Protocatechuate is a universal growth substrate for members of the family Rhizobiaceae, and these bacteria utilize the aromatic compound via the beta-ketoadipate pathway. This report describes transcriptional controls exercised by different subgroups of the Rhizobiaceae over five enzymes that catalyze consecutive reactions in the pathway: protocatechuate oxygenase (EC 1.13.11.3), beta-carboxy-c...

When Shakespeare wrote (46), “What’s in a name? that which we call a rose / By any other name would smell as sweet,” he implied that phenotypes (scent in this case) take precedence over nomenclature. In popular usage, they usually do. Cartoonists classify politicians by their ears or noses. Scientists use physical characteristics to delimit everything from species (e.g., cranium size in the gen...

The periplasmic glucans of Gram-negative bacteria, including the membrane-derived oligosaccharides (MDO) of Escherichia coli and the cyclic glucans of the Rhizobiaceae, have important but poorly understood functions in osmotic adaptation and, in the case of the Rhizobiaceae, in the complex cell-signaling of these bacteria with specific plant hosts. Experiments on the mechanisms of osmotic regul...

Pulsed-field gel electrophoresis was used to analyze the genomic organization of 16 bacteria belonging or related to the family Rhizobiaceae of the alpha subgroup of the class Proteobacteria. The number and sizes of replicons were determined by separating nondigested DNA. Hybridization of an rrn gene probe was used to distinguish between chromosomes and plasmids. Members of the genus Agrobacter...

Members of the genus Agrobacterium constitute a diverse group of organisms, all of which, when harbouring the appropriate plasmids, are capable of causing neoplastic growths on susceptible host plants. The agrobacteria, which are members of the family Rhizobiaceae, can be differentiated into at least three biovars, corresponding to species divisions based on differential biochemical and physiol...

Most plant lectins exhibit other properties. Some also bind plant growth regulators, the cytokinins, which are small hydrophobic molecules derivate from adenine [5,6]. They are secreted proteins and are found in vacuoles, cell walls, or intercellular spaces, of just about every plant organ [7]. Legume root lectins, are involved in the recognition and binding of Rhizobium and Brudyrhizobium sp. ...