Identification and localization of transformed cells in Agrobacterium tumefaciens -induced plant tumors

Planta ◽  
1999 ◽  
Vol 209 (4) ◽  
pp. 399-405 ◽  
Author(s):  
Claudia Rezmer ◽  
Ralf Schlichting ◽  
Rebecca Wächter ◽  
Cornelia I. Ullrich
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Transformed Cells ◽  
Plant Tumors

scholarly journals Different Regulation and Roles of Lactonases AiiB and AttM in Agrobacterium tumefaciens C58

2009 ◽  
Vol 22 (5) ◽  
pp. 529-537 ◽  
Author(s):  
Elise Haudecoeur ◽  
Mélanie Tannières ◽  
Amélie Cirou ◽  
Aurélie Raffoux ◽  
Yves Dessaux ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Selective Advantage ◽  
In Planta ◽  
Host Interaction ◽  
Plant Tumors ◽  
Plant Signals ◽  
Polymerase Chain ◽  
Agrobacterium Tumefaciens C58 ◽  
Regulated Functions

The phytopathogen Agrobacterium tumefaciens C58 expresses two lactonases, AttM and AiiB. We showed that expression of the aiiB gene was controlled by agrocinopines A and B and required the agrocinopine-ABC transporter Acc, but was not affected by the level of quorum-sensing (QS) signal 3-oxo-octanoylhomoserine lactone (OC8-HSL). In the presence of agrocinopines, a constructed aiiB mutant accumulated OC8-HSL at a level 10-fold higher than that of the wild-type strain, and showed an exacerbated expression of a key QS-regulated function, conjugation of Ti plasmid (in vitro and in planta), as well as an increase of the number of emerging tumors on the host plant. The expression and acyl-HSL-degrading activity of AttM were evident in the presence of wounded tissues; however, in unwounded plant tumors, the QS-regulated functions were weakly affected in an attM mutant. By contrast, we observed that attM conferred a selective advantage in the course of colonization of plant tumors. Finally, polymerase chain reaction survey of genes attM and aiiB showed that they were not strictly conserved in the genus Agrobacterium. This work proved that the lactonases AttM and AiiB are regulated by different plant signals and are implicated in different functions in the course of the A. tumefaciens C58–host interaction.

scholarly journals Agrobacterium tumefaciens fitness genes involved in the colonization of plant tumors and roots

2021 ◽  
Author(s):  
Marta Torres ◽  
Audren Jiquel ◽  
Etienne Jeanne ◽  
Delphine Naquin ◽  
Yves Dessaux ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Plant Tumors

scholarly journals Selective agent and A. tumefaciens overgrowth-control antibiotics in Eucalyptus camaldulensis Cotiledonary culture

2009 ◽  
Vol 52 (6) ◽  
pp. 1485-1492 ◽  
Author(s):  
Regina Quisen ◽  
Yohana de Oliveira ◽  
Marcos Pileggi ◽  
Francine Cuquel ◽  
Marguerite Quoirin
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Lethal Dose ◽  
Eucalyptus Camaldulensis ◽  
Transformed Cells ◽  
Selective Agent ◽  
Cotyledonary Explants ◽  
Selection Of

The objectives of the present work were to establish the minimal lethal dose of the selective agent to determine the type and concentration of appropriate antibiotics for the elimination of Agrobacterium tumefaciens inoculated explants, without interfering with the regenerative potential of the E. camaldulensis cotyledonary explants. Non-transformed explants were cultivated in medium supplemented with kanamycin. The results showed that the antibiotic was suitable for the selection of transformed cells in the concentration of 9 mg L-1 as it inhibited the growth of non-transformed cells. Cotyledons infected with A. tumefaciens were cultivated in MS N/2 medium supplemented with BAP, ANA, Km and cefotaxime or AugmentinÒ . The highest average of regenerated shoots by explant (5,4) was observed in the presence of 300 mg L-1 of AugmentinÒ /15 days, followed by 150 mg L-1/15 days and 100 mg L-1/30 days.

scholarly journals Agrobacterium tumefaciens Transformation and Cotransformation Frequencies of Arabidopsis thaliana Root Explants and Tobacco Protoplasts

