Skip Navigation


Plant and Cell Physiology Advance Access originally published online on March 8, 2006
Plant and Cell Physiology 2006 47(5):613-621; doi:10.1093/pcp/pcj028
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
47/5/613    most recent
pcj028v1
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 arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Nomura, M.
Right arrow Articles by Tajima, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nomura, M.
Right arrow Articles by Tajima, S.
Agricola
Right arrow Articles by Nomura, M.
Right arrow Articles by Tajima, S.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?


Phosphoenolpyruvate Carboxylase Plays a Crucial Role in Limiting Nitrogen Fixation in Lotus japonicus Nodules

Mika Nomura1,*, Ha Thu Mai1, Miho Fujii1, Shingo Hata2, Katsura Izui2 and Shigeyuki Tajima1

1 Faculty of Agriculture, Kagawa University, Miki, Kita, Kagawa, 761-0795 Japan
2 Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502 Japan

* Corresponding author: E-mail, nomura{at}ag.kagawa-u.ac.jp; Fax,+81-87-891-3021.

Phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31 [EC] ) is believed to play a significant role in supporting nitrogen fixation via anaplerotic CO2 fixation for recycling carbon in nodules. Using the antisense technique, we decreased the expression levels of the nodule-enhanced PEPC gene (Ljpepc1) in a determinate legume plant (Lotus japonicus) in order to look at the influence of the symbiotic phenotype and biochemical parameters. Three independent transgenic L. japonicus plants (designated as Asppc1, Asppc2 and Asppc3) were prepared using a Ljpepc1 DNA fragment which is under the control of the cauliflower mosaic virus 35S promoter. Extensive suppression of the Ljpepc1 transcript in nodules of Asppc plants (T3 homologous plants) was confirmed by RNA gel blot, Western blot and enzyme activity assays. In nodules of Asppc plants, PEPC activity was reduced to about 10% of that of non-transformants and the plants showed typical nitrogen-deficient symptoms without a supply of nitrogen nutrient, and returned to normal growth when nitrate was supplied at 2.5 mM. The acetylene reduction activity per fresh weight of nodules of these Asppc plants decreased by 29% at 35 dai (days after infection). Various enzyme activities and metabolite levels were surveyed using Asppc plants at 35 dai. Significant reduction of sucrose synthase and asparagine aminotransferase activities was observed in Asppc nodules. In addition, sucrose, succinate, asparagine, aspartate and glutamate contents also decreased in Asppc nodules. The data are discussed in terms of a role for PEPC in the carbon/nitrogen metabolic flux in nodules.

(Received January 23, 2006; Accepted March 2, 2006)
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Plant Physiol.Home page
J. White, J. Prell, E. K. James, and P. Poole
Nutrient Sharing between Symbionts
Plant Physiology, June 1, 2007; 144(2): 604 - 614.
[Full Text] [PDF]


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.