Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Enhanced fixation reveals the apical cortical fringe of actin filaments as a consistent feature of the pollen tube

Journal Article · · Planta

The actin cytoskeleton plays a crucial role in the growth and polarity of the pollen tube. Due to inconsistencies in the conventional preservation methods, we lack a unified view of the organization of actin microfilaments, especially in the apical domain, where tip growth occurs. In an attempt to improve fixation methods, we have developed a rapid freeze-whole mount procedure, in which growing pollen tubes (primarily lily) are frozen in liquid propane at –180°C, substituted at –80°C in acetone containing glutaraldehyde, rehydrated, quenched with sodium borohydride, and probed with antibodies. Confocal microscopy reveals a distinct organization of actin in the apical domain that consists of a dense cortical fringe or collar of microfilaments starting about 1–5 μm behind the extreme apex and extending basally for an additional 5–10 μm. In the shank of the pollen tube, basal to the fringe, actin forms abundant longitudinal filaments that are evenly dispersed throughout the cytoplasm. We have also developed an improved ambient-temperature chemical fixation procedure, modified from a protocol based on simultaneous fixation and phalloidin staining. We removed EGTA, elevated the pH to 9, and augmented the fixative with ethylene glycol bis[sulfosuccinimidylsuccinate] (sulfo-EGS). Notably, this protocol preserves the actin cytoskeleton in a pattern similar to that produced by cryofixation. Furthermore, these procedures provide a reproducible way to preserve the actin cytoskeleton; employing them, we find that a cortical fringe in the apex and finely dispersed longitudinal filaments in the shank are consistent features of the actin cytoskeleton.

Research Organization:
University of Massachusetts, Amherst, MA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division (CSGB); National Science Foundation (NSF); DOE
Grant/Contract Number:
FG02-03ER15421
OSTI ID:
2483278
Journal Information:
Planta, Journal Name: Planta Journal Issue: 1 Vol. 221; ISSN 0032-0935
Publisher:
SpringerCopyright Statement
Country of Publication:
United States
Language:
English

References (47)

Spray-freezing freeze substitution (SFFS) of cell suspensions for improved preservation of ultrastructure journal August 1997
Characterization and localization of profilin in pollen grains and tubes ofLilium longiflorum journal January 1997
Fluorescence microscopic localization of actin in pollen tubes: Comparison of actin antibody and phalloidin staining journal January 1989
An Improved Method for Affinity Probe Localization in Whole Cells of Filamentous Fungi journal June 1998
Rhodamine-phalloidin staining of F-actin in pollen after dimethylsulphoxide permeabilization journal June 1988
Improvements in immunostaining samples embedded in methacrylate: localization of microtubules and other antigens throughout developing organs in plants of diverse taxa journal June 1992
Role of microtubules in the movement of the vegetative nucleus and generative cell in tobacco pollen tubes journal March 1995
Localization of a 170 kDa myosin heavy chain in plant cells journal September 1995
Effects of fixatives and permeabilisation buffers on pollen tubes: implications for localisation of actin microfilaments using phalloidin staining journal March 1996
Actin microfilaments do not form a dense meshwork inLilium longiflorum pollen tube tips journal March 1996
A method for rapid freeze fixation of plant cells journal June 1986
Association of actin with cortical microtubules revealed by immunogold localization inNicotiana pollen tubes journal February 1991
Immunogold labelling of actin on sections of freeze-substituted plant cells journal February 1989
Microtubules are involved in maintaining the cellular polarity in pollen tubes ofNicotiana sylvestris journal March 1994
Organization of the cytoskeleton in pollen tubes ofPyrus communis: a study employing conventional and freeze-substitution electron microscopy, immunofluorescence, and rhodamine-phalloidin journal June 1988
Ultrastructure of freeze-substituted pollen tubes ofLilium longiflorum journal December 1992
The 135 kDa actin-bundling protein fromLilium longiflorum pollen is the plant homologue of villin journal September 1999
Cortical fine actin filaments in higher plant cells visualized by rhodamine-phalloidin after pretreatment with m-maleimidobenzoyl N-hydroxysuccinimide ester journal June 1989
Pollen Tube Cytoskeleton: Structure and Function journal June 2001
Circular F-actin bundles and a G-actin gradient in pollen and pollen tubes of Lilium davidii journal September 2001
Reversible protein phosphorylation regulates the dynamic organization of the pollen tube cytoskeleton: effects of calyculin A and okadaic acid journal October 2002
A new cleavable reagent for cross-linking and reversible immobilization of proteins journal April 1979
The identification of F actin in the pollen tube and protoplast of Amaryllis belladonna journal October 1974
Cell growth: How to grow and where to grow journal May 2001
The cytoskeleton, cellular motility and the reductionist agenda journal April 2003
Freeze shattering: a simple and effective method for permeabilizing higher plant cell walls journal October 1997
Cryofixing single cells and multicellular specimens enhances structure and immunocytochemistry for light microscopy journal May 1996
The cytoskeleton in plant and fungal cell tip growth journal June 2000
A GFP-mouse talin fusion protein labels plant actin filamentsin vivoand visualizes the actin cytoskeleton in growing pollen tubes journal November 1998
Control of pollen tube growth: role of ion gradients and fluxes journal July 2003
A Gelsolin-like Protein from Papaver rhoeas Pollen (PrABP80) Stimulates Calcium-regulated Severing and Depolymerization of Actin Filaments journal May 2004
Growing Pollen Tubes Possess a Constitutive Alkaline Band in the Clear Zone and a Growth-dependent Acidic Tip journal February 1999
ROP Gtpase–Dependent Dynamics of Tip-Localized F-Actin Controls Tip Growth in Pollen Tubes journal March 2001
Immunofluorescence microscopy of organized microtubule arrays in structurally stabilized meristematic plant cells. journal June 1981
Actin Polymerization Is Essential for Pollen Tube Growth journal August 2001
Two Distinct Distributions of F-actin are Present in the Hyphal Apex of the Oomycete Achlya bisexualis journal March 2004
Actin-Bundling Protein Isolated from Pollen Tubes of Lily journal April 1998
The Regulation of Actin Organization by Actin-Depolymerizing Factor in Elongating Pollen Tubes[W] journal September 2002
Latrunculin B Has Different Effects on Pollen Germination and Tube Growth journal December 1999
Fixation induces differential tip morphology and immunolocalization of the cytoskeleton in pollen tubes journal April 1995
Regulation of pollen tube growth journal June 1995
Distribution of microtubules during the growth of tobacco pollen tubes journal January 1993
PHOSPHOINOSITIDE LIPIDS AS SIGNALING MOLECULES: Common Themes for Signal Transduction, Cytoskeletal Regulation, and Membrane Trafficking journal November 1998
Importance of fixation in immunohistochemistry: use of formaldehyde solutions at variable pH for the localization of tyrosine hydroxylase. journal July 1981
Comparison of fixation and penetration enhancement techniques for use in ultrastructural immunocytochemistry. journal February 1983
Identification and localization of three classes of myosins in pollen tubes of Lilium longiflorum and Nicotiana alata journal July 1995
Cytoskeletal elements, cell shaping and movement in the angiosperm pollen tube journal September 1988

Similar Records

Rho-GTPase–dependent filamentous actin dynamics coordinate vesicle targeting and exocytosis during tip growth
Journal Article · Mon Jun 30 00:00:00 EDT 2008 · Journal of Cell Biology · OSTI ID:1625148

A family of ROP proteins that suppress actin dynamics and is essential for polarized growth and cell adhesion
Journal Article · Wed Jul 15 00:00:00 EDT 2015 · Journal of Cell Science · OSTI ID:2483314