Is there a link between cell division and pathogenicity in Xanthomonas citri?

• Grant number: 11/07458-7
• Support Opportunities: Regular Research Grants
• Start date: October 01, 2011
• End date: September 30, 2013
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Henrique Ferreira
• Grantee: Henrique Ferreira
• Host Institution: Instituto de Biociências (IB). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Associated researchers: José Belasque Junior ; Mauricio Bacci Junior

Abstract

Xanthomonas citri subsp. citri (Xac) is a phytopathogenic bacterium that causes citrus canker, a severe disease that affects all the species and cultivars of citrus worldwide. We have recently labeled the ZapA protein of Xac using GFP in order to investigate some molecular aspects of cell division in this bacterium. ZapA is widely conserved among Bacteria, and acts as a positive-regulator of FtsZ-polymerization and FtsZ-filament bundling during bacterial cytokinesis. We noticed, however, that the over-expression of GFP-ZapA into Xac, along with the native ZapA, produced cells with a decreased virulence in planta, albeit exhibiting normal growth in liquid-media and being morphologically similar to the wild-type cells under the microscope. Why would such Xac mutant lose the ability to colonize its host? To address this question, we propose to do a knockout of zapAxac to verify the phenotype described above. Concomitantly, we would like to carry out yeast-two-hybrid analyses using zapAXac as a prey against a library of Xac in order to identify interaction partners of ZapAXac that may indicate traits in which this factor is involved and that may be related with the virulence of Xac. Finally, we intend to compare 2D protein profiles of Xac wild type and the mutant that does not express ZapA in an attempt to detect co-expression and co-repression patterns of factors that could suggest the participation of ZapAXac in pathogenicity systems. (AU)