Genetic Engineering with Nitrogen Fixation
The supply of available nitrogen is a limiting factor in world food production. Green plants do not possess sufficient hereditary traits of their own to be self-sufficient for N-fertilizer. Certain bacteria and blue-green algae are the only organisms known to convert atmospheric nitrogen gas into a form suitable for plant growth, a process called biological nitrogen fixation. In order to manufacture their own supply of N-fertilizer, plants must first attract and somehow domesticate symbiotic soil microbes which have the nitrogen fixation genes which code for the crucial enzyme nitrogenase that catalyzes the synthesis of ammonium ion from the vast reservoir of atmospheric nitrogen gas. Man has learned to harness N2-fixing microorganisms through the domestication and culture of soybeans and other leguminous crops which produce root nodules filled with symbiotic, N2-fixing bacteria. In order to increase world food production, it may be necessary to further exploit these highly beneficial microorganisms. If we are to genetically engineer new hybrid plants which are self-sufficient for N-fertilizer, we must learn to manipulate the hereditary traits responsible for this process. Recent studies on the nature and manipulation of nitrogen fixation genes (Nif) are described in this paper.
KeywordsNitrogen Fixation Glutamine Synthetase Root Nodule Bacterium Carbamyl Phosphate Tropical Grass
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- 3.BERGERSEN, F.J. & HIPSLEY, E.H. J. Gen. MicrobioZ. 60: 61, 1970.Google Scholar
- 5.ST. JOHN, R.T., JOHNSTON, H.M., SEIDMANN, C., GARFINKEL, D., GORDON, J.K., SHAH, V.K. & BRILL, W. J. J. BacterioZ. 121: 759, 1975.Google Scholar
- 8.CANNON, F.C., KENNEDY, C.K., POSTGATE, J.R., TUBB, R.S. & DIXON, R.A. In “Symposium on Dinitrogen Fixation” (Ed. W.E. Newton and C.J. Nyman) Washington State Univ. Press, Pullman, Wash. (in press)Google Scholar
- 9.CLEWELL, D.B. & HELINSKI, D.R. J. BacterioZ 110: 1135, 1972.Google Scholar
- 11.STREICHER, S.L., SHANMUGAM, K.T., AUSUBEL, F., MORANDI, C. & GOLDBERG, R.B. J. BacterioZ. 120: 815, 1974.Google Scholar
- 13.GINSBURG, A. amp, E.R. In “The Enzymes of Glutamine Metabolism” (Ed. S. Pruisner and E.R. Stadtman) Academic Press, N.Y. 1973, p. 9.Google Scholar
- 14.WOHLHUETER, R.M., SCHUTT, H. & HOLZER, H. In “The Enzymes of Glutamine Metabolism” (Ed. S. Prusiner and E.R. Stadtman) Academic Press, N.Y. 1973, p. 45.Google Scholar
- 15.MAGASANIK, B., PRIVAL, M.J., BRENCHLEY, J.E., TYLER, B.M., DELEO, A.B., STREICHER, S.L., BENDER, R.A. & PARIS, C.G. Curr. Top. CeZ ReguZ. 8: 119, 1974.Google Scholar