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Fungi, ecosystems, and global change
Kathleen K Treseder, University of California Irvine
Fungi drive many ecosystem dynamics
Decomposition
CO2
Soil C storage
Ophis
CO2 NYBG
Improve plant growth
CO2
Fungal feedbacks on global change
Fungi
Ecosystem function
Global change
Drought
Fungal groups
Soil C storage
Climate change
Possible scenario
+
?
?
?
The Challenge
Microbes to Ecosystems
Soil carbon stocks
r2: 0.06–0.39
Empirical measurements Model estimates
Todd-Brown et al. 2013, Biogeosciences
40+
0
10
20
30
kg m-2
Harmonized World Soil Database
The Challenge
Microbes to Ecosystems
The Challenge
Genes to Ecosystems
Transformative technology
RFLP – Hinf I
Transformative technology
RFLP – Hinf I
02,000,0004,000,0006,000,0008,000,00010,000,00012,000,00014,000,00016,000,00018,000,000
2000 2005 2010 2015
RFLP
Base pairs per study
Transformative technology
RFLP – Hinf I
02,000,0004,000,0006,000,0008,000,00010,000,00012,000,00014,000,00016,000,00018,000,000
2000 2005 2010 2015
Sanger RFLP
Base pairs per study
Transformative technology
RFLP – Hinf I
02,000,0004,000,0006,000,0008,000,00010,000,00012,000,00014,000,00016,000,00018,000,000
2000 2005 2010 2015
Sanger RFLP
Microarray
Base pairs per study
Transformative technology
RFLP – Hinf I
02,000,0004,000,0006,000,0008,000,00010,000,00012,000,00014,000,00016,000,00018,000,000
2000 2005 2010 2015
RFLP
Microarray
454
Base pairs per study
Sanger
Transformative technology
RFLP – Hinf I
02,000,0004,000,0006,000,0008,000,00010,000,00012,000,00014,000,00016,000,00018,000,000
2000 2005 2010 2015
RFLP
Microarray
454
Base pairs per study
Sanger
Illumina
Evolutionary histories of fungi
Treseder, K. K., M. R. Maltz, B. A. Hawkins, N. Fierer, J. E. Stajich, and K. L. McGuire. 2014. Evolutionary histories of soil fungi are reflected in their large-scale biogeography. Ecology Letters 17 (9): 1086-1093.
Current distributions of fungi
Older phyla
Younger phyla
Treseder et al. 2014, Ecology Letters
Cryp
to
Chyt
ridio
Blas
tocl
adio
Ento
mop
htho
ro
Muc
oro
Zygo
Glo
mer
o
Pezi
zo
Sacc
haro
Pucc
inio
Ust
ilagi
no
Agar
ico
Most predictive variable: Precipitation
0
500
1000
1500
2000
2500
3000
Pref
. mea
n an
nual
pr
ecip
. (m
m y
-1 )
P = 0.023
Treseder et al. 2014
Cryp
to
Chyt
ridio
Blas
tocl
adio
Ento
mop
htho
ro
Muc
oro
Zygo
Glo
mer
o
Pezi
zo
Sacc
haro
Pucc
inio
Ust
ilagi
no
Agar
ico
Past climate events
600–800 million yrs ago
Cosmos Magazine
Drier ecosystems Wetter ecosystems
Treseder et al. 2014, Ecology Letters
β1,3-glucan
K. Vega & M. Kalkum
Fungal cell wall
β1,3-glucan
Cell membrane
Chitin
β1,3-glucan improves drought tolerance (Shima et al. 2008)
157 whole fungal genomes
1000 Fungal Genomes Project
β1,3-glucan may facilitate colonization of drier ecosystems
0
1
2
3
4
5
0 1000 2000 3000 4000 5000
β1,3
-glu
can
synt
hase
gen
es
(# p
er 10
,000
gen
es)
Preferred mean annual precipitation (mm y-1)
P = 0.001
En
Us Mu
Pu
Ag
Pe
Sa
Ch Bl Gl Cr
Treseder & Lennon 2015
β1,3-glucan may facilitate colonization of drier ecosystems
0
1
2
3
4
5
0 1000 2000 3000 4000 5000
β-gl
ucan
syn
thas
e ge
nes
(# p
er 10
,000
gen
es)
Preferred mean annual precipitation (mm y-1)
En
Us Mu
Pu
Ag
Pe
Sa
Ch Bl Gl Cr
Xie et al. 2012
Treseder & Lennon 2015
Drought tolerance Recalcitrant
C residues
Linked traits
β1,3-glucan in cell walls
Drought
Fungi with β-glucan
C residues
Soil C storage
Climate change
Potential feedbacks on climate
Recalcitrant
+
+
+ +?
