title: Metabolism and growth in Arabidopsis depend on the daytime temperature but are temperature-compensated against cool nights.
abstract: Diurnal cycles provide a tractable system to study the response of metabolism and growth to fluctuating temperatures. We reasoned that the response to daytime and night temperature may vary; while daytime temperature affects photosynthesis, night temperature affects use of carbon that was accumulated in the light. Three Arabidopsis thaliana accessions were grown in thermocycles under carbon-limiting conditions with different daytime or night temperatures (12 to 24 °C) and analyzed for biomass, photosynthesis, respiration, enzyme activities, protein levels, and metabolite levels. The data were used to model carbon allocation and growth rates in the light and dark. Low daytime temperature led to an inhibition of photosynthesis and an even larger inhibition of growth. The inhibition of photosynthesis was partly ameliorated by a general increase in protein content. Low night temperature had no effect on protein content, starch turnover, or growth. In a warm night, there is excess capacity for carbon use. We propose that use of this capacity is restricted by feedback inhibition, which is relaxed at lower night temperature, thus buffering growth against fluctuations in night temperature. As examples, the rate of starch degradation is completely temperature compensated against even sudden changes in temperature, and polysome loading increases when the night temperature is decreased.
authors: Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany.
authors: Eva-Theresa
authors: ET
authors: Pyl
authors: Maria
authors: M
authors: Piques
authors: Alexander
authors: A
authors: Ivakov
authors: Waltraud
authors: W
authors: Schulze
authors: Hirofumi
authors: H
authors: Ishihara
authors: Mark
authors: M
authors: Stitt
authors: Ronan
authors: R
authors: Sulpice
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D018533:Biomass; D019069:Cell Respiration; D002940:Circadian Rhythm; D003080:Cold Temperature; D004798:Enzymes / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D006003:Glycogen / Q000378:metabolism; D017440:Photoperiod; D010788:Photosynthesis; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D011132:Polyribosomes / Q000378:metabolism; D013213:Starch / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D004798:Enzymes; D013213:Starch; D006003:Glycogen