title: Starch Biosynthesis in Guard Cells But Not in Mesophyll Cells Is Involved in CO2-Induced Stomatal Closing.
abstract: Starch metabolism is involved in stomatal movement regulation. However, it remains unknown whether starch-deficient mutants affect CO2-induced stomatal closing and whether starch biosynthesis in guard cells and/or mesophyll cells is rate limiting for high CO2-induced stomatal closing. Stomatal responses to [CO2] shifts and CO2 assimilation rates were compared in Arabidopsis (Arabidopsis thaliana) mutants that were either starch deficient in all plant tissues (ADP-Glc-pyrophosphorylase [ADGase]) or retain starch accumulation in guard cells but are starch deficient in mesophyll cells (plastidial phosphoglucose isomerase [pPGI]). ADGase mutants exhibited impaired CO2-induced stomatal closure, but pPGI mutants did not, showing that starch biosynthesis in guard cells but not mesophyll functions in CO2-induced stomatal closing. Nevertheless, starch-deficient ADGase mutant alleles exhibited partial CO2 responses, pointing toward a starch biosynthesis-independent component of the response that is likely mediated by anion channels. Furthermore, whole-leaf CO2 assimilation rates of both ADGase and pPGI mutants were lower upon shifts to high [CO2], but only ADGase mutants caused impairments in CO2-induced stomatal closing. These genetic analyses determine the roles of starch biosynthesis for high CO2-induced stomatal closing.
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, Center for Food and Fuel for the 21st Century, University of California, San Diego, La Jolla, California 92093-0116.
authors.forename: Tamar
authors.identifier: 0000-0002-4291-6901
authors.initials: T
authors.lastname: Azoulay-Shemer
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, Center for Food and Fuel for the 21st Century, University of California, San Diego, La Jolla, California 92093-0116.
authors.forename: Andisheh
authors.identifier: 0000-0003-1083-3981
authors.initials: A
authors.lastname: Bagheri
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, Center for Food and Fuel for the 21st Century, University of California, San Diego, La Jolla, California 92093-0116.
authors.forename: Cun
authors.identifier: 0000-0001-6975-0959
authors.initials: C
authors.lastname: Wang
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, Center for Food and Fuel for the 21st Century, University of California, San Diego, La Jolla, California 92093-0116.
authors.forename: Axxell
authors.identifier: 0000-0002-1101-7559
authors.initials: A
authors.lastname: Palomares
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, Center for Food and Fuel for the 21st Century, University of California, San Diego, La Jolla, California 92093-0116.
authors.forename: Aaron B
authors.initials: AB
authors.lastname: Stephan
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, Center for Food and Fuel for the 21st Century, University of California, San Diego, La Jolla, California 92093-0116 henning.kunz@wsu.edu jischroeder@ucsd.edu.
authors.forename: Hans-Henning
authors.identifier: 0000-0001-8000-0817
authors.initials: HH
authors.lastname: Kunz
authors.affiliation: Division of Biological Sciences, Section of Cell and Developmental Biology, Center for Food and Fuel for the 21st Century, University of California, San Diego, La Jolla, California 92093-0116 henning.kunz@wsu.edu jischroeder@ucsd.edu.
authors.forename: Julian I
authors.initials: JI
authors.lastname: Schroeder
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism*; D005956:Glucose-6-Phosphate Isomerase / Q000235:genetics / Q000378:metabolism; D058503:Mesophyll Cells / Q000502:physiology; D009154:Mutation; D010641:Phenotype; D018515:Plant Leaves / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D054046:Plant Stomata / Q000235:genetics / Q000502:physiology*; D018087:Plastids / Q000201:enzymology; D013213:Starch / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D002245:Carbon Dioxide; D013213:Starch; D005956:Glucose-6-Phosphate Isomerase