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Sheng Wu Gong Cheng Xue Bao = Chinese... Apr 2020Cucumber (Cucumis sativus) is an important vegetable crop in the world. Agrobacterium-mediated transgenic technology is an important way to study plant gene functions... (Review)
Review
Cucumber (Cucumis sativus) is an important vegetable crop in the world. Agrobacterium-mediated transgenic technology is an important way to study plant gene functions and improve varieties. In order to further accelerate the transgenic research and breeding process of cucumber, we described the progress and problems of Agrobacterium tumefaciens-mediated transgenic cucumber, from the influencing factors of cucumber regeneration ability, genetic transformation conditions and various additives in the process. We prospected for improving the genetic transformation efficiency and safety selection markers of cucumber, and hoped to provide reference for the research of cucumber resistance breeding and quality improvement.
Topics: Agrobacterium tumefaciens; Breeding; Cucumis sativus; Plants, Genetically Modified; Research; Transformation, Genetic
PubMed: 32347059
DOI: 10.13345/j.cjb.190265 -
Proceedings of the National Academy of... Feb 2022Bacterial species from diverse phyla contain multiple replicons, yet how these multipartite genomes are organized and segregated during the cell cycle remains poorly...
Bacterial species from diverse phyla contain multiple replicons, yet how these multipartite genomes are organized and segregated during the cell cycle remains poorly understood. has a 2.8-Mb circular chromosome (Ch1), a 2.1-Mb linear chromosome (Ch2), and two large plasmids (pAt and pTi). We used this alpha proteobacterium as a model to investigate the global organization and temporal segregation of a multipartite genome. Using chromosome conformation capture assays, we demonstrate that both the circular and the linear chromosomes, but neither of the plasmids, have their left and right arms juxtaposed from their origins to their termini, generating interarm interactions that require the broadly conserved structural maintenance of chromosomes complex. Moreover, our study revealed two types of interreplicon interactions: " clustering" in which the replication origins of all four replicons interact, and "Ch1-Ch2 alignment" in which the arms of Ch1 and Ch2 interact linearly along their lengths. We show that the centromeric proteins (ParB1 for Ch1 and RepB for Ch2) are required for both types of interreplicon contacts. Finally, using fluorescence microscopy, we validated the clustering of the origins and observed their frequent colocalization during segregation. Altogether, our findings provide a high-resolution view of the conformation of a multipartite genome. We hypothesize that intercentromeric contacts promote the organization and maintenance of diverse replicons.
Topics: Agrobacterium tumefaciens; Bacterial Proteins; Cell Cycle; Chromosomes, Bacterial; Genome, Bacterial; Replicon
PubMed: 35101983
DOI: 10.1073/pnas.2115854119 -
The New Phytologist Jan 2022Agrobacterium tumefaciens colonizes the galls (plant tumors) it causes, and the roots of host and nonhost plants. Transposon-sequencing (Tn-Seq) was used to discover...
Agrobacterium tumefaciens colonizes the galls (plant tumors) it causes, and the roots of host and nonhost plants. Transposon-sequencing (Tn-Seq) was used to discover A.tumefaciens genes involved in reproductive success (fitness genes) on Solanum lycopersicum and Populus trichocarpa tumors and S.lycopersicum and Zea mays roots. The identified fitness genes represent 3-8% of A. tumefaciens genes and contribute to carbon and nitrogen metabolism, synthesis and repair of DNA, RNA and proteins and envelope-associated functions. Competition assays between 12 knockout mutants and wild-type confirmed the involvement of 10 genes (trpB, hisH, metH, cobN, ntrB, trxA, nrdJ, kamA, exoQ, wbbL) in A.tumefaciens fitness under both tumor and root conditions. The remaining two genes (fecA, noxA) were important in tumors only. None of these mutants was nonpathogenic, but four (hisH, trpB, exoQ, ntrB) exhibited impaired virulence. Finally, we used this knowledge to search for chemical and biocontrol treatments that target some of the identified fitness pathways and report reduced tumorigenesis and impaired establishment of A.tumefaciens on tomato roots using tannic acid or Pseudomonas protegens, which affect iron assimilation. This work revealed A.tumefaciens pathways that contribute to its competitive survival in plants and highlights a strategy to identify plant protection approaches against this pathogen.
Topics: Agrobacterium tumefaciens; Carbon; Solanum lycopersicum; Plant Roots; Plant Tumors; Virulence
PubMed: 34655498
DOI: 10.1111/nph.17810 -
Postepy Higieny I Medycyny... Dec 2016For many years attempts are made to develop efficient methods for transformation of medicinal plants via Agrobacterium tumefaciens. It is a soil bacteria which possess a... (Review)
Review
For many years attempts are made to develop efficient methods for transformation of medicinal plants via Agrobacterium tumefaciens. It is a soil bacteria which possess a natural ability to infect plants in places of injures which results in arise of cancerous growths (crown gall). This is possible thanks a transfer of fragment of Ti plasmid into plant cells and stable integration with a plant genome. Efficiency of medicinal plant transformation depends on many factors for example: Agrobacterium strain, methods and procedures of transformation as well as on plant species, type and age of the explants and regeneration conditions. The main goal of plant transformation is to increase the amount of naturally occurring bioactive compounds and the production of biopharmaceuticals. Genetic plant transformation via bacteria of the genus Agrobacterium is a complex process which requires detailed analysis of incorporated transgene expression and occurs only in the case when the plant cell acquires the ability to regenerate. In many cases, the regeneration efficiency observed in medicinal plants are inefficient after applied transformation procedures. To date there have been attempts of genetic transformation by using A. tumefaciens of medicinal plants belonging to the families: Apocynaceae, Araceae, Araliaceae, Asphodelaceae, Asteraceae, Begoniaceae, Crassulaceae, Fabaceae, Lamiaceae, Linaceae, Papaveraceae, Plantaginaceae, Scrophulariaceae and Solanaceae.
