Crop Fertilization in a CO2enriched world: is it good        to be C3       David M. Rosenthal  CCAFS Science Workshop, Ca...
Outline• Plant responses to elevated CO2 and  other agents of climate change at  SoyFACE• Why is photosynthesis of crop pl...
Recent evidence indicates atmospheric [CO2] isincreasing more rapidly than the most aggressive             IPCC AR4 projec...
How does elevated CO2 stimulate photosynthesis that  is the basis for the projected increases in yield?
Rubisco is not the most efficient enzyme
Energy conversion in C3 and C4 plants                   Zhu et al 2008
SoyFACE ExperimentMaize        Soybean
20 meters
[CO2] (µmol mol-1) 750             96% of minute          averages within ±10%550             Fumigation350          On  0...
Increased photosynthesis in C3 crops grown at        elevated CO2 increases yield                   Long, Ainsworth, Leake...
Meta analysis of C3 crops grown at elevated CO2 in                FACE experiments       Crop Yield         Biomass       ...
No CO2 stimulation in Cassava   Greehouse Experiment           Gleadow et al. (2009) Plant Biol 11:79-82
Cassava an increasingly important crop
CassavaFACE         cv 60444                               April 5, 2010                                               Jun...
Growth at elevated [CO2] at SoyFACE stimulates cassava                     photosynthesis                    Rosenthal et ...
Cassava canopies are larger at elevated CO2        plant                Ambient CO2   Elevated CO2   Rosenthal et al. unpu...
Rosenthal et al. unpublished
Cassava harvested  after only 3.5     months !          Elevated   Ambient
Ambient CO2   Elevated CO2   Rosenthal et al. unpublished
Rubisco is down regulated at elevated CO2 in cassava
Cassava leaf Carbon/Nitrogen ratio declines at                elevated CO2                              Rosenthal et al. u...
Growth at elevated [CO2] does not increase leaf or       tuber cyanide content at SoyFACE                                 ...
“[CO2] Fertilization” of C3 cropphotosynthesis falls short of theory               Long, Ainsworth, Leakey, Nosberger, Ort...
Why is photosynthesis of crop plants in the field stimulated less by CO2 than         predicted by theory?
400                                  Current value320240160       Years below 280 ppm, 395 000 (96%)80       Years below 2...
Zhu et al. (2007) Plant Physiol 145: 513-526
Tobacco over-expressing SBPase grown at            elevated [CO2]          WT   SBP 30 SBP 11
Over expression of SBPase enhances photosynthesis at                   elevated [CO2]                                    R...
Over expression of SBPase enhances biomass formation at                    elevated [CO2]                                 ...
PGA                                          PGA      CH2OPO32-                                   CH2OPO32-HO    C    H   ...
Non-green          algae                               C4            Terrestrial             C3Mutants          Prokaryotes
There is a trade off between ability of Rubisco todiscriminate between CO2 and O2 Rubisco catalytic rate                  ...
Lowering   increases light saturated leaf photosynthesis but             lowers light limited photosynthesis              ...
C3Average
Adding „foreign‟ Rubisco         Species               Ac = CANOPY            εc            Asat                          ...
Rising tropospheric ozone                                            0.5 – 2.5 % per yearOzone – Parts Per Billion of Air ...
Relationship between Soybean Yield & Ozone                   Fishman et al.2010 Atmospheric Environment
Summary• Growth at elevated [CO2] stimulated cassava    photosynthesis.•   Rubisco was down regulated in cassava at elevat...
CassavaFACE collaborators:      Becky Slattery (UIUC)      Kat Grennan (UIUC)      Bec Miller (Monash U)      Ros Gleadow ...
Rosenthal - Crop fertilization
Rosenthal - Crop fertilization
Rosenthal - Crop fertilization
Rosenthal - Crop fertilization
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Rosenthal - Crop fertilization

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David Rosenthal - Crop Fertilization in a CO2 enriched world: is it good to be C3? (presentation from Adaptation session at CCAFS Science Workshop, December 2010)

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Rosenthal - Crop fertilization

  1. 1. Crop Fertilization in a CO2enriched world: is it good to be C3 David M. Rosenthal CCAFS Science Workshop, Cancun, Dec 1 and 2, 2010
  2. 2. Outline• Plant responses to elevated CO2 and other agents of climate change at SoyFACE• Why is photosynthesis of crop plants in the field stimulated less by CO2 than predicted by theory?• Some approaches to optimize (adapt) photosynthesis to global change
  3. 3. Recent evidence indicates atmospheric [CO2] isincreasing more rapidly than the most aggressive IPCC AR4 projection .
  4. 4. How does elevated CO2 stimulate photosynthesis that is the basis for the projected increases in yield?
  5. 5. Rubisco is not the most efficient enzyme
  6. 6. Energy conversion in C3 and C4 plants Zhu et al 2008
  7. 7. SoyFACE ExperimentMaize Soybean
  8. 8. 20 meters
  9. 9. [CO2] (µmol mol-1) 750 96% of minute averages within ±10%550 Fumigation350 On 0:00 6.00 12:00 18:00 0.00 Time (h)
  10. 10. Increased photosynthesis in C3 crops grown at elevated CO2 increases yield Long, Ainsworth, Leakey, Nosberger, Ort (2006) Science 312, 1918-21
  11. 11. Meta analysis of C3 crops grown at elevated CO2 in FACE experiments Crop Yield Biomass SLA LAI Plant Height Leaf # Starch Sugar Narea Rubisco Jmax Vcmax ci/ca gs A Asat -40 -20 0 20 40 60 80 100 120 Percent Change in Elevated [CO2] Ainsworth and Long (2005) New Phyt. 165:351=-372
  12. 12. No CO2 stimulation in Cassava Greehouse Experiment Gleadow et al. (2009) Plant Biol 11:79-82
  13. 13. Cassava an increasingly important crop
  14. 14. CassavaFACE cv 60444 April 5, 2010 June 7, 2010August 9, 2010 April 15, 2010 July 2, 2010 July 19, 2010
  15. 15. Growth at elevated [CO2] at SoyFACE stimulates cassava photosynthesis Rosenthal et al. unpublished
  16. 16. Cassava canopies are larger at elevated CO2 plant Ambient CO2 Elevated CO2 Rosenthal et al. unpublished
  17. 17. Rosenthal et al. unpublished
  18. 18. Cassava harvested after only 3.5 months ! Elevated Ambient
  19. 19. Ambient CO2 Elevated CO2 Rosenthal et al. unpublished
  20. 20. Rubisco is down regulated at elevated CO2 in cassava
  21. 21. Cassava leaf Carbon/Nitrogen ratio declines at elevated CO2 Rosenthal et al. unpublished
  22. 22. Growth at elevated [CO2] does not increase leaf or tuber cyanide content at SoyFACE Miller, Gleadow unpublished
  23. 23. “[CO2] Fertilization” of C3 cropphotosynthesis falls short of theory Long, Ainsworth, Leakey, Nosberger, Ort (2006) Science 312, 1918-21
  24. 24. Why is photosynthesis of crop plants in the field stimulated less by CO2 than predicted by theory?
  25. 25. 400 Current value320240160 Years below 280 ppm, 395 000 (96%)80 Years below 240 ppm, 280 000 (67%) Years below 200 ppm, 83 500 (20%) 0 400 320 240 160 80 0 Time before present, 103 years Various sources ; Luthi et al (2008) NATURE 453: 379-382
  26. 26. Zhu et al. (2007) Plant Physiol 145: 513-526
  27. 27. Tobacco over-expressing SBPase grown at elevated [CO2] WT SBP 30 SBP 11
  28. 28. Over expression of SBPase enhances photosynthesis at elevated [CO2] Rosenthal et al. unpublished
  29. 29. Over expression of SBPase enhances biomass formation at elevated [CO2] Rosenthal et al. unpublished
  30. 30. PGA PGA CH2OPO32- CH2OPO32-HO C H CH2OPO32- HO C H O2 CO2 COO- C O COO- H C OH COO- H C OH COO- CH2OPO32- CH2OPO32- HO C H Ribulose-1,5- CH2OPO32- 2-phospho- bisphosphate glycolate PGA
  31. 31. Non-green algae C4 Terrestrial C3Mutants Prokaryotes
  32. 32. There is a trade off between ability of Rubisco todiscriminate between CO2 and O2 Rubisco catalytic rate Increase ? Decrease ? Current C3 crop Rubisco
  33. 33. Lowering increases light saturated leaf photosynthesis but lowers light limited photosynthesis = -10%
  34. 34. C3Average
  35. 35. Adding „foreign‟ Rubisco Species Ac = CANOPY εc Asat PHOTOSYNTH. (% inc.) ( mol m-2 s-1) (mmol m-2 day-1)Current average C3 crop (kcc = 2.5, = 92.5) 1040 0% 14.9 Amaranthus edulis (C4) (kcc = 7.3, = 82) 1250 17% 28.3Amaranthus edulis/current(kcc = 7.3/2.5, = 82/92.5) 1360 31% 28.3 (2004) Plant Cell and Environment, 27, 155-165
  36. 36. Rising tropospheric ozone 0.5 – 2.5 % per yearOzone – Parts Per Billion of Air 80 60 40 2000 2020 2040 2060 2080 2100 (UN-IPCC 2001)
  37. 37. Relationship between Soybean Yield & Ozone Fishman et al.2010 Atmospheric Environment
  38. 38. Summary• Growth at elevated [CO2] stimulated cassava photosynthesis.• Rubisco was down regulated in cassava at elevated [CO2], consistent lower leaf N (no change in cyanide content).• Fresh and dry tuber biomass significantly increased with [CO2], as did harvest index.• Cassava responded similarly to other C3 plants treated with elevated [CO2].• CO2 stimulation of photosynthesis is less than predicted by theory. - lack of adaptation to rapid increase in [CO2] - inhibition due to increasing levels of tropospheric O3 - increased rates of respiration in CO2-grown plants - temperatures above optimum for photosynthesis.
  39. 39. CassavaFACE collaborators: Becky Slattery (UIUC) Kat Grennan (UIUC) Bec Miller (Monash U) Ros Gleadow (Monash U) Claude Fauquet (ILTAB)SBPase overexpression collaborators Christine Raines (U Exeter) Anna Locke (UIUC) Stephen Long (UIUC) SoyFACE 2010

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