Related Experiment Video
Updated: Aug 17, 2026

A Strategy to Validate the Role of Callose-mediated Plasmodesmal Gating in the Tropic Response
Published on: April 17, 2016
Inhibition of Pollen Tube Elongation by Microinjected Anti-Rop1Ps Antibodies Suggests a Crucial Role for Rho-Type
1Department of Plant Biology and Plant Biotechnology Center, Ohio State University, Columbus, Ohio 43210.
Abstract:
Microinjection of anti-Rop1Ps antibodies was used to assess the function of a tip-localized Rho-type GTPase, Rop, in controlling pollen tube growth. Injected antibodies induced sustained growth arrest within 1 to 2 min after injection but did not affect cytoplasmic streaming. Coinjection with Rop rescued antibody-induced growth inhibition, indicating that injected antibodies specifically block the activity of Rop GTPases. Antibody-induced inhibition was significantly enhanced in the presence of a lower threshold of extracellular [Ca2+] or a subinhibitory dosage of caffeine. In contrast, injection of the C3 toxin, which inactivates a different Rho-type GTPase, arrested tube elongation 10 to 20 min after injection. C3-induced growth arrest was accompanied by the cessation of cytoplasmic streaming. These data suggest that Rho-type GTPases play a pivotal role in the control of pollen tube elongation. We propose that Rop may regulate a Ca2+-dependent pathway involved in vesicle docking/fusion, whereas a C3-sensitive Rho GTPase may mediate cytoplasmic streaming.
More Related Videos
13:51Detection of Small GTPase Prenylation and GTP Binding Using Membrane Fractionation and GTPase-linked Immunosorbent Assay
Published on: November 11, 2018
12:35Optogenetic Inhibition of Rho1-Mediated Actomyosin Contractility Coupled with Measurement of Epithelial Tension in Drosophila Embryos
Published on: April 14, 2023
Related Concept Videos
Eukaryotic Transcription Inhibitors
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Drugs that Stabilize Microtubules
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Mechanism of Lamellipodia Formation
Cell Polarization by Rho Proteins
Small GTPases - Ras and Rho
Three regulatory proteins control their activity: