title: Arabidopsis protein phosphatase 2C ABI1 interacts with type I ACC synthases and is involved in the regulation of ozone-induced ethylene biosynthesis.
abstract: Ethylene plays a crucial role in various biological processes and therefore its biosynthesis is strictly regulated by multiple mechanisms. Posttranslational regulation, which is pivotal in controlling ethylene biosynthesis, impacts 1-aminocyclopropane 1-carboxylate synthase (ACS) protein stability via the complex interplay of specific factors. Here, we show that the Arabidopsis thaliana protein phosphatase type 2C, ABI1, a negative regulator of abscisic acid signaling, is involved in the regulation of ethylene biosynthesis under oxidative stress conditions. We found that ABI1 interacts with ACS6 and dephosphorylates its C-terminal fragment, a target of the stress-responsive mitogen-activated protein kinase, MPK6. In addition, ABI1 controls MPK6 activity directly and by this means also affects the ACS6 phosphorylation level. Consistently with this, ozone-induced ethylene production was significantly higher in an ABI1 knockout strain (abi1td) than in wild-type plants. Importantly, an increase in stress-induced ethylene production in the abi1td mutant was compensated by a higher ascorbate redox state and elevated antioxidant activities. Overall, the results of this study provide evidence that ABI1 restricts ethylene synthesis by affecting the activity of ACS6. The ABI1 contribution to stress phenotype underpins its role in the interplay between the abscisic acid (ABA) and ethylene signaling pathways.
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland. Electronic address: ludwika@amu.edu.pl.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Ludwików
authors.affiliation: Institute of Plant Genetics Polish Academy of Science, Strzeszyńska 34, Poznan 60-479, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Cieśla
authors.affiliation: Department of Molecular and Cellular Biology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Kasprowicz-Maluśki
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Filip
authors.initials: F
authors.lastname: Mituła
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Tajdel
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Gałgański
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Piotr A
authors.initials: PA
authors.lastname: Ziółkowski
authors.affiliation: Department of Biotechnology and Food Microbiology, University of Life Sciences, Wojska Polskiego 48, Poznań 60-627, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kubiak
authors.affiliation: Department of Biochemistry, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Arleta
authors.initials: A
authors.lastname: Małecka
authors.affiliation: Department of Biochemistry, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Aneta
authors.initials: A
authors.lastname: Piechalak
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Szabat
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Górska
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Dąbrowski
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland.
authors.forename: Izabela
authors.initials: I
authors.lastname: Ibragimow
authors.affiliation: Department of Biotechnology, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University in Poznań, Umultowska 89, Poznań 61-614, Poland; Institute of Plant Genetics Polish Academy of Science, Strzeszyńska 34, Poznan 60-479, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Sadowski
mesh_terms: D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000378:metabolism*; D005030:Ethylenes / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D008190:Lyases / Q000378:metabolism*; D010126:Ozone; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D011485:Protein Binding; D000071636:Protein Phosphatase 2C; D015398:Signal Transduction / Q000187:drug effects
chemical_list: D029681:Arabidopsis Proteins; D005030:Ethylenes; D010126:Ozone; C036216:ethylene; D010749:Phosphoprotein Phosphatases; D000071636:Protein Phosphatase 2C; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase
keywords: Arabidopsis.; hormonal regulation; protein phosphorylation/dephosphorylation; signal transduction