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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1997-10-23
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pubmed:abstractText |
In this study, confocal ratio analysis was used to image the relationship between cytoplasmic free calcium concentration ([Ca2+]c) and the development of root hairs of Arabidopsis thaliana. Although a localized change in [Ca2+]c that preceded or predicted the site of root hair initiation could not be detected, once initiated the majority of emerging root hairs showed an elevated [Ca2+]c (> 1 microM) in their apical cytoplasm, compared with 100-200 nM in the rest of the cell. These emerging root hairs then moved into a 3-5 h phase of sustained elongation during which they showed variable growth rates. Root hairs that were rapidly elongating exhibited a highly localized, elevated [Ca2+]c at the tip. Non-growing root hairs did not exhibit the [Ca2+]c gradient. The rhd-2 mutant, which is defective in sustained root hair growth, showed an altered [Ca2+]c distribution compared with wild-type. These results implicate [Ca2+]c in regulating the tip growth process. Treatment of elongating wild-type root hairs with the Ca2+ channel blocker verapamil (50 microM) caused dissipation of the elevated [Ca2+]c at the tip and cessation of growth, suggesting a requirement for Ca2+ channel activity at the root hair tip to maintain growth. Manganese treatment also preferentially quenched Indo-1 fluorescence in the apical cytoplasm of the root hair. As manganese is thought to enter cells through Ca(2+)-permeable channels, this result also suggests increased Ca2+ channel activity at the tip of the growing hair. Taken together, these data suggest that although Ca2+ does not trigger the initiation of root hairs, Ca2+ influx at the tip of the root hair leads to an elevated [Ca2+]c that may be required to sustain root hair elongation.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Aug
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pubmed:issn |
0960-7412
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
12
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
427-39
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:9301093-Arabidopsis,
pubmed-meshheading:9301093-Calcium,
pubmed-meshheading:9301093-Cytosol,
pubmed-meshheading:9301093-Fluorescent Dyes,
pubmed-meshheading:9301093-Indoles,
pubmed-meshheading:9301093-Kinetics,
pubmed-meshheading:9301093-Microscopy, Video,
pubmed-meshheading:9301093-Plant Roots
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pubmed:year |
1997
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pubmed:articleTitle |
Cytoplasmic free calcium distributions during the development of root hairs of Arabidopsis thaliana.
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pubmed:affiliation |
Department of Biology, Mueller Lab, Pennsylvania State University, University Park 16802, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, Non-P.H.S.
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