Products of dark CO sub 2 fixation in pea root nodules support bacteroid metabolism. [Pisum sativum L]

Journal Article · Tue May 01 00:00:00 EDT 1990 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.93.1.12· OSTI ID:5957261

Rosendahl, L; Pedersen, W B ^[1]; Vance, C P ^[2]

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1. Riso National Laboratory, Roskilde (Denmark)
2. Univ. of Minnesota, St. Paul (USA)

Products of the nodule cytosol in vivo dark ({sup 14}C)CO{sub 2} fixation were detected in the plant cytosol as well as in the bacteroids of pea (Pisum sativum L. cv Bodil) nodules. The distribution of the metabolites of the dark CO{sub 2} fixation products was compared in effective (fix{sup +}) nodules infected by a wild-type Rhizobium leguminosarum (MNF 300), and ineffective (fix{sup {minus}}) nodules of the R. leguminosarum mutant MNF 3080. The latter has a defect in the dicarboxylic acid transport system of the bacterial membrane. The {sup 14}C incorporation from ({sup 14}C)CO{sub 2} was about threefold greater in the wild-type nodules than in the mutant nodules. Similarly, in wild-type nodules the in vitro phosphoenolpyruvate carboxylase activity was substantially greater than that of the mutant. Almost 90% of the {sup 14}C label in the cytosol was found in organic acids in both symbioses. The results indicate a central role for nodule cytosol dark CO{sub 2} fixation in the supply of the bacteroids with dicarboxylic acids.

• OSTI ID: 5957261
• Journal Information: Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 93:1; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550501 -- Metabolism-- Tracer Techniques
553002* -- Agriculture & Food Technology-- Horticulture-- (1987-)
59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
BACTERIA
CARBON 14 COMPOUNDS
CARBON DIOXIDE FIXATION
CARBOXYLIC ACIDS
COMPARATIVE EVALUATIONS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LEGUMINOSAE
MAGNOLIOPHYTA
MAGNOLIOPSIDA
METABOLISM
METABOLITES
MICROORGANISMS
MUTANTS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PISUM
PLANTS
RHIZOBIUM
SYMBIOSIS
TRACER TECHNIQUES