Molecular Genetic Basis for Variation in Lignocellulosic
Biomass Composition in Shrub Willow (Salix spp.)
Bioenergy Crops
Michelle J. Serapiglia1, Art Stipanovic2, Kim Cameron1, and Larry Smart1
1Department of Horticulture, Cornell University,
2Department of Chemistry, SUNY College
New York State Agricultural Experiment Station, Geneva, NY
of Environmental Science and Forestry, Syracuse, NY
Biomass Conversion to Energy
Combustion
Densification
(pellets/briquettes)
Gasification
Pyrolysis
Fermentation
Methods for rapid biomass characterization
Polymer
Cellulose
Hemicellulose
Lignin
% Composition in Wood
30-50%
15-30%
20 -30%
Somerville CR, et al (2004) Science 306: 2206-2211
Biomass Characterization
Traditional Wet Chemical Analysis
Time consuming – at least 2 days
Harsh chemicals
TAPPI methods
Advanced Instrumental Analysis
Fast – 1.5 hours or less
No chemicals
FT-IR, FT-NIR, PyMBMS, TGA
TA instruments
Regression Analysis
Regression Analysis
Regression Analysis
1999 Progeny Families
9970
99202
99217
99239
Cellulose
HR-TGA Analysis of
Biomass
Composition of 18
Varieties Harvested
at Belleville and
Tully, NY
composition is
significantly different by
variety
% cellulose varies by
site
% cellulose content was
correlated to density
measurements.
Hemicellulose
Lignin
Density Between Belleville and Tully
Harvest Age, Stem
Diameter, and Bark
Composition
Harvest age – years after
coppice
Growth habit of willow
clone – small diameter
stems
Harvest Age – Years
After Coppice
Average cellulose content
was lower in one-year post
coppice stems.
Average lignin content was
higher in one-year post
coppice stems.
% Bark Content
Compositional Impact of Bark
Cellulose
Compositional Impact of Bark
Lignin
Molecular Genetic Basis for
Compositional Variation
Buchanan, Gruissem, & Jones (2000)
CelluloseA
Biomass Composition of
9970 Family and Parents
(S. sachalinensis SX61 x
S. miyabeana SX64)
Hemicellulose
Composition differs
significantly among progeny
Lignin
Young shoot tip of S.
sachalinensis x
S. miyabeana
Shoot apex tissue – 5 cm
from tip down, including
immature unfolded leaves
Young stem tissue – 5 to
12 cm down from the tip.
Shoot Apex
Tissue
Young Stem
Tissue
Phenylpropanoid metabolism
p-coumaric
acid
C3H Caffeic COMT
Acid
4CL
p-coumaroylCoA
4CL
C3H
CCR
p-coumaraldehyde
CAD
p-coumaryl
Alcohol
Ferulic
Acid
F5H
5-Hydroxy
ferulic acid
COMT
Sinapic
acid
4CL
4CL
Caffeoyl- CCoAOMT Feruloyl- F5H
CoA
CoA
CCR
5-Hydroxy CCoAOMT Sinapoylferuloyl CoA
CoA
CCR
F5H
Coniferaldehyde
5-Hydroxy
Coniferaldehyde
COMT Sinapaldehyde
CAD
CAD
Coniferyl F5H
Alcohol
CCR
5-Hydroxy
Coniferl
Alcohol
COMT Sinapyl
Alcohol
UDP-Glucose metabolism
Cellulose synthase (at least 7)
Cellulose
UDP-Glucose
UDP-glucose
dehydrogenase
C-4 epimerase
UDP-Glucuronic Acid
UDP-GA
decarboxylase
CO2
UDP-Xylose
UDP-Galactose
Glycosyltransferases
(families 8, 14, 47A,B,C)
Glucuronoxylan
C-4 epimerase
UDP-galactose
dehydrogenase
UDP-L-arabinose
UDP-GA 4-epimerase
UDP-Galacturonic Acid
α-1,4-Galacturonosyltransferase
and over 40 other GTs
Pectin
UDP-GD
Differential expression
among progeny and
tissue type
Functional analysis
Statistical correlations to
phenotype
UDP-GD apex
expression has a strong
positive correlation to
lignin content (R2 =
0.75, α = 0.031)
- Stem
Glycosyltransferase
Gene Expression
Apex
Stem
GT8
CesA3
Cellulose
Synthase Gene
Expression
Differential expression
among progeny and
tissue type
Potential primary and
secondary cell wall
genes
Strong negative
correlations to lignin and
positive correlations to
cellulose
PtiCesA3 - 2° cell wall
A. thaliana ortholog
Apex
Stem
CesA7
Macrosynteny to Poplar
Salicaceae family
P. trichocarpa genome and the
“salicoid duplication”
European research with Salix
viminalis - linkage maps and
comparative genomics with P.
trichocarpa
Gene order conservation
between species –
microsatellites and QTLs
Genomic Evidence for Divergence of
the Two Genera
Salix = 300 species / Populus = 32
species
Growth habit
Heterozygosity and ploidy levels
(2n=38)
Future Directions for Willow Breeding
and Genomics
Sequencing of the Salix purpurea genome – 454 and
Illumina sequencing and BAC libraries
Transcriptome analysis – EST database
Mapping populations –SNPs and microsatellites
Whole genome selection – yield,
composition, pest and disease
resistance, nitrogen-use efficiency
Phylogenetic studies – divergence
within willow - MatK and ITS
Acknowledgements
Dr. Bill Winter
Dr. Larry Abrahamson
Dr. Tim Volk
Dr. Ed White
Dr. Larry Walker
Dr. Stephane Corgie
Dr. Bill Powell
http://willow.cals.cornell.edu/
McIntireStennis
Cooperative
Forestry
Research
Program
Edna Bailey Sussman
Foundation /Dorothy
Bertine Internship
Josiah Lowe and
Hugh Wilcox
Graduate Scholarship
Award