title: Environmental regulation of stomatal response in the Arabidopsis Cvi-0 ecotype.
abstract: The Arabidopsis Cape Verde Islands (Cvi-0) ecotype is known to differ from other ecotypes with respect to environmental stress responses. We analyzed the stomatal behavior of Cvi-0 plants, in response to environmental signals. We investigated the responses of stomatal conductance and aperture to high [CO₂] in the Cvi-0 and Col-0 ecotypes. Cvi-0 showed constitutively higher stomatal conductance and more stomatal opening than Col-0. Cvi-0 stomata opened in response to light, but the response was slow. Under low humidity, stomatal opening was increased in Cvi-0 compared to Col-0. We then assessed whether low humidity affects endogenous ABA levels in Cvi-0. In response to low humidity, Cvi-0 had much higher ABA levels than Col-0. However, epidermal peels experiments showed that Cvi-0 stomata were insensitive to ABA. Measurements of organic and inorganic ions in Cvi-0 guard cell protoplasts indicated an over-accumulation of osmoregulatory anions (malate and Cl⁻). This irregular anion homeostasis in the guard cells may explain the constitutive stomatal opening phenotypes of the Cvi-0 ecotype, which lacks high [CO₂]-induced and low humidity-induced stomatal closure.
authors.affiliation: Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Keina
authors.initials: K
authors.lastname: Monda
authors.forename: Juntaro
authors.initials: J
authors.lastname: Negi
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Iio
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kusumi
authors.forename: Mikiko
authors.initials: M
authors.lastname: Kojima
authors.forename: Mimi
authors.initials: M
authors.lastname: Hashimoto
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sakakibara
authors.forename: Koh
authors.initials: K
authors.lastname: Iba
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D000393:Air Pollutants; D017360:Arabidopsis / Q000187:drug effects / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D055726:Cabo Verde; D002245:Carbon Dioxide; D060146:Ecotype; D018506:Gene Expression Regulation, Plant; D014644:Genetic Variation; D019441:Plant Epidermis / Q000187:drug effects; D054046:Plant Stomata / Q000235:genetics* / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D000393:Air Pollutants; D029681:Arabidopsis Proteins; D002245:Carbon Dioxide; D000040:Abscisic Acid