RESUMO
Octopine and nopaline Ti-plasmids confer upon Agrobacterium tumefaciens C58C1 the ability to respond chemotactically to the vir-inducing phenolic wound exudate, acetosyringone. A. tumefaciens C58C1 containing Ti-plasmids with Tn5 insertions in virB, C, D or E exhibited marked chemotaxis towards acetosyringone. However, Ti-plasmids with mutations in virA or virG were unable to confer the responsive phenotype. Of the cosmid clones pVK219 (virAB) pVK221 (virBGC) pVK225 (virGCDE) and pVK257 (virABGC) mobilized to cured A. tumefaciens C58C1, only pVK257 bestowed acetosyringone chemotaxis. virA and virG are thus required for chemotaxis of A. tumefaciens towards acetosyringone. This suggests a multifunctional role for virA and virG: at low concentrations of acetosyringone they mediate chemotaxis and at higher concentrations they effect vir-induction.
Assuntos
Acetofenonas/fisiologia , Proteínas de Bactérias , Quimiotaxia , Plasmídeos , Rhizobium/genética , Arginina/análogos & derivados , Arginina/genética , Fatores Quimiotáticos/fisiologia , Mapeamento Cromossômico , Clonagem Molecular , Cosmídeos , Regulação da Expressão Gênica , Proteínas de Membrana/fisiologia , Proteínas Quimiotáticas Aceptoras de Metil , Mutação , TransfecçãoRESUMO
o-Aminoacetophenone is a pheromone produced by virgin honeybee queens and released with feces. In small social groups, the pheromone repels and is used to terminate agonistic interactions between queens and workers.
