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NASA NTRS · 20040089644

An electric current associated with gravity sensing in maize roots

Bjorkman, T.·Leopold, A. C.
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Abstract

The study of gravisensing would be greatly enhanced if physiological events associated with gravity sensing could be detected separately from subsequent growth processes. This report presents a means to discriminate sensing from the growth processes. By using a vibrating probe, we have found an electric current generated by the gravity sensing region of the root cap of maize (Zea mays cv Merit) in response to gravistimulation. On the upper surface of the root cap, the change from the endogenous current has a density of 0.55 microampere per square centimeter away from gravity. The onset of the current shift has a characteristic of lag of three to four minutes after gravistimulation, which corresponds to the presentation time for gravity sensing in this tissue. A description of the current provides some information about the sensing mechanism, as well as being a valuable means to detect gravity sensing independently of differential growth.

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NASA Discipline Number 40-10NASA Program Space BiologyNASA Discipline Plant BiologyNon-NASA CenterPlant Root Cap/growth & development/physiologyZea mays/growth & development/physiologyPlant Roots/physiologyGravitropism/physiologyGravity Perception/physiologyElectrophysiologySignal Transduction/physiologySupport, U.S. Gov't, P.H.SSupport, U.S. Gov't, Non-P.H.SProton PumpsElectric ConductivityTime Factors

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Bjorkman, T., Leopold, A. C.. 1987-01-01. An electric current associated with gravity sensing in maize roots. https://ntrs.nasa.gov/citations/20040089644

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