Lignin is one of the major substance in the world. This slide presented lignin, role in the plant, biosynthesis, lignin evolution, and bioengineering or lignin.

1. LIGNIN
A Twenty-first Century Challenge
Isroi (http://isroi.com)
BIOMASS RECALCITRANE

2. Cell Wall Model: Cellulose, Hemicellulose
and Lignin

3. Cell Wall Model: Cellulose, Hemicellulose
and Lignin

4. Cell Wall Model: Cellulose, Hemicellulose
and Lignin

5. Pseudocolor SEM micrograph of lignin redeposited on cellulose (10,000X).
www.nrel.gov/.../technology.cfm/tech=18

7. Lignin:
• Nature’s second abundant organic
substances
• Product of phenylpropanoid
pathway
• Lignin – monolignol/lignin-forming
pathway steps evolved during
transition (evolution) of plants from
the water habitat to the land
habitat.

8. Plant evolution
LIGNIN: Moleculer Basis and role in plant adaptation

9. Diagram showing changes in cell wall
composition during the course of
evolution.
Sarkar P et al. J. Exp. Bot. 2009;60:3615-3635
© The Author [2009]. Published by Oxford University Press [on behalf of the Society for Experimental Biology]. All rights
reserved. For Permissions, please e-mail: journals.permissions@oxfordjournals.org

10. Sarkar P et al. J. Exp. Bot. 2009;60:3615-3635

11. Figure 3. Phylogenetic tree
showing the distribution of
lignin monomer composition
across major lineages. *, S-
units are only found in cell
cultures of Ginkgo, not in wood
(Novo Uzal et al., 2009). **,
Lignin-like structures are
reported in some mosses and
green algae, but the presence of
real lignin in these nonvascular
species remains questionable;
red algae have been barely
studied (Weng et al., 2008b;
Martone et al., 2009).
Vanholme R. et.al. Plant Physiol. 2010:153:895-905
Copyright © 2010. © 2010 American Society of Plant Biologists. All rights reserved.
LIGNIN: Moleculer Basis and role in plant adaptation

12. Red Seaweed
Like many land plants, this red seaweed produces lignin, a
primary component of wood. (Credit: Kathy Ann Miller)

13. http://www.science20.com/news_releases/biofuels_research_makes_a_plant_evolution_discovery
Selaginela

14. Selaginela
http://esciencenews.com/
Both lignin and cellulose are found in the rigid cell walls of the xylem cells (those that conduct
water) in the primitive plant, Selaginella. (Credit: Zina Deretsky, National Science Foundation;
Selaginella cross section SEM by Jing-Ke Weng, Clint Chapple, Purdue University; Lignin
structure from Wout Bergjan, John Ralph, Marie Baucher (Annual Review of Plant Biology, Vol.
54:519-546, June 2003); Cellulose structure from http://www.chusa.jussieu.fr/disc/bio_cell/)

15. Fossil Ginkgo leaves from the Jurassic of
England. Some 160 million years ago.
Modern Ginkgo leaves.

16. Corn Stover

17. Wood
http://siteresources.worldbank.org

18. Softwood Hardwood
• Larger, longer cells
• Water transported by cells
• Contains large-diameter vessels
• Water transported by these vessels

19. Lignin: Major monolignols of lignins.
Hatfield R., Vermerris W. Plant Physiol. 2001:126:1351-1357
H-unit
P-hydroxyphenyl
G-unit
guaiacyl
S-unit
syringyl

20. Lignin: Major monolignols of lignins.
(A) Monolignol esters 30-32 found in grasses.
(D) Several dominant
substructures present in
native lignins.

21. Lignin Structure:
Freudenbrerg (1965)

22. Brunow et al. 1998
Lignin Structure:

23. Lignin Structure:

24. Lignin Biosynthesis Pathway

25. Lignin Pathway Evolution
Humphreys, J. M., C. C. S. Chapple. 2002. Rewriting the lignin roadmap. Plant Bio. 5, 224–229.

26. Lignin Pathway Evolution
Humphreys, J. M., C. C. S. Chapple. 2002. Rewriting the lignin roadmap. Plant Bio. 5, 224–229.

