Linked Life Data

7568166

Source:http://linkedlifedata.com/resource/pubmed/id/7568166

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
1995-11-14
pubmed:abstractText
Abscisic acid (ABA) modulates the activities of three major classes of ion channels--inward- and outward-rectifying K+ channels (IK,in and IK,out, respectively) and anion channels--at the guard-cell plasma membrane to achieve a net efflux of osmotica and stomatal closure. Disruption of ABA sensitivity in wilty abi1-1 mutants of Arabidopsis and evidence that this gene encodes a protein phosphatase suggest that protein (de)-phosphorylation contributes to guard-cell transport control by ABA. To pinpoint the role of ABI1, the abi1-1 dominant mutant allele was stably transformed into Nicotiana benthamiana and its influence on IK,in, IK,out, and the anion channels was monitored in guard cells under voltage clamp. Compared with guard cells from wild-type and vector-transformed control plants, expression of the abi1-1 gene was associated with 2- to 6-fold reductions in IK,out and an insensitivity of both IK,in and IK,out to 20 microM ABA. In contrast, no differences between control and abi1-1 transgenic plants were observed in the anion current or its response to ABA. Parallel measurements of intracellular pH (pHi) using the fluorescent dye 2',7'-bis(2-carboxyethyl)-5-(and -6)-carboxyfluorescein (BCECF) in every case showed a 0.15- to 0.2-pH-unit alkalinization in ABA, demonstrating that the transgene was without effect on the pHi signal that mediates in ABA-evoked K+ channel control. In guard cells from the abi1-1 transformants, normal sensitivity of both K+ channels to and stomatal closure in ABA was recovered in the presence of 100 microM H7 and 0.5 microM staurosporine, both broad-range protein kinase antagonists. These results demonstrate an aberrant K+ channel behavior--including channel insensitivity to ABA-dependent alkalinization of pHi--as a major consequence of abi1-1 action and implicate AB11 as part of a phosphatase/kinase pathway that modulates the sensitivity of guard-cell K+ channels to ABA-evoked signal cascades.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-1333658, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-1375754, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-1534380, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-16593964, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-2549856, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-7681590, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-7827492, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-7858204, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-7910981, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-8006956, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-8130798, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-8185946, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-8196617, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-8197457, http://linkedlifedata.com/resource/pubmed/commentcorrection/7568166-8265579
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
92
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9520-4
pubmed:dateRevised
2010-9-13
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Sensitivity to abscisic acid of guard-cell K+ channels is suppressed by abi1-1, a mutant Arabidopsis gene encoding a putative protein phosphatase.
pubmed:affiliation
University of London, Wye College, Kent, England.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't