, 364–369 (2018).

    Article  CAS  Google Scholar 

  24. Monshi, A., Foroughi, M. R. & Monshi, M. R. Modified Scherrer equation to estimate more accurately nano-crystallite size using XRD. World J. Nano Sci. Eng. 2, 154–160 (2012).

    Article  Google Scholar 

  25. Leppänen, K. et al. Structure of cellulose and microcrystalline cellulose from various wood species, cotton and flax studied by X-ray scattering. Cellulose 16, 999–1015 (2009).

    Article  Google Scholar 

  26. Jakob, H., Fengel, D., Tschegg, S. & Fratzl, P. The elementary cellulose fibril in Picea abies: comparison of transmission electron microscopy, small-angle X-ray scattering, and wide-angle X-ray scattering results. Macromolecules 28, 8782–8787 (1995).

    Article  CAS  Google Scholar 

  27. Martínez-Sanz, M., Mikkelsen, D., Flanagan, B., Gidley, M. J. & Gilbert, E. P. Multi-scale model for the hierarchical architecture of native cellulose hydrogels. Carbohydr. Polym. 147, 542–555 (2016).

    Article  PubMed  Google Scholar 

  28. Hult, E.-L., Iversen, T. & Sugiyama, J. Characterization of the supermolecular structure of cellulose in wood pulp fibres. Cellulose 10, 103–110 (2003).

    Article  CAS  Google Scholar 

  29. Rosén, T. et al. Cross-sections of nanocellulose from wood analyzed by quantized polydispersity of elementary microfibrils. ACS Nano 14, 16743–16754 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  30. Thomas, L. H. et al. Structure and spacing of cellulose microfibrils in woody cell walls of dicots. Cellulose 21, 3887–3895 (2014).

    Article  CAS  Google Scholar 

  31. Mueller, S. C. & Brown, R. M. Jr. Evidence for an intramembrane component associated with a cellulose microfibril-synthesizing complex in higher plants. J. Cell Biol. 84, 315–326 (1980).

    Article  CAS  PubMed  Google Scholar 

  32. Nixon, B. T. et al. Comparative structural and computational analysis supports eighteen cellulose synthases in the plant cellulose synthesis complex. Sci. Rep. 6, 28696 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Haigler, C. H. & Roberts, A. W. Structure/function relationships in the rosette cellulose synthesis complex illuminated by an evolutionary perspective. Cellulose 26, 227–247 (2019).

    Article  CAS  Google Scholar 

  34. Jarvis, M. C. Structure of native cellulose microfibrils, the starting point for nanocellulose manufacture. Philos. Trans. A 376, 20170045 (2018).

    Google Scholar 

  35. Newman, R. H., Hill, S. J. & Harris, P. J. Wide-angle X-ray scattering and solid-state nuclear magnetic resonance data combined to test models for cellulose microfibrils in mung bean cell walls. Plant Physiol. 163, 1558–1567 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  36. Jarvis, M. C. Cellulose biosynthesis: counting the chains. Plant Physiol. 163, 1485–1486 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Penttilä, P. A., Paajanen, A. & Ketoja, J. A. Combining scattering analysis and atomistic simulation of wood–water interactions. Carbohydr. Polym. 251, 117064 (2021).

    Article  PubMed  Google Scholar 

  38. Terrett, O. M. et al. Molecular architecture of softwood revealed by solid-state NMR. Nat. Commun. 10, 4978 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Kubicki, J. D. et al. The shape of native plant cellulose microfibrils. Sci. Rep. 8, 13983 (2018).

    Article  PubMed  PubMed Central  Google Scholar 

  40. Jakob, H., Fratzl, P. & Tschegg, S. Size and arrangement of elementary cellulose fibrils in wood cells: a small-angle X-ray scattering study of Picea abies. J. Struct. Biol. 113, 13–22 (1994).

    Article  Google Scholar 

  41. Penttilä, P. A. et al. Moisture-related changes in the nanostructure of woods studied with X-ray and neutron scattering. Cellulose 27, 71–87 (2020).

    Article  Google Scholar 

  42. Smith, A. J., MacDonald, M. J., Ellis, L. D., Obrovac, M. N. & Dahn, J. R. A small angle X-ray scattering and electrochemical study of the decomposition of wood during pyrolysis. Carbon 50, 3717–3723 (2012).

    Article  CAS  Google Scholar 

  43. Suzuki, H. & Kamiyama, T. Structure of cellulose microfibrils and the hydration effect in Cryptomeria japonica: a small-angle X-ray scattering study. J. Wood Sci. 50, 351–357 (2004).

