Cadmium uptake by Pinus resinosa Ait. pollen and the effect on cation release and membrane permeability
- Tennessee Valley Authority, Muscle Shoals, AL
Cadmium uptake by red pine (Pinus resinosa Ait.) pollen from a graded series of Cd/sup 2 +/ solutions (0 to 2.88 microequivalents per 50 milligrams pollen) and its effect on membrane integrity were examined by atomic absorption spectroscopy. Uptake was strongly dependent on Cd/sup 2 +/ concentration and was limited to adsorption and cation exchange in pollen walls during a 3-hour measurement period. Good correlation between measured Cd/sup 2 +/ uptake and that predicted by the Langmuir and Freundlich isotherm equations indicated the adsorptive nature of Cd/sup 2 +/ uptake. While substantial quantities of Ca/sup 2 +/ and Mg/sup 2 +/ were released by exchange mechanisms concurrent with Cd/sup 2 +/ uptake, there was no evidence for leakage of cations due to membrane impairment as indicated by a poor correlation between Cd/sup 2 +/ uptake and K/sup +/ efflux. Virtually all Cd/sup 2 +/ removed from solution was freely exchangeable with 0.5 millimolar CaCl/sub 2/ and demonstrated that Cd/sup 2 +/ did not readily enter pine pollen but was adsorbed on the pollen wall. Ultraviolet transmission spectra of treatment solutions and analyses of phosphate and reducing sugar efflux also indicated that the potent toxicity of Cd/sup 2 +/ to pollen germination and germ tube elongation was not the result of membrane damage.
- OSTI ID:
- 5557182
- Journal Information:
- Plant Physiol.; (United States), Vol. 64:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CADMIUM
UPTAKE
ABSORPTION SPECTROSCOPY
CALCIUM CHLORIDES
CATIONS
MAGNESIUM
MEMBRANES
METABOLISM
PERMEABILITY
PINES
POLLEN
POTASSIUM
SPECTROSCOPY
ULTRAVIOLET SPECTRA
ALKALI METALS
ALKALINE EARTH METAL COMPOUNDS
ALKALINE EARTH METALS
CALCIUM COMPOUNDS
CALCIUM HALIDES
CHARGED PARTICLES
CHLORIDES
CHLORINE COMPOUNDS
CONIFERS
ELEMENTS
GAMETES
GERM CELLS
HALIDES
HALOGEN COMPOUNDS
IONS
METALS
PLANTS
SPECTRA
TREES
560303* - Chemicals Metabolism & Toxicology- Plants- (-1987)