title: SIZ1 deficiency causes reduced stomatal aperture and enhanced drought tolerance via controlling salicylic acid-induced accumulation of reactive oxygen species in Arabidopsis.
abstract: Transpiration and gas exchange occur through stomata. Thus, the control of stomatal aperture is important for the efficiency and regulation of water use, and for the response to drought. Here, we demonstrate that SIZ1-mediated endogenous salicylic acid (SA) accumulation plays an important role in stomatal closure and drought tolerance. siz1 reduced stomatal apertures. The reduced stomatal apertures of siz1 were inhibited by the application of peroxidase inhibitors, salicylhydroxamic acid and azide, which inhibits SA-dependent reactive oxygen species (ROS) production, but not by an NADPH oxidase inhibitor, diphenyl iodonium chloride, which inhibits ABA-dependent ROS production. Furthermore, the introduction of nahG into siz1, which reduces SA accumulation, restored stomatal opening. Stomatal closure is generally induced by water deficit. The siz1 mutation caused drought tolerance, whereas nahG siz1 suppressed the tolerant phenotype. Drought stresses also induced expression of SA-responsive genes, such as PR1 and PR2. Furthermore, other SA-accumulating mutants, cpr5 and acd6, exhibited stomatal closure and drought tolerance, and nahG suppressed the phenotype of cpr5 and acd6, as did siz1 and nahG siz1. Together, these results suggest that SIZ1 negatively affects stomatal closure and drought tolerance through the accumulation of SA.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tukuba, 305-8572, Japan.|Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907-2010, USA.
authors.forename: Kenji
authors.initials: K
authors.lastname: Miura
authors.affiliation: Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Okamoto
authors.affiliation: Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Okuma
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tukuba, 305-8572, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Shiba
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tukuba, 305-8572, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamada
authors.affiliation: Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN, 47907-2010, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Hasegawa
authors.affiliation: Graduate School of Natural Science and Technology, Okayama University, Okayama, 700-8530, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Murata
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics / Q000502:physiology; D017360:Arabidopsis / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology; D003681:Dehydration / Q000503:physiopathology; D008025:Ligases / Q000172:deficiency* / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D010937:Plant Growth Regulators / Q000502:physiology*; D054046:Plant Stomata / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D010937:Plant Growth Regulators; D017382:Reactive Oxygen Species; D008025:Ligases; C502552:SIZ1 protein, Arabidopsis; D020156:Salicylic Acid