title: Photorespiration Is Crucial for Dynamic Response of Photosynthetic Metabolism and Stomatal Movement to Altered CO2Availability.
abstract: The photorespiratory pathway or photorespiration is an essential process in oxygenic photosynthetic organisms, which can reduce the efficiency of photosynthetic carbon assimilation and is hence frequently considered as a wasteful process. By comparing the response of the wild-type plants and mutants impaired in photorespiration to a shift in ambient CO2concentrations, we demonstrate that photorespiration also plays a beneficial role during short-term acclimation to reduced CO2availability. The wild-type plants responded with few differentially expressed genes, mostly involved in drought stress, which is likely a consequence of enhanced opening of stomata and concomitant water loss upon a shift toward low CO2. In contrast, mutants with impaired activity of photorespiratory enzymes were highly stressed and not able to adjust stomatal conductance to reduced external CO2availability. The transcriptional response of mutant plants was congruent, indicating a general reprogramming to deal with the consequences of reduced CO2availability, signaled by enhanced oxygenation of ribulose-1,5-bisphosphate and amplified by the artificially impaired photorespiratory metabolism. Central in this reprogramming was the pronounced reallocation of resources from growth processes to stress responses. Taken together, our results indicate that unrestricted photorespiratory metabolism is a prerequisite for rapid physiological acclimation to a reduction in CO2availability.
authors.affiliation: Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences, Heinrich Heine University, 40225 Düsseldorf, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Eisenhut
authors.affiliation: Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences, Heinrich Heine University, 40225 Düsseldorf, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bräutigam
authors.affiliation: Department of Plant Physiology, University of Rostock, Albert-Einstein-Straße 3, 18051 Rostock, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Timm
authors.affiliation: Department of Molecular Physiology, Max-Planck Institute for Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Florian
authors.affiliation: Department of Molecular Physiology, Max-Planck Institute for Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tohge
authors.affiliation: Department of Molecular Physiology, Max-Planck Institute for Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
authors.affiliation: Department of Plant Physiology, University of Rostock, Albert-Einstein-Straße 3, 18051 Rostock, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Bauwe
authors.affiliation: Institute of Plant Biochemistry, Cluster of Excellence on Plant Sciences, Heinrich Heine University, 40225 Düsseldorf, Germany. Electronic address: andreas.weber@uni-duesseldorf.de.
authors.forename: Andreas P M
authors.initials: APM
authors.lastname: Weber
mesh_terms: D017360:Arabidopsis; D002245:Carbon Dioxide / Q000378:metabolism*; D009154:Mutation; D010788:Photosynthesis / Q000235:genetics; D018515:Plant Leaves / Q000378:metabolism; D054046:Plant Stomata / Q000378:metabolism*; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism
chemical_list: D002245:Carbon Dioxide; D012273:Ribulose-Bisphosphate Carboxylase
keywords: Arabidopsis thaliana; photorespiration; starvation; stomata; stress; transcription