Linked Life Data

12857833

Source:http://linkedlifedata.com/resource/pubmed/id/12857833

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2003-7-14
pubmed:abstractText
Light-mediated chloroplast movements are common in plants. When leaves of Alocasia brisbanensis (F.M. Bailey) Domin are exposed to dim light, mesophyll chloroplasts spread along the periclinal walls normal to the light, maximizing absorbance. Under high light, the chloroplasts move to anticlinal walls. It has been proposed that movement to the high-light position shortens the diffusion path for CO(2) from the intercellular air spaces to the chloroplasts, thus reducing CO(2) limitation of photosynthesis. To test this hypothesis, we used pulsed photoacoustics to measure oxygen diffusion times as a proxy for CO(2) diffusion in leaf cells. We found no evidence that chloroplast movement to the high-light position enhanced gas diffusion. Times for oxygen diffusion were not shorter in leaves pretreated with white light, which induced chloroplast movement to the high-light position, compared with leaves pretreated with 500 to 700 nm light, which did not induce movement. From the oxygen diffusion time and the diffusion distance from chloroplasts to the intercellular gas space, we calculated an oxygen permeability of 2.25 x 10(-)(6) cm(2) s(-)(1) for leaf cells at 20 degrees C. When leaf temperature was varied from 5 degrees C to 40 degrees C, the permeability for oxygen increased between 5 degrees C and 20 degrees C but changed little between 20 degrees C and 40 degrees C, indicating changes in viscosity or other physical parameters of leaf cells above 20 degrees C. Resistance for CO(2) estimated from oxygen permeability was in good agreement with published values, validating photoacoustics as another way of assessing internal resistances to CO(2) diffusion.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-10750712, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-11251116, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-11296882, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-11309623, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-11371609, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-11424903, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-11978863, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-12011343, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-12481082, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-12490952, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-12540824, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-16593952, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-16662498, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-16667697, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-8416987, http://linkedlifedata.com/resource/pubmed/commentcorrection/12857833-8551742
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1529-39
pubmed:dateRevised
2010-9-14
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Photoacoustic analysis indicates that chloroplast movement does not alter liquid-phase CO2 diffusion in leaves of Alocasia brisbanensis.
pubmed:affiliation
Department of Biology, St. Mary's College of Maryland, St. Mary's City, Maryland 20686-3001, USA. hlgorton@smcm.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't