Resumen de Manganese transporter protein MntH is required for virulence of Xylophilus ampelinus, the causal agent of bacterial necrosis in grapevine
Silvia Sevillano Nistal, Rebeca Cobos Román, Penélope García-Angulo, A. Alonso Monroy, María Luisa Álvarez Rodríguez, José Manuel Álvarez-Pérez, Miguel Ángel Olego Morán, J. L. Acebes, José Enrique Garzón Jimeno, Juan José Rubio Coque
Background and Aims The aim of this study is to identify proteins involved in the pathogenicity/virulence of Xylophilus ampelinus. Characterisation of these proteins could provide new insights into putative targets for controlling bacterial necrosis in grapevines.
Methods and Results Transposon insertion mutagenesis was used to isolate X. ampelinus mutants exhibiting an altered virulence. Characterisation of one of the avirulent mutants revealed the insertion of a transposon into the mntH gene encoding the major manganese transporter. Virulence tests on grapevine leaves clearly showed that the virulence of these mutants was significantly reduced. Phenotypic analysis of an mntH mutant indicated that the MntH protein is a Mn++ transporter but that MntH does not play a significant role in the transport of Fe++ or Cu++. The MntH mutants exhibited an increased sensitivity to hydrogen peroxide, although catalase and superoxide dismutase activities were not significantly affected.
Conclusion The MntH protein plays a significant role in the virulence of X. ampelinus.
Significance of the Study This is the first report showing that transposon mutagenesis is an effective strategy for the isolation of X. ampelinus mutants. It is also the first report characterising a gene encoding a protein involved in virulence in this grapevine pathogen.
