Wright, L.P.* ; Rohwer, J.M.* ; Ghirardo, A. ; Hammerbacher, A.* ; Ortiz, M.* ; Raguschke, B.* ; Schnitzler, J.-P. ; Gershenzon, J.* ; Phillips, M.A.*
1-Deoxyxylulose 5-phosphate synthase controls flux through the 2-C-methylerythritol 4-phosphate pathway in Arabidopsis thaliana.
Plant Physiol. 165, 1488-1504 (2014)
The 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway supplies precursors for plastidial isoprenoid biosynthesis including carotenoids, redox cofactor side chains, and biogenic volatile organic compounds. We examined the first enzyme of this pathway, 1-deoxy-D-xylulose-5-phosphate (DXP) synthase (DXS), using metabolic control analysis. Multiple Arabidopsis lines presenting a range of DXS activities were dynamically labeled with 13CO2 in an illuminated, climate-controlled, gas exchange cuvette. C was rapidly assimilated into MEP pathway intermediates, but not into the mevalonate pathway. A flux control coefficient (FCC) of 0.82 was calculated for DXS by correlating absolute flux to enzyme activity under photosynthetic steady state conditions, indicating that DXS is the major controlling enzyme of the MEP pathway. DXS manipulation also revealed a second pool of a downstream metabolite, 2-C-methyl-D-erythritol-2,4-cyclodiphosphate (MEcDP), metabolically isolated from the MEP pathway. DXS overexpression led to a 3-4 fold increase in MEcDP pool size but to a two-fold drop in maximal labeling. The existence of this pool was supported by residual MEcDP levels detected in dark-adapted transgenic plants. Both pools of MEcDP are closely modulated by DXS activity, as shown by the fact that the concentration control coefficient of DXS was twice as high for MEcDP (0.74) as for DXP (0.35) or dimethylallyl diphosphate (0.34). Despite the high FCC for DXS, its overexpression led to only modest increases in isoprenoid end products and photosynthetic rate. Diversion of flux via MEcDP may partly explain these findings and suggests new opportunities to engineer the MEP pathway.
Impact Factor
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Times Cited
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Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Typ der Hochschulschrift
Herausgeber
Schlagwörter
Plastidic Isoprenoid Biosynthesis; Poplar Leaves; Dimethylallyl Diphosphate; 2-c-methyl-d-erythritol 2,4-cyclodiphosphate; Liquid-chromatography; Plant Isoprenoids; Carbon-dioxide; Quercus-robur; Mep Pathway; Cross-talk
Keywords plus
Sprache
englisch
Veröffentlichungsjahr
2014
Prepublished im Jahr
HGF-Berichtsjahr
2014
ISSN (print) / ISBN
0032-0889
e-ISSN
1532-2548
ISBN
Bandtitel
Konferenztitel
Konferzenzdatum
Konferenzort
Konferenzband
Quellenangaben
Band: 165,
Heft: 4,
Seiten: 1488-1504
Artikelnummer: ,
Supplement: ,
Reihe
Verlag
American Society of Plant Biologists (ASPB)
Verlagsort
Rockville
Tag d. mündl. Prüfung
0000-00-00
Betreuer
Gutachter
Prüfer
Topic
Hochschule
Hochschulort
Fakultät
Veröffentlichungsdatum
0000-00-00
Anmeldedatum
0000-00-00
Anmelder/Inhaber
weitere Inhaber
Anmeldeland
Priorität
Begutachtungsstatus
Peer reviewed
POF Topic(s)
20402 - Sustainable Plant Production
30202 - Environmental Health
Forschungsfeld(er)
Environmental Sciences
PSP-Element(e)
G-504900-003
G-504991-001
Förderungen
Copyright
Erfassungsdatum
2014-07-30