Abstract
Boron enters plant roots as undissociated boric acid (H3BO3). Significant differences in B uptake are frequently observed even when plants are grown under identical conditions. It has been theorized that these differences reflect species differences in permeability coefficient of H3BO3 across plasma membrane. The permeability coefficient of boric acid however, has not been experimentally determined across any artificial or plant membrane. In the experiments described here the permeability coefficient of boric acid in liposomes made of phosphatidylcholine was 4.9 × 10−6 cm sec−1, which is in good agreement with the theoretical value. The permeability coefficient varied from 7 × 10−6 to 9.5 × 10−9 cm sec−1 with changes in sterols (cholesterol), the type of phospholipid head group, the length of the fatty acyl chain, and the pH of the medium. In this study we also used Arabidopsis thaliana mutants which differ in lipid composition to study the effect of lipid composition on B uptake. The chs1-1 mutant which has lower proportion of sterols shows 30% higher B uptake compared with the wild type, while the act1-1 mutant which has an increased percentage of longer fatty acids, exhibited 35% lower uptake than the wild type. Lipid composition changes in each of the remaining mutants influenced B uptake to various extents. These data suggest that lipid composition of the plasma membrane can affect total B uptake.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 15 October 1999/Revised: 11 February 2000
Rights and permissions
About this article
Cite this article
Dordas, C., Brown, P. Permeability of Boric Acid Across Lipid Bilayers and Factors Affecting It. J. Membrane Biol. 175, 95–105 (2000). https://doi.org/10.1007/s002320001058
Published:
Issue Date:
DOI: https://doi.org/10.1007/s002320001058