title: Action of gibberellins on growth and metabolism of Arabidopsis plants associated with high concentration of carbon dioxide.
abstract: Although the positive effect of elevated CO(2) concentration [CO(2)] on plant growth is well known, it remains unclear whether global climate change will positively or negatively affect crop yields. In particular, relatively little is known about the role of hormone pathways in controlling the growth responses to elevated [CO(2)]. Here, we studied the impact of elevated [CO(2)] on plant biomass and metabolism in Arabidopsis (Arabidopsis thaliana) in relation to the availability of gibberellins (GAs). Inhibition of growth by the GA biosynthesis inhibitor paclobutrazol (PAC) at ambient [CO(2)] (350 µmol CO(2) mol(-1)) was reverted by elevated [CO(2)] (750 µmol CO(2) mol(-1)). Thus, we investigated the metabolic adjustment and modulation of gene expression in response to changes in growth of plants imposed by varying the GA regime in ambient and elevated [CO(2)]. In the presence of PAC (low-GA regime), the activities of enzymes involved in photosynthesis and inorganic nitrogen assimilation were markedly increased at elevated [CO(2)], whereas the activities of enzymes of organic acid metabolism were decreased. Under ambient [CO(2)], nitrate, amino acids, and protein accumulated upon PAC treatment; however, this was not the case when plants were grown at elevated [CO(2)]. These results suggest that only under ambient [CO(2)] is GA required for the integration of carbohydrate and nitrogen metabolism underlying optimal biomass determination. Our results have implications concerning the action of the Green Revolution genes in future environmental conditions.
authors.affiliation: University of Potsdam, Institute of Biochemistry and Biology, 14476 Potsdam-Golm, Germany.
authors.forename: Dimas M
authors.initials: DM
authors.lastname: Ribeiro
authors.forename: Wagner L
authors.initials: WL
authors.lastname: Araújo
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
authors.forename: Jos H M
authors.initials: JH
authors.lastname: Schippers
authors.forename: Bernd
authors.initials: B
authors.lastname: Mueller-Roeber
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D050260:Carbohydrate Metabolism / Q000187:drug effects / Q000235:genetics; D002245:Carbon Dioxide / Q000494:pharmacology*; D002264:Carboxylic Acids / Q000378:metabolism; D002473:Cell Wall / Q000187:drug effects / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005875:Gibberellins / Q000494:pharmacology*; D050356:Lipid Metabolism / Q000187:drug effects / Q000235:genetics; D009584:Nitrogen / Q000378:metabolism; D010641:Phenotype; D018515:Plant Leaves / Q000187:drug effects / Q000378:metabolism; D018520:Plant Shoots / Q000187:drug effects / Q000201:enzymology; D011725:Pyridines / Q000378:metabolism; D013213:Starch / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D002264:Carboxylic Acids; D005875:Gibberellins; D011725:Pyridines; D002245:Carbon Dioxide; D013213:Starch; D009584:Nitrogen