Using a newly developed vibrating electrode, we have explored the electric fields around lily pollen germinating in vitro. From these field measurements, we infer that each weeted pollen drives a steady current of a few hundred picoamperes through itself. Considered as a flow of positive ions, this current enters an ungerminated grain's prospective growth site and leaves it opposite end. After a grain germinates and forms a tube, this current enters most of the growing tube and leaves the whole grain. The current densities over both of these extended surface regions are relatively uniform, and the boundary zone, near the tube's base, is relatively narrow. This current continues as long as the tube grows, and even continues when elongation, as well as cytoplasmic streaming, are blocked by 1 mug/ml of cytochalasin B. After a otherwise indistinguishable minority of tubes have grown to lengths of a millimeter or more, their current comes to include an endless train of discrete and characteristic current pulses as well as a steady component. These pulses are about 30s long, never overlap, recur every 60-100s, and seem to enter a region more restricted to be growing tip than the steady current's sink. In most ways, the current through growing lily pollen resembles that known to flow through focoid eggs.
Large electrical currents traverse growing pollen tubes
M. Weisenseel,R. Nuccitelli,L. Jaffe
Published 1975 in Journal of Cell Biology
ABSTRACT
PUBLICATION RECORD
- Publication year
1975
- Venue
Journal of Cell Biology
- Publication date
1975-09-01
- Fields of study
Biology, Medicine, Physics
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- current density
The amount of electric current per unit area at the pollen surface or tube surface.
Aliases: density of current
- current pulses
Discrete transient current events superimposed on the steady current in some long pollen tubes.
Aliases: pulses
- cytochalasin b
An actin-disrupting compound used here to block tube elongation and cytoplasmic streaming.
Aliases: CB
- electric fields
The spatial electric-field signals recorded around the pollen during in vitro germination.
Aliases: field measurements
- lily pollen
Pollen grains from lily used as the biological material in the experiments.
Aliases: lily pollen grains
- pollen tube
The elongated outgrowth that develops from a pollen grain during germination.
Aliases: growing tube, tube
- steady current
A sustained electric current inferred to pass through the pollen grain or tube.
Aliases: continuous current
- vibrating electrode
An oscillating electrode probe used to measure local electric fields near the germinating pollen.
Aliases: vibrating-electrode probe
REFERENCES
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