    Article  CAS  Google Scholar 

  44. Viljanen, M., Ahvenainen, P., Penttilä, P., Help, H. & Svedstrm, K. Ultrastructural X-ray scattering studies of tropical and temperate hardwoods used as tonewoods. IAWA J. 41, 301–319 (2020).

    Article  Google Scholar 

  45. Paris, O., Zollfrank, C. & Zickler, G. A. Decomposition and carbonisation of wood biopolymers—a microstructural study of softwood pyrolysis. Carbon 43, 53–66 (2005).

    Article  CAS  Google Scholar 

  46. Jungnikl, K., Paris, O., Fratzl, P. & Burgert, I. The implication of chemical extraction treatments on the cell wall nanostructure of softwood. Cellulose 15, 407–418 (2008).

    Article  CAS  Google Scholar 

  47. Martínez-Sanz, M., Pettolino, F., Flanagan, B., Gidley, M. J. & Gilbert, E. P. Structure of cellulose microfibrils in mature cotton fibres. Carbohydr. Polym. 175, 450–463 (2017).

    Article  PubMed  Google Scholar 

  48. Zeng, L. et al. Resolution of deep angiosperm phylogeny using conserved nuclear genes and estimates of early divergence times. Nat. Commun. 5, 4956 (2014).

  49. Wang, X. Q. & Ran, J. H. Evolution and biogeography of gymnosperms. Mol. Phylogenet. Evol. 75, 24–40 (2014).

    Article  PubMed  Google Scholar 

  50. Andersson, S., Wikberg, H., Pesonen, E., Maunu, S. L. & Serimaa, R. Studies of crystallinity of Scots pine and Norway spruce cellulose. Trees Struct. Funct. 18, 346–353 (2004).

    Article  CAS  Google Scholar 

  51. Wikberg, H. & Maunu, S. L. Characterisation of thermally modified hard-and softwoods by 13C CPMAS NMR. Carbohydr. Polym. 58, 461–466 (2004).

    Article  CAS  Google Scholar 

  52. Yang, H. & Kubicki, J. D. A density functional theory study on the shape of the primary cellulose microfibril in plants: effects of C6 exocyclic group conformation and H-bonding. Cellulose 27, 2389–2402 (2020).

    Article  CAS  Google Scholar 

  53. Yuan, E. C. et al. Faster magic angle spinning reveals cellulose conformations in woods. Chem. Commun. 57, 4110–4113 (2021).

    Article  CAS  Google Scholar 

  54. Phyo, P., Wang, T., Yang, Y., O’Neill, H. & Hong, M. Direct determination of hydroxymethyl conformations of plant cell wall cellulose using 1H polarization transfer solid-state NMR. Biomacromolecules 19, 1485–1497 (2018).

    Article  CAS  PubMed  Google Scholar 

  55. Bourmaud, A. et al. Evolution of flax cell wall ultrastructure and mechanical properties during the retting step. Carbohydr. Polym. 206, 48–56 (2019).

    Article  CAS  PubMed  Google Scholar 

  56. Newman, R. & Hemmingson, J. Determination of the degree of cellulose crystallinity in wood by carbon-13 nuclear magnetic resonance spectroscopy. Holzforschung 44, 351–356 (1990).

    Article  CAS  Google Scholar 

  57. Kranitz, K., Sonderegger, W., Bues, C.-T. & Niemz, P. Effects of aging on wood: a literature review. Wood Sci. Technol. 50, 7–22 (2016).

    Article  CAS  Google Scholar 

  58. Tai, H. C. et al. Chemical distinctions between Stradivari’s maple and modern tonewood. Proc. Natl Acad. Sci. USA 114, 27–32 (2017).

    Article  CAS  PubMed  Google Scholar 

  59. Su, C. K. et al. Materials engineering of violin soundboards by Stradivari and Guarneri. Angew. Chem. Int. Ed. 60, 19144–19154 (2021).

    Article  CAS  Google Scholar 

  60. Cai, W., Cheng, Y. K., Tseng, H. H., Tai, H. C. & Lo, S. F. Identification and characterization of wood from antique Chinese guqin zithers. J. Cult. Herit. 53, 72–79 (2022).

    Article  Google Scholar 

  61. Wojtasz-Mucha, J., Hasani, M. & Theliander, H. Dissolution of wood components during hot water extraction of birch. Wood Sci. Tech. 55, 811–835 (2021).

