Penetration by Artificial Electron Acceptors of the Plasma Membrane-Bound Redox System into Intact Zea mays L. Roots Investigated by Proton-Induced X-Ray Emission.
AUTOR(ES)
Luthje, S.
RESUMO
Proton-induced x-ray emission was used to investigate the penetration of compounds of the membrane-impermeant electron acceptors hexabromoiridate IV, hexachloroiridate IV, and hexacyanoferrate III into corn (Zea mays L.) roots. Maps of the heavy element distribution in cross-sections of fixed, epoxy-embedded roots showed for hexabromoiridate IV small amounts of Br in samples treated for 24 h with concentrations normally used in physiological experiments (0.02 mM). After treatment with high concentrations (0.8 mM) of these complexes, Fe and Ir as well as Br were found in root cross-sections. In samples taken at a distance of 5 mm behind the root tip, we found an even distribution of Fe, Ir, and Br over the whole cross-section. In samples taken 15 mm behind the root tip, about 99% of both Br and Ir was confined to the rhizodermal cell layer. The distribution did not change with the complex used. These data are consistent with the view that apoplastic diffusion of the electron acceptors was blocked by the hypodermal Casparian band.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=159019Documentos Relacionados
- Purification, crystallization and preliminary X-ray analysis of the membrane-bound [NiFe] hydrogenase from Allochromatium vinosum
- Electron Transport-Linked Compared with Proton-Induced ATP Generation in Thiobacillus novellus
- A Comparison of X-Ray and Ultraviolet Effects on Chromosomes of Zea Mays
- Ion Distribution in Roots of Barley Seedlings Measured by Electron Probe X-Ray Microanalysis 1
- Membrane-bound Adenosine Triphosphatase Activities of Oat Roots 1