–?
What other traits coincide with β1,3-glucan?
Stress tolerance
∗ Trehalose ∗ Cold-induced RNA
helicase
Decomposition
∗ Lignin breakdown ∗ Cellulose breakdown
Treseder, K. K. and J. T. Lennon. 2015. Fungal traits that drive ecosystem dynamics. Microbiology and Molecular Biology Reviews 79(2): 243-262.
Stress tolerance traits
Trehalose: drought & freezing tolerance Gene: NTH1
Stress tolerance traits
Cold-induced RNA helicase Gene: MRH4
Stabilized RNA: non-functional
RNA helicase
RNA helicase
RNA helicase
Sigrid Hart
Unwound RNA: translatable
Decomposition traits
Lignin peroxidase Gene families: LIP, MNP, VPL
Talbot et al. 2012
Blanchette/Jurgens
Decomposition traits
Quiroz-Castañeda/Folch-Mallol
Crystalline cellulase Gene family: AA9
Decomposition traits
Quiroz-Castañeda/Folch-Mallol
Cellobiohydrolase Gene family: GH7
Morphological groups
Free-living filamentous
fungi
Yeasts
Mycorrhizal fungi
Research questions
Extremes (drought)
Moderate conditions
Decreased soil C storage
Increased soil C storage
Yeast respond positively
Free-living filamentous fungi respond positively
Response traits?
More production of recalcitrant C
Stronger ability to decompose
recalcitrant C
Effect Traits?
Climate ↑CO2
Trait linkage?
↓CO2
More production of recalcitrant C
Stronger ability to decompose
recalcitrant C
157 whole fungal genomes
1000 Fungal Genomes Project
Groups differ in traits
Decomposition Stress tolerance
Treseder & Lennon 2015
Which traits are linked?
0
10
20
30
40
0 5 10 15
Crys
talli
ne c
ellu
lase
AA
9 ge
ne fr
eque
ncy
(# p
er 10
,000
)
Cellobiohydrolase GH7 gene frequency (# per 10,000)
Ind contrast r = 0.47 Spearman’s rho = 0.84
Treseder & Lennon 2015
Linked traits
Trehalase β1,3-glucan synthase
RNA helicase
Lignin peroxidase
Cellulase AA9
Cellulase GH7
Yeasts
Free-living Filamentous fungi
Positive
Negative
Treseder & Lennon 2015
Implications
Extremes (e.g., drought)
Moderate conditions
Decreased soil C storage
Increased soil C storage
Yeast: ↑β1,3-glucan, trehalose, RNA
helicase
Filamentous: ↓β1,3-glucan, trehalose,
RNA helicase
Response traits
Effect traits
Climate ↑CO2 ↓CO2
β1,3-glucan = More recalcitrant C
↑Lignin peroxidase, Cellulases
Next steps?
Genes to Ecosystems
Trait-based models of ecosystems
Initialize
Allison 2012, Ecology Letters
Ophis
NYBG
Acknowledgements
∗ 1000 Fungal Genomes Project
∗ Steve Allison ∗ Linh Anh Cat ∗ Igor Grigoriev ∗ Caitlin Looby ∗ Yev Marusenko ∗ Jim Randerson ∗ Adriana Romero ∗ Michael Buchmeier
∗ DOE Joint Genome Institute
∗ NSF Ecosystems ∗ NSF Integrated Earth
Systems ∗ DOE Program in Microbial
Communities and Carbon Cycling
∗ DOE JGI Community Sequencing Program
Phylogenetic distribution
Gene frequency (# per 10,000 genes)