INVESTIGADORES
VOJNOV Adrian Alberto
artículos
Título:
Mutation in the xpsD gene of Xanthomonas axonopodis pv. citri affects cellulose degradation and virulence
Autor/es:
JULIANA CRISTINA BAPTISTA; MARCOS ANTONIO MACHADO; RAFAEL AUGUSTO HOMEM; PABLO SEBASTIÁN TORRES; ADRIAN ALBERTO VOJNOV; ALEXANDRE MORAIS DO AMARAL
Revista:
GENETICS AND MOLECULAR BIOLOGY
Editorial:
SOC BRASIL GENETICA
Referencias:
Año: 2010 vol. 33 p. 146 - 153
ISSN:
1415-4757
Resumen:
The Gram-negative bacterium Xanthomonas axonopodis pv. citri, the causal agent of citrus canker, is a major threat
to the citrus industry worldwide. Although this is a leaf spot pathogen, it bears genes highly related to degradation of
plant cell walls, which are typically found in plant pathogens that cause symptoms of tissue maceration. Little is
known on Xac capacity to cause disease and hydrolyze cellulose. We investigated the contribution of various open
reading frames on degradation of a cellulose compound by means of a global mutational assay to selectively screen
for a defect in carboxymethyl cellulase (CMCase) secretion in X. axonopodis pv. citri. Screening on CMC agar revealed
one mutant clone defective in extracellular glycanase activity, out of nearly 3,000 clones. The insertion was located
in the xpsD gene, a component of the type II secretion system (T2SS) showing an influence in the ability of Xac
to colonize tissues and hydrolyze cellulose. In summary, these data show for the first time, that X. axonopodis pv. citri
is capable of hydrolyzing cellulose in a T2SS-dependent process. Furthermore, it was demonstrated that the ability
to degrade cellulose contributes to the infection process as a whole.