Linked Life Data

18685043

Source:http://linkedlifedata.com/resource/pubmed/id/18685043

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2008-10-7
pubmed:abstractText
Peroxisomes are important for recycling carbon and nitrogen that would otherwise be lost during photorespiration. The reduction of hydroxypyruvate to glycerate catalyzed by hydroxypyruvate reductase (HPR) in the peroxisomes is thought to be facilitated by the production of NADH by peroxisomal malate dehydrogenase (PMDH). PMDH, which is encoded by two genes in Arabidopsis (Arabidopsis thaliana), reduces NAD(+) to NADH via the oxidation of malate supplied from the cytoplasm to oxaloacetate. A double mutant lacking the expression of both PMDH genes was viable in air and had rates of photosynthesis only slightly lower than in the wild type. This is in contrast to other photorespiratory mutants, which have severely reduced rates of photosynthesis and require high CO(2) to grow. The pmdh mutant had a higher O(2)-dependent CO(2) compensation point than the wild type, implying that either Rubisco specificity had changed or that the rate of CO(2) released per Rubisco oxygenation was increased in the pmdh plants. Rates of gross O(2) evolution and uptake were similar in the pmdh and wild-type plants, indicating that chloroplast linear electron transport and photorespiratory O(2) uptake were similar between genotypes. The CO(2) postillumination burst and the rate of CO(2) released during photorespiration were both greater in the pmdh mutant compared with the wild type, suggesting that the ratio of photorespiratory CO(2) release to Rubisco oxygenation was altered in the pmdh mutant. Without PMDH in the peroxisome, the CO(2) released per Rubisco oxygenation reaction can be increased by over 50%. In summary, PMDH is essential for maintaining optimal rates of photorespiration in air; however, in its absence, significant rates of photorespiration are still possible, indicating that there are additional mechanisms for supplying reductant to the peroxisomal HPR reaction or that the HPR reaction is altogether circumvented.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-10938843, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-11030421, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-11128005, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-11154287, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-11960735, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-14507432, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-16367965, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-16492470, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-16660715, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-16663924, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-16667032, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-17046077, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-17376163, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-17400706, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-4362741, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-4840839, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-7092229, http://linkedlifedata.com/resource/pubmed/commentcorrection/18685043-7628449
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0032-0889
pubmed:author
pubmed:issnType
Print
pubmed:volume
148
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
786-95
pubmed:dateRevised
2010-9-22
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Peroxisomal malate dehydrogenase is not essential for photorespiration in Arabidopsis but its absence causes an increase in the stoichiometry of photorespiratory CO2 release.
pubmed:affiliation
School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA. acousins@wsu.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't