Changes in Whole-Plant Metabolism during the Grain-Filling Stage in Sorghum Grown under Elevated CO2 and Drought.
Projections indicate an elevation of the atmospheric CO2 concentration ([CO2]) concomitant with an intensification of drought for this century, increasing the challenges to food security. On the one hand, drought is a main environmental factor responsible for decreasing crop productivity and grain quality, especially when occurring during the grain-filling stage. On the other hand, elevated [CO2] is predicted to mitigate some of the negative effects of drought. Sorghum (Sorghum bicolor) is a C4 grass that has important economical and nutritional values in many parts of the world. Although the impact of elevated [CO2] and drought in photosynthesis and growth has been well documented for sorghum, the effects of the combination of these two environmental factors on plant metabolism have yet to be determined. To address this question, sorghum plants (cv BRS 330) were grown and monitored at ambient (400 µmol mol(-1)) or elevated (800 µmol mol(-1)) [CO2] for 120 d and subjected to drought during the grain-filling stage. Leaf photosynthesis, respiration, and stomatal conductance were measured at 90 and 120 d after planting, and plant organs (leaves, culm, roots, prop roots, and grains) were harvested. Finally, biochemical composition and intracellular metabolites were assessed for each organ. As expected, elevated [CO2] reduced the stomatal conductance, which preserved soil moisture and plant fitness under drought. Interestingly, the whole-plant metabolism was adjusted and protein content in grains was improved by 60% in sorghum grown under elevated [CO2].
Laboratory of Plant Physiological Ecology, Department of Botany, Institute of Biosciences, University of Sao Paulo, 05508-090 Sao Paulo, Brazil (A.P.D.S., A.C.G., M.S.B.); andDepartment of Molecular Genetics (J.-C.C., A.P.A.) and Center for Applied Plant Sciences (J.-C.C.), The Ohio State University, Columbus, Ohio 43210.
Amanda P
http://orcid.org/0000-0002-7237-6483
AP
De Souza
Laboratory of Plant Physiological Ecology, Department of Botany, Institute of Biosciences, University of Sao Paulo, 05508-090 Sao Paulo, Brazil (A.P.D.S., A.C.G., M.S.B.); andDepartment of Molecular Genetics (J.-C.C., A.P.A.) and Center for Applied Plant Sciences (J.-C.C.), The Ohio State University, Columbus, Ohio 43210.
Jean-Christophe
http://orcid.org/0000-0002-2394-2485
JC
Cocuron
Laboratory of Plant Physiological Ecology, Department of Botany, Institute of Biosciences, University of Sao Paulo, 05508-090 Sao Paulo, Brazil (A.P.D.S., A.C.G., M.S.B.); andDepartment of Molecular Genetics (J.-C.C., A.P.A.) and Center for Applied Plant Sciences (J.-C.C.), The Ohio State University, Columbus, Ohio 43210.
Ana Carolina
AC
Garcia
Laboratory of Plant Physiological Ecology, Department of Botany, Institute of Biosciences, University of Sao Paulo, 05508-090 Sao Paulo, Brazil (A.P.D.S., A.C.G., M.S.B.); andDepartment of Molecular Genetics (J.-C.C., A.P.A.) and Center for Applied Plant Sciences (J.-C.C.), The Ohio State University, Columbus, Ohio 43210 alonso.19@osu.edu msbuck@usp.br.
Ana Paula
http://orcid.org/0000-0003-4696-1811
AP
Alonso
Laboratory of Plant Physiological Ecology, Department of Botany, Institute of Biosciences, University of Sao Paulo, 05508-090 Sao Paulo, Brazil (A.P.D.S., A.C.G., M.S.B.); andDepartment of Molecular Genetics (J.-C.C., A.P.A.) and Center for Applied Plant Sciences (J.-C.C.), The Ohio State University, Columbus, Ohio 43210 alonso.19@osu.edu msbuck@usp.br.
Marcos S
http://orcid.org/0000-0002-5455-8136
MS
Buckeridge
D002245:Carbon Dioxide / Q000378:metabolism*; D055864:Droughts; D002523:Edible Grain; D055442:Metabolome; D010788:Photosynthesis / Q000502:physiology; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D018526:Plant Transpiration / Q000502:physiology; D045868:Sorghum / Q000187:drug effects / Q000254:growth & development / Q000502:physiology*
D002245:Carbon Dioxide