title: Mathematical modelling of the diurnal regulation of the MEP pathway in Arabidopsis.
abstract: Isoprenoid molecules are essential elements of plant metabolism. Many important plant isoprenoids, such as chlorophylls, carotenoids, tocopherols, prenylated quinones and hormones are synthesised in chloroplasts via the 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway. Here we develop a mathematical model of diurnal regulation of the MEP pathway in Arabidopsis thaliana. We used both experimental and theoretical approaches to integrate mechanisms potentially involved in the diurnal control of the pathway. Our data show that flux through the MEP pathway is accelerated in light due to the photosynthesis-dependent supply of metabolic substrates of the pathway and the transcriptional regulation of key biosynthetic genes by the circadian clock. We also demonstrate that feedback regulation of both the activity and the abundance of the first enzyme of the MEP pathway (1-deoxy-D-xylulose 5-phosphate synthase, DXS) by pathway products stabilizes the flux against changes in substrate supply and adjusts the flux according to product demand under normal growth conditions. These data illustrate the central relevance of photosynthesis, the circadian clock and feedback control of DXS for the diurnal regulation of the MEP pathway.
authors.affiliation: Institute for Complex Systems and Mathematical Biology, King's College, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, UK.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Pokhilko
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193, Barcelona, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Bou-Torrent
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193, Barcelona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Pulido
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193, Barcelona, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Rodríguez-Concepción
authors.affiliation: Institute for Complex Systems and Mathematical Biology, King's College, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, UK.|Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, Universitätsstraße 1, D-40225, Düsseldorf, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Ebenhöh
mesh_terms: D017360:Arabidopsis / Q000378:metabolism* / Q000528:radiation effects; D057906:Circadian Clocks; D002940:Circadian Rhythm; D004896:Erythritol / Q000031:analogs & derivatives* / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D008954:Models, Biological; D010788:Photosynthesis; D013403:Sugar Phosphates / Q000378:metabolism*
chemical_list: C114232:2-C-methylerythritol 4-phosphate; D013403:Sugar Phosphates; D004896:Erythritol
keywords: 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway; Arabidopsis thaliana; isoprenoids; mathematical modelling; plant metabolism; systems biology; whole plant physiology