Factors Influencing T-DNA Transfer into Wheat and Barley Cells by Agrobacterium Tumefaciens

1998 ◽  
Vol 26 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Guangqin Guo ◽  
Frank Maiwald ◽  
Petra Lorenzen ◽  
Hans-Henning Steinbiss
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Dna Transfer ◽  
Factors Influencing

Identification of the signal molecules produced by wounded plant cells that activate T-DNA transfer in Agrobacterium tumefaciens

Nature ◽  
1985 ◽  
Vol 318 (6047) ◽  
pp. 624-629 ◽  
Author(s):  
Scott E. Stachel ◽  
Eric Messens ◽  
Marc Van Montagu ◽  
Patricia Zambryski
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Plant Cells ◽  
Dna Transfer ◽  
Signal Molecules

scholarly journals Trans-kingdom T-DNA transfer from Agrobacterium tumefaciens to Saccharomyces cerevisiae.

1995 ◽  
Vol 14 (13) ◽  
pp. 3206-3214 ◽  
Author(s):  
P. Bundock ◽  
A. den Dulk-Ras ◽  
A. Beijersbergen ◽  
P.J. Hooykaas
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Agrobacterium Tumefaciens ◽  
Dna Transfer

Gene-Expression Following T-DNA Transfer Into Plant Cells Is Aphidicolin-Sensitive

1994 ◽  
Vol 21 (2) ◽  
pp. 125 ◽  
Author(s):  
AM Chaudhury ◽  
ES Dennis ◽  
RIS Brettell
Keyword(s):  
Gene Expression ◽  
Dna Replication ◽  
Agrobacterium Tumefaciens ◽  
Plant Cells ◽  
Nicotiana Plumbaginifolia ◽  
Dna Transfer ◽  
Host Cells ◽  
35S Promoter ◽  
Glucuronidase Activity ◽  
Pass Through

A transient assay for gene-expression was used to study the early events of T-DNA transfer. Particularly, it was asked if gene expression following T-DNA transfer required DNA replication in the host cell. A β-glucuronidase gene, linked to a CaMV 35S promoter (35S-GUS, engineered so that it was inactive in Agrobacterium tumefaciens) was introduced into Nicotiana plumbaginifolia protoplasts via a disarmed supervirulent strain of Agrobacterium tumefaciens. High β-glucuronidase activity appeared after 3 days of co-cultivation. The activity required the presence of the vir functions of agrobacteria. The activity was drastically reduced if the plant cells were treated with aphidicolin, an inhibitor of DNA replication in eukaryotic cells. While double-stranded (ds) 35S-GUS DNA, introduced by electroporation, showed undiminished expression in the presence of aphidicolin, gene expression from single-stranded (ss) 35S-GUS DNA was inhibited by aphidicolin. These results suggest that DNA replication in host cells is not required for gene expression if ds-DNA is introduced by electroporation, but is required if ss-DNA is introduced by electroporation, or if DNA is transferred via A. tumefaciens. The findings are consistent with a model of T-DNA transfer in which ss-DNA molecules, once introduced into plant cells, must pass through an aphidicolin sensitive step before they can be transcribed. The simplest interpretation is that the ss-DNA is replicated by the host cell's aphidicolin-sensitive DNA polymerase before being integrated into the host genome.

scholarly journals Transcriptome Profiling and Functional Analysis of Agrobacterium tumefaciens Reveals a General Conserved Response to Acidic Conditions (pH 5.5) and a Complex Acid-Mediated Signaling Involved in Agrobacterium-Plant Interactions

2007 ◽  
Vol 190 (2) ◽  
pp. 494-507 ◽  
Author(s):  
Ze-Chun Yuan ◽  
Pu Liu ◽  
Panatda Saenkham ◽  
Kathleen Kerr ◽  
Eugene W. Nester
Keyword(s):  
Gene Expression ◽  
Agrobacterium Tumefaciens ◽  
Expression Patterns ◽  
Dna Transfer ◽  
Plant Interactions ◽  
Type Vi Secretion System ◽  
Two Component System ◽  
Component System ◽  
Two Component ◽  
Acidic Conditions

ABSTRACT Agrobacterium tumefaciens transferred DNA (T-DNA) transfer requires that the virulence genes (vir regulon) on the tumor-inducing (Ti) plasmid be induced by plant phenolic signals in an acidic environment. Using transcriptome analysis, we found that these acidic conditions elicit two distinct responses: (i) a general and conserved response through which Agrobacterium modulates gene expression patterns to adapt to environmental acidification and (ii) a highly specialized acid-mediated signaling response involved in Agrobacterium-plant interactions. Overall, 78 genes were induced and 74 genes were repressed significantly under acidic conditions (pH 5.5) compared to neutral conditions (pH 7.0). Microarray analysis not only confirmed previously identified acid-inducible genes but also uncovered many new acid-induced genes which may be directly involved in Agrobacterium-plant interactions. These genes include virE0, virE1, virH1, and virH2. Further, the chvG-chvI two-component system, previously shown to be critical for virulence, was also induced under acid conditions. Interestingly, acidic conditions induced a type VI secretion system and a putative nonheme catalase. We provide evidence suggesting that acid-induced gene expression was independent of the VirA-VirG two-component system. Our results, together with previous data, support the hypothesis that there is three-step sequential activation of the vir regulon. This process involves a cascade regulation and hierarchical signaling pathway featuring initial direct activation of the VirA-VirG system by the acid-activated ChvG-ChvI system. Our data strengthen the notion that Agrobacterium has evolved a mechanism to perceive and subvert the acidic conditions of the rhizosphere to an important signal that initiates and directs the early virulence program, culminating in T-DNA transfer.

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