Perturbation of spermine synthase gene expression and transcript profiling provide new insights on the role of spermine in Arabidopsis thaliana defence against Pseudomonas viridiflava.

M. ELISA GONZALEZ; FRANCISCO MARCO; EUGENIO GOMEZ MINGUET; PEDRO CARRASCO SORLI; MIGUEL ANGEL BLAZQUEZ; JUAN CARBONELL; OSCAR ADOLFO RUIZ; FERNANDO LUIS PIECKENSTAIN

PLANT PHYSIOLOGY.

AMER SOC PLANT BIOLOGISTS

Lugar: Rockville; Año: 2011 vol. 156 p. 2266 - 2277

0032-0889

The role of the tetraamine spermine in plant defense against pathogens was investigated by using the Arabidopsis thaliana-Pseudomonas viridiflava pathosystem. The effects of perturbations of plant spermine levels on susceptibility to bacterial infection were evaluated in transgenic plants (35S::SPMS) that over-expressed the spermine synthase (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 (WT) plants, while the latter were more susceptible. Exogenous supply of spermine to WT plants also increased disease resistance. Increased resistance provided by spermine was partly counteracted by the polyamineoxidase 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 analysed by transcript profiling 35S::SPMS-9 and spms-2 plants. Overexpression of 602 genes was detected in 35S::SPMS-9 plants, while 211 genes were down regulated, as compared to the WT. 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 over-expressed only in 35S::SPMS-9 participate in pathogen perception and defense responses. Notably, several families of disease resistance genes, transcription factors, kinases, nucleotide and DNA/RNA binding proteins were over-expressed in this line. Thus, a number of spermine-responsive genes potentially involved in resistance to P. viridiflava were identified. As a whole, results obtained support the idea that spermine plays a role in plant defense against pathogen attack.