title: Protein phosphatase AP2C1 negatively regulates basal resistance and defense responses to Pseudomonas syringae.
abstract: Mitogen-activated protein kinases (MAPKs) mediate plant immune responses to pathogenic bacteria. However, less is known about the cell autonomous negative regulatory mechanism controlling basal plant immunity. We report the biological role of Arabidopsis thaliana MAPK phosphatase AP2C1 as a negative regulator of plant basal resistance and defense responses to Pseudomonas syringae. AP2C2, a closely related MAPK phosphatase, also negatively controls plant resistance. Loss of AP2C1 leads to enhanced pathogen-induced MAPK activities, increased callose deposition in response to pathogen-associated molecular patterns or to P. syringae pv. tomato (Pto) DC3000, and enhanced resistance to bacterial infection with Pto. We also reveal the impact of AP2C1 on the global transcriptional reprogramming of transcription factors during Pto infection. Importantly, ap2c1 plants show salicylic acid-independent transcriptional reprogramming of several defense genes and enhanced ethylene production in response to Pto. This study pinpoints the specificity of MAPK regulation by the different MAPK phosphatases AP2C1 and MKP1, which control the same MAPK substrates, nevertheless leading to different downstream events. We suggest that precise and specific control of defined MAPKs by MAPK phosphatases during plant challenge with pathogenic bacteria can strongly influence plant resistance.
authors.affiliation: Max F. Perutz Laboratories, University and Medical University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria.
authors.forename: Volodymyr
authors.initials: V
authors.lastname: Shubchynskyy
authors.affiliation: Max F. Perutz Laboratories, University and Medical University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria.
authors.forename: Justyna
authors.initials: J
authors.lastname: Boniecka
authors.affiliation: Max F. Perutz Laboratories, University and Medical University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria.|Institute of Biotechnology (IBT), University of Vilnius, Saulėtekio al. 7, LT-10257 Vilnius, Lithuania.
authors.forename: Alois
authors.initials: A
authors.lastname: Schweighofer
authors.affiliation: Institute of Biotechnology (IBT), University of Vilnius, Sauletekio al. 7, LT-10257 Vilnius, Lithuania.
authors.forename: Justinas
authors.initials: J
authors.lastname: Simulis
authors.affiliation: Institute of Biotechnology (IBT), University of Vilnius, Sauletekio al. 7, LT-10257 Vilnius, Lithuania.
authors.forename: Kotryna
authors.initials: K
authors.lastname: Kvederaviciute
authors.affiliation: Department of Biology, Chemin du Musée 10, CH-1700 Fribourg, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Stumpe
authors.affiliation: Department of Biology, Chemin du Musée 10, CH-1700 Fribourg, Switzerland.
authors.forename: Felix
authors.initials: F
authors.lastname: Mauch
authors.affiliation: Max-Planck-Institute for Molecular Plant Physiology, Golm and University of Potsdam, D-14476, Germany.
authors.forename: Salma
authors.initials: S
authors.lastname: Balazadeh
authors.affiliation: Max-Planck-Institute for Molecular Plant Physiology, Golm and University of Potsdam, D-14476, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Mueller-Roeber
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK.
authors.forename: Freddy
authors.initials: F
authors.lastname: Boutrot
authors.affiliation: The Sainsbury Laboratory, Norwich Research Park, Norwich NR4 7UH, UK.
authors.forename: Cyril
authors.initials: C
authors.lastname: Zipfel
authors.affiliation: Max F. Perutz Laboratories, University and Medical University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria.|Institute of Biotechnology (IBT), University of Vilnius, Saulėtekio al. 7, LT-10257 Vilnius, Lithuania.|Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
authors.forename: Irute
authors.initials: I
authors.lastname: Meskiene
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D010749:Phosphoprotein Phosphatases / Q000235:genetics* / Q000378:metabolism; D057865:Plant Immunity; D017027:Protein Tyrosine Phosphatases / Q000235:genetics* / Q000378:metabolism; D044224:Pseudomonas syringae / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; D020928:Mitogen-Activated Protein Kinases; C524430:AP2C1 protein, Arabidopsis; D010749:Phosphoprotein Phosphatases; C499612:MKP1 protein, Arabidopsis; D017027:Protein Tyrosine Phosphatases
keywords: Callose; MAPK; MAPK phosphatase; PAMP; PP2C phosphatase; Pseudomonas syringae; defense genes; salicylic acid; transcription factors.