Document Detail


Plant cell proliferation and growth are altered by microgravity conditions in spaceflight.
MedLine Citation:
PMID:  19864040     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Seeds of Arabidopsis thaliana were sent to space and germinated in orbit. Seedlings grew for 4d and were then fixed in-flight with paraformaldehyde. The experiment was replicated on the ground in a Random Positioning Machine, an effective simulator of microgravity. In addition, samples from a different space experiment, processed in a similar way but fixed in glutaraldehyde, including a control flight experiment in a 1g centrifuge, were also used. In all cases, comparisons were performed with ground controls at 1g. Seedlings grown in microgravity were significantly longer than the ground 1g controls. The cortical root meristematic cells were analyzed to investigate the alterations in cell proliferation and cell growth. Proliferation rate was quantified by counting the number of cells per millimeter in the specific cell files, and was found to be higher in microgravity-grown samples than in the control 1g. Cell growth was appraised through the rate of ribosome biogenesis, assessed by morphological and morphometrical parameters of the nucleolus and by the levels of the nucleolar protein nucleolin. All these parameters showed a depletion of the rate of ribosome production in microgravity-grown samples versus samples grown at 1g. The results show that growth in microgravity induces alterations in essential cellular functions. Cell growth and proliferation, which are strictly associated functions under normal ground conditions, appeared divergent after gravity modification; proliferation was enhanced, whereas growth was depleted. We suggest that the cause of these changes could be an alteration in the cell cycle regulation, at the levels of checkpoints regulating cell cycle progression, leading to a shortened G2 period.
Authors:
Isabel Mat?a; Fernando Gonz?lez-Camacho; Ra?l Herranz; John Z Kiss; Gilbert Gasset; Jack J W A van Loon; Roberto Marco; Francisco Javier Medina
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-10-27
Journal Detail:
Title:  Journal of plant physiology     Volume:  167     ISSN:  1618-1328     ISO Abbreviation:  J. Plant Physiol.     Publication Date:  2010 Feb 
Date Detail:
Created Date:  2010-02-01     Completed Date:  2010-04-27     Revised Date:  2010-05-24    
Medline Journal Info:
Nlm Unique ID:  9882059     Medline TA:  J Plant Physiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  184-93     Citation Subset:  IM    
Copyright Information:
Copyright 2009 Elsevier GmbH. All rights reserved.
Affiliation:
Centro de Investigaciones Biol?gicas (CSIC), Ramiro de Maeztu 9, E-28040 Madrid, Spain.
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MeSH Terms
Descriptor/Qualifier:
Arabidopsis / growth & development
Cell Enlargement*
Cell Proliferation*
Hypogravity*
Meristem / growth & development*
Seedling / growth & development*
Space Flight
Comments/Corrections
Comment In:
Plant Signal Behav. 2010 Feb;5(2):176-9   [PMID:  20173415 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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