Topics: Agrobacterium tumefaciens; Plants, Genetically Modified; Plants, Medicinal; Transformation, Genetic
PubMed: 28026825
DOI: No ID Found -
Molecular Plant Pathology Mar 2021The plant pathogen Agrobacterium tumefaciens causes crown gall disease and is a widely used tool for generating transgenic plants owing to its virulence. The pathogenic...
The plant pathogen Agrobacterium tumefaciens causes crown gall disease and is a widely used tool for generating transgenic plants owing to its virulence. The pathogenic process involves a shift from an independent to a living form within a host plant. However, comprehensive analyses of metabolites, genes, and reactions contributing to this complex process are lacking. To gain new insights about the pathogenicity from the viewpoints of physiology and cellular metabolism, a genome-scale metabolic model (GSMM) was reconstructed for A. tumefaciens. The model, referred to as iNX1344, contained 1,344 genes, 1,441 reactions, and 1,106 metabolites. It was validated by analyses of in silico cell growth on 39 unique carbon or nitrogen sources and the flux distribution of carbon metabolism. A. tumefaciens metabolic characteristics under three ecological niches were modelled. A high capacity to access and metabolize nutrients is more important for rhizosphere colonization than in the soil, and substantial metabolic changes were detected during the shift from the rhizosphere to tumour environments. Furthermore, by integrating transcriptome data for tumour conditions, significant alterations in central metabolic pathways and secondary metabolite metabolism were identified. Overall, the GSMM and constraint-based analysis could decode the physiological and metabolic features of A. tumefaciens as well as interspecific interactions with hosts, thereby improving our understanding of host adaptation and infection mechanisms.
Topics: Agrobacterium tumefaciens; Bacterial Proteins; Metabolic Networks and Pathways; Plant Tumors; Plants, Genetically Modified; Transcriptome; Virulence
PubMed: 33433944
DOI: 10.1111/mpp.13032 -
Bioengineered 2015In May 2012, the first plant-derived biopharmaceutical protein received full regulatory approval for therapeutic use in humans. Although plant-based expression systems... (Review)
Review
In May 2012, the first plant-derived biopharmaceutical protein received full regulatory approval for therapeutic use in humans. Although plant-based expression systems have many advantages, they can suffer from low expression levels and, depending on the species, the presence of potentially toxic secondary metabolites. Transient expression mediated by Agrobacterium tumefaciens can be used to increase product yields but may also increase the concentration of secondary metabolites generated by plant defense responses. We have recently investigated the sequence of defense responses triggered by A. tumefaciens in tobacco plants and considered how these can be modulated by the transient expression of type III effectors from Pseudomonas syringae. Here we discuss the limitations of this approach, potential solutions and additional issues concerning transient expression in plants that should be investigated in greater detail.
Topics: Agrobacterium tumefaciens; Bacterial Proteins; DNA, Bacterial; Gene Expression; Gene Transfer Techniques; Plant Immunity; Plants, Genetically Modified; Pseudomonas syringae; Recombinant Proteins; Nicotiana
PubMed: 25997443
DOI: 10.1080/21655979.2015.1052920 -
Journal of Bacteriology Apr 2023Agrobacterium tumefaciens incites the formation of readily visible macroscopic structures known as crown galls on plant tissues that it infects. Records from biologists... (Review)
Review
Agrobacterium tumefaciens incites the formation of readily visible macroscopic structures known as crown galls on plant tissues that it infects. Records from biologists as early as the 17th century noted these unusual plant growths and began examining the basis for their formation. These studies eventually led to isolation of the infectious agent, A. tumefaciens, and decades of study revealed the remarkable mechanisms by which A. tumefaciens causes crown gall through stable horizontal genetic transfer to plants. This fundamental discovery generated a barrage of applications in the genetic manipulation of plants that is still under way. As a consequence of the intense study of A. tumefaciens and its role in plant disease, this pathogen was developed as a model for the study of critical processes that are shared by many bacteria, including host perception during pathogenesis, DNA transfer and toxin secretion, bacterial cell-cell communication, plasmid biology, and more recently, asymmetric cell biology and composite genome coordination and evolution. As such, studies of A. tumefaciens have had an outsized impact on diverse areas within microbiology and plant biology that extend far beyond its remarkable agricultural applications. In this review, we attempt to highlight the colorful history of A. tumefaciens as a study system, as well as current areas that are actively demonstrating its value and utility as a model microorganism.
Topics: Agrobacterium tumefaciens; Host Microbial Interactions; Plant Tumors; Plant Diseases; Plants; Bacteria; Biology
PubMed: 36892285
DOI: 10.1128/jb.00005-23 -
International Journal of Molecular... Sep 2018This review archives the achievements made in the last two decades and presents a brief outline of some significant factors influencing the -mediated transformation of .... (Review)
Review
This review archives the achievements made in the last two decades and presents a brief outline of some significant factors influencing the -mediated transformation of . Recently, progress in successful transformation has been made for this particular monocot crop through direct DNA delivery method and indirect method via However, lower transformation rate still proved to be a bottleneck in genetic modification of sorghum. An efficient transformation system could be attained by optimizing the preliminary assays, comprising of explant source, growth media, antibiotics, strains and agro-infection response of callus. The selection of competent strains for genetic transformation is also one of the key factors of consideration. Successful transformation is highly dependent on genome configuration of selected cultivar, where non-tannin genotype proved the best suited. Immature embryos from the field source have higher inherent adaptation chances than that of the greenhouse source. A higher concentration of may damage the explant source. Utilization of anti-necrotic treatments and optimized tissue culture timeframe are the adequate strategies to lower down the effect of phenolic compounds. Appropriate selection of culture media vessels at different stages of tissue culture may also assist in a constructive manner. In conclusion, some aspects such as culture environment with medium composition, explant sources, and genotypes play an indispensable role in successful -mediated sorghum transformation system.
Topics: Agrobacterium tumefaciens; Phenols; Sorghum; Tissue Culture Techniques; Transformation, Genetic
PubMed: 30274323
DOI: 10.3390/ijms19102983 -
Molecular Plant Pathology Sep 2020Ferritins are a large family of iron storage proteins, which are used by bacteria and other organisms to avoid iron toxicity and as a safe iron source in the cytosol....
Ferritins are a large family of iron storage proteins, which are used by bacteria and other organisms to avoid iron toxicity and as a safe iron source in the cytosol. Agrobacterium tumefaciens, a phytopathogen, has two ferritin-encoding genes: atu2771 and atu2477. Atu2771 is annotated as a Bfr-encoding gene (Bacterioferritin, Bfr) and atu2477 as a Dps-encoding gene (DNA binding protein from starved cells, Dps). Three deletion mutants (Δbfr, Δdps, and bfr-dps double-deletion mutant ΔbdF) of these two ferritin-encoding genes were constructed to investigate the effects of ferritin deficiency on the iron homeostasis, oxidative stress resistance, and pathogenicity of A. tumefaciens. Deficiency of two ferritins affects the growth of A. tumefaciens under iron starvation and excess. When supplied with moderate iron, the growth of A. tumefaciens is not affected by the deficiency of ferritin. Deficiency of ferritin significantly reduces iron accumulation in the cells of A. tumefaciens, but the effect of Bfr deficiency on iron accumulation is severer than Dps deficiency and the double mutant ΔbdF has the least intracellular iron content. All three ferritin-deficient mutants showed a decreased tolerance to 3 mM H O in comparison with the wild type. The tumour induced by each of three ferritin-deficient mutants is less than that of the wild type. Complementation reversed the effects of ferritin deficiency on the growth, iron homeostasis, oxidative stress resistance, and tumorigenicity of A. tumefaciens. Therefore, ferritin plays an important role in the pathogenesis of A. tumefaciens through regulating iron homeostasis and oxidative stress survival.
Topics: Agrobacterium tumefaciens; Bacterial Proteins; Cytochrome b Group; Ferritins; Homeostasis; Hydrogen Peroxide; Iron; Mutation; Oxidative Stress; Virulence
PubMed: 32678502
DOI: 10.1111/mpp.12969 -
Molecular Microbiology Jan 2018The AbcR small RNAs (sRNAs) are a fascinating example of two highly conserved sRNAs that differ tremendously at the functional level among organisms. From their... (Review)
Review
The AbcR small RNAs (sRNAs) are a fascinating example of two highly conserved sRNAs that differ tremendously at the functional level among organisms. From their transcriptional activation to their regulatory capabilities, the AbcR sRNAs exhibit varying characteristics in three well-studied bacteria belonging to the Rhizobiales order: the plant symbiont Sinorhizobium meliloti, the plant pathogen Agrobacterium tumefaciens, and the animal pathogen Brucella abortus. This review outlines the similarities and differences of the AbcR sRNAs between each of these organisms, and discusses reasons as to why this group of sRNAs has diverged in their genetic organization and regulatory functions across species. In the end, this review will shed light on how regulatory systems, although seemingly conserved among bacteria, can vary based on the environmental niche and lifestyle of an organism.
Topics: Agrobacterium tumefaciens; Biological Evolution; Brucella abortus; Gene Expression Regulation, Bacterial; Phylogeny; RNA, Bacterial; RNA, Small Untranslated; RNA, Untranslated; Rhizobiaceae; Sinorhizobium meliloti
PubMed: 29076560
DOI: 10.1111/mmi.13869