N sub 2 -fixation by freshly isolated Nostoc from coralloid roots of the cycad Macrozamia riedlei (Fisch. ex Gaud. ) Gardn

Journal Article · Fri Mar 01 00:00:00 EST 1991 · Plant Physiology; (United States)

DOI:https://doi.org/10.1104/pp.95.3.753· OSTI ID:6053981

Lindblad, P; Atkins, C A; Pate, J S ^[1]

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1. Univ. of Uppsala (Sweden) Univ. of Western Australia, Nedlands (Australia)

Nitrogenase (EC 1.7.99.2) activity (acetylene reduction) and nitrogen fixation ({sup 15}N{sub 2} fixation) were measured in cyanobacteria freshly isolated from the coralloid roots of Macrozamia riedlei (Fisch. ex Gaud.) Gardn. The data indicate that cyanobacteria within cycad coralloid roots are differentiated specifically for symbiotic functioning in a microaerobic environment. Specializations include a high heterocyst frequency, enhanced permeability to O{sub 2}, and a direct dependence on the cycad for substrates to support nitrogenase activity.

• OSTI ID: 6053981
• Journal Information: Plant Physiology; (United States), Vol. 95:3; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CYANOBACTERIA
NITROGEN FIXATION
CARBON DIOXIDE
ENZYME ACTIVITY
NITROGEN
NITROGEN 15
PHOTOSYNTHESIS
PHOTOSYNTHETIC REACTION CENTERS
PLANTS
ROOTS
TRACER TECHNIQUES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
ISOTOPE APPLICATIONS
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
NITROGEN ISOTOPES
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
STABLE ISOTOPES
SYNTHESIS
551001* - Physiological Systems- Tracer Techniques