title: Systems Analysis of the Response of Photosynthesis, Metabolism, and Growth to an Increase in Irradiance in the Photosynthetic Model Organism Chlamydomonas reinhardtii.
abstract: We investigated the systems response of metabolism and growth after an increase in irradiance in the nonsaturating range in the algal model Chlamydomonas reinhardtii. In a three-step process, photosynthesis and the levels of metabolites increased immediately, growth increased after 10 to 15 min, and transcript and protein abundance responded by 40 and 120 to 240 min, respectively. In the first phase, starch and metabolites provided a transient buffer for carbon until growth increased. This uncouples photosynthesis from growth in a fluctuating light environment. In the first and second phases, rising metabolite levels and increased polysome loading drove an increase in fluxes. Most Calvin-Benson cycle (CBC) enzymes were substrate-limited in vivo, and strikingly, many were present at higher concentrations than their substrates, explaining how rising metabolite levels stimulate CBC flux. Rubisco, fructose-1,6-biosphosphatase, and seduheptulose-1,7-bisphosphatase were close to substrate saturation in vivo, and flux was increased by posttranslational activation. In the third phase, changes in abundance of particular proteins, including increases in plastidial ATP synthase and some CBC enzymes, relieved potential bottlenecks and readjusted protein allocation between different processes. Despite reasonable overall agreement between changes in transcript and protein abundance (R2= 0.24), many proteins, including those in photosynthesis, changed independently of transcript abundance.
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Tabea
authors.initials: T
authors.lastname: Mettler
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Timo
authors.initials: T
authors.lastname: Mühlhaus
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Hemme
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Mark-Aurel
authors.initials: MA
authors.lastname: Schöttler
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Rupprecht
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Adam
authors.initials: A
authors.lastname: Idoine
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Veyel
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Pal
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Liliya
authors.initials: L
authors.lastname: Yaneva-Roder
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany.
authors.forename: Flavia Vischi
authors.initials: FV
authors.lastname: Winck
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Frederik
authors.initials: F
authors.lastname: Sommer
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Vosloh
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Bettina
authors.initials: B
authors.lastname: Seiwert
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Erban
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Asdrubal
authors.initials: A
authors.lastname: Burgos
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany.
authors.forename: Samuel
authors.initials: S
authors.lastname: Arvidsson
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Schönfelder
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Arnold
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Manuela
authors.initials: M
authors.lastname: Günther
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Ursula
authors.initials: U
authors.lastname: Krause
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Marc
authors.initials: M
authors.lastname: Lohse
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Kopka
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Zoran
authors.initials: Z
authors.lastname: Nikoloski
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany Institute of Biochemistry and Biology, University of Potsdam, 14476 Potsdam-Golm, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Mueller-Roeber
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Lothar
authors.initials: L
authors.lastname: Willmitzer
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Bock
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schroda
authors.affiliation: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany mstitt@mpimp-golm.mpg.de.
authors.forename: Mark
authors.initials: M
authors.lastname: Stitt