title: Methylglyoxal-induced stomatal closure accompanied by peroxidase-mediated ROS production in Arabidopsis.
abstract: Methylglyoxal (MG) is an oxygenated short aldehyde and a glycolytic intermediate that accumulates in plants under environmental stresses. Being a reactive α-oxoaldehyde, MG may act as a signaling molecule in plants during stresses. We investigated whether MG induces stomatal closure, reactive oxygen species (ROS) production, and cytosolic free calcium concentration ([Ca²⁺](cyt)) to clarify roles of MG in Arabidopsis guard cells. MG induced production of ROS and [Ca²⁺](cyt) oscillations, leading to stomatal closure. The MG-induced stomatal closure and ROS production were completely inhibited by a peroxidase inhibitor, salicylhydroxamic acid (SHAM), but were not affected by an NAD(P)H oxidase mutation, atrbohD atrbohF. Furthermore, the MG-elicited [Ca²⁺](cyt) oscillations were significantly suppressed by SHAM but not by the atrbohD atrbohF mutation. Neither endogenous abscisic acid nor endogenous methyl jasmonate was involved in MG-induced stomatal closure. These results suggest that intrinsic metabolite MG can induce stomatal closure in Arabidopsis accompanied by extracellular ROS production mediated by SHAM-sensitive peroxidases, intracellular ROS accumulation, and [Ca²⁺](cyt) oscillations.
authors.affiliation: Division of Bioscience, Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
authors.forename: Tahsina Sharmin
authors.initials: TS
authors.lastname: Hoque
authors.forename: Misugi
authors.initials: M
authors.lastname: Uraji
authors.forename: Wenxiu
authors.initials: W
authors.lastname: Ye
authors.forename: Mohammad Anowar
authors.initials: MA
authors.lastname: Hossain
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Nakamura
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Murata
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology*; D020013:Calcium Signaling / Q000187:drug effects; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009195:Peroxidase / Q000378:metabolism*; D054046:Plant Stomata / Q000166:cytology / Q000187:drug effects* / Q000502:physiology*; D011765:Pyruvaldehyde / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D011765:Pyruvaldehyde; D009195:Peroxidase