Linked Life Data

14750517

Source:http://linkedlifedata.com/resource/pubmed/id/14750517

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2004-1-30
pubmed:databankReference
pubmed:abstractText
Expansins are members of a multigene family of extracellular proteins, which increase cell wall extensibility in vitro and thus are thought to be involved in cell expansion. The major significance of the presence of this large gene family may be that distinctly expressed genes can independently regulate cell expansion in place and time. Here we report on LeExp9, a new expansin gene from tomato, and compare its expression in the shoot tip with that of LeExp2 and LeExp18. LeExp18 gene is expressed in very young tissues of the tomato shoot apex and the transcript levels are upregulated in the incipient primordium. LeExp2 mRNA accumulated in more mature tissues and transcript levels correlated with cell elongation in the elongation zone. In situ hybridization experiments showed a uniform distribution of LeExp9 mRNA in submeristematic tissues. When gibberellin-deficient mutant tomatoes that lacked elongation of the internodes were treated with gibberellin, the phenotypic rescue was correlated with an increase in LeExp9 and LeExp2, but not LeExp18 levels. We propose that the three expansins define three distinct growing zones in the shoot tip. In the meristem proper, gibberellin-independent LeExp18 mediates the cell expansion that accompanies cell division. In the submeristematic zone, LeExp9 mediates cell expansion at a time that cell division comes to a halt. LeExp9 expression requires gibberellin but the hormone is not normally limiting. Finally, LeExp2 mediates cell elongation in young stem tissue. LeExp2 expression is limited by the available gibberellin. These data suggest that regulation of cell wall extensibility is controlled, at least in part, by differential regulation of expansin genes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0167-4412
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
267-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Domains of expansin gene expression define growth regions in the shoot apex of tomato.
pubmed:affiliation
Institute of Plant Sciences, University of Berne, Altenbergrain 21, CH-3013 Berne, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't