Document Detail

Cellular basis of growth suppression by submergence in azuki bean epicotyls.
MedLine Citation:
PMID:  18940853     Owner:  NLM     Status:  MEDLINE    
BACKGROUND AND AIMS: Complete submergence severely reduces growth rate and productivity of terrestrial plants, but much remains to be elucidated regarding the mechanisms involved. The aim of this study was to clarify the cellular basis of growth suppression by submergence in stems.
METHODS: The effects of submergence on the viscoelastic extensibility of the cell wall and the cellular osmotic concentration were studied in azuki bean epicotyls. Modifications by submergence to chemical properties of the cell wall; levels of osmotic solutes and their translocation from the seed to epicotyls; and apoplastic pH and levels of ATP and ethanol were also examined. These cellular events underwater were compared in etiolated and in light-grown seedlings.
KEY RESULTS: Under submergence, the osmotic concentration of the cell sap was substantially decreased via decreased concentrations of organic compounds including sugars and amino acids. In contrast, the viscoelastic extensibility of the cell wall was kept high. Submergence also decreased ATP and increased the pH of the apoplastic solution. Alcoholic fermentation was stimulated underwater, but the resulting accumulated ethanol was not directly involved in growth suppression. Light partially relieved the inhibitory effects of submergence on growth, osmoregulation and sugar translocation.
CONCLUSIONS: A decrease in the levels of osmotic solutes is a main cause of underwater growth suppression in azuki bean epicotyls. This may be brought about by suppression of solute uptake via breakdown of the H(+) gradient across the plasma membrane due to a decrease in ATP. The involvement of cell wall properties in underwater growth suppression remains to be fully elucidated.
Kentaro Ooume; Yuki Inoue; Kouichi Soga; Kazuyuki Wakabayashi; Shuhei Fujii; Ryoichi Yamamoto; Takayuki Hoson
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Publication Detail:
Type:  Journal Article     Date:  2008-10-21
Journal Detail:
Title:  Annals of botany     Volume:  103     ISSN:  1095-8290     ISO Abbreviation:  Ann. Bot.     Publication Date:  2009 Jan 
Date Detail:
Created Date:  2009-01-12     Completed Date:  2009-02-11     Revised Date:  2013-06-05    
Medline Journal Info:
Nlm Unique ID:  0372347     Medline TA:  Ann Bot     Country:  England    
Other Details:
Languages:  eng     Pagination:  325-32     Citation Subset:  IM    
Department of Biology, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.
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MeSH Terms
Adenosine Triphosphate / metabolism
Cell Wall / metabolism,  radiation effects
Elasticity / radiation effects
Ethanol / metabolism
Fabaceae / cytology*,  growth & development*,  radiation effects
Hydrogen-Ion Concentration / radiation effects
Osmosis / radiation effects
Seedling / cytology*,  growth & development*,  radiation effects
Water-Electrolyte Balance / radiation effects
Reg. No./Substance:
56-65-5/Adenosine Triphosphate; 64-17-5/Ethanol

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

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