Disturbing carbon metabolism in plants to help humans stay in this 

planet

Marcos Buckeridge

LAFIECO 

Department of Botany, USP

Light TemperatureCO2Water

NutrientsWater Microorganisms

CellPlant

Molecule

The concentration of CO2 follows the climatic changes

inter-glacial

glacial

inter-glacial

glacial

inter-glacial

glacial

inter-glacial

glacial

inter-glacial

Ar nas amostras de gelo da Antartida

Ruddiman, W.F. (2005) Scentific American n.35

ANTROPOCENO

Ruddiman, W.F. (2005) Scentific American n.35

Global carbon stocks in vegetation and top 1 m of soils (based on WBGU, 1998).

Carbon Stocks (Gt C)Biome

Area(106 km2) Vegetation Soils Total

Tropical forests 17.6 212 216 428Temperate forests 10.4 59 100 159Boreal forests 13.7 88 471 559Tropical savannas 22.5 66 264 330Temperate grasslands 12.5 9 295 304Deserts and semideserts 45.5 8 191 199Tundra 9.5 6 121 127Wetlands 3.5 15 225 240Croplands 16.0 3 128 131

Total 151.2 466 2011 2477

Physiological responses of plants to the climatic changes

PEPc & RUBISCOSTOMATA MITOCHONDRIA NUCLEUS

Water and carbohydrate status in leaves 

Carbonic anhydrase and RUBISCO

ABI4

Respiration

Photosynthesis

Cond

uctance

‐

+

‐

Transpiration‐

Stom

atal density 

e‐ transport+

C assimilation+

Starch, leaf area, biomass, root growth, stress tolerance, defence and  fertility

+

N Assimilation and micorrizal association 

‐

Photosynthetic protein‐

Cel

lLe

afP

lant

Buckeridge et al. 2008. Biologia & Mudanças Climáticas no Brasil. Rima Editora, São Carlos

Light, water and Nutrients CO2

PHOTOSYNTHESIS

SUCROSE STARCH

CELLULOSE

GROWTHMitigation of CO2 emissions

Forest and ecosystem services

Agriculture and Biofuels

Hymenaea in the future ?Hymenaea in the future ?

Experiments in open top chambers

2001 2001 -- 360 ppm CO360 ppm CO222050 2050 -- 720 ppm CO720 ppm CO22

Hymenaea

Hymenaea and assai palm growing under elevated CO2 and elevated temperature (+3oC)

Aidar et al. 2002 V2 (2) (www.biotaneotropica.org.br)

Figure 9 – Responses of the light saturated net photosynthesis (Amax) for eophylls from Hymenaea courbaril seedlings with cotyledons to atmospheric CO2 concentrations. Values for 360 and 720 pmm CO2 concentrations were measured in our open top chambers; values for CO2 concentration of 120 and 1200 ppm were obtained through the A x Ci curves simulated by IRGA (Li-Cor 6400).

y = 6.2979Ln(x) - 26.932r = 0.989

0

2

4

6

8

10

12

14

16

18

20

0 360 720 1080 1440CO2 atmospheric concentration (ppm)

Amax

(µm

ol C

O2

m-2 s

-1)

Plântulas de Hymenaea durante os primeiros 90 dias de crescimento com e sem cotilédones

*

1997

2006

Foto

s M

arce

lo M

acha

do &

Mar

cos

Buc

kerid

ge –

IB U

SP

200

7

Chloroplast

Starch

Starch in leaf cells of jatoba growing under elevated CO2

Plant obesity?

Vacuole containingsucrose

Elevated CO2

Current CO2

COLUNA NEOTRÓPICAS http://www.revistapesquisa.fapesp.br

Hymenaea, CO2 and temperature

+CO2+CO2+3oC

CTR +3oC

SucroseSucrose

CO2CO2

Triose‐PTriose‐P

Hexose‐PHexose‐P

PhotosynthesisPhotosynthesis ADP‐GlcADP‐Glc

StarchStarch

UDP‐GlcUDP‐Glc

ADP‐GPP

UDP‐GPP

Sucrose‐PSucrose‐P

Chloroplast

HK

Glc & FruGlc & Fru

INV

SPS

cytoplasm

vacuole

CellWallCellWall

GRO

WTH

TREES

STORA

GE

SucroseSucrose

CO2CO2

Triose‐PTriose‐P

Hexose‐PHexose‐P

PhotosynthesisPhotosynthesis ADP‐GlcADP‐Glc StarchStarch

UDP‐GlcUDP‐Glc

ADP‐GPP

UDP‐GPP

Sucrose‐PSucrose‐P

Chloroplast

HK

Glc & FruGlc & Fru

INV

SPS

cytoplasm

vacuole

CellWallCellWall

GRO

WTH

STORA

GE

TREESElevated CO2

CO2CO2

SucroseSucrose

Triose‐PTriose‐P

Hexose‐PHexose‐P

PhotosynthesisPhotosynthesis ADP‐GlcADP‐Glc

StarchStarch

UDP‐GlcUDP‐Glc

ADP‐GPP

UDP‐GPP

Sucrose‐PSucrose‐P

Chloroplast

HK

Glc & FruGlc & Fru

INV

SPS

cytoplasm

vacuole

CellWallCellWall

GRO

WTH

TREESElevated CO2 + 3oC

STORA

GE

Photosynthesis in sugarcane

Sugarcane leaves performe C4 photosynthesis

CO2

CO2

CO2

CO2Mesophyll cellsBundle Sheath

Débora Leite, Wanderley dos Santos, Amanda Souza & Marcos Buckeridge – Res. não publicados

