Evidence for Covalent Complexes Between Lignin and Pectin in Plant Cell Walls

March 27, 2024
SANS of a lignin – homogalacturonan (pectin) composite at the contrast match points for pectin (40% D2O, brown curve) and d5-lignin (80% D2O, yellow curve). Inset schematic depictions of match points: lignin-brown particles, pectin-orange chains.

Scientific Achievement

Evidence for lignin–carbohydrate complexes (LCCs) formed between lignin and pectin was obtained by synthesis and biophysical characterization of deuterated lignin–pectin composites.

Significance and Impact

Engineered plants with reduced pectin exhibit lower recalcitrance towards conversion to biofuels. This work shows that interactions between pectin and lignin may explain this pectin knockdown effect.

Research Details

  • Partially deuterated d5-coniferyl alcohol was synthesized at the Center for Nanoscale Material Science at ORNL.
  • Coniferyl alcohol was polymerized to lignin in vitro in the presence of the pectin homogalacturonan to form composites.
  • Composites characterized by SANS, FTIR, solid-state NMR and SAXS, and compared with native and pectin-deficient switchgrasses.

Katie L. Browning, Andrew S. Westover, James F. Browning, Mathieu Doucet, Robert L. Sacci, and Gabriel M. Veith,
“In Situ Measurement of Buried Electrolyte–Electrode Interfaces for Solid State Batteries with Nanometer Level Precision,”
ACS Energy Lett. (2023), 8, 4, 1985–1991, doi:10.1021/acsenergylett.3c00488