scholarly journals Transcriptomic Analysis of Arabidopsis Seedlings in Response to an Agrobacterium-Mediated Transformation Process

2018 ◽  
Vol 31 (4) ◽  
pp. 445-459 ◽  
Author(s):  
Kaixuan Duan ◽  
Christopher J. Willig ◽  
Joann R. De Tar ◽  
William G. Spollen ◽  
Zhanyuan J. Zhang
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Defense Response ◽  
Time Course ◽  
Basic Research ◽  
Defense Responses ◽  
Transformation Process ◽  
Host Responses ◽  
Nucleic Acid Metabolism ◽  
Agrobacterium Strain ◽  
Agrobacterium Mediated Transformation

Agrobacterium tumefaciens is a plant pathogen that causes crown gall disease. This pathogen is capable of transferring the T-DNA from its Ti plasmid to the host cell and, then, integrating it into the host genome. To date, this genetic transformation ability has been harnessed as the dominant technology to produce genetically modified plants for both basic research and crop biotechnological applications. However, little is known about the interaction between Agrobacterium tumefaciens and host plants, especially the host responses to Agrobacterium infection and its associated factors. We employed RNA-seq to follow the time course of gene expression in Arabidopsis seedlings infected with either an avirulent or a virulent Agrobacterium strain. Gene Ontology analysis indicated many biological processes were involved in the Agrobacterium-mediated transformation process, including hormone signaling, defense response, cellular biosynthesis, and nucleic acid metabolism. RNAseq and quantitative reverse transcription-polymerase chain reaction results indicated that expression of genes involved in host plant growth and development were repressed but those involved in defense response were induced by Agrobacterium tumefaciens. Further analysis of the responses of transgenic Arabidopsis lines constitutively expressing either the VirE2 or VirE3 protein suggested Vir proteins act to enhance plant defense responses in addition to their known roles facilitating T-DNA transformation.

Agrobacterium tumefaciens-mediated transformation of wheat using suspension cells as a model system and green fluorescent protein as a visual marker

2001 ◽  
Vol 28 (8) ◽  
pp. 807 ◽  
Author(s):  
Brian Weir ◽  
Xu Gu ◽  
Mingbo Wang ◽  
Narayana Upadhyaya ◽  
Adrian R. Elliott ◽  
...  
Keyword(s):  
Green Fluorescent Protein ◽  
Agrobacterium Tumefaciens ◽  
Fluorescent Protein ◽  
Model System ◽  
35S Promoter ◽  
Suspension Cells ◽  
Agrobacterium Strain ◽  
Agrobacterium Mediated Transformation ◽  
Green Fluorescent ◽  
Visual Marker

Conditions for Agrobacterium-mediated transformation of wheat (Triticum aestivum L.) were defined using wheat suspension cells as a model system and green fluorescent protein (GFP) as a visual marker. Different strains of Agrobacterium tumefaciens were compared using established wheat cell suspension cultures, where the frequency of cell clusters showing transient activity of GFP ranged from 2 to 52%. High levels of transient GFP activity and stable transformed callus lines were obtained with plasmid pTO134 containing a gfp gene with an enhanced CaMV 35S promoter and a bar gene with a 35S promoter in combination with Agrobacterium strain AGL0. These results suggest that the important variables in Agrobacterium-mediated transformation of wheat cells include media composition, Agrobacterium strain, plasmid vector and the addition of virulence-inducing agents such as acetosyringone. The conditions deemed optimal for transformation of wheat suspension cell lines were applied to scutella isolated from immature embryos and scutella-derived calli. Transient GFP expression in these tissues ranged from 10 to 75% and, while quite variable among and within cultivars, stably transformed scutellum-derived callus was obtained. Further studies with scutellum-derived calli suggested that variables such as duration of pre-inoculation culture and co-cultivation, as well as co-cultivation temperature, were also important. Optimisation of these variables resulted in the recovery of transformed wheat plants at a transformation frequency of 1.8%, which is comparable with other reports.

scholarly journals Deletion of the SACPD-C Locus Alters the Symbiotic Relationship Between Bradyrhizobium japonicum USDA110 and Soybean, Resulting in Elicitation of Plant Defense Response and Nodulation Defects

