Related Experiment Video
Updated: Apr 8, 2026
14:16
A New Application of the Electrical Penetration Graph EPG for Acquiring and Measuring Electrical Signals in Phloem Sieve Elements
Published on: July 2, 2015
15.5K
The influence of electrical charge on plasmodesma conductivity
Alexander H Howell1, Vincent James1, Anneline H Christensen2
1School of Biological Sciences, Washington State University, Pullman, WA 99164.
Summary
Plant cell connections called plasmodesmata (PD) are assumed to only restrict molecule movement by size. Our study reveals PD are unexpectedly selective for anions, challenging current models of PD structure.
Area of Science:
- Plant biology
- Cell biology
- Biophysics
Background:
- Plant tissues utilize symplasms, where cells connect via plasmodesmata (PD).
- PD facilitate cell-to-cell transport of cytosolic components.
- Current models primarily consider molecular size (hydrodynamic radius) for transport through PD.
Purpose of the Study:
- To investigate the role of electrical charge in molecular transport through plasmodesmata.
- To test the physical theory predicting charge-based selectivity in nanopores.
- To re-evaluate current models of plasmodesmata structure and function.
Main Methods:
- Utilized fluorophores with varying molecular mass and electrical charge.
- Quantified cell-to-cell movement across plasmodesmata in different plant cell types.
- Applied physical theory of charged nanopore selectivity.
Main Results:
- Confirmed the applicability of physical theory to plasmodesmata transport.
- Observed unexpected anion permselectivity in narrow plasmodesmata.
- Contradicted the prediction of cation selectivity based on negatively charged membranes.
Conclusions:
- Current understanding of plasmodesmata structure is significantly flawed.
- Plasmodesmata exhibit unexpected anion selectivity, challenging existing models.
- Hypothesized that intrinsic structural proteins may create a cationic electrostatic environment within plasmodesmata.
Related Concept Videos
02:32Plasmodesmata
36.3K
The organs in a multicellular organism’s body are made up of tissues formed by cells. To work together cohesively, cells must communicate. One way that cells communicate is through direct contact with other cells. The points of contact that connect adjacent cells are called intercellular junctions.
36.3K
01:20Plasmodesmata
4.6K
In a multicellular organism, cells must communicate to work together in a coordinated manner. One way that cells communicate is through direct contact with other cells. The points of contact that connect adjacent cells are called intercellular junctions.
Intercellular junctions are a feature of fungal, plant, and animal cells. However, different types of junctions are found in different kinds of cells. Intercellular junctions found in animal cells include tight junctions, gap junctions, and...
Intercellular junctions are a feature of fungal, plant, and animal cells. However, different types of junctions are found in different kinds of cells. Intercellular junctions found in animal cells include tight junctions, gap junctions, and...
4.6K
01:13Electrical Conductivity
2.2K
In perfect conductors, the electric field inside is always zero due to the abundance of free electrons, which nullify any field by flowing. As a result, any residual charge resides on the surface.
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
In a practical conductor, an applied electric field may be sustained, causing a flow of electrons, which produce a current. The differential form of the current, the current density, is related to the electric field.
More generally, it is related to the force per unit charge, which involves the...
2.2K
01:28Debye–Huckel–Onsager Conductance Equation
221
The Debye-Hückel-Onsager equation is a cornerstone of physical chemistry, providing a method to determine the molar conductance (Λm) and molar conductance at infinite dilution (Λ°m) for uni-univalent electrolytes.Uni-univalent electrolytes are electrolytes that dissociate in solution to produce one cation with a +1 charge and one anion with a –1 charge per formula unit.This equation addresses two crucial phenomena: the asymmetry effect and the electrophoretic effect.
221
01:29Electrical Transport
147
The electrical transport property of a material is defined by its resistance and conductivity. Resistance is the measure of a material's ability to resist the flow of electric current, while conductivity gauges its ability to allow the current to pass through, depending on the geometry of the measurement cell, such as electrode spacing and area. Conductivity is measured in Siemens (S). There are different types of conductance, including specific conductance, equivalent conductance, and molar...
147
01:30The Electrical Double Layer
176
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...
176