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Molecular Biotechnology Jun 2023Agrobacterium tumefaciens-mediated plant transformation is the most dominant technique for the transformation of plants. It is used to transform monocotyledonous and... (Review)
Review
Agrobacterium tumefaciens-mediated plant transformation is the most dominant technique for the transformation of plants. It is used to transform monocotyledonous and dicotyledonous plants. A. tumefaciens apply for stable and transient transformation, random and targeted integration of foreign genes, as well as genome editing of plants. The Advantages of this method include cheapness, uncomplicated operation, high reproducibility, a low copy number of integrated transgenes, and the possibility of transferring larger DNA fragments. Engineered endonucleases such as CRISPR/Cas9 systems, TALENs, and ZFNs can be delivered with this method. Nowadays, Agrobacterium-mediated transformation is used for the Knock in, Knock down, and Knock out of genes. The transformation effectiveness of this method is not always desirable. Researchers applied various strategies to improve the effectiveness of this method. Here, a general overview of the characteristics and mechanism of gene transfer with Agrobacterium is presented. Advantages, updated data on the factors involved in optimizing this method, and other useful materials that lead to maximum exploitation as well as overcoming obstacles of this method are discussed. Moreover, the application of this method in the generation of genetically edited plants is stated. This review can help researchers to establish a rapid and highly effective Agrobacterium-mediated transformation protocol for any plant species.
PubMed: 37340198
DOI: 10.1007/s12033-023-00788-x -
EcoSal Plus Dec 2022In the late 1950s, a number of laboratories took up the study of plasmids once the discovery was made that extrachromosomal antibiotic resistance (R) factors are the... (Review)
Review
In the late 1950s, a number of laboratories took up the study of plasmids once the discovery was made that extrachromosomal antibiotic resistance (R) factors are the responsible agents for the transmissibility of multiple antibiotic resistance among the enterobacteria. The use of incompatibility for the classification of plasmids is now widespread. It seems clear now on the basis of the limited studies to date that the number of incompatibility groups of plasmids will likely be extremely large when one includes plasmids obtained from bacteria that are normal inhabitants of poorly studied natural environments. The presence of both linear chromosomes and linear plasmids is now established for several species. One of the more fascinating developments in plasmid biology was the discovery of linear plasmids in the 1980s. A remarkable feature of the Ti plasmids of Agrobacterium tumefaciens is the presence of two DNA transfer systems. A definitive demonstration that plasmids consisted of duplex DNA came from interspecies conjugal transfer of plasmids followed by separation of plasmid DNA from chromosomal DNA by equilibrium buoyant density centrifugation. The formation of channels for DNA movement and the actual steps involved in DNA transport offer many opportunities for the discovery of proteins with novel activities and for establishing fundamentally new concepts of macromolecular interactions between DNA and specific proteins, membranes, and the peptidoglycan matrix.
Topics: Plasmids; Agrobacterium tumefaciens; Plant Tumor-Inducing Plasmids; Bacteria; DNA, Bacterial
PubMed: 35373578
DOI: 10.1128/ecosalplus.esp-0028-2021 -
Plant Communications Apr 2024Plant genetic transformation strategies serve as essential tools for the genetic engineering and advanced molecular breeding of plants. However, the complicated...
Plant genetic transformation strategies serve as essential tools for the genetic engineering and advanced molecular breeding of plants. However, the complicated operational protocols and low efficiency of current transformation strategies restrict the genetic modification of most plant species. This paper describes the development of the regenerative activity-dependent in planta injection delivery (RAPID) method based on the active regeneration capacity of plants. In this method, Agrobacterium tumefaciens is delivered to plant meristems via injection to induce transfected nascent tissues. Stable transgenic plants can be obtained by subsequent vegetative propagation of the positive nascent tissues. The method was successfully used for transformation of plants with strong regeneration capacity, including different genotypes of sweet potato (Ipomoea batatas), potato (Solanum tuberosum), and bayhops (Ipomoea pes-caprae). Compared with traditional transformation methods, RAPID has a much higher transformation efficiency and shorter duration, and it does not require tissue culture procedures. The RAPID method therefore overcomes the limitations of traditional methods to enable rapid in planta transformation and can be potentially applied to a wide range of plant species that are capable of active regeneration.
