Mathematical modelling of the diurnal regulation of the MEP pathway in Arabidopsis

• Published in: The New phytologist Vol. 206; no. 3; pp. 1075 - 1085
• Main Authors: Pokhilko, Alexandra, Bou‐Torrent, Jordi, Pulido, Pablo, Rodríguez‐Concepción, Manuel, Ebenhöh, Oliver
• Format: Journal Article
• Language: English
• Published: England Academic Press 01.05.2015; New Phytologist Trust; Wiley Subscription Services, Inc
• Subjects: 2‐C‐methyl‐D‐erythritol 4‐phosphate (MEP) pathway; Arabidopsis - metabolism; Arabidopsis - radiation effects; Arabidopsis thaliana; Biological clocks; Carotenoids; Chlorophyll; Chloroplasts; Circadian Clocks; Circadian Rhythm; Circadian rhythms; Diurnal; Erythritol; Erythritol - analogs & derivatives; Erythritol - metabolism; Feedback; Feedback control; Fluctuations; Flux; Gene regulation; genes; Growth conditions; Hormones; isoprenoids; Mathematical analysis; mathematical modelling; Mathematical models; Metabolic Networks and Pathways; Model testing; Models, Biological; Phosphates; Photosynthesis; Plant metabolism; Quinones; Substrates; Sugar Phosphates - metabolism; systems biology; Terpenes; Tocopherols; Transcription; transcription (genetics); whole plant physiology; Xylulose; Arabidopsis thaliana; systems biology; mathematical modelling; isoprenoids; 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway; whole plant physiology; plant metabolism
• ISSN: 0028-646X; 1469-8137; 1469-8137
• DOI: 10.1111/nph.13258

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.