Related Experiment Video
Updated: Aug 8, 2026

Two-Dimensional Visualization and Quantification of Labile, Inorganic Plant Nutrients and Contaminants in Soil
Published on: September 1, 2020
Physical and morphological constraints on transport in nodules
1Agronomy Department, Science and Education Administration, Agricultural Research, Cornell University, Ithaca, New York 14853.
Abstract:
For active nodule nitrogen fixation, O(2), N(2), and carbohydrate must be transported throughout the nodule. No quantitative analysis of these transport processes in the nodules has been presented. By invoking several simplifying assumptions, a second-order differential equation for the various gradients and concentrations in the nodule was solved. Even though the nodule can only be approximated in this analysis, it indicates clearly that intercellular gas spaces must exist in nodules for adequate O(2) distribution. To preserve low O(2) concentrations and protect the nitrogenase, these gas spaces cannot be in direct contact with the ambient atmosphere. It is hypothesized that a gas barrier exists in the cortical region of the nodule to limit O(2) diffusion. This barrier would not substantially inhibit N(2) transport. Carbohydrate transport from the vascular tissue via diffusion in the liquid phase can adequately accommodate the requirements within the nodule.
Related Concept Videos
Short-distance Transport of Resources
Directionality of Nuclear Transport
Water and Mineral Acquisition
Nuclear Protein Sorting
Proteins targeted to the nucleus carry nuclear localization signals or NLS recognized by import receptors in the cytosol. Similarly, proteins with nuclear export signals are recognized by export receptors. Import and export receptors are...
Regulation of Nuclear Protein Sorting
Morphogenesis

