title: The HT1 protein kinase is essential for red light-induced stomatal opening and genetically interacts with OST1 in red light and CO2 -induced stomatal movement responses.
abstract: The question of whether red light-induced stomatal opening is mediated by a photosynthesis-derived reduction in intercellular [CO2 ] (Ci ) remains controversial and genetic analyses are needed. The Arabidopsis thaliana protein kinase HIGH TEMPERATURE 1 (HT1) is a negative regulator of [CO2 ]-induced stomatal closing and ht1-2 mutant plants do not show stomatal opening to low [CO2 ]. The protein kinase mutant ost1-3 exhibits slowed stomatal responses to CO2 . The functions of HT1 and OPEN STOMATA 1 (OST1) to changes in red, blue light or [CO2 ] were analyzed. For comparison we assayed recessive ca1ca4 carbonic anhydrase double mutant plants, based on their slowed stomatal response to CO2 . Here, we report a strong impairment in ht1 in red light-induced stomatal opening whereas blue light was able to induce stomatal opening. The effects on photosynthetic performance in ht1 were restored when stomatal limitation of CO2 uptake, by control of [Ci ], was eliminated. HT1 was found to interact genetically with OST1 both during red light- and low [CO2 ]-induced stomatal opening. Analyses of ca1ca4 plants suggest that more than a low [Ci ]-dependent pathway may function in red light-induced stomatal opening. These results demonstrate that HT1 is essential for red light-induced stomatal opening and interacts genetically with OST1 during stomatal responses to red light and altered [CO2 ].
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Matrosova
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden.
authors.forename: Hanumakumar
authors.initials: H
authors.lastname: Bogireddi
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Mateo-Peñas
authors.affiliation: Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Mimi
authors.initials: M
authors.lastname: Hashimoto-Sugimoto
authors.affiliation: Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, 812-8581, Japan.
authors.forename: Koh
authors.initials: K
authors.lastname: Iba
authors.affiliation: Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, CA, 92093-0116, USA.
authors.forename: Julian I
authors.initials: JI
authors.lastname: Schroeder
authors.affiliation: Umeå Plant Science Center, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Israelsson-Nordström
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism*; D017343:Genes, Plant; D008027:Light; D009154:Mutation; D010788:Photosynthesis / Q000235:genetics*; D054046:Plant Stomata; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D002245:Carbon Dioxide; C000610355:HT1 protein, Arabidopsis; D011494:Protein Kinases; C472139:OST1 protein, Arabidopsis
keywords: Arabidopsis thaliana; HIGH TEMPERATURE 1 (HT1); OPEN STOMATA 1 (OST1); low [CO2]; photosynthesis; red light; stomata