title: The MeJA-inducible copper amine oxidase AtAO1 is expressed in xylem tissue and guard cells.
abstract: Copper amine oxidases oxidize the polyamine putrescine to 4-aminobutanal with the production of the plant signal molecule hydrogen peroxide (H2O2) and ammonia. The Arabidopsis (Arabidopsis thaliana) gene At4g14940 (AtAO1, previously referred to as ATAO1) encodes an apoplastic copper amine oxidase expressed in lateral root cap cells and developing xylem, especially in root protoxylem and metaxylem precursors. In our recent study, we demonstrated that AtAO1 expression is strongly induced in the root vascular tissues by the wound-signal hormone methyl jasmonate (MeJA). Furthermore, we also demonstrated that the H2O2 derived by the AtAO1-driven oxidation of putrescine, mediates the MeJA-induced early protoxylem differentiation in Arabidopsis roots. H2O2 may contribute to protoxylem differentiation by signaling developmental cell death and by acting as co-substrate in peroxidase-mediated cell wall stiffening and lignin polymerization. Here, by the means of AtAO1 promoter::green fluorescent protein-β-glucuronidase (AtAO1::GFP-GUS) fusion analysis, we show that a strong AtAO1 gene expression occurs also in guard cells of leaves and flowers. The high expression levels of AtAO1 in tissues or cell types regulating water supply and water loss may suggest a role of the encoded protein in water balance homeostasis, by modulating coordinated adjustments in anatomical and functional features of xylem tissue and guard cells during acclimation to adverse environmental conditions.
authors.affiliation: a Department of Science ; Università Roma Tre ; Rome , Italy.
authors.forename: Sandip A
authors.initials: SA
authors.lastname: Ghuge
authors.affiliation: a Department of Science ; Università Roma Tre ; Rome , Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Carucci
authors.affiliation: b Department of Life ; Health, and Environmental Sciences; Università dell'Aquila ; L'Aquila , Italy.
authors.forename: Renato A
authors.initials: RA
authors.lastname: Rodrigues-Pousada
authors.affiliation: a Department of Science ; Università Roma Tre ; Rome , Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Tisi
authors.affiliation: a Department of Science ; Università Roma Tre ; Rome , Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Franchi
authors.affiliation: a Department of Science ; Università Roma Tre ; Rome , Italy.|c Istituto Nazionale Biostrutture e Biosistemi (INBB) ; Rome , Italy.
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Tavladoraki
authors.affiliation: a Department of Science ; Università Roma Tre ; Rome , Italy.|c Istituto Nazionale Biostrutture e Biosistemi (INBB) ; Rome , Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Angelini
authors.affiliation: a Department of Science ; Università Roma Tre ; Rome , Italy.|c Istituto Nazionale Biostrutture e Biosistemi (INBB) ; Rome , Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Cona
mesh_terms: D000085:Acetates / Q000378:metabolism; D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism*; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism; D035264:Flowers / Q000378:metabolism; D005966:Glucuronidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D054883:Oxylipins / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D054046:Plant Stomata / Q000378:metabolism* / Q000502:physiology; D018526:Plant Transpiration; D030821:Plants, Genetically Modified; D011073:Polyamines / Q000378:metabolism; D011700:Putrescine / Q000378:metabolism; D014867:Water; D052584:Xylem / Q000378:metabolism* / Q000502:physiology
chemical_list: D000085:Acetates; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D011073:Polyamines; D014867:Water; C072239:methyl jasmonate; D006861:Hydrogen Peroxide; D010088:Oxidoreductases; C000605231:AO1 copper amine oxidase, Arabidopsis; D006631:Amine Oxidase (Copper-Containing); D005966:Glucuronidase; D011700:Putrescine
keywords: amine oxidases; cell wall; hydrogen peroxide; methyl sasmonate; polyamines; stomata; xylem differentiation