Crops can be devastated by pathogenic strains of Agrobacterium tumefaciens that cause crown gall tumors. This devastation can be prevented by the nonpathogenic biocontrol agent A. radiobacter K84, which prevents disease by production of the "Trojan horse" toxin agrocin 84, which is specifically imported into tumorgenic A. tumefaciens strains to cause cell death. We demonstrate that this biocont...

The 5.67-megabase genome of the plant pathogen Agrobacterium tumefaciens C58 consists of a circular chromosome, a linear chromosome, and two plasmids. Extensive orthology and nucleotide colinearity between the genomes of A. tumefaciens and the plant symbiont Sinorhizobium meliloti suggest a recent evolutionary divergence. Their similarities include metabolic, transport, and regulatory systems t...

Crown gall of walnut (Juglans sp.), caused by the bacterium Agrobacterium tumefaciens, greatly impacts the CA walnut industry. To determine the genetic diversity of A. tumefaciens throughout the Central Valley of CA, we collected isolates from ten walnut growing counties. A total of 340 A. tumefaciens biovar 1 isolates were collected and tested for the presence of the Ti plasmid by PCR; 190 iso...

Experiments using different species of the plant Nicotiana and strains of the bacterium Agrobacterium tumefaciens showed that teratoma formation from crown galls was dependent on the combination of bacterial Ti plasmid and host plant used.

Agrobacterium tumefaciens is the main plant biotechnology gene transfer tool with host range which can be extended to non-plant eukaryotic organisms under laboratory conditions. Known medical cases of Agrobacterium species isolation from bloodstream infections necessitate the assessment of biosafety-related risks of A. tumefaciens encounters with mammalian organisms. Here, we studied the surviv...

Introducción. La transformación del arroz (Oryza sativa L. ssp indica) mediada por Agrobacterium, representa una oportunidad para la investigación científica y el mejoramiento genético. Es necesaria optimización protocolo obtener mayor eficiencia de transformación. Objetivo. Evaluar diferentes factores que afectan genética en callos embriogénicos subespecie indica vía Agrobacterium tumefaciens....

Agrobacterium tumefaciens is the causative agent of crown gall, a disease of dicotyledonous plants characterized by a tumorous phenotype. Earlier in this century, scientific interest in A. tumefaciens was based on the possibility that the study of plant tumors might reveal mechanisms that were also operating in animal neoplasia. In the recent past, the tumorous growth was shown to result from t...

Agrobacterium tumefaciens can cause crown gall tumors on a wide range of host plants. As a natural genetic engineer, the bacterium can transfer both single-stranded DNA (ssDNA) [transferred DNA (T-DNA)] molecules and bacterial virulence proteins into various recipient cells. Among Agrobacterium-delivered proteins, VirE2 is an ssDNA binding protein that is involved in various steps of the transf...

RosR is a transcriptional regulator important for determining cell-surface characteristics and nodulation competitiveness in Rhizobium etli CE3. We identified a 15-kb region that contains genes with similarity to members of the virB, virC, virG, and virE operons of Agrobacterium tumefaciens and demonstrated that RosR directly regulates one operon in this region. These genes were located on plas...

We constructed the broad-host-range plasmid pUCD800 containing the sacB gene of Bacillus subtilis for use in the positive selection and isolation of insertion sequence (IS) elements in gram-negative bacteria. Cells containing pUCD800 do not grow on medium containing 5% sucrose unless the sacB gene is inactivated. By using pUCD800, we isolated a 1.4-kilobase putative IS element from Agrobacteriu...