Topics: Plants, Genetically Modified; Agrobacterium tumefaciens; Ipomoea batatas
PubMed: 38243598
DOI: 10.1016/j.xplc.2024.100822 -
Molecular Microbiology Mar 2021Bacterial type IV secretion systems (T4SSs) are a functionally diverse translocation superfamily. They consist mainly of two large subfamilies: (i) conjugation systems... (Review)
Review
Bacterial type IV secretion systems (T4SSs) are a functionally diverse translocation superfamily. They consist mainly of two large subfamilies: (i) conjugation systems that mediate interbacterial DNA transfer and (ii) effector translocators that deliver effector macromolecules into prokaryotic or eukaryotic cells. A few other T4SSs export DNA or proteins to the milieu, or import exogenous DNA. The T4SSs are defined by 6 or 12 conserved "core" subunits that respectively elaborate "minimized" systems in Gram-positive or -negative bacteria. However, many "expanded" T4SSs are built from "core" subunits plus numerous others that are system-specific, which presumptively broadens functional capabilities. Recently, there has been exciting progress in defining T4SS assembly pathways and architectures using a combination of fluorescence and cryoelectron microscopy. This review will highlight advances in our knowledge of structure-function relationships for model Gram-negative bacterial T4SSs, including "minimized" systems resembling the Agrobacterium tumefaciens VirB/VirD4 T4SS and "expanded" systems represented by the Helicobacter pylori Cag, Legionella pneumophila Dot/Icm, and F plasmid-encoded Tra T4SSs. Detailed studies of these model systems are generating new insights, some at atomic resolution, to long-standing questions concerning mechanisms of substrate recruitment, T4SS channel architecture, conjugative pilus assembly, and machine adaptations contributing to T4SS functional versatility.
Topics: Agrobacterium tumefaciens; Amino Acid Motifs; Animals; Bacterial Proteins; Conjugation, Genetic; Cryoelectron Microscopy; Fimbriae, Bacterial; Gram-Negative Bacteria; Gram-Negative Bacterial Infections; Helicobacter pylori; Humans; Legionella pneumophila; Molecular Docking Simulation; Protein Translocation Systems; Structure-Activity Relationship; Type IV Secretion Systems
PubMed: 33326642
DOI: 10.1111/mmi.14670 -
Plant Biotechnology Journal Aug 2022Plant genetic transformation is a crucial step for applying biotechnology such as genome editing to basic and applied plant science research. Its success primarily...
Plant genetic transformation is a crucial step for applying biotechnology such as genome editing to basic and applied plant science research. Its success primarily relies on the efficiency of gene delivery into plant cells and the ability to regenerate transgenic plants. In this study, we have examined the effect of several developmental regulators (DRs), including PLETHORA (PLT5), WOUND INDUCED DEDIFFERENTIATION 1 (WIND1), ENHANCED SHOOT REGENERATION (ESR1), WUSHEL (WUS) and a fusion of WUS and BABY-BOOM (WUS-P2A-BBM), on in planta transformation through injection of Agrobacterium tumefaciens in snapdragons (Antirrhinum majus). The results showed that PLT5, WIND1 and WUS promoted in planta transformation of snapdragons. An additional test of these three DRs on tomato (Solanum lycopersicum) further demonstrated that the highest in planta transformation efficiency was observed from PLT5. PLT5 promoted calli formation and regeneration of transformed shoots at the wound positions of aerial stems, and the transgene was stably inherited to the next generation in snapdragons. Additionally, PLT5 significantly improved the shoot regeneration and transformation in two Brassica cabbage varieties (Brassica rapa) and promoted the formation of transgenic calli and somatic embryos in sweet pepper (Capsicum annum) through in vitro tissue culture. Despite some morphological alternations, viable seeds were produced from the transgenic Bok choy and snapdragons. Our results have demonstrated that manipulation of PLT5 could be an effective approach for improving in planta and in vitro transformation efficiency, and such a transformation system could be used to facilitate the application of genome editing or other plant biotechnology application in modern agriculture.
Topics: Agrobacterium tumefaciens; Brassica; Capsicum; Solanum lycopersicum; Plants, Genetically Modified; Transformation, Genetic; Transgenes
PubMed: 35524453
DOI: 10.1111/pbi.13837 -
Metal Ions in Life Sciences Mar 2020Zinc finger (ZF) domains, that represent the majority of the DNA-binding motifs in eukaryotes, are involved in several processes ranging from RNA packaging to...
Zinc finger (ZF) domains, that represent the majority of the DNA-binding motifs in eukaryotes, are involved in several processes ranging from RNA packaging to transcriptional activation, regulation of apoptosis, protein folding and assembly, and lipid binding. While their amino acid composition varies from one domain to the other, a shared feature is the coordination of a zinc ion, with a structural role, by a different combination of cysteines and histidines. The classical zinc finger domain (also called Cys2His2) that represents the most common class, uses two cysteines and two histidines to coordinate the metal ion, and forms a compact ββα architecture consisting in a β-sheet and an α-helix. GAG-knuckle resembles the classical ZF, treble clef and zinc ribbon are also well represented in the human genome. Zinc fingers are also present in prokaryotes. The first prokaryotic ZF domain found in the transcriptional regulator Ros protein was identified in Agrobacterium tumefaciens. It shows a Cys2His2 metal ion coordination sphere and folds in a domain significantly larger than its eukaryotic counterpart arranged in a βββαα topology. Interestingly, this domain does not strictly require the metal ion coordination to achieve the functional fold. Here, we report what is known on the main classes of eukaryotic and prokarotic ZFs, focusing our attention to the role of the metal ion, the folding mechanism, and the DNA binding. The hypothesis of a horizontal gene transfer from prokaryotes to eukaryotes is also discussed.
