Tumor formation in cucurbit cultivars resulting from infection by various strains of Agrobacterium tumefaciens and Agrobacterium rhizogenes is environmentally affected. In all instances, tumors could be induced on excised cotyledons while inoculating attached cotyledons or stems resulted in no tumor formation. In addition, buttercup squash (Cucurbita maxima Duch. buttercup) was most susceptible...

The floral-dip method for Agrobacterium-mediated transformation of Arabidopsis allows efficient plant transformation without need for tissue culture. To facilitate use with other plant species, we investigated the mechanisms that underlie this method. In manual outcrossing experiments, application of Agrobacterium tumefaciens to pollen donor plants did not produce any transformed progeny, where...

Inducible virulence (vir) genes of the Agrobacterium tumefaciens tumor-inducing (Ti) plasmid are under control of a two-component regulatory system. In response to environmental factors (phenolic compounds, sugars, pH) VirA protein phosphorylates VirG, which in turn interacts with the promoters of other vir genes, causing induction. A mutation of virG, virGN54D (which codes for a Asn-54-->Asp a...

Agrobacterium tumefaciens causes crown gall disease on a variety of plants. During the infection process Agrobacterium transfers a nucleoprotein complex, the VirD2 T-complex, and at least two Vir proteins, VirE2 and VirF, into the plant cell via the VirB/VirD4 type IV secretion system. Recently, we found that T-DNA could also be transferred from Agrobacterium to Saccharomyces cerevisiae. Here, ...

Agrobacterium-mediated plant genetic transformation requires a two-step process for its success: selection and regeneration of transformed tissues, and the elimination of the transformation vector, Agrobacterium. This study uses carbenicillin (CA), cefotaxime (CF) and vancomycin (VA) singly, or in combination, to eliminate Agrobacterium tumefaciens LBA4404 and AGLO growing on Agrobacterium-favo...

The nutritional requirements of the tumor-inducing phytopathogenic bacteria and soil saprophytes which Conn (1942) has placed in the genus Agrobacterium have received somewhat more attention than have the requirements of most of the other groups of plant-disease bacteria. It is clear from the literature (Sagen, Riker, and Baldwin, 1934; Riker, Lyneis, and Locke, 1941; Hofer, 1941) that the crow...

Genetic transformation of plants by Agrobacterium, which in nature causes neoplastic growths, represents the only known case of trans-kingdom DNA transfer. Furthermore, under laboratory conditions, Agrobacterium can also transform a wide range of other eukaryotic species, from fungi to sea urchins to human cells. How can the Agrobacterium virulence machinery function in such a variety of evolut...

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