    Article  CAS  Google Scholar 

  62. Geng, W. et al. The influence of lignin content and structure on hemicellulose alkaline extraction for non-wood and hardwood lignocellulosic biomass. Cellulose 26, 3219–3230 (2019).

    Article  CAS  Google Scholar 

  63. Xu, P., Donaldson, L. A., Gergely, Z. R. & Staehelin, L. A. Dual-axis electron tomography: a new approach for investigating the spatial organization of wood cellulose microfibrils. Wood Sci. Technol. 41, 101–116 (2007).

    Article  CAS  Google Scholar 

  64. Donaldson, L. Cellulose microfibril aggregates and their size variation with cell wall type. Wood Sci. Technol. 41, 443–460 (2007).

    Article  CAS  Google Scholar 

  65. Kennedy, C. J. et al. Microfibril diameter in celery collenchyma cellulose: X-ray scattering and NMR evidence. Cellulose 14, 235–246 (2007).

    Article  CAS  Google Scholar 

  66. Kennedy, C. J., Šturcová, A., Jarvis, M. C. & Wess, T. J. Hydration effects on spacing of primary-wall cellulose microfibrils: a small angle X-ray scattering study. Cellulose 14, 401–408 (2007).

    Article  CAS  Google Scholar 

  67. Penttilä, P. A. et al. Bundling of cellulose microfibrils in native and polyethylene glycol-containing wood cell walls revealed by small-angle neutron scattering. Sci. Rep. 10, 20844 (2020).

  68. Plaza, N. Z., Pingali, S. V., Qian, S., Heller, W. T. & Jakes, J. E. Informing the improvement of forest products durability using small angle neutron scattering. Cellulose 23, 1593–1607 (2016).

    Article  CAS  Google Scholar 

  69. Thomas, L. H., Martel, A., Grillo, I. & Jarvis, M. C. Hemicellulose binding and the spacing of cellulose microfibrils in spruce wood. Cellulose 27, 4249–4254 (2020).

    Article  CAS  Google Scholar 

  70. Agarwal, U. P., Reiner, R. R. & Ralph, S. A. Estimation of cellulose crystallinity of lignocelluloses using near-IR FT-Raman spectroscopy and comparison of the Raman and Segal-WAXS methods. J. Agr. Food Chem. 61, 103–113 (2013).

    Article  CAS  Google Scholar 

  71. Rayirath, P., Avramidis, S. & Mansfield, S. D. The effect of wood drying on crystallinity and microfibril angle in black spruce (Picea mariana). J. Wood Chem. Technol. 28, 167–179 (2008).

    Article  CAS  Google Scholar 

  72. Wang, Z., Winestrand, S., Gillgren, T. & Jönsson, L. J. Chemical and structural factors influencing enzymatic saccharification of wood from aspen, birch and spruce. Biomass Bioenergy 109, 125–134 (2018).

    Article  CAS  Google Scholar 

  73. Thygesen, A., Oddershede, J., Lilholt, H., Thomsen, A. B. & Stahl, K. On the determination of crystallinity and cellulose content in plant fibres. Cellulose 12, 563–576 (2005).

    Article  CAS  Google Scholar 

  74. Thomas, L. H. et al. Structure of cellulose microfibrils in primary cell walls from collenchyma. Plant Physiol. 161, 465–476 (2013).

    Article  CAS  PubMed  Google Scholar 

  75. Harris, D. M. et al. Cellulose microfibril crystallinity is reduced by mutating C-terminal transmembrane region residues CESA1A903V and CESA3T942I of cellulose synthase. Proc. Natl Acad. Sci. USA 109, 4098–4103 (2012).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  76. Song, B., Zhao, S., Shen, W., Collings, C. & Ding, S.-Y. Direct measurement of plant cellulose microfibril and bundles in native cell walls. Front. Plant Sci. 11, 479 (2020).

    Article  PubMed  PubMed Central  Google Scholar 

  77. Newman, R. H., Davies, L. M. & Harris, P. J. Solid-state 13C nuclear magnetic resonance characterization of cellulose in the cell walls of Arabidopsis thaliana leaves. Plant Physiol. 111, 475–485 (1996).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  78. Hill, J. L. Jr., Hammudi, M. B. & Tien, M. The Arabidopsis cellulose synthase complex: a proposed hexamer of CESA trimers in an equimolar stoichiometry. Plant Cell 26, 4834–4842 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  79. Zhang, X. et al. Cellulose synthase stoichiometry in aspen differs from Arabidopsis and Norway spruce. Plant Physiol. 177, 1096–1107 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  80. Purushotham, P. et al. A single heterologously expressed plant cellulose synthase isoform is sufficient for cellulose microfibril formation in vitro. Proc. Natl Acad. Sci. USA 113, 11360–11365 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  81. Alkadri, A. et al. Relationships between anatomical and vibrational properties of wavy sycamore maple. IAWA J. 39, 63–86 (2018).

