Plant root absorption and metabolic fate of technetium in plants

Conference · Mon Oct 01 04:00:00 EDT 1984

OSTI ID:6200937

Cataldo, D A; Garland, T R; Wildung, R E

Root absorption characteristics for the pertechnetate ion (TcO/sub 4//sup -/) were determined using hydroponically grown soybean seedlings (Glycine max, cv. Williams). Absorption of TcO/sub 4//sup -/ was found to be linear with time, sensitive to metabolic inhibitors, and exhibit multiple absorption isotherms over the concentration range 0.02 to 10 ..mu..M. The isotherms had calculated K/sub s/ values of 0.09, 8.9, and 54 ..mu..M for intact seedlings. The uptake of TcO/sub 4//sup -/ (0.25 ..mu..M) was inhibited by a fourfold concentration excess of sulfate, phosphate, and selenate, but not by borate, nitrate, tungstate, perrhenate, iodate or vanadate. Kinetic studies demonstrated that sulfate, phosphate, and selenate were competitive inhibitors of TcO/sub 4//sup -/ absorption. Once absorbed, Tc was readily transported as TcO/sub 4//sup -/ to shoot tissues of soybean and subsequently associated with protein constituents. The chemical fate of Tc in plants varies with plant species. Plants high in nonprotein sulfhydryl compounds (Allium species) exhibited markedly different root/shoot distribution and protein incorporation patterns from species with low sulfur requirements (soybean, alfalfa, mustard). Based on these differences, Tc/S/Se tracer studies were employed to resolve the comparative fate of these probable analogs. 20 references, 5 figures, 5 tables.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6200937
• Report Number(s): PNL-SA-12715; CONF-8410157-5; ON: DE85003600
• Country of Publication: United States
• Language: English

Related Subjects

560172* -- Radiation Effects-- Nuclide Kinetics & Toxicology-- Animals-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ABSORPTION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
CHALCOGENIDES
DATA
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
GLYCINE HISPIDA
HOURS LIVING RADIOISOTOPES
INFORMATION
INHIBITION
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LEAVES
LEGUMINOSAE
LIGHT NUCLEI
METABOLISM
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
OXYGEN COMPOUNDS
PERTECHNETATES
PH VALUE
PLANT STEMS
PLANTS
RADIOISOTOPES
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
ROOTS
SELENATES
SELENIDES
SELENIUM 75
SELENIUM COMPOUNDS
SELENIUM ISOTOPES
SULFATES
SULFUR 35
SULFUR COMPOUNDS
SULFUR ISOTOPES
TECHNETIUM 99
TECHNETIUM COMPOUNDS
TECHNETIUM ISOTOPES
TIME DEPENDENCE
TISSUE DISTRIBUTION
TRACER TECHNIQUES
TRANSITION ELEMENT COMPOUNDS
YEARS LIVING RADIOISOTOPES