Format

Send to

Choose Destination
See comment in PubMed Commons below
J Exp Bot. 2004 Jul;55(402):1455-62. Epub 2004 Jun 18.

The import of phosphoenolpyruvate by plastids from developing embryos of oilseed rape, Brassica napus (L.), and its potential as a substrate for fatty acid synthesis.

Author information

  • 1Department of Metabolic Biology, John Innes Centre, Norwich Research Park, Colney, Norwich NR4 7UH, UK.

Abstract

The plastidial phosphoenolpyruvate (PEP)/phosphate translocator (PPT) is expressed in the developing embryos of oilseed rape (Brassica napus L.). PEP can be imported by plastids isolated from embryos and used for fatty acid synthesis at rates that are sufficient to account for one-third of the rate of fatty acid synthesis in vivo. This provides the first experimental evidence for uptake of PEP and incorporation of carbon from it into fatty acids by plastids. PEP metabolism in isolated plastids is able to provide some of the ATP required for fatty acid synthesis. Expression of the PPT and related glucose 6-phosphate (Glc-6-P) translocator (GPT) is high in early embryo and leaf development and then declines. The marked decline in the abundance of PPT and GPT transcripts between the pre- and mid-oil accumulating stages of embryo development in B. napus does not correlate with the corresponding translocator activities, which both increase over the same period. This means that transcript abundance cannot be used to infer the activity of the translocators.

PMID:
15208349
DOI:
10.1093/jxb/erh157
[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center