The impact of temperature on marine
phytoplankton resource allocation
and metabolism
Thomas Mock
School of Environmental Sciences
University of East Anglia
Norwich Research Park
UK
Missing slide (animation)
Latitudinal gradient in the optimal temperature for growth of
phytoplankton strains (n=194, R2 = 0.55, p-value < 0.0001)
Mridul K. Thomas et al. (2012), Science 338, 1085
The predicted impact of global warming on phytoplankton diversity
Mridul K. Thomas et al. (2012), Science 338, 1085
Loss of phytoplankton biomass due to global warming
DG Boyce et al. Nature 466, 591-596 (2010) doi:10.1038/nature09268
Physical drivers of phytoplankton trends
DG Boyce et al. Nature 466, 591-596 (2010) doi:10.1038/nature09268
How does global warming impact
phytoplankton resource allocation and
biogeochemical cycles in the ocean?
1) Identify how temperature impacts
metabolism and resource allocation in
phytoplankton on a global scale
2) Identify whether there are species-specific
differences in temperature-dependent
metabolism and resource allocation
3) Linking temperature-dependent algal
subcellular physiology to the global scale
to predict future trends in biogeochemical
cycling in the surface ocean
Eukaryotic phytoplankton metatranscriptomes
Strong seasonality
Medium nutrient conc. -1°C
Strong seasonality
+1°C
Medium nutrient conc.
Strong seasonality +12°C
High nutrient conc.
Low seasonality
+27°C
HNLC
NPAC
EPAC
Strong seasonality
-2°C
HNLC
ANT
ARC
NATL
Sampling and libraries
Toseland et al., 2013, Nature Climate Change, 3:979-984
temperate cluster
polar cluster
PhymmBL taxonomy
GO: biological processes
Canonical Correspondence Analysis
Ribosomal transcripts (mRNA)
Temperature-dependence of translation in eukaryotic phytoplankton
Andrew Toseland
Experimental validation of the
temperature-dependence of translation in eukaryotic phytoplankton
A) Ribosomes
Eukaryotic ribosomal protein S14 (Western Blots)
Temperature experiments
with F. cylindrus (qPCRs)
Amy Kirkham, Jan Strauss
N=3
B) “Translation efficiency” experiment with inducible (NO3) GFP in T. pseudonana
mGFP 20°C = 0.260 %/min
mGFP 11°C = 0.094 %/min
20°C
% GFP
11°C
20°C Lag
11°C Lag
Time (minutes after the addition of nitrate)
Amy Kirkham
B) Synthesis of RNA (rRNA)
Purine and Pyrimidine metabolism
in metatranscriptomes
Jan Strauss
Temperature impact on phytoplankton
Cold temperature
Warm temperature
Plastid
Ribosome
Mitochondrion
Nucleus
Any impact on biogeochemical cycles?
• Translation machinery: ribosomes
rRNA
Single largest pool
of phosphorous
in a cell
N:P ratio
Linking temperature-dependent algal subcellular physiology to the global scale
A) Cell model
Stuart Daines, James Clark
GO-term Term Clouds
Overrepresented
in EPAC (hot)
vs ANT (cold)
Overrepresented
in ANT (cold)
vs EPAC (hot)
Linking temperature-dependent algal subcellular physiology to the global scale
B) Coupling the cell model with a global circulation model (MIT)
Stuart Daines, James Clark
Making predictions
Stuart Daines, James Clark
Conclusions
• First study that links Omics with
resource allocation and global
biogeochemical cycles
• First study on phytoplankton that shows
that temperature is as significant as
nutrients and light for metabolism and
resource allocation
Challenges
Fundamental biochemical data
(such as peptide elongation rates in phytoplankton)
Acknowledgements
My group in Norwich:
Dr. Jan Strauss
Dr. Amy Kirkham
Dr. Bobbie Lyon
Dr. Andrew Curson
Andrew Toseland (PhD student)
Katrin Schmidt (PhD student)
Krisztina Sarkozi (PhD student)
Matt Beckers (PhD student)
Amanda Hopes (PhD student)
Rob Utting (Technician)
NRP, Uni. Exeter, AWI, Faro, PML
Vincent Moulton (CMP)
Mario Caccamo (TGAC)
Tim Lenton (Exeter)
Stuart Daines (Exeter)
Klaus Valentin, Christiane Uhlig (AWI)
Gareth Pearson (Faro)
Jim Clark (PML)