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The molecular structure of plant sporopollenin

Nature Plants volume 5, pages 41–46 (2019)Cite this article

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Abstract

Sporopollenin is a ubiquitous and extremely chemically inert biopolymer that constitutes the outer wall of all land-plant spores and pollen grains1. Sporopollenin protects the vulnerable plant gametes against a wide range of environmental assaults, and is considered a prerequisite for the migration of early plants onto land2. Despite its importance, the chemical structure of plant sporopollenin has remained elusive1. Using a newly developed thioacidolysis degradative method together with state-of-the-art solid-state NMR techniques, we determined the detailed molecular structure of pine sporopollenin. We show that pine sporopollenin is primarily composed of aliphatic-polyketide-derived polyvinyl alcohol units and 7-O-p-coumaroylated C16 aliphatic units, crosslinked through a distinctive dioxane moiety featuring an acetal. Naringenin was also identified as a minor component of pine sporopollenin. This discovery answers the long-standing question about the chemical make-up of plant sporopollenin, laying the foundation for future investigations of sporopollenin biosynthesis and for the design of new biomimetic polymers with desirable inert properties.

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Fig. 1: Pine sporopollenin preparation and degradative analysis by thioacidolysis.
Fig. 2: Structural characterization of pine sporopollenin by whole-polymer derivatization followed by thioacidolysis.
Fig. 3: 13C solid-state NMR spectra of untreated and treated pine sporopollenin for structure determination.
Fig. 4: Structural model of pine sporopollenin highlighting the major units and linkages elucidated through this study.

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Data availability

The data that support the findings of this study are available from the corresponding author upon request.

References

  1. Kim, S. S. & Douglas, C. J. Sporopollenin monomer biosynthesis in Arabidopsis. J. Plant Biol. 56, 1–6 (2013).

    Article  Google Scholar 

  2. Weng, J.-K., Philippe, R. N. & Noel, J. P. The rise of chemodiversity in plants. Science 336, 1667–1670 (2012).

    Article  CAS  Google Scholar 

  3. Mansfield, S. D., Kim, H., Lu, F. & Ralph, J. Whole plant cell wall characterization using solution-state 2D NMR. Nat. Protoc. 7, 1579–1589 (2012).

    Article  CAS  Google Scholar 

  4. Ahlers, F., Thom, I., Lambert, J., Kuckuk, R. & Wiermann, R. 1H NMR analysis of sporopollenin from Typha angustifolia. Phytochem. 50, 1095–1098 (1999).

    Article  CAS  Google Scholar 

  5. Rolando, C., Monties, B. & Lapierre, C. in Methods in Lignin Chemistry (eds Lin, S. Y. & Carlton, W.) 334–349 (Springer, Berlin, 1992).

  6. Seco, J. M., Quiñoá, E. & Riguera, R. The assignment of absolute configuration by NMR. Chem. Rev. 104, 17–118 (2004).

    Article  CAS  Google Scholar 

  7. Imaizumi, K., Terasima, H., Akasaka, K. & Ohrui, H. Highly potent chiral labeling reagents for the discrimination of chiral alcohols. Anal. Sci. 19, 1243–1249 (2003).

    Article  CAS  Google Scholar 

  8. Ohrui, H. Development of highly potent chiral discrimination methods that solve the problems of diastereomer method. Anal. Sci. 24, 31–38 (2008).

    Article  CAS  Google Scholar 

  9. Ohtaki, T., Akasaka, K., Kabuto, C. & Ohrui, H. Chiral discrimination of secondary alcohols by both 1H-NMR and HPLC after labeling with a chiral derivatization reagent, 2-(2, 3-anthracenedicarboximide) cyclohexane carboxylic acid. Chirality 17, 171–176 (2005).

    Article  Google Scholar 

  10. Zhang, Y.-J., Dayoub, W., Chen, G.-R. & Lemaire, M. Environmentally benign metal triflate-catalyzed reductive cleavage of the C–O bond of acetals to ethers. Green Chem. 13, 2737–2742 (2011).

    Article  CAS  Google Scholar 

  11. Zhang, Y. J., Dayoub, W. & Chen, G. R. TMDS as a dual-purpose reductant in the regioselective ring cleavage of hexopyranosyl acetals to ethers. Eur. J. Org. Chem. 10, 1960–1966 (2012).

    Article  Google Scholar 

  12. Dick-Pérez, M. et al. Structure and interactions of plant cell-wall polysaccharides by two- and three-dimensional magic-angle-spinning solid-state NMR. Biochemistry 50, 989–1000 (2011).

    Article  Google Scholar 

  13. Wang, T., Phyo, P. & Hong, M. Multidimensional solid-state NMR spectroscopy of plant cell walls. Solid State Nucl. Magn. Reson. 78, 56–63 (2016).

    Article  CAS  Google Scholar 

  14. 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  Google Scholar 

  15. Phyo, P. et al. Gradients in wall mechanics and polysaccharides along growing inflorescence stems. Plant Physiol. 175, 1593–1607 (2017).

    Article  CAS  Google Scholar 

  16. Guilford, W. J., Schneider, D. M., Labovitz, J. & Opella, S. J. High resolution solid state C NMR spectroscopy of sporopollenins from different plant taxa. Plant Physiol. 86, 134–136 (1988).

    Article  CAS  Google Scholar 

  17. Mao, J., Cory, R. M., McKnight, D. M. & Schmidt-Rohr, K. Characterization of a nitrogen-rich fulvic acid and its precursor algae from solid state NMR. Org. Geochem. 38, 1277–1292 (2007).

