title: Engineered polyamine catabolism preinduces tolerance of tobacco to bacteria and oomycetes.
abstract: Polyamine oxidase (PAO) catalyzes the oxidative catabolism of spermidine and spermine, generating hydrogen peroxide. In wild-type tobacco (Nicotiana tabacum 'Xanthi') plants, infection by the compatible pathogen Pseudomonas syringae pv tabaci resulted in increased PAO gene and corresponding PAO enzyme activities; polyamine homeostasis was maintained by induction of the arginine decarboxylase pathway and spermine was excreted into the apoplast, where it was oxidized by the enhanced apoplastic PAO, resulting in higher hydrogen peroxide accumulation. Moreover, plants overexpressing PAO showed preinduced disease tolerance against the biotrophic bacterium P. syringae pv tabaci and the hemibiotrophic oomycete Phytophthora parasitica var nicotianae but not against the Cucumber mosaic virus. Furthermore, in transgenic PAO-overexpressing plants, systemic acquired resistance marker genes as well as a pronounced increase in the cell wall-based defense were found before inoculation. These results reveal that PAO is a nodal point in a specific apoplast-localized plant-pathogen interaction, which also signals parallel defense responses, thus preventing pathogen colonization. This strategy presents a novel approach for producing transgenic plants resistant to a broad spectrum of plant pathogens.
authors.affiliation: Department of Biology, University of Crete, Crete, 71409 Heraklion, Greece.
authors.forename: Panagiotis N
authors.initials: PN
authors.lastname: Moschou
authors.forename: Panagiotis F
authors.initials: PF
authors.lastname: Sarris
authors.forename: Nicholas
authors.initials: N
authors.lastname: Skandalis
authors.forename: Athina H
authors.initials: AH
authors.lastname: Andriopoulou
authors.forename: Konstantinos A
authors.initials: KA
authors.lastname: Paschalidis
authors.forename: Nickolas J
authors.initials: NJ
authors.lastname: Panopoulos
authors.forename: Kalliopi A
authors.initials: KA
authors.lastname: Roubelakis-Angelakis
mesh_terms: D000222:Adaptation, Physiological; D017799:Cucumovirus / Q000472:pathogenicity; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005818:Genetic Engineering; D054884:Host-Pathogen Interactions; D006861:Hydrogen Peroxide / Q000378:metabolism; D008969:Molecular Sequence Data; D009868:Oomycetes / Q000472:pathogenicity / Q000502:physiology*; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology / Q000821:virology; D030821:Plants, Genetically Modified; D011073:Polyamines / Q000378:metabolism*; D044224:Pseudomonas syringae / Q000472:pathogenicity / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000378:metabolism; D013312:Stress, Physiological; D014026:Nicotiana / Q000201:enzymology / Q000235:genetics / Q000382:microbiology* / Q000821:virology; D014774:Virulence; D000097667:Polyamine Oxidase
chemical_list: D006861:Hydrogen Peroxide; D000587:Oxidoreductases Acting on CH-NH Group Donors; D011073:Polyamines; D012333:RNA, Messenger; D020156:Salicylic Acid; D000097667:Polyamine Oxidase