title: Natural Variation in Arabidopsis Cvi-0 Accession Reveals an Important Role of MPK12 in Guard Cell CO2 Signaling.
abstract: Plant gas exchange is regulated by guard cells that form stomatal pores. Stomatal adjustments are crucial for plant survival; they regulate uptake of CO2 for photosynthesis, loss of water, and entrance of air pollutants such as ozone. We mapped ozone hypersensitivity, more open stomata, and stomatal CO2-insensitivity phenotypes of the Arabidopsis thaliana accession Cvi-0 to a single amino acid substitution in MITOGEN-ACTIVATED PROTEIN (MAP) KINASE 12 (MPK12). In parallel, we showed that stomatal CO2-insensitivity phenotypes of a mutant cis (CO2-insensitive) were caused by a deletion of MPK12. Lack of MPK12 impaired bicarbonate-induced activation of S-type anion channels. We demonstrated that MPK12 interacted with the protein kinase HIGH LEAF TEMPERATURE 1 (HT1)-a central node in guard cell CO2 signaling-and that MPK12 functions as an inhibitor of HT1. These data provide a new function for plant MPKs as protein kinase inhibitors and suggest a mechanism through which guard cell CO2 signaling controls plant water management.
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Liina
authors.initials: L
authors.lastname: Jakobson
authors.affiliation: Division of Plant Biology, Department of Biosciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
authors.forename: Lauri
authors.initials: L
authors.lastname: Vaahtera
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Kadri
authors.initials: K
authors.lastname: Tõldsepp
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Maris
authors.initials: M
authors.lastname: Nuhkat
authors.affiliation: Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California, United States of America.
authors.forename: Cun
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Yuh-Shuh
authors.initials: YS
authors.lastname: Wang
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Hanna
authors.initials: H
authors.lastname: Hõrak
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Ervin
authors.initials: E
authors.lastname: Valk
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Priit
authors.initials: P
authors.lastname: Pechter
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Yana
authors.initials: Y
authors.lastname: Sindarovska
authors.affiliation: College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Tang
authors.affiliation: College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Chuanlei
authors.initials: C
authors.lastname: Xiao
authors.affiliation: College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
authors.forename: Ulvi
authors.initials: U
authors.lastname: Gerst Talas
authors.affiliation: Institute of Chemistry, University of Tartu, Tartu, Estonia.
authors.forename: Alfonso T
authors.initials: AT
authors.lastname: García-Sosa
authors.affiliation: Molecular Plant Biology, Department of Biochemistry, University of Turku, Turku, Finland.
authors.forename: Saijaliisa
authors.initials: S
authors.lastname: Kangasjärvi
authors.affiliation: Institute of Chemistry, University of Tartu, Tartu, Estonia.
authors.forename: Uko
authors.initials: U
authors.lastname: Maran
authors.affiliation: Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
authors.forename: Maido
authors.initials: M
authors.lastname: Remm
authors.affiliation: Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, University of Würzburg, Würzburg, Germany.
authors.forename: M Rob G
authors.initials: MR
authors.lastname: Roelfsema
authors.affiliation: College of Life Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Honghong
authors.initials: H
authors.lastname: Hu
authors.affiliation: Division of Plant Biology, Department of Biosciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.|Distinguished Scientist Fellowship Program, College of Science, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kangasjärvi
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Mart
authors.initials: M
authors.lastname: Loog
authors.affiliation: Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California, United States of America.
authors.forename: Julian I
authors.initials: JI
authors.lastname: Schroeder
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.
authors.forename: Hannes
authors.initials: H
authors.lastname: Kollist
authors.affiliation: Institute of Technology, University of Tartu, Tartu, Estonia.|Division of Plant Biology, Department of Biosciences, Viikki Plant Science Centre, University of Helsinki, Helsinki, Finland.
authors.forename: Mikael
authors.initials: M
authors.lastname: Brosché
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism*; D002874:Chromosome Mapping; D014644:Genetic Variation; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010126:Ozone / Q000378:metabolism; D010788:Photosynthesis; D040641:Quantitative Trait Loci; D015398:Signal Transduction; D014867:Water
chemical_list: D029681:Arabidopsis Proteins; D014867:Water; D002245:Carbon Dioxide; D010126:Ozone; C436292:AtMPK4 protein, Arabidopsis; C583609:MPK12 protein, Arabidopsis; D020928:Mitogen-Activated Protein Kinases