    Article  Google Scholar 

  82. Viala, R., Placet, V. & Cogan, S. Simultaneous non-destructive identification of multiple elastic and damping properties of spruce tonewood to improve grading. J. Cult. Herit. 42, 108–116 (2020).

    Article  Google Scholar 

  83. Wang, S. et al. Structural characterization and pyrolysis behavior of cellulose and hemicellulose isolated from softwood Pinus armandii Franch. Energy Fuels 30, 5721–5728 (2016).

    Article  CAS  Google Scholar 

  84. Hirata, K. et al. Achievement of protein micro-crystallography atSPring-8 beamline BL32XU. J. Phys. Conf. Ser. 425, 012002 (2013).

  85. Glaeser, R. et al. Characterization of conditions required for X-ray diffraction experiments with protein microcrystals. Biophys. J. 78, 3178–3185 (2000).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  86. Kim, H. J., Liu, Y., French, A. D., Lee, C. M. & Kim, S. H. Comparison and validation of Fourier transform infrared spectroscopic methods for monitoring secondary cell wall cellulose from cotton fibers. Cellulose 25, 49–64 (2017).

    Article  CAS  Google Scholar 

  87. Duchemin, B. et al. Ultrastructure of cellulose crystallites in flax textile fibres. Cellulose 19, 1837–1854 (2012).

    Article  CAS  Google Scholar 

  88. Guo, J., Rennhofer, H., Yin, Y. & Lichtenegger, H. C. The influence of thermo-hygro-mechanical treatment on the micro- and nanoscale architecture of wood cell walls using small- and wide-angle X-ray scattering. Cellulose 23, 2325–2340 (2016).

    Article  CAS  Google Scholar 

  89. Park, S., Baker, J. O., Himmel, M. E., Parilla, P. A. & Johnson, D. K. Cellulose crystallinity index: measurement techniques and their impact on interpreting cellulase performance. Biotechnol. Biofuels 3, 10 (2010).

    Article  PubMed  PubMed Central  Google Scholar 

  90. Paredes, J. J., Mills, R., Howell, C., Shaler, S. M. & Heiningen, A. V. Surface characterization of red maple strands after hot water extraction. Wood Fiber Sci. 41, 38–50 (2009).

    CAS  Google Scholar 

  91. Newman, R. H., Ha, M. A. & Melton, L. D. Solid-state 13C NMR investigation of molecular ordering in the cellulose of apple cell walls. J. Agric. Food Chem. 42, 1402–1406 (1994).

    Article  CAS  Google Scholar 

  92. Newman, R. H. & Condron, L. M. Separating subspectra from cross-polarization magic-angle spinning nuclear magnetic resonance spectra by proton spin relaxation editing. Solid State Nucl. Magn. Reson. 4, 259–266 (1995).

    Article  CAS  PubMed  Google Scholar 

  93. Massiot, D. et al. Modelling one-and two-dimensional solid-state NMR spectra. Magn. Reson. Chem. 40, 70–76 (2002).

    Article  CAS  Google Scholar 

  94. Mori, T. et al. Exploring the conformational space of amorphous cellulose using NMR chemical shifts. Carbohydr. Polym. 90, 1197–1203 (2012).

    Article  CAS  PubMed  Google Scholar 

  95. Kono, H. et al. CP/MAS 13C NMR study of cellulose and cellulose derivatives. 1. Complete assignment of the CP/MAS 13C NMR spectrum of the native cellulose. J. Am. Chem. Soc. 124, 7506–7511 (2002).

    Article  CAS  PubMed  Google Scholar 

  96. Teeäär, R., Serimaa, R. & Paakkarl, T. Crystallinity of cellulose, as determined by CP/MAS NMR and XRD methods. Polym. Bull. 17, 231–237 (1987).

    Article  Google Scholar 

  97. Meier, B. H. Cross polarization under fast magic angle spinning: thermodynamical considerations. Chem. Phys. Lett. 188, 201–207 (1992).

