The Density of the External Medium Affects Gravity Sensing in Plants.
Presentation Type
Oral and/or Visual Presentation
Presenter Major(s)
Biology
Mentor Information
Mark Staves, stavesm@gvsu.edu
Department
Cell and Molecular Biology
Location
Kirkhof Center 2266
Start Date
13-4-2011 10:30 AM
End Date
13-4-2011 11:00 AM
Keywords
Life Science
Abstract
The generally accepted model for plant gravity sensing invokes sedimenting, intracellular particles (statoliths) as gravity sensors. However, statolith-free plant cells, tissues and organs respond to gravity. We developed a new model for plant gravity sensing in which the entire protoplast acts as the gravity sensor. We can distinguish between the statolith model and the new gravitational pressure model by changing the density of the extracellular medium surrounding statolith-containing cells. The statolith model predicts that density of the external medium will not affect gravity sensing. The gravitational pressure model predicts that changing the density of the external medium will affect gravity sensing because it will change the buoyancy of the protoplast. We find that changing the density of the external medium does affect gravitropic curvature. These data are inconsistent with the statolith model for plant gravity sensing but are predicted by the gravitational pressure model.
The Density of the External Medium Affects Gravity Sensing in Plants.
Kirkhof Center 2266
The generally accepted model for plant gravity sensing invokes sedimenting, intracellular particles (statoliths) as gravity sensors. However, statolith-free plant cells, tissues and organs respond to gravity. We developed a new model for plant gravity sensing in which the entire protoplast acts as the gravity sensor. We can distinguish between the statolith model and the new gravitational pressure model by changing the density of the extracellular medium surrounding statolith-containing cells. The statolith model predicts that density of the external medium will not affect gravity sensing. The gravitational pressure model predicts that changing the density of the external medium will affect gravity sensing because it will change the buoyancy of the protoplast. We find that changing the density of the external medium does affect gravitropic curvature. These data are inconsistent with the statolith model for plant gravity sensing but are predicted by the gravitational pressure model.