Environmental regulation of stomatal response in the Arabidopsis Cvi-0 ecotype

• Published in: Planta 2011-09, Vol.234 (3), p.555-563
• Main Authors: Monda, Keina, Negi, Juntaro, Iio, Atsuhiro, Kusumi, Kensuke, Kojima, Mikiko, Hashimoto, Mimi, Sakakibara, Hitoshi, Iba, Koh
• Format: Article
• Language: English
• Subjects: Abscisic Acid - metabolism; Agriculture; Air Pollutants; Anions; Arabidopsis - drug effects; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological and medical sciences; Biomedical and Life Sciences; Cabo Verde; Carbon Dioxide; Ecology; Ecotype; Ecotypes; Environmental regulations; Environmental stress; Forestry; Fundamental and applied biological sciences. Psychology; Gene expression regulation; Gene Expression Regulation, Plant; Genetic Variation; Guard cells; Humidity; Life Sciences; Original Article; Phenotypes; Plant cells; Plant Epidermis - drug effects; Plant Sciences; Plant Stomata - genetics; Plant Stomata - physiology; Plants; Signal Transduction - drug effects; Stomata; Stomatal conductance
• ISSN: 0032-0935; 1432-2048
• DOI: 10.1007/s00425-011-1424-x

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 osmo-regulatory 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.