title: Identification of a plant nitric oxide synthase gene involved in hormonal signaling.
abstract: Nitric oxide (NO) serves as a signal in plants. An Arabidopsis mutant (Atnos1) was identified that had impaired NO production, organ growth, and abscisic acid-induced stomatal movements. Expression of AtNOS1 with a viral promoter in Atnos1 mutant plants resulted in overproduction of NO. Purified AtNOS1 protein used the substrates arginine and nicotinamide adenine dinucleotide phosphate and was activated by Ca2+ and calmodulin-like mammalian endothelial nitric oxide synthase and neuronal nitric oxide synthase, yet it is a distinct enzyme with no sequence similarities to any mammalian isoform. Thus, AtNOS1 encodes a distinct nitric oxide synthase that regulates growth and hormonal signaling in plants.
authors.affiliation: Section of Cell and Developmental Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.
authors.forename: Fang-Qing
authors.initials: FQ
authors.lastname: Guo
authors.forename: Mamoru
authors.initials: M
authors.lastname: Okamoto
authors.forename: Nigel M
authors.initials: NM
authors.lastname: Crawford
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017343:Genes, Plant; D007700:Kinetics; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D009599:Nitroprusside / Q000494:pharmacology; D019441:Plant Epidermis / Q000187:drug effects / Q000502:physiology; D018515:Plant Leaves / Q000201:enzymology / Q000254:growth & development / Q000502:physiology; D018517:Plant Roots / Q000254:growth & development; D018520:Plant Shoots / Q000254:growth & development; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D009599:Nitroprusside; D009569:Nitric Oxide; D000040:Abscisic Acid; C521947:NOA1 protein, Arabidopsis; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester