Agrobacterium tumefaciens transfers the T-DNA portion of its Ti plasmid to the nuclear genome of plant cells. Upon cocultivation of A. tumefaciens strain A348 with regenerating tobacco leaf protoplasts, restriction endonuclease fragments of the T-DNA were generated that are consistent with double-stranded cleavage of the T-DNA at the border sequences. The T-DNA border cleavage was also induced ...

Eastern Washington is compromised by various pollution sources, of which agricultural burning is a particular burden. Smoke from field burning is a nuisance to nearby communities and is a concern for health. This study evaluates levoglucosan (LG) and methoxyphenols (MPs) as potential tracers for apportioning field burning smoke. PM2.5 (particulate matter < 2.5 microM m in aerodynamic diameter) ...

The vir genes of Agrobacterium tumefaciens tumor-inducing (Ti) plasmids direct the transfer of oncogenic portion of the Ti (tumor-inducing) plasmid that is transferred to plant cells (T-DNA) into plant cells and are coordinately induced by plant-released phenolic chemical signals. We have used DNA microarrays, representing all genes of the octopine- and nopaline-type Ti plasmids, to identify al...

vir regulon expression in Agrobacterium tumefaciens involves both chromosome- and Ti-plasmid-encoded gene products. We have isolated and characterized a new chromosomal gene that when mutated results in a 2- to 10-fold reduction in the induced expression of vir genes by acetosyringone. This reduced expression occurs in AB minimal medium (pH 5.5) containing either sucrose or glucose and containi...

Ethylene evolution from plants inhibits Agrobacterium-mediated genetic transformation, but the mechanism is little understood. In this study, the possible role of ethylene in Agrobacterium-mediated genetic transformation was clarified. It was tested whether or not plant ethylene sensitivity affected genetic transformation; the sensitivity might regulate bacterial growth during co-cultivation an...

The pckA gene, encoding phosphoenolpyruvate carboxykinase, catalyzes the reversible decarboxylation and phosphorylation of oxaloacetate to form phosphoenolpyruvate. Located on the circular chromosome of Agrobacterium, this locus is adjacent to the loci chvG and chvI, encoding a two-component regulatory system that has been shown to be important in virulence. Using a reporter gene fusion, studie...

A newly identified extracellular laccase produced by Streptomyces ipomoea CECT 3341 (SilA) was cloned and overexpressed, and its physicochemical characteristics assessed together with its capability to decolorize and detoxify an azotype dye. Molecular analysis of the deduced sequence revealed that SilA contains a TAT-type signal peptide at the N-terminus and only two cupredoxine domains; this i...

Agrobacterium tumefaciens induces crown gall tumors by transferring a piece of its tumor-inducing plasmid into plant cells. This transferred DNA encodes the synthesis of indole acetic acid (IAA) and cytokinin, and their overproduction results in tumor formation. The transfer is initiated by a two-component regulatory system, VirA/G recognizing plant signal molecules in the plant rhizosphere and...

The proteins encoded by three Agrobacterial genes, atu5117, atu4860, and atu4856, are highly homologous to each other in amino acid sequence. All three proteins can bind to VirD2 and are named VBP1, VBP2, and VBP3 (VirD2-binding protein), respectively. VBP is involved in T-DNA transfer by recruiting the T-complex from the cytosol to the polar transport apparatus T4SS (type IV secretion system) ...

Expression of Agrobacterium tumefaciens virulence (vir) genes requires virA, virG, and a plant-derived inducing compound such as acetosyringone. To identify the critical functional domains of virA and virG, a mutational approach was used. Agrobacterium A136 harboring plasmid pGP159, which contains virA, virG, and a reporter virB:lacZ gene fusion, was mutagenized with UV light or nitrosoguanidin...