title: Kinematic evidence that atmospheric nitrogen dioxide increases the rates of cell proliferation and enlargement to stimulate leaf expansion in Arabidopsis.
abstract: To elucidate the stimulation of leaf growth by atmospheric nitrogen dioxide (NO2), we performed a kinematic analysis of the eighth leaves of Arabidopsis thaliana (accession C24) plants grown for 17-35 days after sowing in the presence or absence of 50 ppb NO2 (designated +NO2 plants and -NO2 plants, respectively). We found that the peak and mean values of the relative rates of leaf expansion, cell division and cell expansion were always greater in +NO2 plants than in -NO2 plants. No evidence for prolonged duration was obtained. Thus, NO2 treatment increased the rates of both cell proliferation and enlargement to increase leaf size. Furthermore, a fold-change analysis showed that cell proliferation and enlargement differentially regulated NO2-induced leaf expansion.
authors.affiliation: a Department of Mathematical and Life Sciences ; Hiroshima University ; Higashi-Hiroshima , Japan.
authors.forename: Misa
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: a Department of Mathematical and Life Sciences ; Hiroshima University ; Higashi-Hiroshima , Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Morikawa
mesh_terms: D017360:Arabidopsis / Q000166:cytology*; D001272:Atmosphere / Q000737:chemistry*; D001696:Biomechanical Phenomena; D002452:Cell Count; D049109:Cell Proliferation / Q000187:drug effects; D048429:Cell Size; D009585:Nitrogen Dioxide / Q000494:pharmacology*; D018515:Plant Leaves / Q000166:cytology* / Q000187:drug effects / Q000254:growth & development
chemical_list: D009585:Nitrogen Dioxide
keywords: Arabidopsis thaliana; cell division; cell expansion; kinematic analysis; leaf expansion; leaf size; nitrogen dioxide (NO2)