2016 ◽  
Vol 29 (11) ◽  
pp. 862-877 ◽  
Author(s):  
Hari B. Krishnan ◽  
Alaa A. Alaswad ◽  
Nathan W. Oehrle ◽  
Jason D. Gillman
Keyword(s):  
Plant Defense ◽  
Defense Response ◽  
Acyl Carrier Protein ◽  
Defense Responses ◽  
Nodule Development ◽  
Plant Defense Response ◽  
Wild Type ◽  
Two Dimensional Gel Electrophoresis ◽  
Symbiotic Associations ◽  
Soybean Nodule

Legumes form symbiotic associations with soil-dwelling bacteria collectively called rhizobia. This association results in the formation of nodules, unique plant-derived organs, within which the rhizobia are housed. Rhizobia-encoded nitrogenase facilitates the conversion of atmospheric nitrogen into ammonia, which is utilized by the plants for its growth and development. Fatty acids have been shown to play an important role in root nodule symbiosis. In this study, we have investigated the role of stearoyl-acyl carrier protein desaturase isoform C (SACPD-C), a soybean enzyme that catalyzes the conversion of stearic acid into oleic acid, which is expressed in developing seeds and in nitrogen-fixing nodules. In-depth cytological investigation of nodule development in sacpd-c mutant lines M25 and MM106 revealed gross anatomical alteration in the sacpd-c mutants. Transmission electron microscopy observations revealed ultrastructural alterations in the sacpd-c mutants that are typically associated with plant defense response to pathogens. In nodules of two sacpd-c mutants, the combined jasmonic acid (JA) species (JA and the isoleucine conjugate of JA) were found to be reduced and 12-oxophytodienoic acid (OPDA) levels were significantly higher relative to wild-type lines. Salicylic acid levels were not significantly different between genotypes, which is divergent from previous studies of sacpd mutant studies on vegetative tissues. Soybean nodule phytohormone profiles were very divergent from those of roots, and root profiles were found to be almost identical between mutant and wild-type genotypes. The activities of antioxidant enzymes, ascorbate peroxidase, and superoxide dismutase were also found to be higher in nodules of sacpd-c mutants. PR-1 gene expression was extremely elevated in M25 and MM106, while the expression of nitrogenase was significantly reduced in these sacpd-c mutants, compared with the parent ‘Bay’. Two-dimensional gel electrophoresis and matrix-assisted laser desorption-ionization time of flight mass spectrometry analyses confirmed sacpd-c mutants also accumulated higher amounts of pathogenesis-related proteins in the nodules. Our study establishes a major role for SACPD-C activity as essential for proper maintenance of soybean nodule morphology and physiology and indicates that OPDA signaling is likely to be involved in attenuation of nodule biotic defense responses.

The defense response of Caenorhabditis elegans to Cutibacterium acnes SK137 via the TIR-1-p38 MAPK signaling pathway

2021 ◽  
Author(s):  
Ayano Tsuru ◽  
Yumi Hamazaki ◽  
Shuta Tomida ◽  
Mohammad Shaokat Ali ◽  
Eriko Kage-Nakadai
Keyword(s):  
Caenorhabditis Elegans ◽  
Signaling Pathway ◽  
P38 Mapk ◽  
Defense Response ◽  
Mapk Pathway ◽  
Defense Responses ◽  
Mapk Signaling ◽  
Dependent Manner ◽  
Healthy Skin ◽  
Cutibacterium Acnes

Abstract Cutibacterium acnes plays roles in both acne disease and healthy skin ecosystem. We observed that mutations in the tir-1/SARM1 and p38 MAPK cascade genes significantly shortened Caenorhabditis elegans lifespan upon Cutibacterium acnes SK137 infection. Antimicrobial molecules were induced by SK137 in a TIR-1-dependent manner. These results suggest that defense responses against SK137 involve the TIR-1-p38 MAPK pathway in Caenorhabditis elegans.