Topics: Agrobacterium tumefaciens; Amino Acid Sequence; Humans; Proteins; Zinc; Zinc Fingers
PubMed: 32851833
DOI: 10.1515/9783110589757-018 -
Nature Plants Jun 2020An in planta gene editing approach was developed wherein Cas9 transgenic plants are infected with an RNA virus that expresses single guide RNAs (sgRNAs). The sgRNAs are...
An in planta gene editing approach was developed wherein Cas9 transgenic plants are infected with an RNA virus that expresses single guide RNAs (sgRNAs). The sgRNAs are augmented with sequences that promote cell-to-cell mobility. Mutant progeny are recovered in the next generation at frequencies ranging from 65 to 100%; up to 30% of progeny derived from plants infected with a virus expressing three sgRNAs have mutations in all three targeted loci.
Topics: Agrobacterium tumefaciens; Gene Editing; Plants, Genetically Modified; RNA Viruses; RNA, Viral; Nicotiana
PubMed: 32483329
DOI: 10.1038/s41477-020-0670-y -
Journal of Fungi (Basel, Switzerland) Jun 2022The use of broad-spectrum antimycotic therapy, immunosuppressive therapy, and indwelling medical devices has contributed to the increased frequency of mucosal and...
The use of broad-spectrum antimycotic therapy, immunosuppressive therapy, and indwelling medical devices has contributed to the increased frequency of mucosal and systemic infections caused by . A major concern for and other spp. infections is the increase in drug resistance. To address these issues, additional molecular tools for the study of are needed. In this investigation, we developed an transformation system for . A number of parameters were investigated to determine their effect on transformation frequency, and then an optimized protocol was developed. The optimal conditions for the transformation of were found to be an infection incubation temperature of 26 °C, 0.2 mM acetosyringone in both induction media and co-culture media, 0.7% agar concentration, and a multiplicity of infection of 50:1 to . Importantly, the frequency of multiple integrations was low (5%), demonstrating that generally integrates at single sites in , which is consistent with other fungal transformation systems. The development of this system in adds another tool for the molecular manipulation of this increasingly important fungal pathogen.
PubMed: 35736079
DOI: 10.3390/jof8060596 -
Biotechnology Advances Dec 2021Almost 40 years ago the first transgenic plant was generated through Agrobacterium tumefaciens-mediated transformation, which, until now, remains the method of choice... (Review)
Review
Almost 40 years ago the first transgenic plant was generated through Agrobacterium tumefaciens-mediated transformation, which, until now, remains the method of choice for gene delivery into plants. Ever since, optimized Agrobacterium strains have been developed with additional (genetic) modifications that were mostly aimed at enhancing the transformation efficiency, although an optimized strain also exists that reduces unwanted plasmid recombination. As a result, a collection of very useful strains has been created to transform a wide variety of plant species, but has also led to a confusing Agrobacterium strain nomenclature. The latter is often misleading for choosing the best-suited strain for one's transformation purposes. To overcome this issue, we provide a complete overview of the strain classification. We also indicate different strain modifications and their purposes, as well as the obtained results with regard to the transformation process sensu largo. Furthermore, we propose additional improvements of the Agrobacterium-mediated transformation process and consider several worthwhile modifications, for instance, by circumventing a defense response in planta. In this regard, we will discuss pattern-triggered immunity, pathogen-associated molecular pattern detection, hormone homeostasis and signaling, and reactive oxygen species in relationship to Agrobacterium transformation. We will also explore alterations that increase agrobacterial transformation efficiency, reduce plasmid recombination, and improve biocontainment. Finally, we recommend the use of a modular system to best utilize the available knowledge for successful plant transformation.
Topics: Agrobacterium tumefaciens; Gene Transfer Techniques; Plants, Genetically Modified; Recombination, Genetic; Transformation, Genetic
PubMed: 33290822
DOI: 10.1016/j.biotechadv.2020.107677 -
Phytopathology Apr 2023The phytopathogenic bacterium causes crown gall disease in plants, characterized by the formation of tumor-like galls where wounds were present. Nowadays, however, the... (Review)
Review
The phytopathogenic bacterium causes crown gall disease in plants, characterized by the formation of tumor-like galls where wounds were present. Nowadays, however, the bacterium and its Ti (tumor-inducing) plasmid is better known as an effective vector for the genetic manipulation of plants and fungi. In this review, I will briefly summarize some of the major discoveries that have led to this bacterium now playing such a prominent role worldwide in plant and fungal research at universities and research institutes and in agricultural biotechnology for the production of genetically modified crops. I will then delve a little deeper into some aspects of biology and discuss the diversity among agrobacteria and the taxonomic position of these bacteria, the diversity in Ti plasmids, the molecular mechanism used by the bacteria to transform plants, and the discovery of protein translocation from the bacteria to host cells as an essential feature of -mediated transformation.
Topics: Plant Tumor-Inducing Plasmids; Crops, Agricultural; Plant Diseases; Plants, Genetically Modified; Agrobacterium tumefaciens; Plant Tumors; Plasmids
PubMed: 37098885
DOI: 10.1094/PHYTO-11-22-0432-IA