Journal Article

FZJ-2014-03481

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Metabolic Flux Analysis of Plastidic Isoprenoid Biosynthesis in Poplar Leaves Emitting and Nonemitting Isoprene

Ghirardo, A. (Corresponding Author) ; Wright, L. P. ; Bi, Z. ; Rosenkranz, M. ; Pulido, P. ; Rodriguez-Concepcion, M. ; Niinemets, U. ; Bruggemann, N.FZJ* ; Gershenzon, J. ; Schnitzler, J.-P.

2014
JSTOR Rockville, Md.: Soc.

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Please use a persistent id in citations: doi:10.1104/pp.114.236018

Abstract: The plastidic 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway is one of the most important pathways in plants andproduces a large variety of essential isoprenoids. Its regulation, however, is still not well understood. Using the stableisotope 13C-labeling technique, we analyzed the carbon fluxes through the MEP pathway and into the major plastidicisoprenoid products in isoprene-emitting and transgenic isoprene-nonemitting (NE) gray poplar (Populus 3 canescens). Weassessed the dependence on temperature, light intensity, and atmospheric [CO2]. Isoprene biosynthesis was by far (99%) themain carbon sink of MEP pathway intermediates in mature gray poplar leaves, and its production required severalfold highercarbon fluxes compared with NE leaves with almost zero isoprene emission. To compensate for the much lower demand forcarbon, NE leaves drastically reduced the overall carbon flux within the MEP pathway. Feedback inhibition of 1-deoxy-Dxylulose-5-phosphate synthase activity by accumulated plastidic dimethylallyl diphosphate almost completely explained thisreduction in carbon flux. Our data demonstrate that short-term biochemical feedback regulation of 1-deoxy-D-xylulose-5-phosphate synthase activity by plastidic dimethylallyl diphosphate is an important regulatory mechanism of the MEPpathway. Despite being relieved from the large carbon demand of isoprene biosynthesis, NE plants redirected onlyapproximately 0.5% of this saved carbon toward essential nonvolatile isoprenoids, i.e. b-carotene and lutein, most probablyto compensate for the absence of isoprene and its antioxidant properties.

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Contributing Institute(s):

1. Agrosphäre (IBG-3)

Research Program(s):

1. 246 - Modelling and Monitoring Terrestrial Systems: Methods and Technologies (POF2-246) (POF2-246)
2. 255 - Terrestrial Systems: From Observation to Prediction (POF3-255) (POF3-255)

Appears in the scientific report 2014

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Database coverage:
; BIOSIS Previews ; Current Contents - Agriculture, Biology and Environmental Sciences ; Current Contents - Life Sciences ; JCR ; NCBI Molecular Biology Database ; National-Konsortium ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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