Molecular basis of a microbe-mediated enhancement of symbiotic N/sub 2/-fixation. [Rhizobium meliloti; Pseudomonas syringae pv. tabaci]

Conference · Wed Apr 01 00:00:00 EST 1987 · Plant Physiol., Suppl.; (United States)

OSTI ID:5957172

Unkefer, P J; Knight, T J

Improvement of biological nitrogen fixation represents a potential source of both increased food production and decreased dependence on costly chemical fertilizer. They report the results of an investigation of the molecular basis of a unique, microbial-mediated mechanism for increased growth and nitrogen fixation rates in alfalfa. Inoculation of alfalfa plants with both Rhizobium meliloti and Pseudomonas syringae pv tabaci provides increased growth and N/sub 2/-fixation rates of alfalfa. Tabaci produces tabtoxinine-..beta..-lactam (T..beta..L), an exocellular product and glutamine synthetase (GS) inhibitor. The association of this pathogen with nodulating alfalfa plants appears to alter the normal regulation of nitrogen fixation such that nitrogenase activity is stimulated and GS activity is inhibited. Studies of the soluble amino acids in these nodules and the activities of the ammonia assimilatory enzymes indicate alternative pathways of ammonia assimilation are being employed.

• Research Organization: Los Alamos National Lab., NM
• OSTI ID: 5957172
• Report Number(s): CONF-8707108-
• Journal Information: Plant Physiol., Suppl.; (United States), Vol. 83:4; Conference: Annual meeting of the American Society of Plant Physiologists, St. Louis, MO, USA, 19 Jul 1987
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ALFALFA
NITROGEN FIXATION
STIMULATION
PSEUDOMONAS
BIOLOGICAL FUNCTIONS
RHIZOBIUM
AMINO ACIDS
ENZYME INHIBITORS
PLANT GROWTH
SYMBIOSIS
BACTERIA
CARBOXYLIC ACIDS
FUNCTIONS
GROWTH
LEGUMINOSAE
MICROORGANISMS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PLANTS
551000* - Physiological Systems
550300 - Cytology