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Updated: Aug 6, 2026
12:18
A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response
Published on: April 17, 2016
Cytochalasin D does not inhibit gravitropism in roots
M P Staves1, R Wayne, A C Leopold
1Section of Plant Biology, Cornell University, Ithaca, New York 14853, USA.
American Journal of Botany
|September 7, 2001
Summary
Higher plants
Area of Science:
- Plant Biology
- Cell Biology
- Biophysics
Background:
- The statolith hypothesis posits that sedimenting plastids (amyloplasts) are crucial for gravity sensing in plants.
- This hypothesis suggests gravity perception involves the interaction between amyloplasts and actin microfilaments.
Purpose of the Study:
- To directly test the role of actin microfilaments in the statolith hypothesis of plant gravitropism.
- To determine if amyloplast-actin interactions are essential for gravity sensing in higher plants.
Main Methods:
- Treatment of primary roots of rice, corn, and cress with cytochalasin D, an actin microfilament disruptor.
- Observation and analysis of gravitropism and growth responses in treated and untreated plant roots.
Main Results:
- Plant roots exhibited normal gravitropism and growth despite exposure to cytochalasin D.
- Disruption of actin microfilaments did not impede the plants' ability to sense gravity.
Conclusions:
- The interaction between amyloplasts and the actin cytoskeleton is not critical for gravity sensing in higher plants.
- These findings challenge the current statolith hypothesis, suggesting alternative mechanisms for plant gravitropism.
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