    Article  CAS  Google Scholar 

  98. Massiot, D. et al. Modelling one- and two-dimensional solid-state NMR spectra. Magn. Reson. Chem. 40, 70–76 (2002).

    Article  CAS  Google Scholar 

  99. Newville, M., Stensitzki, T., Allen, D. B. & Ingargiola, A. LMFIT: non-linear least-square minimization and curve-fitting for Python. Zenodo https://doi.org/10.5281/zenodo.11813 (2014).

  100. Kline, S. R. Reduction and analysis of SANS and USANS data using IGOR Pro. J. Appl. Crystallogr. 39, 895–900 (2006).

    Article  CAS  Google Scholar 

  101. Kline, S. R. SANS model function documentation. GitHub https://github.com/sansigormacros/docs/blob/main/SANS_Model_Docs.pdf (2012).

  102. Jakob, H., Tschegg, S. & Fratzl, P. Hydration dependence of the wood-cell wall structure in Picea abies. A small-angle X-ray scattering study. Macromolecules 29, 8435–8440 (1996).

    Article  CAS  Google Scholar 

  103. Penttilä, P. A. et al. Water-accessibility of interfibrillar spaces in spruce wood cell walls. Cellulose 28, 11231–11245 (2021).

    Article  Google Scholar 

  104. Chen, P. et al. Small angle neutron scattering shows nanoscale PMMA distribution in transparent wood biocomposites. Nano Lett. 21, 2883–2890 (2021).

    Article  PubMed  PubMed Central  Google Scholar 

  105. Kang, X. et al. Lignin–polysaccharide interactions in plant secondary cell walls revealed by solid-state NMR. Nat. Commun. 10, 347 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  106. Glatter, O. & Kratky, O. Small-Angle X-Ray Scattering (Academic Press, 1981).

  107. Hallac, B. B. & Ragauskas, A. J. Analyzing cellulose degree of polymerization and its relevancy to cellulosic ethanol. Biofuel. Bioprod. Biorefin. 5, 215–225 (2011).

    Article  CAS  Google Scholar 

  108. Pettersen, R. C. in The Chemistry of Solid Wood (ed Rowell, R.) 57–126 (American Chemical Society, 1984).

Download references

Acknowledgements

We thank I. Burgert and Y. Nishiyama for useful manuscript discussions. We thank K. W. Tong, S. Chiao, B.-T. Lee, D. Lu and Y.-H. Chu for providing wood samples. We thank National Synchrotron Radiation Research Center, Taiwan, for the provision of beamtime at TPS-BL13A, TLS-BL23A and TLS-BL01C2 endstations. We thank U.-S. Jeng for assistance with SAXS measurements. We thank the NTU-AMS Laboratory for radiocarbon dating and NTU Instrument Center for NMR measurements. This research received no external funding.

Author information

Authors and Affiliations

Authors

Contributions

C.H.C. and J.H.L. were involved in methodology, investigation and formal analysis. W.C. undertook conceptualization, methodology and resources. S.J.H. contributed to investigation and formal analysis. Q.Y.L., E.C.Y.Y. and S.L.L. were involved in investigation, software and formal analysis. Y.C.J.L. contributed to conceptualization. J.C.C.C., C.S.T. and H.C.T. undertook conceptualization, methodology, formal analysis and writing.

Corresponding authors

Correspondence to Hwan-Ching Tai, Jerry Chun Chung Chan or Cheng-Si Tsao.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Plants thanks James Kubicki, Nayomi Plaza and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 SAXS fitting models.

(a) The SAXS intensities of dry maple samples (ambient humidity) and fully wetted samples, together with model-fitted intensities based on circular cylinders with 1.1 nm radius and finite lengths. (b) Previous wood SAXS studies modelled CMFs as infinitely long cylinders16,21,25,40,41,42,43,44, which was equivalent to the 2D scattering model of hard discs, and the fitted diameter (D) was misinterpreted as CMF width. (c) Porod analysis for maple SAXS profile showing a smooth interface in the high-q region. (d) The SAXS profiles calculated by Eq. (1) based on different radii, in comparison with those calculated by Eq. (2) based on the same radius but different lengths. (e) This study considers the 3D scattering model of CMFs with core-shell structures and finite lengths (L). Three models are considered: circular cylinders (CYL), rectangular parallelepipeds (PARA), and elliptical cylinders (ELL). The crystalline-ordered core is shown in red and semidisordered shell in white. The cross-sectional aspect ratio is defined as x:y or A:B.

Extended Data Fig. 2 SAXS analyses of Chinese fir and catalpa wood.

