title: POLYAMINE OXIDASE2 of Arabidopsis contributes to ABA mediated plant developmental processes.
abstract: Polyamines (PA) are catabolised by two groups of amine oxidases, the copper-binding amine oxidases (CuAOs) and the FAD-binding polyamine oxidases (PAOs). Previously, we have shown that CuAO1 is involved in ABA associated growth responses and ABA- and PA-mediated rapid nitric oxide (NO) production. Here we report the differential regulation of expression of POLYAMINE OXIDASE2 of Arabidopsis (AtPAO2) in interaction with ABA, nitrate and ammonium. Without ABA treatment germination, cotyledon growth and fresh weight of pao2 knockdown mutants as well as PAO2OX over-expressor plants were comparable to those of the wild type (WT) plants irrespective of the N source. In the presence of ABA, in pao2 mutants cotyledon growth and fresh weights were more sensitive to inhibition by ABA while PAO2OX over-expressor plants showed a rather similar response to WT. When NO3(-) was the only N source primary root lengths and lateral root numbers were lower in pao2 mutants both without and with exogenous ABA. PAO2OX showed enhanced primary and lateral root growth in media with NO3(-) or NH4(+). Vigorous root growth of PAO2OX and the hypersensitivity of pao2 mutants to ABA suggest a positive function of AtPAO2 in root growth. ABA-induced NO production in pao2 mutants was lower indicating a potential contributory function of AtPAO2 in NO-mediated effects on root growth.
authors: Leibniz Universität Hannover, Institute of Horticultural Production Systems, Section of Molecular Developmental Physiology, Herrenhäuser Strasse 2, D-30419 Hannover, Germany.
authors: Rinukshi
authors: R
authors: Wimalasekera
authors: Leibniz Universität Hannover, Institute of Biostatistics, Herrenhäuser Strasse 2, D-30419 Hannover, Germany.
authors: Frank
authors: F
authors: Schaarschmidt
authors: Department of Science, University 'Roma Tre', Viale Guglielmo Marconi 446, 00146 Rome, Italy.
authors: Riccardo
authors: R
authors: Angelini
authors: Department of Science, University 'Roma Tre', Viale Guglielmo Marconi 446, 00146 Rome, Italy.
authors: Alessandra
authors: A
authors: Cona
authors: Department of Science, University 'Roma Tre', Viale Guglielmo Marconi 446, 00146 Rome, Italy.
authors: Parasklevi
authors: P
authors: Tavladoraki
authors: Leibniz Universität Hannover, Institute of Horticultural Production Systems, Section of Molecular Developmental Physiology, Herrenhäuser Strasse 2, D-30419 Hannover, Germany. Electronic address: scherer@zier.uni-hannover.de.
authors: Günther F E
authors: GF
authors: Scherer
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics / Q000378:metabolism*; D000097667:Polyamine Oxidase
chemical_list: D000587:Oxidoreductases Acting on CH-NH Group Donors; D000097667:Polyamine Oxidase
keywords: Abscisic acid; Ammonia; NO: nitric oxide; Nitrate; POLYAMINE OXIDASE2; Root development