Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.
Silencer Select siRNAs

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 19 August 1988:
Vol. 241. no. 4868, pp. 951 - 954
DOI: 10.1126/science.241.4868.951
Prev | Table of Contents | Next

Articles

Enhancement of Symbiotic Dinitrogen Fixation by a Toxin-Releasing Plant Pathogen

THOMAS J. KNIGHT 1 and PAT J. LANGSTON-UNKEFER 1

1 Isotope and Nuclear Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545.

An approximate doubling in plant growth, total plant nitrogen, nodulation, and overall dinitrogen fixation of alfalfa are the consequences of the action of a toxin delivered by a Pseudomonas infesting the alfalfa rhizosphere. The toxin, tabtoxinine-beta-lactam, inactivates selectively one form of glutamine synthetase in the nodules. Thus, normal glutamine synthetase-catalyzed ammonia assimilation is significantly impaired; yet these plants assimilated about twice the normal amount of nitrogen. How plants regulate dinitrogen fixing symbiotic associations is an important and unresolved question; the current results imply that the glutamine synthetase-catalyzed step in ammonia assimilation, a plant function, strongly influences overall dinitrogen fixation in legumes.

Submitted on February 29, 1988
Accepted on June 14, 1988

ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)