title: Distinct responses to ozone of abaxial and adaxial stomata in three Euramerican poplar genotypes.
abstract: Ozone induces stomatal sluggishness, which impacts photosynthesis and transpiration. Stomatal responses to variation of environmental parameters are slowed and reduced by ozone and may be linked to difference of ozone sensitivity. Here we determine the ozone effects on stomatal conductance of each leaf surface. Potential causes of this sluggish movement, such as ultrastructural or ionic fluxes modification, were studied independently on both leaf surfaces of three Euramerican poplar genotypes differing in ozone sensitivity and in stomatal behaviour. The element contents in guard cells were linked to the gene expression of ion channels and transporters involved in stomatal movements, directly in microdissected stomata. In response to ozone, we found a decrease in the stomatal conductance of the leaf adaxial surface correlated with high calcium content in guard cells compared with a slight decrease on the abaxial surface. No ultrastructural modifications of stomata were shown except an increase in the number of mitochondria. The expression of vacuolar H(+) /Ca(2+) -antiports (CAX1 and CAX3 homologs), β-carbonic anhydrases (βCA1 and βCA4) and proton H(+) -ATPase (AHA11) genes was strongly decreased under ozone treatment. The sensitive genotype characterized by constitutive slow stomatal response was also characterized by constitutive low expression of genes encoding vacuolar H(+) /Ca(2+) -antiports.
authors: INRA, UMR 1137, Ecologie et Ecophysiologie Forestières, Champenoux, F-54280, France; Université de Lorraine, UMR 1137, Ecologie et Ecophysiologie Forestières, Vandoeuvre-lès-Nancy, F-54500, France; IFR110 EFABA, Vandoeuvre-lès-Nancy, F-54500, France.
authors: Jennifer
authors: J
authors: Dumont
authors: David
authors: D
authors: Cohen
authors: Joëlle
authors: J
authors: Gérard
authors: Yves
authors: Y
authors: Jolivet
authors: Pierre
authors: P
authors: Dizengremel
authors: Didier
authors: D
authors: LE Thiec
mesh_terms: D004602:Elements; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005838:Genotype; D042282:Microdissection; D010126:Ozone / Q000494:pharmacology*; D054046:Plant Stomata / Q000033:anatomy & histology* / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D032107:Populus / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*
chemical_list: D004602:Elements; D010126:Ozone
keywords: Populus deltoides × Populus nigra; abaxial and adaxial surfaces; element content; gas exchange; gene expression; guard cell; ultrastructure.