    Article  CAS  Google Scholar 

  18. Mao, J.-D. et al. Abundant and stable char residues in soils: implications for soil fertility and carbon sequestration. Environ. Sci. Technol. 46, 9571–9576 (2012).

    Article  CAS  Google Scholar 

  19. Johnson, R. L. & Schmidt-Rohr, K. Quantitative solid-state 13C NMR with signal enhancement by multiple cross polarization. J. Magn. Reson. 239, 44–49 (2014).

    Article  CAS  Google Scholar 

  20. Kim, S. S., Grienenberger, E. & Lallemand, B. LAP6/POLYKETIDE SYNTHASE A and LAP5/POLYKETIDE SYNTHASE B encode hydroxyalkyl α-pyrone synthases required for pollen development and sporopollenin biosynthesis in Arabidopsis thaliana. Plant Cell 22, 4045–4066 (2010).

    Article  CAS  Google Scholar 

  21. Grienenberger, E. et al. Analysis of TETRAKETIDE α-PYRONE REDUCTASE function in Arabidopsis thaliana reveals a previously unknown, but conserved, biochemical pathway in sporopollenin monomer biosynthesis. Plant Cell 22, 4067–4083 (2010).

    Article  CAS  Google Scholar 

  22. Rasouli, M., Ostovar-Ravari, A. & Shokri-Afra, H. Characterization and improvement of phenol-sulfuric acid microassay for glucose-based glycogen. Eur. Rev. Med. Pharmacol. Sci. 18, 2020–2024 (2014).

    CAS  PubMed  Google Scholar 

  23. Mao, J. D. & Schmidt-Rohr, K. Accurate quantification of aromaticity and nonprotonated aromatic carbon fraction in natural organic matter by 13C solid-state nuclear magnetic resonance. Environ. Sci. Technol. 38, 2680–2684 (2004).

    Article  CAS  Google Scholar 

  24. Mao, J.-D. & Schmidt-Rohr, K. Methylene spectral editing in solid-state 13C NMR by three-spin coherence selection. J. Magn. Reson. 176, 1–6 (2005).

    Article  CAS  Google Scholar 

  25. Liu, R., He, B. & Chen, X. Degradation of poly(vinyl butyral) and its stabilization by bases. Polym. Degrad. Stab. 93, 846–853 (2008).

    Article  CAS  Google Scholar 

  26. Weng, J.-K. & Chapple, C. The origin and evolution of lignin biosynthesis. New Phytol. 187, 273–285 (2010).

    Article  CAS  Google Scholar 

  27. Hayatsu, R., Botto, R. E., McBeth, R. L., Scott, R. G. & Winans, R. Chemical structure of a sporinite from a lignite: comparison with a synthetic sporinite transformed from sporopollenin. Prepr. Pap. Am. Chem. Soc. Div. Fuel Chem. 32, 1–8 (1987).

    CAS  Google Scholar 

  28. Dobritsa, A. A. et al. CYP704B1 is a long-chain fatty acid ω-hydroxylase essential for sporopollenin synthesis in pollen of Arabidopsis. Plant Physiol. 151, 574–589 (2009).

    Article  CAS  Google Scholar 

  29. Morant, M. et al. CYP703 is an ancient cytochrome P450 in land plants catalyzing in-chain hydroxylation of lauric acid to provide building blocks for sporopollenin synthesis in pollen. Plant Cell 19, 1473–1487 (2007).

    Article  CAS  Google Scholar 

  30. Austin, M. B. & Noel, J. P. The chalcone synthase superfamily of type III polyketide synthases. Nat. Prod. Rep. 20, 79–110 (2003).

    Article  CAS  Google Scholar 

  31. De Azevedo Souza, C. et al. A novel fatty Acyl-CoA Synthetase is required for pollen development and sporopollenin biosynthesis in Arabidopsis. Plant Cell 21, 507–525 (2009).

    Article  Google Scholar 

  32. Shibuya, T., Funamizu, M. & Kitahara, Y. Novel p-coumaric acid esters from Pinus densiflora pollen. Phytochemistry 17, 979–981 (1978).

    Article  CAS  Google Scholar 

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Acknowledgements

This work was supported by the Pew Scholar Program in the Biomedical Sciences (J.-K.W.) and the Searle Scholars Program (J.-K.W.). The solid-state NMR part of this work (by P.P. and M.H.) was supported by the Center for Lignocellulose Structure and Formation, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Basic Energy Sciences under award number DE-SC0001090.

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Authors and Affiliations

  1. Whitehead Institute for Biomedical Research, Cambridge, MA, USA

    Fu-Shuang Li, Joseph Jacobowitz & Jing-Ke Weng

  2. Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA

    Pyae Phyo & Mei Hong

  3. Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA

    Joseph Jacobowitz & Jing-Ke Weng

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  1. Fu-Shuang Li
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  2. Pyae Phyo
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  5. Jing-Ke Weng
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Contributions

F.-S.L. and J.-K.W. designed the research. F.-S.L. developed thioacidolysis and pretreatment methods for studying sporopollenin, and carried out structural elucidation of all degradative products. P.P. performed SSNMR experiments. J.J. performed electron microscopy imaging. F.-S.L, P.P., M.H. and J.-K.W. interpreted the results and wrote the paper.

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Correspondence to Jing-Ke Weng.

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Supplementary Information

Supplementary Notes 1–3, Supplementary Methods, Supplementary Figures 1–39, Supplementary Tables 1–5, Supplementary NMR data and Supplementary References.

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Li, FS., Phyo, P., Jacobowitz, J. et al. The molecular structure of plant sporopollenin. Nature Plants 5, 41–46 (2019). https://doi.org/10.1038/s41477-018-0330-7

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