The SAXS patterns of Chinese fir is shown in (a), and the curve fitting results with CYL, ELL, and PARA models are shown in (ce). Corresponding results for catalpa are shown in (b) and (fh). Sample size: three trees per species and three locations per tree were measured, n = 9.

Extended Data Fig. 3 PSRE analyses of Chinese fir and catalpa wood.

13C{1H} cross-polarization spectrum of Chinese fir (a) and catalpa (b), separated into subspectrum A for cellulosic components and subspectrum B for non-cellulosic components using the PSRE method. The deconvolution of subspectrum A are shown for Chinese fir (c) and catalpa (d). Four trees per species were measured.

Extended Data Fig. 4 Pulse sequence of the GIFTED experiment.

The filled rectangle denotes a \(\pi /2\) pulse. The spin-locking duration (\({\tau }_{{\rm{SL}}}\)) was systematically varied in the range of 0.3 to 20 ms, whereas the CP contact time was fixed at 2 ms.

Extended Data Fig. 5 NMR spectral deconvolution.

Deconvolution of reference compounds of Avicel cellulose (a), extracted spruce hemicellulose (b), and extracted maple hemicellulose (c). For (b) and (c), only the peaks inside the dashed boxes were taken for the subsequent analyses of the spruce and maple GIFTED spectra.

Extended Data Fig. 6 Optimization of NMR parameters for GIFTED experiments.

(a) 13C{1H} CPMAS spectra of spruce acquired with the recycle delay (rd) of 3 and 10 s. (b) 13C{1H} CPMAS spectra of spruce acquired with contact times (\({\tau }_{{\rm{CP}}})\) equal to 1, 2, and 3 ms. (c) 13C{1H} CPMAS spectra of spruce with spinning frequency (\({\nu }_{{\rm{S}}}\)) at 10 and 15 kHz. The spectrum in red was scaled up by 1.5 times for comparison.

Extended Data Fig. 7 Optimization of spin-locking conditions.

(a) 13C{1H} CPMAS spectrum of 13C-labelled bacterial cellulose. The experimental spectrum (black) was deconvoluted, where the spectral components were shown in dashed lines, and their sum was shown in green. (b) \({T}_{1\rho }\) dispersion of 13C-labelled bacterial cellulose under spin-locking field B1,SL 30, 50, and 70 kHz. The colours of dashed lines were consistent with those in (a). (TC: total cellulose, CC: crystalline cellulose, SC: semidisordered cellulose).

Extended Data Fig. 8 GIFTED spin-locking spectra.

\({T}_{1\rho }\)-edited 13C{1H} CPMAS (GIFTED) spectra of spruce (a) and maple (b) at various spin-locking durations. Spectra on the right-hand side were scaled up to match the intensity at 89.0 ppm to compare relative intensity difference. Spectral components of cellulose are labelled in green, and non-cellulose labelled in orange. The peak positions of hemicellulose in the region of 50–105 ppm are indicated by orange arrows. Different intensity attenuations were observed, especially the non-cellulose spectral components. (TC: total cellulose, CC: crystalline cellulose, SC: semidisordered cellulose, H: hemicellulose, L: lignin).

Extended Data Fig. 9 XRD analyses of Chinese fir and catalpa wood.

XRD patterns of Chinese fir (a) and catalpa (b), with peak deconvolution analyses in (c) and (d), respectively. Four trees per species were measured.

Extended Data Fig. 10 SAXS analyses of artificially aged spruce and maple wood.

SAXS profile comparisons for untreated spruce and spruce treated with KOH, Ca(OH)2, and hot water are shown in (a). The mean and standard deviation are plotted for cross-section areas (b) and cross-section aspect ratios (c). Sample size: untreated n = 9 (three location form three trees) and treated n = 3 (three locations per tree). The p values are calculated using two-tailed Welch’s t-test against untreated controls. (d) The mean and standard deviation are plotted for crystallite widths along the directions of (110), (1–10), and (200) (untreated n = 5, treated n = 1).

Source data

Supplementary information

Supplementary Information

Supplementary Tables 1–5.

Reporting Summary

Supplementary Code

GIFTED fitting code.

Source data

Source Data Fig. 2

Statistical source data.

Source Data Fig. 5

Statistical source data.

Source Data Fig. 6

Statistical source data.

Source Data Extended Data Fig. 10

Statistical source data.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tai, HC., Chang, CH., Cai, W. et al. Wood cellulose microfibrils have a 24-chain core–shell nanostructure in seed plants. Nat. Plants 9, 1154–1168 (2023). https://doi.org/10.1038/s41477-023-01430-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41477-023-01430-z

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing