title: Perturbation of spermine synthase gene expression and transcript profiling provide new insights on the role of the tetraamine spermine in Arabidopsis defense against Pseudomonas viridiflava.
abstract: The role of the tetraamine spermine in plant defense against pathogens was investigated by using the Arabidopsis (Arabidopsis thaliana)-Pseudomonas viridiflava pathosystem. The effects of perturbations of plant spermine levels on susceptibility to bacterial infection were evaluated in transgenic plants (35S::spermine synthase [SPMS]) that overexpressed the SPMS gene and accumulated spermine, as well as in spms mutants with low spermine levels. The former exhibited higher resistance to P. viridiflava than wild-type plants, while the latter were more susceptible. Exogenous supply of spermine to wild-type plants also increased disease resistance. Increased resistance provided by spermine was partly counteracted by the polyamine oxidase inhibitor SL-11061, demonstrating that the protective effect of spermine partly depends on its oxidation. In addition, global changes in gene expression resulting from perturbations of spermine levels were analyzed by transcript profiling 35S::SPMS-9 and spms-2 plants. Overexpression of 602 genes was detected in 35S::SPMS-9 plants, while 312 genes were down-regulated, as compared to the wild type. In the spms-2 line, 211 and 158 genes were up- and down-regulated, respectively. Analysis of gene ontology term enrichment demonstrated that many genes overexpressed only in 35S::SPMS-9 participate in pathogen perception and defense responses. Notably, several families of disease resistance genes, transcription factors, kinases, and nucleotide- and DNA/RNA-binding proteins were overexpressed in this line. Thus, a number of spermine-responsive genes potentially involved in resistance to P. viridiflava were identified. The obtained results support the idea that spermine contributes to plant resistance to P. viridiflava.
authors.affiliation: Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús/Universidad Nacional de San Martín-Consejo Nacional de Investigaciones Científificas y Técnicas, CC 164 (B7130IWA) Chascomus, Argentina.
authors.forename: María Elisa
authors.initials: ME
authors.lastname: Gonzalez
authors.forename: Francisco
authors.initials: F
authors.lastname: Marco
authors.forename: Eugenio Gómez
authors.initials: EG
authors.lastname: Minguet
authors.forename: Pedro
authors.initials: P
authors.lastname: Carrasco-Sorli
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Blázquez
authors.forename: Juan
authors.initials: J
authors.lastname: Carbonell
authors.forename: Oscar Adolfo
authors.initials: OA
authors.lastname: Ruiz
authors.forename: Fernando Luis
authors.initials: FL
authors.lastname: Pieckenstain
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D015169:Colony Count, Microbial; D020869:Gene Expression Profiling; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics; D009154:Mutation / Q000235:genetics; D010084:Oxidation-Reduction; D030821:Plants, Genetically Modified; D011549:Pseudomonas / Q000254:growth & development / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D013096:Spermine / Q000378:metabolism*; D013097:Spermine Synthase / Q000235:genetics* / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D013096:Spermine; D013097:Spermine Synthase