Plant Physiology 95:740-747 (1991)
© 1991 American Society of Plant Biologists
Metabolism and Enzymology
Glutamate Oxaloacetate Transaminase in Pea Root Nodules 1
Participation in a Malate/Aspartate Shuttle between Plant and Bacteroid
Michiel A. Appels and
Huub Haaker
Department of Biochemistry, Agricultural University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
Glutamate oxaloacetate transaminase (L-glutamate: oxaloacetate aminotransferase, EC 2.6.1.1 [GOT]), a key enzyme in the flow of carbon between the organic acid and amino acid pools in pea (Pisum sativum L.) root nodules, was studied. By ion exchange chromatography, the presence of two forms of GOT in the cytoplasm of pea root nodule cells was established. The major root nodule form was present in only a small quantity in the cytoplasm of root cells. Fractionation of root nodule cell extracts demonstrated that the increase in the GOT activity during nodule development was due to the increase of the activity in the cytoplasm of the plant cells, and not to an increase in activity in the plastids or in the mitochondria. The kinetic properties of the different cytoplasmic forms of GOT were studied. Some of the Km values differed, but calculations indicated that not the kinetic properties but a high concentration of the major root nodule form caused the observed increase in GOT activity in the pea root nodules. It was found that the reactions of the malate/aspartate shuttle are catalyzed by intact bacteroids, and that these reactions can support nitrogen fixation. It is proposed that the main function of the nodule-stimulated cytoplasmic form of GOT is participation in this shuttle.
1 This investigation was supported by the Netherlands Foundation for Biological Research, with financial aid from the Netherlands Organization for Advancement of Research.
This article has been cited by other articles:
|
|
|
|
 
S. Batista, E. J. Patriarca, R. Tate, G. Martinez-Drets, and P. R. Gill
An Alternative Succinate (2-Oxoglutarate) Transport System in Rhizobium tropici Is Induced in Nodules of Phaseolus vulgaris
J. Bacteriol.,
August 15, 2009;
191(16):
5057 - 5067.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. P. White, J. Prell, V. K. Ramachandran, and P. S. Poole
Characterization of a {gamma}-Aminobutyric Acid Transport System of Rhizobium leguminosarum bv. viciae 3841
J. Bacteriol.,
March 1, 2009;
191(5):
1547 - 1555.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
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]
|
|
|
|
|
|
|
M. A. Fox, J. P. White, A. H. F. Hosie, E. M. Lodwig, and P. S. Poole
Osmotic Upshift Transiently Inhibits Uptake via ABC Transporters in Gram-Negative Bacteria.
J. Bacteriol.,
July 1, 2006;
188(14):
5304 - 5307.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Kumar, A. Bourdes, and P. Poole
De Novo Alanine Synthesis by Bacteroids of Mesorhizobium loti Is Not Required for Nitrogen Transfer in the Determinate Nodules of Lotus corniculatus
J. Bacteriol.,
August 1, 2005;
187(15):
5493 - 5495.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Ramirez, M. A. Graham, L. Blanco-Lopez, S. Silvente, A. Medrano-Soto, M. W. Blair, G. Hernandez, C. P. Vance, and M. Lara
Sequencing and Analysis of Common Bean ESTs. Building a Foundation for Functional Genomics
Plant Physiology,
April 1, 2005;
137(4):
1211 - 1227.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Silvente, A. Camas, and M. Lara
Molecular cloning of the cDNA encoding aspartate aminotransferase from bean root nodules and determination of its role in nodule nitrogen metabolism
J. Exp. Bot.,
June 1, 2003;
54(387):
1545 - 1551.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. K. Waters, B. L. Hughes II, L. C. Purcell, K. O. Gerhardt, T. P. Mawhinney, and D. W. Emerich
Alanine, not ammonia, is excreted from N2-fixing soybean nodule bacteroids
PNAS,
September 29, 1998;
95(20):
12038 - 12042.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
