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Mathematical modelling of the diurnal regulation of the MEP pathway in Arabidopsis
Author(s) -
Pokhilko Alexandra,
BouTorrent Jordi,
Pulido Pablo,
RodríguezConcepción Manuel,
Ebenhöh Oliver
Publication year - 2015
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13258
Subject(s) - flux (metallurgy) , arabidopsis thaliana , metabolic pathway , circadian clock , biology , arabidopsis , biochemistry , chloroplast , photosynthesis , circadian rhythm , microbiology and biotechnology , chemistry , metabolism , gene , organic chemistry , neuroscience , mutant
Summary 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.