U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Plant Science Research: St. Paul, MN
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    CareersSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Midwest Area St. Paul, Minnesota Plant Science Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            DENTON, MATTHEW - UNIV OF MINNESOTAitem
                                            SCHULZE, JOACHIM - UNIV OF MINNESOTAitem
                                            TEMPLE, STEPHEN - UNIV OF MINNESOTAitem
                                            Russelle, Michaelitem
                                            ALLAN, DEBORAH - UNIV OF MINNESOTAitem
                                            Samac, Deborah

                                                         - *Debby*item
                                            Vance, Carroll
  Submitted to: American Society of Plant Biologists Annual Meeting
                                    Publication Type: Abstract Only
                                    Publication Acceptance Date: 8/8/2002
                                    Publication  Date: 8/8/2002
                                    Citation: Denton, M.D., Schulze, J., Temple, S.J., Russelle, M.P., Allan, D., Samac, D.A., Vance, C.P. 2002. Overexpression of a nodule-enhanced malate dehydrogenase increases nitrogen fixation in alfalfa. American Society of Plant Biologists Annual Meeting. Available: http://Z16.133.76.127/pb2002/public/P60/1042.html.Interpretive Summary:
                                Technical Abstract: Malate is crucial for symbiotic dinitrogen (N2) fixation, occurring in high concentrations in N2-fixing nodules as the major carbon source for bacteroid respiration. Malate also provides carbon skeletons for the assimilation of fixed nitrogen from ammonia into amino acids and is proposed to be involved in the regulation of the nodule oxygen diffusion barrier, important for the maintenance of nitrogenase. An alfalfa nodule-enhanced malate dehydrogenase (neMDH; EC 1.1.1.37) with high affinity for the reduction of oxaloacetate to malate, was overexpressed in transgenic alfalfa using the CaMV35S promoter. Overexpression of the transgene increased neMDH transcript abundance in leaves and roots. Western blots indicated that neMDH protein concentration was increased in root and leaf tissue of transgenic alfalfa. Experiments using 15N2 labeling confirmed that transformed alfalfa had significantly higher N2 fixation rates (0.406 nmol N2/hr/plant) than control plants (0.257 nmol N2/hr/plant). Enhancing the expression of genes involved in malic acid synthesis appears to be a suitable strategy to increase nitrogen fixation in legumes.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov