scholarly journals Morfogênese in vitro de variedades brasileiras de cana-de-açúcar

2006 ◽  
Vol 41 (3) ◽  
pp. 385-391 ◽  
Author(s):  
Daniela Anhel de Paula Cidade ◽  
Renata de Oliveira Garcia ◽  
Aline Castellar Duarte ◽  
Gilberto Sachetto-Martins ◽  
Elisabeth Mansur
Keyword(s):  
Agrobacterium Tumefaciens

O objetivo deste trabalho foi estabelecer sistemas de multiplicação de plantas de cana-de-açúcar in vitro e avaliar sua utilização, como material inicial, para a indução de regeneração a partir de ápices caulinares. Três métodos de cultivo foram avaliados: cultura em meio semi-sólido, cultura líquida estacionária e cultura líquida sob agitação. A taxa de multiplicação mais elevada foi alcançada por meio da cultura líquida sob agitação. Ápices caulinares, excisados dessas plantas, apresentaram taxas de regeneração in vitro compatíveis com sua utilização em protocolos de transformação. Calos resistentes a PPT e GUS-positivos foram obtidos de explantes da variedade Chunnee com inoculação de Agrobacterium tumefaciens C58C1 (pMP90) (pDUBarA9). O protocolo estabelecido a partir de cultivo in vitro pode ser utilizado para a produção de plantas transgênicas de cana-de-açúcar, visando à realização de estudos de regulação da expressão gênica, assim como à introdução de características de interesse agronômico.

scholarly journals Functional Characterization of the mazEF Toxin-Antitoxin System in the Pathogenic Bacterium Agrobacterium tumefaciens

2021 ◽  
Vol 9 (5) ◽  
pp. 1107
Author(s):  
Wonho Choi ◽  
Yoshihiro Yamaguchi ◽  
Ji-Young Park ◽  
Sang-Hyun Park ◽  
Hyeok-Won Lee ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Physiological Function ◽  
Functional Characterization ◽  
Site Directed Mutagenesis ◽  
In Vitro Assays ◽  
Cell Growth Inhibition ◽  
The Right

Agrobacterium tumefaciens is a pathogen of various plants which transfers its own DNA (T-DNA) to the host plants. It is used for producing genetically modified plants with this ability. To control T-DNA transfer to the right place, toxin-antitoxin (TA) systems of A. tumefaciens were used to control the target site of transfer without any unintentional targeting. Here, we describe a toxin-antitoxin system, Atu0939 (mazE-at) and Atu0940 (mazF-at), in the chromosome of Agrobacterium tumefaciens. The toxin in the TA system has 33.3% identity and 45.5% similarity with MazF in Escherichia coli. The expression of MazF-at caused cell growth inhibition, while cells with MazF-at co-expressed with MazE-at grew normally. In vivo and in vitro assays revealed that MazF-at inhibited protein synthesis by decreasing the cellular mRNA stability. Moreover, the catalytic residue of MazF-at was determined to be the 24th glutamic acid using site-directed mutagenesis. From the results, we concluded that MazF-at is a type II toxin-antitoxin system and a ribosome-independent endoribonuclease. Here, we characterized a TA system in A. tumefaciens whose understanding might help to find its physiological function and to develop further applications.

scholarly journals In Vitro Characterization of the Enzyme Properties of the Phospholipid N-Methyltransferase PmtA from Agrobacterium tumefaciens

2009 ◽  
Vol 191 (7) ◽  
pp. 2033-2041 ◽  
Author(s):  
Meriyem Aktas ◽  
Franz Narberhaus
Keyword(s):  
Agrobacterium Tumefaciens ◽  
In Vitro Assay ◽  
Enzyme Properties ◽  
Vitro Assay ◽  
Plant Infection ◽  
In Vitro Characterization ◽  
End Products ◽  
And Control

ABSTRACT Agrobacterium tumefaciens requires phosphatidylcholine (PC) in its membranes for plant infection. The phospholipid N-methyltransferase PmtA catalyzes all three transmethylation reactions of phosphatidylethanolamine (PE) to PC via the intermediates monomethylphosphatidylethanolamine (MMPE) and dimethylphosphatidylethanolamine (DMPE). The enzyme uses S-adenosylmethionine (SAM) as the methyl donor, converting it to S-adenosylhomocysteine (SAH). Little is known about the activity of bacterial Pmt enzymes, since PC biosynthesis in prokaryotes is rare. In this article, we present the purification and in vitro characterization of A. tumefaciens PmtA, which is a monomeric protein. It binds to PE, the intermediates MMPE and DMPE, the end product PC, and phosphatidylglycerol (PG) and phosphatidylinositol. Binding of the phospholipid substrates precedes binding of SAM. We used a coupled in vitro assay system to demonstrate the enzymatic activity of PmtA and to show that PmtA is inhibited by the end products PC and SAH and the antibiotic sinefungin. The presence of PG stimulates PmtA activity. Our study provides insights into the catalysis and control of a bacterial phospholipid N-methyltransferase.

scholarly journals EFFICACY OF BIOCHEMICAL PREPARATIONS AND EXTRACT FROM Hypericum perforatum AGAINST BACTERIAL DISEASES

2019 ◽  
Vol 18 (3) ◽  
Author(s):  
Małgorzata Schollenberger ◽  
Sylwia Pudło ◽  
Elżbieta Paduch-Cichal ◽  
Ewa Mirzwa-Mróz
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Pseudomonas Syringae ◽  
Pathogenic Bacteria ◽  
Hypericum Perforatum ◽  
Agar Plate ◽  
Nutrient Agar ◽  
Bacterial Strains ◽  
Bacterial Diseases ◽  
Nutrient Agar Medium

The biotechnical preparations: Biosept Active (based on a grapefruit extract) and BioZell (based on thyme oil) as well as Hypericum perforatum extract, streptomycin solution and fungicide Champion 50WP (active ingredient substance – e.i. 50% copper hydroxide) were investigated for antimicrobial effects against plant pathogenic bacteria: Agrobacterium tumefaciens, Pseudomonas syringae pv. syringae and Xanthomonas ar- boricola pv. corylina. The screening was carried out in vitro on three media: Nutrient Agar (NA Difco), Pseudomonas Agar F (Merck) – analogue of King B and 523. In the experiments, the agar plate method was applied. There were no statistically significant differences in the effect of streptomycin and Champion 50WP on the growth inhibition of three bacteria strains for medium 523 and Nutrient Agar and of P. syringae pv. syringae and X. arboricola pv. corylina for medium King B. It was determined that the antibacterial activity of Biosept Active and BioZell biopreparations and H. perforatum extract against Agrobacterium tumefaciens (strain C58), Pseudomonas syringae pv. syringae (strain 760) and Xanthomonas arboricola pv. corylina (strain RIPF-x13) were dependent on the strain of pathogen as well as the growth medium used. According to the research results obtained, the Biosept Active preparation and H. perforatum extract demonstrated high bacteriostatic activity against three bacterial strains grown on the Nutrient Agar medium.

scholarly journals In vitro plant regeneration and Agrobacterium tumefaciens -mediated transformation of Datura stramonium (Solanaceae)

2019 ◽  
Vol 7 (2) ◽  
pp. e01220
Author(s):  
Alex C. Rajewski ◽  
Kevan B. Elkins ◽  
Ashley Henry ◽  
Joyce Van Eck ◽  
Amy Litt
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Plant Regeneration ◽  
Datura Stramonium ◽  
In Vitro Plant Regeneration ◽  
In Vitro Plant

scholarly journals Agrobacterium tumefaciens Transformation of the Radiation Hypersensitive Arabidopsis thaliana Mutants uvh1 and rad5

1998 ◽  
Vol 11 (11) ◽  
pp. 1136-1141 ◽  
Author(s):  
Jaesung Nam ◽  
Kirankumar S. Mysore ◽  
Stanton B. Gelvin
Keyword(s):  
Arabidopsis Thaliana ◽  
Agrobacterium Tumefaciens ◽  
Transformation Process ◽  
Stable Transformation ◽  
Wild Type ◽  
Dna Integration ◽  
Agrobacterium Tumefaciens Transformation ◽  
Inoculation Assay

The Arabidopsis thaliana mutants uvh1 and rad5, originally identified as radiation hypersensitive, were reported to be deficient in T-DNA integration based on the relative efficiencies of stable transformation and T-DNA transfer. We reassessed these mutants for susceptibility to transformation by Agrobacterium tumefaciens. The mutant rad5 showed a significant reduction in the efficiency of transient as well as stable transformation, compared with its wild-type progenitor. These data indicate that rad5 is blocked at a step in the transformation process prior to T-DNA integration. We additionally found, using both an in vitro root inoculation and an in vivo flower bolt inoculation assay, that the mutant uvh1 is as susceptible to A. tumefaciens-mediated transformation as is its wild-type progenitor, C10.

scholarly journals Sequencing and Heterologous Expression of an Epimerase and Two Lyases from Iminodisuccinate-Degrading Bacteria

2006 ◽  
Vol 72 (4) ◽  
pp. 2824-2828 ◽  
Author(s):  
Bettina Bäuerle ◽  
Željko Cokesa ◽  
Silvia Hofmann ◽  
Paul-Gerhard Rieger
Keyword(s):  
Amino Acid ◽  
Agrobacterium Tumefaciens ◽  
Heterologous Expression ◽  
Bacterial Strain ◽  
Amino Acid Sequences ◽  
Complexing Agent ◽  
Recombinant Enzymes ◽  
Gene Encoding ◽  
Degrading Bacteria

ABSTRACT Recently, degradation of all existing epimers of the complexing agent iminodisuccinate (IDS) in the bacterial strain Agrobacterium tumefaciens BY6 was proven to depend on an epimerase and a C-N lyase (Cokesa et al., Appl. Environ. Microbiol. 70:3941-3947, 2004). In the bacterial strain Ralstonia sp. strain SLRS7, a corresponding C-N lyase is responsible for the initial degradation step (Cokesa et al., Biodegradation 15:229-239, 2004). The ite gene, encoding the IDS-transforming epimerase, and the genes icl B and icl S, encoding the IDS-converting BY6-lyase and SLRS7-lyase, respectively, were cloned and sequenced. The epimerase gene encodes a protein with a predicted subunit molecular mass of 47.6 kDa. The highest degree of epimerase amino acid sequence identities was found with proteins of unknown function, indicating a novel protein. For the lyases, the deduced amino acid sequences show high similarity to enzymes of the fumarase II family. A classification into a new subfamily within the enzyme family is proposed. The subunit molecular masses of the lyases were calculated to be 54.4 and 54.7 kDa, respectively. In Agrobacterium tumefaciens BY6, the ite gene was on an approximately 180-kb circular plasmid, whereas the icl B gene was chromosomal like the corresponding icl S gene in Ralstonia sp. strain SLRS7. Heterologous expression in Escherichia coli and subsequent purification revealed recombinant enzymes with in vitro activity similar to that of the corresponding enzymes from the wild-type strains.

scholarly journals Reconstitution of the Biochemical Activities of the AttJ Repressor and the AttK, AttL, and AttM Catabolic Enzymes of Agrobacterium tumefaciens

2007 ◽  
Vol 189 (9) ◽  
pp. 3674-3679 ◽  
Author(s):  
Yunrong Chai ◽  
Ching Sung Tsai ◽  
Hongbaek Cho ◽  
Stephen C. Winans
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Succinic Semialdehyde ◽  
Metabolic Intermediates ◽  
Acylhomoserine Lactone ◽  
Catabolic Enzymes ◽  
Gamma Hydroxybutyrate ◽  
Gamma Butyrolactone

ABSTRACT The attKLM operon encodes a lactonase (AttM) that hydrolyzes acylhomoserine lactone autoinducers, as well as two putative dehydrogenases (AttK and AttL). Here we show that AttK, AttL, and AttM collectively covert gamma-butyrolactone to succinate. Two metabolic intermediates, gamma-hydroxybutyrate and succinic semialdehyde, inactivated the AttJ repressor in vitro and induced attKLM transcription in vivo.

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