Skip Navigation


Plant and Cell Physiology Advance Access originally published online on February 26, 2008
Plant and Cell Physiology 2008 49(4):604-616; doi:10.1093/pcp/pcn032
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplementary Data
Right arrow All Versions of this Article:
49/4/604    most recent
pcn032v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Okada, K.
Right arrow Articles by Yamane, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Okada, K.
Right arrow Articles by Yamane, H.
Agricola
Right arrow Articles by Okada, K.
Right arrow Articles by Yamane, H.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2008. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org

Genetic Evidence for the Role of Isopentenyl Diphosphate Isomerases in the Mevalonate Pathway and Plant Development in Arabidopsis

Kazunori Okada1,*, Hiroyuki Kasahara2, Shinjiro Yamaguchi2, Hiroshi Kawaide3, Yuji Kamiya2, Hideaki Nojiri1 and Hisakazu Yamane1

1Biotechnology Research Center, The University of Tokyo, Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan
2RIKEN Plant Science Center, Tsurumi-ku, Yokohama, Kanagawa, 230-0045 Japan
3Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, Fuchu, Tokyo, 183-8509 Japan

*Corresponding author: E-mail, ukokada{at}mail.ecc.u-tokyo.ac.jp; Fax, +81-35841-8070.


  Abstract

Isopentenyl/dimethylallyl diphosphate isomerase (IPI) catalyzes the interconversion of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), which are the universal C5 units of isoprenoids. In plants, IPP and DMAPP are synthesized via the cytosolic mevalonate (MVA) and plastidic methylerythritol phosphate (MEP) pathways, respectively. However, the role of IPI in each pathway and in plant development is unknown due to a lack of genetic studies using IPI-defective mutants. Here, we show that the atipi1atipi2 double mutant, which is defective in two Arabidopsis IPI isozymes, exhibits dwarfism and male sterility under long-day conditions and decreased pigmentation under continuous light, whereas the atipi1 and atipi2 single mutants are phenotypically normal. We also show that the sterol and ubiquinone levels in the double mutant are <50% of those in wild-type plants, and that the male-sterile phenotype is chemically complemented by squalene, a sterol precursor. In vivo isotope labeling experiments using the atipi1atipi2 double mutant revealed a decrease in the incorporation of MVA (in its lactone form) into sterols, with no decrease in the incorporation of MEP pathway intermediates into tocopherol. These results demonstrate a critical role for IPI in isoprenoid biosynthesis via the MVA pathway, and they imply that IPI is essential for the maintenance of appropriate levels of IPP and DMAPP in different subcellular compartments in plants.

Keywords: Dimethylallyl diphosphate - IPP isomerase - Isopentenyl diphosphate - MEP pathway - MVA pathway

Abbreviations: ABRC, Arabidopsis Biological Resource Center; CaMV, cauliflower mosaic virus; DMAPP, dimethylallyl diphosphate; DX, 1-deoxy-D-xylulose; DXR, DX-5-phosphate reductoisomerase; FPP, farnesyl diphosphate; GC-MS, gas chromatography–mass spectrometry; GFP, green fluorescent protein; GGPP, geranylgeranyl diphosphate; GS, glutamine synthetase; HMG-CoA, 3-hydroxy-3-methylglutalyl coenzyme A; IPP, isopentenyl diphosphate; IPI, isopentenyl/dimethylallyl diphosphate isomerase; LD, long-day; MEP, 2-C-methyl-D-erythritol 4-phosphate; MS, Murashige–Skoog; MVA, mevalonate; MVL, mevalonolactone; QRT–PCR, quantitative reverse transcription–PCR; TMRI, Torrey Mesa Research Institute; TMS, trimethylsilyl; UTR, untranslated region.

(Received November 18, 2007; Accepted February 20, 2008)
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.