Right-border sequences enable the left border of an Agrobacterium tumefaciens nopaline Ti-plasmid to produce single-stranded DNA

1988 ◽  
Vol 11 (4) ◽  
pp. 389-399 ◽  
Author(s):  
Francisco A. Culianez-Macia ◽  
Angus G. Hepburn
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Ti Plasmid ◽  
Single Stranded Dna ◽  
Left Border ◽  
Right Border ◽  
Border Sequences

The interaction of Agrobacterium Ti-plasmid DNA and plant cells

1980 ◽  
Vol 210 (1180) ◽  
pp. 351-365 ◽  
Keyword(s):  
Plant Cells ◽  
Ti Plasmid ◽  
Insertion Mutagenesis ◽  
Left Hand ◽  
Left Border ◽  
Transposon Insertion ◽  
Right Hand ◽  
Ti Plasmids ◽  
Right Border ◽  
The Right

The tumour-inducing plasmids of Agrobacterium tumefaciens (Ti-plasmids) reveal several interesting properties. They are catabolic plasmids, which, instead of rendering Agrobacterium strains capable of catabolizing compounds found in Nature, force a plant to synthesize these catabolites (denoted ‘opines’). This situation is obtained by insertion of a segment of the Ti-plasmid (the T-DNA) into the plant nucleus, where T-DNA genes become expressed and intervene in the biosynthesis of these opines. Cells containing the T-DNA behave as neoplasms (crown gall cells). Southern blotting shows that the insertion process responsible for T-DNA transfer probably recognizes special sequences on the T-DNA since the length of the T-DNA segment observed in different, independently isolated tumour lines was found to be similar. For the nopaline Tiplasmids both left-hand and right-hand borders were found to be constant. For the octopine plasmid the left border was constant and at least two classes of right-hand borders were found. Upon redifferentiation of the transformed plant cells, the T-DNA was found to be conserved in all somatic cells examined. However, small deletions at the border fragments of the T-DNA have been observed. The exact arrangement and copy number of the T-DNA in a nucleus is still under study, but genomic cloning has already revealed that an interspersed tandem arrangement is dominant in nopaline tumours. Clones containing both the right border of one T-DNA and the left border of the neighbouring tandem T-DNA were isolated. In order to identify the different T-plasmid encoded functions an extensive use was made of transposon insertion mutagenesis. When an antibiotic resistance transposon was inserted into the non-essential regions of the T-DNA, a linked transfer to the plant DNA of the transposon together with the T-DNA was observed. This indicates that Ti-plasmids are possible vectors for genetic engineering in plants. A strategy is described for insertion of any cloned DNA segment into the T-DNA.

scholarly journals A T-DNA from the Agrobacterium tumefaciens Limited-Host-Range Strain AB2/73 Contains a Single Oncogene

1998 ◽  
Vol 11 (5) ◽  
pp. 335-342 ◽  
Author(s):  
Léon Otten ◽  
Julien Schmidt
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Host Range ◽  
Dna Sequence ◽  
Ti Plasmid ◽  
Dna Homology ◽  
Agrobacterium Vitis ◽  
E Gene ◽  
Limited Host Range ◽  
Border Sequences ◽  
Border Sequence

Agrobacterium tumefaciens strain AB2/73 isolated from Lippia canescens has been described as a limited-host-range strain. Its tumor-inducing (Ti) plasmid has been found to lack DNA homology to known T-DNAs (L. Unger, S. F. Ziegler, G. A. Huffman, V. C. Knauf, R. Peet, L. W. Moore, M. P. Gordon, and E. W. Nester. J. Bacteriol. 164:723–730, 1985). We have isolated a T-DNA from AB2/73 by using a heterologous border sequence as a probe. The AB2/73 T-DNA sequence (3,504 bp) is flanked by canonical border sequences, has no detectable DNA homology with other T-DNAs, and contains only two genes: lsn ( Lippia strain nopaline synthaselike gene) and lso ( Lippia strain oncogene). The lso gene induces nondif-ferentiating tumors on a limited number of hosts when transferred by a Ti plasmid from a wide-host-range strain. Part of the predicted Lso protein is weakly homologous to other Agrobacterium oncoproteins encoded by rolB, rolBTR, orf13, gene e, gene 5, and gene 3′. A 28-kb fragment corresponding to the virA to virE region was cloned by using a heterologous vir fragment as probe. The AB2/73 vir region is homologous to most of the C58 virulence region; however, the virA gene is most related to the virA gene of the Agrobacterium vitis limited-host-range strain Ag162.

scholarly journals Correction: characterization of the virB operon from Agrobacterium tumefaciens Ti plasmid.

