1. EFFECT OF THE HIGH CONCENTRATION OF ATMOSPHERIC CO 2 ON GROWTH AND DEVELOPMENT OF SUGAR CANE (SACCHARUM OFFICINARUM) M. Gaspar, A.P. Souza, M. Marabesi, J.R.L. Godoy, M.P.M. Aidar, M.S.Buckeridge

2. CO 2 INCREASE: WHY STUDYING C4 PLANTS? Research on the effect of CO 2 enrichment on C4 plants is limited compared to C3 plants. Although C4 plants represent a small percentage (about 3%) of the total Angiosperm species, they make a substantial contribution to productivity on a global scale. Many agronomically important crops are C4 plants (maize, sorghum and sugar cane...).

3. C4 PLANTS AND CO 2 C4 plants have a photosynthetic metabolism that concentrates CO 2 3 to 8 times the atmospheric CO 2 concentrations.

4. What is C4 metabolism?

5. C4 PLANTS AND CO 2 This led to the suggestion that the rise in CO 2 may have little or no effect on C4 photosynthesis and growth...

6. WHY STUDYING SUGARCANE? One ton has an energy potential that is equivalent to 1.2 oil barrels. Besides sugar and alcohol, sugarcane generates several products: biodegradable plastic, paper, pharmaceutical products, fertilizers, herbicides and insecticides, etc. SUCEST: database containing 238.000 EST from several organs and tissues sampled at different developmental stages.

7. Lima et al. 2001 Genetics and Molecular Biology 459 cell wall related genes in Sugar Cane, 9 of them belong to the family CesA

8. SUGARCANE IN BRAZIL Brazil is the highest world producer, followed by India and Australia. 55% of Brazilian sugarcane is turned into alcohol and 45% into sugar.

10. Sugar cane plants grown in open top chambers in the atmosphere of 360ppm (control) and 720ppm. Short-term experiments: 50 days CO 2 TREATMENT

11. SUGARCANE RESPONSE TO CO 2 ENRICHMENT Plant height Increase of 16% in plant height

12. SUGARCANE RESPONSE TO CO 2 ENRICHMENT Leaf area Number of leaves Slight increase in the rate of leaf production Trend to increasing in leaf area

13. SUGARCANE RESPONSE TO CO 2 ENRICHMENT Net CO 2 Assimilation Increase of about 25% in CO 2 assimilation

14. SUGARCANE RESPONSE TO CO 2 ENRICHMENT Biomass 59% 38%

15. SUGARCANE RESPONSE TO CO 2 ENRICHMENT No significant differences in the levels of soluble sugars and cellulose Higher assimilation of carbon by sugar cane plants is stored as biomass rather than sugar

16. PERSPECTIVES Long-term experiments (  1.5 years) Expression analysis from different genes expressed in leaves and stem (photosynthesis, sugar metabolism, cell wall and others) using SUCEST database HPLC analysis from cell wall components