The citrus canker is a disease that attacks citric plants in various citric producing countries, which has no treatment until now, causing economic losses. It is a disease caused by bacteria from the genus Xanthomonas, specifically species X. citri (Xac) and X. fuscans. Proteomic comparative analysis of subcellular fractions from Xac, previously conducted in our laboratory (LBBMM, Ufscar) as part of a Jovem Pesquisador project, showed that higher expression of the enzyme phosphoglucomutase (PGM) occurs under the in vitro pathogenicity-induction condition, in comparison with the non-induction condition, what suggests the potential relation of the enzyme with Xac pathogenicity. PGM is involved in mobilization and storage of energetic resource and has a role in the exopolissacharydes biosynthesis (biofilms) in Xanthomonas spp. Investigations about the effects of the PGM inactivation in the pathogenicithy are rare. The few reports available only proved its involvement in xanthan gum synthesis in X. campestris. This work aims to obtain a Xac mutant strain for the PGM gene, by means of gene deletion. The methodology to be adopted will be standardized and will consist in the in tandem cloning of the 5' and 3' flanking regions in pNPTS138 vector, which after introduction in Xanthomonas, will allow the deletion of the chromosomal gene by a double recombination event. The mutant will be compared to the wild strain in terms of in vivo infeccious potential. The results will highlight for the first time the relationship between PGM and Xac pathogenicity. In the future, the standardized methodology will make possible the deletion of other Xac genes of biotechnologic interest.
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