Plant Physiol. Journal of Pharmacology and Experimental Therapeutics
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

First published online November 14, 2002; 10.1104/pp.012534

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
130/4/2095    most recent
pp.012534v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via ISI Web of Science (6)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Schwuchow, J. M.
Right arrow Articles by Sack, F. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schwuchow, J. M.
Right arrow Articles by Sack, F. D.
Agricola
Right arrow Articles by Schwuchow, J. M.
Right arrow Articles by Sack, F. D.

Plant Physiol, December 2002, Vol. 130, pp. 2095-2100

Tip-Growing Cells of the Moss Ceratodon purpureus Are Gravitropic in High-Density Media1

Jochen Michael Schwuchow, Volker Dieter Kern,2 and Fred David Sack*

Department of Plant Biology, Ohio State University, Columbus, Ohio 43210-1293

Gravity sensing in plants and algae is hypothesized to rely upon either the mass of the entire cell or that of sedimenting organelles (statoliths). Protonemata of the moss Ceratodon purpureus show upward gravitropism and contain amyloplasts that sediment. If moss sensing were whole-cell based, then media denser than the cell should prevent gravitropism or reverse its direction. Cells that were inverted or reoriented to the horizontal displayed distinct negative gravitropism in solutions of iodixanol with densities of 1.052 to 1.320 as well as in bovine serum albumin solutions with densities of 1.037 to 1.184 g cm-3. Studies using tagged molecules of different sizes and calculations of diffusion times suggest that both types of media penetrate through the apical cell wall. Estimates of the density of the apical cell range from 1.004 to 1.085. Because protonemata grow upward when the cells have a density that is lower than the surrounding medium, gravitropic sensing probably utilizes an intracellular mass in moss protonemata. These data provide additional support for the idea that sedimenting amyloplasts function as statoliths in gravitropism.

1 This work was supported by the National Aeronautics and Space Administration Fundamental Biology Program (grant nos. NAG10-0179 and NAG10-0263 to F.D.S.) and by the Deutsche Forschungsgemeinschaft (to J.M.S.).

2 Present address: Lockheed Martin Space Operations, National Aeronautics and Space Administration Ames Research Center, Moffett Field, CA 94035-0168.

* Corresponding author; e-mail sack.1{at}osu.edu; fax 614-292-6345.

© 2002 American Society of Plant Biologists


This article has been cited by other articles:


Home page
 Plant Physiol.Home page
E. B. Blancaflor and P. H. Masson
Plant Gravitropism. Unraveling the Ups and Downs of a Complex Process
Plant Physiology, December 1, 2003; 133(4): 1677 - 1690.
[Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 2002 by the American Society of Plant Biologists