Search results for "Agrobacterium"

Seasonal fluctuations and long-term persistence of pathogenic populations of Agrobacterium spp. in soils.

2002

ABSTRACT Short- and long-term persistence of pathogenic (i.e., tumor forming) agrobacteria in soil was investigated in six nursery plots with a history of high crown gall incidence. No pathogenic Agrobacterium strains were isolated in soil samples taken in fall and winter in any plots, but such strains were isolated from both bulk soils and weed rhizospheres (over 0.5 × 10 5 pathogenic CFU/g of bulk soil or rhizosphere) in three out of six plots in spring and summer. PCR amplifications of a vir sequence from DNA extracted from soil confirmed the presence of Ti plasmids in summer and their absence in fall and winter. The results indicate that strains that harbor a Ti plasmid had an unforesee…

Effect of rhizosphère bacteria and endomycorrhizal fungi on the growth of Christmas rose (Helleborus niger L.)

2010

International audience; Micropropagated and vegetative (by rhizome cuttings) propagated plants of Christmas rose ( Helleborus niger L.) were tested for their responses to the inoculation with microorganisms in order to optimize root growth and development. In our experiment, plants were inoculated with arbuscular endomycorrhizal fungi or/and Agrobacterium radiobacter . The investigation indicated that inoculation with A. radiobacter had significantly positive effect on growth and development of plants multiplicated by in vitro techniques as compared to the dual inoculation. This study indicates that, biotization can be beneficial to plant growth in in vitro plant production systems but inoc…

A mathematical method for determining genome divergence and species delineation using AFLP.

2002

The delineation of bacterial species is presently achieved using direct DNA-DNA relatedness studies of whole genomes. It would be helpful to obtain the same genomically based delineation by indirect methods, provided that descriptions of individual genome composition of bacterial genomes are obtained and included in species descriptions. The amplified fragment length polymorphism (AFLP) technique could provide the necessary data if the nucleotides involved in restriction and amplification are fundamental to the description of genomic divergences. Firstly, in order to verify that AFLP analysis permits a realistic exploration of bacterial genome composition, the strong correspondence between …

Vers la validation fonctionnelle du gène WEE1 dans l’acquisition de la résistance au stress abiotique chez des protéagineux

2017

Etude comparative de deux méthodes de transformation et de deux milieux de culture chez Agrobacterium tumefaciens souche LBA4404

2013

Rapport de stage de master 1 BAP GEAPSI

Plant hormones and Agrobacterium tumefaciens strain 82.139 induce efficient plant regeneration in the cardenolide-producing plant Digitalis minor

2002

Summary Shoot formation in explants of Digitalis minor was achieved, through axillary bud proliferation and adventitious bud differentiation, by varying the amount and source of plant hormones. Shoot regeneration was also obtained after infection of D. minor with the wild-type Agrobacterium tumefaciens strain 82.139, which induced shooty tumours. These shoots were not transgenic, as revealed by nopaline assays and the use of a C58pMP90/T139GUS-INT strain harbouring the intron inactivated gusA gene. Plants were easily rooted and transplanted into the greenhouse. Shoot cultures of D. minor accumulated up to 226 μg cardenolides per g dry mass when cultured on agar-solidified medium. Cardenolid…

Neutralizing antibodies against rotavirus produced in transgenically labelled purple tomatoes

2011

Edible fruits are inexpensive biofactories for human health-promoting molecules that can be ingested as crude extracts or partially purified formulations. We show here the production of a model human antibody for passive protection against the enteric pathogen rotavirus in transgenically labelled tomato fruits. Transgenic tomato plants expressing a recombinant human immunoglobulin A (hIgA_2A1) selected against the VP8* peptide of rotavirus SA11 strain were obtained. The amount of hIgA_2A1 protein reached 3.6 ± 0.8% of the total soluble protein in the fruit of the transformed plants. Minimally processed fruit-derived products suitable for oral intake showed anti-VP8* binding activity and str…

Estimation of the density of the protocatechuate-degrading bacterial community in soil by real-time PCR

2008

Summary The β-ketoadipate pathway is the major route for degradation of aromatic compounds by various soil microorganisms. Protocatechuate 3,4-dioxygenase, a key enzyme of this pathway and which is encoded by pcaGH genes, catalyses the ring cleavage of protocatechuate. Microorganisms harbouring pcaGH genes are widely distributed in the environment but little is known about their relative abundance within the total microflora. Hence, this paper reports the development of a real-time PCR assay to quantify the bacterial pcaH sequence that encodes the β sub-unit of the protocatechuate 3,4-dioxygenase. This real-time PCR assay was linear over seven orders of magnitude with a calculated efficienc…