title: Biosynthesis and defensive function of Nδ-acetylornithine, a jasmonate-induced Arabidopsis metabolite.
abstract: Since research on plant interactions with herbivores and pathogens is often constrained by the analysis of already known compounds, there is a need to identify new defense-related plant metabolites. The uncommon nonprotein amino acid N(δ)-acetylornithine was discovered in a targeted search for Arabidopsis thaliana metabolites that are strongly induced by the phytohormone methyl jasmonate (MeJA). Stable isotope labeling experiments show that, after MeJA elicitation, Arg, Pro, and Glu are converted to Orn, which is acetylated by NATA1 to produce N(δ)-acetylornithine. MeJA-induced N(δ)-acetylornithine accumulation occurs in all tested Arabidopsis accessions, other Arabidopsis species, Capsella rubella, and Boechera stricta, but not in less closely related Brassicaceae. Both insect feeding and Pseudomonas syringae infection increase NATA1 expression and N(δ)-acetylornithine accumulation. NATA1 transient expression in Nicotiana tabacum and the addition of N(δ)-acetylornithine to an artificial diet both decrease Myzus persicae (green peach aphid) reproduction, suggesting a direct toxic or deterrent effect. However, since broad metabolic changes that are induced by MeJA in wild-type Arabidopsis are attenuated in a nata1 mutant strain, there may also be indirect effects on herbivores and pathogens. In the case of P. syringae, growth on a nata1 mutant is reduced compared with wild-type Arabidopsis, but growth in vitro is unaffected by N(δ)-acetylornithine addition.
authors.affiliation: Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA.
authors.forename: Adewale M
authors.initials: AM
authors.lastname: Adio
authors.forename: Clare L
authors.initials: CL
authors.lastname: Casteel
authors.forename: Martin
authors.initials: M
authors.lastname: De Vos
authors.forename: Jae Hak
authors.initials: JH
authors.lastname: Kim
authors.forename: Vijay
authors.initials: V
authors.lastname: Joshi
authors.forename: Baohua
authors.initials: B
authors.lastname: Li
authors.forename: Caroline
authors.initials: C
authors.lastname: Juéry
authors.forename: Josquin
authors.initials: J
authors.lastname: Daron
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Kliebenstein
authors.forename: Georg
authors.initials: G
authors.lastname: Jander
mesh_terms: D000085:Acetates / Q000494:pharmacology*; D000107:Acetylation; D000818:Animals; D001042:Aphids / Q000502:physiology; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000378:metabolism; D003517:Cyclopentanes / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant; D060434:Herbivory; D055442:Metabolome; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation; D009952:Ornithine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D054883:Oxylipins / Q000494:pharmacology*; D010935:Plant Diseases; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D044224:Pseudomonas syringae / Q000472:pathogenicity
chemical_list: D000085:Acetates; D029681:Arabidopsis Proteins; D003517:Cyclopentanes; D054883:Oxylipins; C021951:N(delta)-acetylornithine; C072239:methyl jasmonate; D009952:Ornithine