0,0 2,5 5,0 7,5 10,0 12,5 15,0 17,5 20,0 22,5 25,00

100

200

300

400

500 Experimento 24 horas #7 Folha CO2 10h ECD_1nC

min

1 - 5

,308

2 - G

licos

e - 5

,567

3 - F

ruto

se -

6,29

24

- 6,9

585

- 7,2

506

- 7,8

837

- 8,4

83

8 - 9

,458

9 - 9

,867

10 -

10,3

92

11 -

Sac

aros

e - 1

1,32

5

12 -

13,7

0013

- 14

,325

14 -

14,5

17

15 -

15,7

08

16 -

17,2

50

17 -

18,4

08

18 -

Raf

inos

e - 1

9,67

5

19 -

20,6

1720

- 21

,017

21 -

21,0

67

Galactose

Growing sugarcane under elevated CO2

Elevated

30% less transpiration60% higher 

WUE

Ambient

ElevatedAmbientProductivity

50% more Biomass2005

1 year in elevated CO2

De Souza et al. 2008Plant Cell & Environment, Volume 31, pg 1116

Microarray analysis of the CO2 experiments3 months

Categories Gene descriptionRatio

(elevated/ambient)

Development light-induced protein 1,194Photosynthesis photosystem II protein K; psbK 1,315Photosynthesis Ferredoxin I; chloroplast precursor 1,26

Photosynthesisphotosystem I reaction centre subunit n,

chloroplast precursor 1,583

Cell wall metabolismxyloglucan endo-

transglycosylase/hydrolase 2,582Photosynthesis Chlorophyll A-B binding protein 1,508Stress response ASR-like 1,735

Lipid, fatty-acid and isoprenoid metabolism AE9 stearoyl-ACP desaturase 3,59

Carbohydrate metabolism beta-glucosidase isozyme 2 precursor -2,189

Carbohydrate metabolismputative glucose-6-phosphate

dehydrogenase -1,232Protein metabolism translational initiation factor eIF-4A -1,606

De Souza et al. (2008) Plant Cell & Environment, Volume 31, pg 1116

5 monthsProtein metabolism large ribosomal protein 2 1,454

Carbohydr. metabolism/Photosynthesis phosphoenolpyruvate carboxylase 1,245

Cell wall metabolism Alpha-L-arabinofuranosidase 1,37

Protein metabolism cathepsin B-like cysteine protease 1,349

Development dormancy-associated protein 2,299

Transporters Sugar transporter 1,252

Receptors serine/threonine-protein kinase NAK 1,706

unknow 1,271

Protein metabolism putative glutamate-tRNA ligase 1,504

Protein metabolism cathepsin B-like cysteine protease 1,395

Protein metabolism Aldo/keto reductase; Sigma-54 factor 1,229

putative nucleostemin (GTPase of unknown function) 1,397

Development putative auxin-independent growth promoter 1,909

Transcription pre-mRNA splicing factor 1,541

Nucleic acid metabolism chromodomain-helicase-DNA-binding protein 0,17

Stress response dehydrin -1,42

unknow -1,398

Secondary metabolism caffeoyl-CoA 3-O-methyltransferase 1 -1,354

Carbohydrate metabolism cell wall invertase -1,615

Stress response ferritin -2,768

Protein metabolism C2 domain-containing protein-like -1,342

Pathogenicity Thaumatin -1,367

Transcription auxin response factor 2 -1,352

Development Lateral organ boudaries protein -1,494

Cell cycle kelch repeat-containing F-box family protein -1,541

Cell cycle cyclin H-1 -1,632

Leaves of sugarcane stained withiodine

Débora Leite, Wanderley dos Santos, Amanda Souza & Marcos Buckeridge – Res. não publicados

Sugarcane culm

No starch is present in culms

Leite, Wanderley dos Santos, Amanda Souza & Marcos Buckeridge – Res. não publicados

SucroseSucrose

CO2CO2

Triose‐PTriose‐P

Hexose‐PHexose‐P

PhotosynthesisPhotosynthesis

UDP‐GlcUDP‐GlcUDP‐GPP

Sucrose‐PSucrose‐P

Chloroplast

HK

Glc & FruGlc & Fru

INV

SPP

cytoplasm

vacuole

CellWallCellWall

GRO

WTH

STORA

GE

SUGARCANE

ADP‐GlcADP‐Glc

StarchStarchADP‐GPP

SPS

CO2CO2

SucroseSucrose

Triose‐PTriose‐P

Hexose‐PHexose‐P

PhotosynthesisPhotosynthesis

UDP‐GlcUDP‐Glc

ADP‐GPP

UDP‐GPP

Sucrose‐PSucrose‐P

Chloroplast

HK

Glc & FruGlc & Fru

INV

SPS

cytoplasm

vacuole

CellWallCellWall

GRO

WTH

ADP‐GlcADP‐GlcStarchStarch

STORA

GE

SUGARCANEElevated CO2

SPP

CO2 accelerates light capture? What are the signalling mechanisms involved?

We found alteration in the genes related to light capture that seem to lead to anincrease in biomass and consequently in bioethanol

Can we artificially express these genes in sugarcane and obtain the benefits of a biomass increase now?

This could increase productivity and freeland for other purposes