1990 ◽  
Vol 265 (8) ◽  
pp. 4768
Author(s):  
J E Ward ◽  
D E Akiyoshi ◽  
D Regier ◽  
A Datta ◽  
M P Gordon ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Ti Plasmid ◽  
Virb Operon

Physical mapping of DNA base sequence homologies between an octopine and a nopaline Ti plasmid of Agrobacterium tumefaciens

1981 ◽  
Vol 152 (2) ◽  
pp. 183-208 ◽  
Author(s):  
G. Engler ◽  
A. Depicker ◽  
R. Maenhaut ◽  
R. Villarroel ◽  
M. Van Montagu ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Physical Mapping ◽  
Ti Plasmid ◽  
Base Sequence ◽  
Dna Base ◽  
Sequence Homologies

scholarly journals Mutational analysis of the virulence region of an Agrobacterium tumefaciens Ti plasmid.

1983 ◽  
Vol 153 (2) ◽  
pp. 878-883 ◽  
Author(s):  
H J Klee ◽  
F F White ◽  
V N Iyer ◽  
M P Gordon ◽  
E W Nester
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Mutational Analysis ◽  
Ti Plasmid

scholarly journals A novel plasmid-transcribed regulatory sRNA, QfsR, controls chromosomal polycistronic mRNAs in Agrobacterium tumefaciens

2019 ◽  
Author(s):  
Benjamin Diel ◽  
Magali Dequivre ◽  
Florence Wisniewski-Dyé ◽  
Ludovic Vial ◽  
Florence Hommais
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Small Rna ◽  
Regulatory Networks ◽  
Target Prediction ◽  
Ti Plasmid ◽  
Conjugative Transfer ◽  
Polycistronic Mrna ◽  
Cell Functions ◽  
Coordinated Expression ◽  
Cellular Behaviour

AbstractPlasmids are mobile DNAs that adjust host cell functions for their own amplification and dissemination. We identified QfsR, a small RNA, transcribed from the Ti plasmid in the phytopathogen Agrobacterium fabrum. QfsR is widely conserved throughout RepABC plasmids carried by Rhizobiaceae. Target prediction, expression analysis and site-direct mutagenesis experiments show that QfsR directly pairs within polycistronic mRNAs transcribed from chromosomes (involved in flagella apparatus and succinoglycan biosynthesis) and Ti plasmid (involved in conjugative transfer). QfsR leads to a coordinated expression of whole polycistronic mRNA molecules. Whereas a lack of QfsR induces motility and reduces succinoglycan production, its overproduction increases the quorum sensing signal accumulation and the Ti plasmid conjugative transfer. Based on these observations, we propose QfsR as a hub connecting regulatory networks of motility, succinoglycan biosynthesis and plasmid conjugative transfer. To our knowledge, QfsR is the first example of a plasmid-encoded sRNA that controls chromosomal polycistronic mRNAs.SignificancePlasmids represent an important cost for the hosting cell although some are beneficial under certain circumstances. Agrobacterium tumefaciens harboring Tumor inducing plasmid (pTi) are able to infect plants and to use specific resources produced by the infected cells. We characterized QfsR, a novel small RNA (sRNA) from pTi, that directly regulates plasmid polycistronic mRNA but also chromosomal ones. QfsR contributes to a fine-tuned regulation of bacterial motility, exopolysaccharide biosynthesis and conjugative dissemination of pTi. Our results report the first plasmid-encoded sRNA able to modify and coordinate cellular behaviour probably for the benefit of the plasmid dissemination and tight crosstalk between plasmid and chromosome. This could be widespread since QfsR homologs were predicted in other plasmids of Rhizobiaceae symbionts and pathogens.

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