1998 ◽  
Vol 11 (6) ◽  
pp. 449-457 ◽  
Author(s):  
Sylvie De Buck ◽  
Anni Jacobs ◽  
Marc Van Montagu ◽  
Ann Depicker
Keyword(s):  
Arabidopsis Thaliana ◽  
Agrobacterium Tumefaciens ◽  
High Frequency ◽  
Dna Marker ◽  
Plant Cells ◽  
Transformation Frequency ◽  
Transformed Cells ◽  
Root Explants ◽  
Tobacco Protoplasts ◽  
Agrobacterium Tumefaciens Transformation

In view of the recent finding that different T-DNAs tend to ligate and integrate as repeats at single chromosomal positions, the frequency of transformation and cotransformation was determined during cocultivation of Arabidopsis thaliana root explants and Nicotiana tabacum protoplasts with two Agrobacterium strains. The transformation frequency of unselected A. thaliana shoots was lower than 1% whereas that of cocultivated tobacco protoplasts was approximately 18%. The cotransformation frequencies, defined as the frequencies with which cells transformed with a first T-DNA contained a second unselected T-DNA, were approximately 40% reproducible, irrespective of the selection, the transformation frequency, and the plant system used. Extrapolation of these results suggests that at least two independently transferred T-DNAs were present in 64% of the transformed plant cells. Molecular analysis of cocultivated N. tabacum shoots regenerated on nonselective medium showed that only a few transformants had a silenced (2/46) or truncated (1/46) T-DNA. Therefore, most integrated T-DNAs expressed their selectable or screenable markers in primary transgenic plants. Remarkably, 10 to 30% of the selected A. thaliana shoots or progenies lost the T-DNA marker they were selected on. As these regenerants contained the unselected T-DNA with a high frequency (17%), these selected plants might result from the expression of unstable, transiently expressed T-DNAs. In conclusion, a significant part of the T-DNAs is lost from the transformed cells.

Flavonoid-related regulation of auxin accumulation in Agrobacterium tumefaciens -induced plant tumors

Planta ◽  
2003 ◽  
Vol 218 (2) ◽  
pp. 163-178 ◽  
Author(s):  
Katja Schwalm ◽  
Roni Aloni ◽  
Markus Langhans ◽  
Werner Heller ◽  
Susanne Stich ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Plant Tumors ◽  
Auxin Accumulation

Structural basis for two efficient modes of agropinic acid opine import into the bacterial pathogen Agrobacterium tumefaciens

2019 ◽  
Vol 476 (1) ◽  
pp. 165-178 ◽  
Author(s):  
Loïc Marty ◽  
Armelle Vigouroux ◽  
Magali Aumont-Nicaise ◽  
Franck Pelissier ◽  
Thibault Meyer ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Time Course ◽  
Genetically Modify ◽  
Bacterial Pathogen ◽  
Binding Mode ◽  
Structural Basis ◽  
Crystallization Time ◽  
Periplasmic Binding Proteins ◽  
Plant Tumors ◽  
Nanomolar Range

AbstractAgrobacterium tumefaciens pathogens genetically modify their host plants to drive the synthesis of opines in plant tumors. The mannityl-opine family encompasses mannopine, mannopinic acid, agropine and agropinic acid. These opines serve as nutrients and are imported into bacteria via periplasmic-binding proteins (PBPs) in association with ABC transporters. Structural and affinity data on agropine and agropinic acid opines bound to PBPs are currently lacking. Here, we investigated the molecular basis of AgtB and AgaA, proposed as the specific PBP for agropine and agropinic acid import, respectively. Using genetic approaches and affinity measurements, we identified AgtB and its transporter as responsible for agropine uptake in agropine-assimilating agrobacteria. Nonetheless, we showed that AgtB binds agropinic acid with a higher affinity than agropine, and we structurally characterized the agropinic acid-binding mode through three crystal structures at 1.4, 1.74 and 1.9 Å resolution. In the crystallization time course, obtaining a crystal structure of AgtB with agropine was unsuccessful due to the spontaneous lactamization of agropine into agropinic acid. AgaA binds agropinic acid only with a similar affinity in nanomolar range as AgtB. The structure of AgaA bound to agropinic acid at 1.65 Å resolution defines a different agropinic acid-binding signature. Our work highlights the structural and functional characteristics of two efficient agropinic acid assimilation pathways, of which one is also involved in agropine assimilation.

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