title: The Arabidopsis aquaporin PIP1;2 rules cellular CO(2)  uptake.
abstract: The membrane CO(2) flux into Arabidopsis mesophyll cells was studied using a scanning pH microelectrode. Arabidopsis thaliana mesophyll cells were exposed to photosynthesis-triggering light intensities, which induced cellular CO(2) uptake. Data obtained on a AtPIP1;2 T-DNA insertion line indicated that under these conditions, cellular CO(2) transport was not limited by unstirred layer effects but was dependent on the expression of the aquaporin AtPIP1;2. Complementation of the AtPIP1;2 knockout restored membrane CO(2) transport levels to that of controls. The results provide new arguments for the ongoing debate about the validity of the lipid bilayer model system and the Meyer - Overton rule for cellular gas transport. In conclusion, we suggest a modified model of molecular gas transport mechanisms in living cells.
authors.affiliation: Applied Plant Sciences, Technische Universität Darmstadt, Schnittspahnstr. 10, D-64287 Darmstadt, Germany. uehlein@bio.tu-darmstadt.de
authors.forename: Norbert
authors.initials: N
authors.lastname: Uehlein
authors.forename: Henrik
authors.initials: H
authors.lastname: Sperling
authors.forename: Marlies
authors.initials: M
authors.lastname: Heckwolf
authors.forename: Ralf
authors.initials: R
authors.lastname: Kaldenhoff
mesh_terms: D020346:Aquaporins / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D004269:DNA, Bacterial; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D005816:Genetic Complementation Test; D006863:Hydrogen-Ion Concentration; D058503:Mesophyll Cells / Q000378:metabolism; D016254:Mutagenesis, Insertional
chemical_list: D020346:Aquaporins; D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; C036483:T-DNA; D002245:Carbon Dioxide