Agrobacterium tumefaciens causes crown gall disease on various plant species by introducing its T-DNA into the genome. Therefore, Agrobacterium has been extensively studied both as a pathogen and an important biotechnological tool. The infection process involves the transfer of T-DNA and virulence proteins into the plant cell. At that time the gene expression patterns of host plants differ depe...

The common use of Agrobacterium as a gene vector for plants has somewhat ob-scured the fact that this bacterium remains an important plant pathogen. Pathogenic strainsof the genus Agrobacterium cause unorganized tissue growth called crown gall or profuseabnormal root development called hairy root. Agrobacterium tumefaciens induces galls onroots and crowns of several fruit and fo...

Knowledge of the initiation mechanism of the crown-gall disease incited by Agrobacterium tuimefaciens (Smith & Town.) and the subsequent growth of the abnormal tissue is fundamental to understanding diseased growth (2, 18, 24). The nutritional requirements for normal and gall tissues have been intensively studied (25), and the necessity for proper balance of amino acids and growth substances in...

A nonpathogenic strain of Rhizobium vitis ARK-1 was tested as a biological control agent for grapevine crown gall. When grapevine roots were soaked in a cell suspension of strain ARK-1 before planting in the field, the number of plants with tumors was reduced. The results from seven field trials from 2009 to 2012 were combined in a meta-analysis. The integrated relative risk after treatment wit...

Agrobacterium Ti (tumor-inducing) plasmids, the causative agents of crown gall disease, fall into four genetic groups based on the patterns of octopine and nopaline synthesis (by crown gall tumors) and catabolism (by Agrobacterium tumefaciens) for which they are responsible. Two classes of Ti plasmids induce tumors that synthesize neither octopine nor nopaline. The existence of these Ti plasmid...

The importance of growth substances in the normal development of plant tissues has suggested that, when present in. unusual amounts, they may be more or less directly responsible for atypical and pathological growth. Attention has been directed especially to such growths as crown gall caused by Phytomonas tumefaciens (Smith and Town.) Bergey et al. Beta-indole-acetic acid and substances related...