IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
artículos
Título:
Xanthan pyruvilation is essential for the virulence of Xanthomonas campestris pv. campestris
Autor/es:
PABLO YARYURA; ROXANA ROESCHLIN; ADRIAN VOJNOV; LAILA TOUM (*); GUSTAVO GUDESBLAT; LUIS IELPI; ISABEL BIANCO (*); NATALIA MIELNICHUK; MARIA ROSA MARANO
Revista:
MOLECULAR PLANT-MICROBE INTERACTIONS
Editorial:
AMER PHYTOPATHOLOGICAL SOC
Referencias:
Lugar: Saint Paul, Minnesota; Año: 2016 vol. 29 p. 688 - 699
ISSN:
0894-0282
Resumen:
Xanthan, the main exopolysaccharide synthesized by Xanthomonas spp.,contributes to bacterial stress tolerance and enhances attachment to plant surfaces by helping in biofilm formation. Therefore, xanthan is essential for successful colonization and growth in planta and has also been proposed to be involved in the promotion of pathogenesis by calcium ion chelation and, hence, in the suppression of the plant defense responses where this cation acts as a signal. The aim of this work was to study the relationship between xanthan structure and its role as a virulence factor. We analyzed four Xanthomonas campestris pv. campestris mutants that synthesize structural variants of xanthan. We found that the lack of acetyl groups that decorate the internal mannose residues, ketal-pyruvate groups and external mannose residues affect bacterial adhesion and biofilm architecture.In addition, the mutants that synthesized exopolysaccharide without pyruvilation or without the external mannose residues did not develop disease symptoms inArabidopsis thaliana. We also observed that the presence of the external mannoseresidues, and hence pyruvilation, is required for xanthan to suppress callosedeposition as well as to interfere with stomatal defense. In conclusion, pyruvilation of xanthan seems to be essential for Xanthomonas campestris pv. campestris virulence.