Phospholipids were utilized as a membrane marker to test for transformation-induced alteration of cellular membranes of cultured crown gall cells of Vinca rosea L. Fully transformed cells contained less than half the amount of phospholipids (7.8 micrograms lipid P per gram fresh weight) of normal V. rosea cells (21.4 micrograms lipid P per gram fresh weight). The normal V. rosea callus cells we...

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...

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...

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...

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 12 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; 267 isol...

nant animal cells are distinguished from healthy or inflaznmstory cells. In emphasizing the perma nency of the cellular alteration, Kidd (6) states that “Cancercells remain such until they die . . they never turn back en masse towards the benign or normal state. . . .“The inability to accomplish a reversal of malignant to normal cells under con trolled conditions has, however, served as a s...

The nine decades since Smith and Townsend demonstrated that Agrobacterium tumefaciens causes plant tumors (95) have been marked by a series of surprises. Among the most important of these was the report in 1958 that these tumors could be excised and propagated in vitro without exogenous plant hormones (7). Equally important were a series of reports beginning about the same time that tumors rele...

A combination of the crown gall biocontrol strain K-84 and another antagonist JH-l was better than K-84 alone in controlling some Agrobacterium strains. Strain K-84 surprisingly controlled some resistant Agrobacterium strains when heavy concentrations of K-84 were used. Strain K-84 could control sensitive strains of Agrobacterium up to 48 hr. after wounds were inoculated with the pathogen at te...