27. Vascular Plant Diversification and Lignification

28. Vascular Plant Diversification and Lignification
Pinus taeda
Medicago sativa

29. Vascular Plant Diversification and Lignification

30. Loblolly pine
(Pinus taeda)

32. Tamarack (Larix laricina) Ebony (Diospyros ebenum)
Douglas fir
compression
normal
Black cottonwood
tension
normal

33. Monilignol Biosynthesis

34. 7.3.2
Monilignol Biosynthesis

35. 7.3.3
Monilignol Biosynthesis

36. 7.3.4
Monilignol Biosynthesis

37. 7.3.5
Monilignol Biosynthesis

38. 7.3.6
Monilignol Biosynthesis

39. 7.3.7
Monilignol Biosynthesis

40. 7.3.8
Monilignol Biosynthesis

41. http://aob.oxfordjournals.org/content/91/6/673/F3.expansion
Monilignol Biosynthesis

42. Inherent Shortcomings in lignin analyses: a critical juncture and
the urgent need
Lignin Isolation Procedure:
• Strong acid (sulphite pulping proceses)
• Strong alkaline (kraft pulping)
• Milled wood lignin
• Björkman lignin

43. Figure 2. Representation of a lignin polymer from poplar, as predicted from NMR-based lignin
analysis (adapted from Stewart et al., 2009).
Vanholme R. et.al. Plant Physiol. 2010:153:895-905
Copyright © 2010. © 2010 American Society of Plant Biologists. All rights reserved.
Lignin Structure: Lignin subunit and lignin structural analyses by NMR spectroscopy

44. Quantification of lignin amounts, lignin degradation protocols, and synthetic
dehydropolymerizates
• Klason Lignin
Various non-lignin
componens, such as tannins,
was determined
• Acetyl bromide
• Thioglycolic acid

45. Modulation of monolignol pathway and peroxidase enzymatic
step

53. Lignin, a key component of plant cell
walls, is normally synthesized from
three simple monolignols (top). The
hydroxyl group (OH), shown in red,
must remain unmodified for these
precursors to link up. Liu's team created
a novel enzyme (green "ribbon"
structure) that can methylate this
specific hydroxyl group. This enzyme
may therefore lead to ways to interfere
with lignin biosynthesis in plants to
make them easier to break down for
biofuels.
Chang-Jun Liu

54. Native Lignin Macromolecular Configuration
Freudenbrerg (1965)
1965

55. Lignin Structure: 1970s-1980s

56. Adler (1977)
Lignin Structure:

57. Lignin Structure:
Partial structure of a
hypothetical lignin molecule
from European beech (Fagus
sylvatica ). The phenylpropanoid
units that make up lignin are not
linked in a simple, repeating
way. The lignin of beech
contains units derived from
coniferyl alcohol, sinapyl
alcohol, and para-coumaryl
alcohol in the approximate ratio
100:70:7 and is typical of
angiosperm lignin. Gymnosperm
lignin contains relatively fewer
sinapyl alcohol units. (After
Nimz 1974.)

58. Brunow et al. 1998
Lignin Structure: 1990s and 2000s

59. Figure 2. Representation of a lignin polymer from poplar, as predicted from NMR-based lignin
analysis (adapted from Stewart et al., 2009).
Vanholme R. et.al. Plant Physiol. 2010:153:895-905
Copyright © 2010. © 2010 American Society of Plant Biologists. All rights reserved.
Lignin Structure: Lignin subunit and lignin structural analyses by NMR spectroscopy

60. Future Outlook

61. Future Outlook
1. Monolignol transport to the cell/wall
2. Lignin initiation sites
3. Lignin Primary Sequences/New Chemistries
4. Re-oxidation of the growing lignin chains
5. Monolignol radical and lignin primary chain
interactions, proposed template polymerization,
and lignin association
6. Transcriptional control of individual cell wall
formation processes, biomechanics, and
biodegradation of plant cell walls.

62. Thanks You
Biomass Recalcitrance

63. Alkali nitrobenzene oxidation/thioacidolysis/permanganate
oxidation degradation procedures