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An Optimized Rhizobox Protocol to Visualize Root Growth and Responsiveness to Localized Nutrients
Published on: October 22, 2018
Nitrogen source interacts with ROP signalling in root hair tip-growth
Daria Bloch1, Gabriele Monshausen, Meromit Singer
1Department of Plant Sciences, Tel Aviv University, Tel Aviv, Israel Department of Botany, University of Wisconsin, Madison, WI, USA.
Plant, Cell & Environment
|September 10, 2010
Summary
Root hair swelling induced by Rho of Plant (ROP) GTPases requires specific nutrient conditions. Ammonium and nitrate regulate root hair tip growth by influencing pH oscillations and actin organization.
Area of Science:
- Plant biology
- Cellular growth mechanisms
- Molecular plant science
Background:
- Root hairs exhibit polarized tip growth.
- Constitutively active Rho of Plant (ROP)/RAC GTPases mutants cause root hair swelling.
Purpose of the Study:
- Investigate the role of growth medium composition in Atrop11(CA)-induced root hair swelling.
- Elucidate the relationship between ROP GTPases, nutrient availability, and root hair tip growth.
Main Methods:
- Genetic manipulation of ROP GTPases in Arabidopsis.
- Controlled modification of nutrient media composition (ammonium, nitrate).
- Fluorescence microscopy to observe actin organization, reactive oxygen species, and pH dynamics.
Main Results:
- Ammonium depletion prevented Atrop11(CA)-induced swelling and promoted elongation in wild-type plants.
- Ammonium (>1 mM) and nitrate were necessary for swelling induction.
- Buffering the medium reduced swelling; NH₄NO₃ increased pH oscillation amplitude and decreased apical cytoplasmic pH.
Conclusions:
- ROP GTPases and nitrogen-dependent pH oscillations act in parallel pathways.
- A positive feedback loop between ROP signaling and pH oscillations regulates root hair growth.
- Nutrient availability critically influences ROP-mediated root hair tip growth dynamics.
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