TY  - JOUR
A1  - Mettler, Tabea
A1  - Mühlhaus, Timo
A1  - Hemme, Dorothea
A1  - Schöttler, Mark Aurel
A1  - Rupprecht, Jens
A1  - Idoine, Adam
A1  - Veyel, Daniel
A1  - Pal, Sunil Kumar
A1  - Yaneva-Roder, Liliya
A1  - Winck, Flavia Vischi
A1  - Sommer, Frederik
A1  - Vosloh, Daniel
A1  - Seiwert, Bettina
A1  - Erban, Alexander
A1  - Burgos, Asdrubal
A1  - Arvidsson, Samuel Janne
A1  - Schoenfelder, Stephanie
A1  - Arnold, Anne
A1  - Guenther, Manuela
A1  - Krause, Ursula
A1  - Lohse, Marc
A1  - Kopka, Joachim
A1  - Nikoloski, Zoran
A1  - Müller-Röber, Bernd
A1  - Willmitzer, Lothar
A1  - Bock, Ralph
A1  - Schroda, Michael
A1  - Stitt, Mark
T1  - Systems analysis of the response of photosynthesis, metabolism, and growth to an increase in irradiance in the photosynthetic model organism chlamydomonas reinhardtii
JF  - The plant cell
N2  - 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 (R-2 = 0.24), many proteins, including those in photosynthesis, changed independently of transcript abundance.
Y1  - 2014
U6  - https://doi.org/10.1105/tpc.114.124537
SN  - 1040-4651
SN  - 1532-298X
VL  - 26
IS  - 6
SP  - 2310
EP  - 2350
PB  - American Society of Plant Physiologists
CY  - Rockville
ER  - 
TY  - JOUR
A1  - Annunziata, Maria Grazia
A1  - Apelt, Federico
A1  - Carillo, Petronia
A1  - Krause, Ursula
A1  - Feil, Regina
A1  - Mengin, Virginie
A1  - Lauxmann, Martin A.
A1  - Koehl, Karin
A1  - Nikoloski, Zoran
A1  - Stitt, Mark
A1  - Lunn, John Edward
T1  - Getting back to nature: a reality check for experiments in controlled environments
JF  - Journal of experimental botany
N2  - Irradiance from sunlight changes in a sinusoidal manner during the day, with irregular fluctuations due to clouds, and light-dark shifts at dawn and dusk are gradual. Experiments in controlled environments typically expose plants to constant irradiance during the day and abrupt light-dark transitions. To compare the effects on metabolism of sunlight versus artificial light regimes, Arabidopsis thaliana plants were grown in a naturally illuminated greenhouse around the vernal equinox, and in controlled environment chambers with a 12-h photoperiod and either constant or sinusoidal light profiles, using either white fluorescent tubes or light-emitting diodes (LEDs) tuned to a sunlight-like spectrum as the light source. Rosettes were sampled throughout a 24-h diurnal cycle for metabolite analysis. The diurnal metabolite profiles revealed that carbon and nitrogen metabolism differed significantly between sunlight and artificial light conditions. The variability of sunlight within and between days could be a factor underlying these differences. Pairwise comparisons of the artificial light sources (fluorescent versus LED) or the light profiles (constant versus sinusoidal) showed much smaller differences. The data indicate that energy-efficient LED lighting is an acceptable alternative to fluorescent lights, but results obtained from plants grown with either type of artificial lighting might not be representative of natural conditions.
KW  - Amino acid
KW  - Arabidopsis thaliana
KW  - controlled environment
KW  - LED lighting
KW  - visible light spectrum
KW  - organic acid
KW  - starch
KW  - sucrose
KW  - trehalose 6-phosphate
Y1  - 2017
U6  - https://doi.org/10.1093/jxb/erx220
SN  - 0022-0957
SN  - 1460-2431
VL  - 68
SP  - 4463
EP  - 4477
PB  - Oxford Univ. Press
CY  - Oxford
ER  -