1. CHARACTERISATION OF LIGNIN AND CELLULOSE
GENES IN BIOMASS AND ENERGY GRASSES
(POACEAE)
VISHNU MOHANAN
TREVOR HODKINSON, SUSANNE BARTH, NICOLAS SALAMIN, ELIZABETH
KELLOGG

2. BIOENERGY GRASSES
Biomass for bioenergy and
fibre production –up to 40
tonnes per hectare
BP –Bioenergy institute –USA
Bioenergy – bioethanol or
direct combustion
Low carbon or carbon
neutral alternatives to
petroleum

3. GRASSES AS BIOMASS
 Lignocellulosic biomass highly
recalcitrant to bioconversion
 Presence of lignin impedes pretreatment
making the process expensive
 Lignin Genes (10)
 CELLULOSE Gene families unique to
grasses
 Cellulose synthase-like (Csl)
 Gene families unique to Poales
 CslF
 Understanding the evolution of
lignocellulosic biosynthesis and gene
families is key

4. Dendrocalamus Fargesia
Woody grasses are common in some groups eg.
bamboos - Bambusoids

5. Zea (maize)Saccharum officinarum
Panicoids are a mix of woody and non woody forms
including sugarcane, maize, Miscanthus & sorghum

6. Salamin, Hodkinson, Savolainen. 2002

7. Assess
lignocellulose
evolution across
the BEP clade
BAMBOOS - INTERESTING EVOLUTIONARY
HISTORY

8. OBJECTIVES
 Evolution of genes/gene families important in
woodiness in grasses
 CELLULOSE: CslH, CslJ, CslF etc
 LIGNIN: CAD, COMT, CCR
 Effects of woodiness on grass evolution
 Whether it was a significant innovation for
speciation and diversification

9. METHODS
 Identify genes and gene families using exhaustive
search – GenBank
 Target sequences for primer development
(Geneious)
 Use primers for sequencing fresh material
 Phylogenetic analyses

10. GENEIOUS
 Lignin
• PAL
• C4H
• 4CL
• HCT
• CCOAMT
• CCR
• F5H
• COMT
• CAD
 Creating database of lignin and cellulose genes

11. GENEIOUS
 Lignin
• PAL
• C4H
• 4CL
• HCT
• CCOAMT
• CCR
• F5H
• COMT
• CAD
 Creating database of lignin and cellulose genes

12. PHYLOGENETIC RECONSTRUCTION OF GENES
 Reconstruct gene trees
 Assess appearances (of forms)
 Assess convergence in genes
 Test for positive selection
 Assess co-evolution of genes

13. LIGNIN/CELLULOSE QUANTIFICATION
 NIRS method to measure
lignin, cellulose and
hemicellulose
 H,G and S cinnamyl
alcohols
 Herbarium specimens

14. EFFECTS OF WOODINESS ON GRASS EVOLUTION
Effects of woodiness on grass evolution
Character reconstruction and diversification studies on
large phylogenetic trees
Whether it was a significant innovation for speciation
and diversification
Dating of woody trait evolution and diversification
statistics.