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 -