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Updated: Mar 27, 2026
05:57
Quantitative 31P NMR Analysis of Lignins and Tannins
Published on: August 2, 2021
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Precursor-Dependent Routing of Aromatic Amino Acids Determines Lignin Structure in Grasses by Sensitivity-Enhanced
Priya Sahu1, Debkumar Debnath1, Peng Xiao1
1Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States.
Journal of the American Chemical Society
|March 26, 2026
Summary
Phenylalanine and tyrosine contribute differently to grass lignin biosynthesis. Tyrosine-derived lignin acts as a compensatory pathway, revealing metabolic plasticity in plant cell walls.
Area of Science:
- Plant biology
- Biochemistry
- Metabolic pathways
Background:
- Lignin biosynthesis in grasses shows metabolic flexibility.
- Precursor-specific carbon routing into lignin polymers is not well understood in plants.
Purpose of the Study:
- To directly track phenylalanine- and tyrosine-derived carbon incorporation into lignin in Brachypodium distachyon.
- To elucidate precursor-specific control over lignin composition and metabolic plasticity.
Main Methods:
- Combined 13C-isotope labeling with dynamic nuclear polarization (DNP)-enhanced solid-state NMR.
- Utilized 2D 13C-13C correlation NMR to resolve distinct lignin moieties.
- Investigated the role of p-coumarate 3-hydroxylase (C3H) in lignification.
Main Results:
- Phenylalanine is the primary source for guaiacyl and syringyl lignins.
- Tyrosine preferentially enriches hydroxyphenyl lignin and ferulates.
- Disruption of C3H impairs phenylalanine-derived lignification but not tyrosine-derived lignification.
- Tyrosine-mediated lignification serves as a compensatory pathway.
Conclusions:
- Lignin composition is under precursor-dependent control in grasses.
- Tyrosine-mediated lignification represents a compensatory metabolic route.
- Precursor-resolved solid-state NMR and DNP provide a powerful framework for studying lignin biosynthesis and plant cell wall plasticity.
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