title: PECTIN METHYLESTERASE34 Contributes to Heat Tolerance through Its Role in Promoting Stomatal Movement.
abstract: Pectin, a major component of the primary cell wall, is synthesized in the Golgi apparatus and exported to the cell wall in a highly methylesterified form, then is partially demethylesterified by pectin methylesterases (PMEs; EC 3.1.1.11). PME activity on the status of pectin methylesterification profoundly affects the properties of pectin and, thereby, is critical for plant development and the plant defense response, although the roles of PMEs under heat stress (HS) are poorly understood. Functional genome annotation predicts that at least 66 potentialPMEgenes are contained in Arabidopsis (Arabidopsis thaliana). Thermotolerance assays ofPMEgene T-DNA insertion lines revealed two null mutant alleles ofPME34(At3g49220) that both consistently showed reduced thermotolerance. Nevertheless, their impairment was independently associated with the expression of HS-responsive genes. It was also observed thatPME34transcription was induced by abscisic acid and highly expressed in guard cells. We showed that thePME34mutation has a defect in the control of stomatal movement and greatly altered PME and polygalacturonase (EC 3.2.1.15) activity, resulting in a heat-sensitive phenotype.PME34has a role in the regulation of transpiration through the control of the stomatal aperture due to its cell wall-modifying enzyme activity during the HS response. Hence, PME34 is required for regulating guard cell wall flexibility to mediate the heat response in Arabidopsis.
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (Y.C.H., H.C.W., Y.D.W., C.H.L., C.C.L., D.L.L., T.L.J.); and.|Department of Biological Sciences and Technology, National University of Tainan, Tainan 70005, Taiwan (H.C.W.).
authors.forename: Ya-Chen
authors.identifier: http://orcid.org/0000-0002-2090-0378
authors.initials: YC
authors.lastname: Huang
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (Y.C.H., H.C.W., Y.D.W., C.H.L., C.C.L., D.L.L., T.L.J.); and.|Department of Biological Sciences and Technology, National University of Tainan, Tainan 70005, Taiwan (H.C.W.).
authors.forename: Hui-Chen
authors.identifier: http://orcid.org/0000-0002-4991-7616
authors.initials: HC
authors.lastname: Wu
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (Y.C.H., H.C.W., Y.D.W., C.H.L., C.C.L., D.L.L., T.L.J.); and.|Department of Biological Sciences and Technology, National University of Tainan, Tainan 70005, Taiwan (H.C.W.).
authors.forename: Yin-Da
authors.initials: YD
authors.lastname: Wang
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (Y.C.H., H.C.W., Y.D.W., C.H.L., C.C.L., D.L.L., T.L.J.); and.|Department of Biological Sciences and Technology, National University of Tainan, Tainan 70005, Taiwan (H.C.W.).
authors.forename: Chia-Hung
authors.initials: CH
authors.lastname: Liu
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (Y.C.H., H.C.W., Y.D.W., C.H.L., C.C.L., D.L.L., T.L.J.); and.|Department of Biological Sciences and Technology, National University of Tainan, Tainan 70005, Taiwan (H.C.W.).
authors.forename: Ching-Chih
authors.identifier: http://orcid.org/0000-0002-7586-5178
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (Y.C.H., H.C.W., Y.D.W., C.H.L., C.C.L., D.L.L., T.L.J.); and.|Department of Biological Sciences and Technology, National University of Tainan, Tainan 70005, Taiwan (H.C.W.).
authors.forename: Dan-Li
authors.initials: DL
authors.lastname: Luo
authors.affiliation: Institute of Plant Biology, National Taiwan University, Taipei 10617, Taiwan (Y.C.H., H.C.W., Y.D.W., C.H.L., C.C.L., D.L.L., T.L.J.); and jinnt@ntu.edu.tw.|Department of Biological Sciences and Technology, National University of Tainan, Tainan 70005, Taiwan (H.C.W.) jinnt@ntu.edu.tw.
authors.forename: Tsung-Luo
authors.identifier: http://orcid.org/0000-0002-5185-7691
authors.initials: TL
authors.lastname: Jinn
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D018869:Heat-Shock Response / Q000502:physiology*; D009154:Mutation; D054046:Plant Stomata / Q000502:physiology*; D018526:Plant Transpiration / Q000502:physiology; D030821:Plants, Genetically Modified
chemical_list: D029681:Arabidopsis Proteins; D000040:Abscisic Acid; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase