CHARACTERISATION OF LIGNIN AND CELLULOSE

GENES IN BIOMASS AND ENERGY GRASSES

(POACEAE)

VISHNU MOHANAN

TREVOR HODKINSON, SUSANNE BARTH, NICOLAS SALAMIN, ELIZABETH

KELLOGG

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

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

Dendrocalamus Fargesia

Woody grasses are common in some groups eg.

bamboos - Bambusoids

Zea (maize) Saccharum officinarum

Panicoids are a mix of woody and non woody forms

including sugarcane, maize, Miscanthus & sorghum

Salamin, Hodkinson, Savolainen. 2002

Assess

lignocellulose

evolution across

the BEP clade

BAMBOOS - INTERESTING EVOLUTIONARY

HISTORY

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

METHODS

Identify genes and gene families using exhaustive

search – GenBank

Target sequences for primer development

(Geneious)

Use primers for sequencing fresh material

Phylogenetic analyses

GENEIOUS

Lignin • PAL

• C4H

• 4CL

• HCT

• CCOAMT

• CCR

• F5H

• COMT

• CAD

Creating database of lignin and cellulose genes

GENEIOUS

Lignin • PAL

• C4H

• 4CL

• HCT

• CCOAMT

• CCR

• F5H

• COMT

• CAD

Creating database of lignin and cellulose genes

PHYLOGENETIC RECONSTRUCTION OF GENES

Reconstruct gene trees

Assess appearances (of forms)

Assess convergence in genes

Test for positive selection

Assess co-evolution of genes

LIGNIN/CELLULOSE QUANTIFICATION

NIRS method to measure

lignin, cellulose and

hemicellulose

H,G and S cinnamyl

alcohols

Herbarium specimens

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.