Analysis of the Pseudomonas solanacearum polygalacturonase encoded by pglA and its involvement in phytopathogenicity.
AUTOR(ES)
Schell, M A
RESUMO
A major endopolygalacturonase excreted by Pseudomonas solanacearum was purified to greater than 95% homogeneity and shown to have an isoelectric point of 9.0 and a subunit molecular mass of 52 kilodaltons (kDa). The gene encoding this enzyme (pglA) was isolated from a genomic library of P. solanacearum DNA based on its expression in Escherichia coli and shown to be contained on a 1.8-kilobase DNA fragment. The identity of the pglA gene product and the 52-kDa polygalacturonase was demonstrated by immunoadsorption and isoelectric focusing experiments. The cloned pglA gene was apparently expressed from its own promoter in E. coli and its product was partially secreted into the periplasm. The pglA gene was insertionally inactivated in vitro and used to mutate the chromosomal pglA gene of P. solanacearum by marker exchange mutagenesis. The resulting mutant strain was deficient in production of the 52-kDa polygalacturonase and took twice as long to wilt and kill tomato plants as the wild-type parent in plant bioassay experiments. Complementation in trans with the wild-type cloned pglA gene restored virulence to near wild-type levels. The data indicate that the pglA gene is important, but not absolutely necessary, for pathogenesis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=211482Documentos Relacionados
- DNA sequence analysis of pglA and mechanism of export of its polygalacturonase product from Pseudomonas solanacearum.
- Cloning of the egl gene of Pseudomonas solanacearum and analysis of its role in phytopathogenicity.
- Bacteriocin-resistant mutants of Erwinia chrysanthemi: possible involvement of iron acquisition in phytopathogenicity.
- sid1, a gene initiating siderophore biosynthesis in Ustilago maydis: molecular characterization, regulation by iron, and role in phytopathogenicity.
- A Xanthomonas campestris pv. campestris protein similar to catabolite activation factor is involved in regulation of phytopathogenicity.