Perception and first defense responses against Pseudomonas syringae pv. phaseolicola in Phaseolus vulgaris L.: identification of Wall-Associated Kinase receptors

2021 ◽  
Author(s):  
Alfonso Gonzalo De la Rubia ◽  
María Luz Centeno ◽  
Victor Moreno-González ◽  
María De Castro ◽  
Penélope García-Angulo
Keyword(s):  
Phaseolus Vulgaris ◽  
Pseudomonas Syringae ◽  
Time Course ◽  
Early Time ◽  
Experimental System ◽  
Antioxidant Response ◽  
Defense Responses ◽  
Cellular Damage ◽  
Initial Increase ◽  
Phaseolus Vulgaris L

Common bean (Phaseolus vulgaris L.) is attacked by several pathogens such as the biotrophic gamma-proteobacterium Pseudomonas syringae pv. phaseolicola (Pph). In order to study the Pph-bean interaction during the first stages of infection, leaf disks of a susceptible bean variety named Riñón were infected with a pathogenic Pph. Using this experimental system, six new putative Wall-Associated Kinase (WAKs) receptors, previously identified in silico, were tested. These six bean WAKs (PvWAKs) showed high protein sequence homology to the well-described Arabidopsis WAK1 (AtWAK1) receptor and, by phylogenetic analysis, clustered together with AtWAKs. The expression of PvWAK1 increased at very early stages after the Pph infection. Time course experiments were performed to evaluate the accumulation of apoplastic H2O2, Ca2+ influx, total H2O2, antioxidant enzymatic activities, lipid peroxidation, and the concentrations of abscisic acid (ABA) and salicylic acid (SA), as well as the expression of six defense-related genes – MEKK-1, MAPKK, WRKY33, RIN4, PR1 and NPR1. The results showed that overexpression of PR1 occurred 2 h after Pph infection without a concomitant increase in SA levels. Although apoplastic H2O2 increased after infection, the oxidative burst was neither intense nor rapid and an efficient antioxidant response did not occur, suggesting that the observed cellular damage was due to the initial increase in total H2O2 at early time points after infection. In conclusion, the Riñón variety can perceive the presence of Pph, but this recognition only results in a modest and slow activation of host defenses, leading to high susceptibility to Pph.

scholarly journals A Faster and a Stronger Defense Response: One of the Key Elements in Grapevine Explaining Its Lower Level of Susceptibility to Esca?

2013 ◽  
Vol 103 (10) ◽  
pp. 1028-1034 ◽  
Author(s):  
Carole Lambert ◽  
Ian Li Kim Khiook ◽  
Sylvia Lucas ◽  
Nadège Télef-Micouleau ◽  
Jean-Michel Mérillon ◽  
...  
Keyword(s):  
Defense Response ◽  
Defense Mechanisms ◽  
Defense Responses ◽  
Cabernet Sauvignon ◽  
Susceptible Cultivar ◽  
Pathogenesis Related ◽  
Leaf Level ◽  
Plant Pathogen Interaction ◽  
Related Proteins ◽  
Stilbene Compounds

Wood diseases like Esca are among the most damaging afflictions in grapevine. The defense mechanisms in this plant–pathogen interaction are not well understood. As some grapevine cultivars have been observed to be less susceptible to Esca than others, understanding the factors involved in this potentially stronger defense response can be of great interest. To lift part of this veil, we elicited Vitis vinifera plants of two cultivars less susceptible to Esca (‘Merlot’ and ‘Carignan’) and of one susceptible cultivar (‘Cabernet Sauvignon’), and monitored their defense responses at the leaf level. Our model of elicitation consisted in grapevine cuttings absorbing a culture filtrate of one causal agent of Esca, Phaemoniella chlamydospora. This model might reflect the early events occurring in Esca-affected grapevines. The two least susceptible cultivars showed an earlier and stronger defense response than the susceptible one, particularly with regard to induction of the PAL and STS genes, and a higher accumulation of stilbene compounds and some pathogenesis-related proteins.

scholarly journals Using physiological signals to predict temporal defense responses: a multi-modality analysis

2020 ◽  
Author(s):  
Tae-jun Choi ◽  
Honggu Lee
Keyword(s):  
Defense Response ◽  
Defense Responses ◽  
Physiological Signals ◽  
Classification Model ◽  
Post Traumatic Stress ◽  
Obsessive Compulsive ◽  
Compulsive Disorder ◽  
Novel Approach ◽  
Data Driven Approach ◽  
Response Classification

AbstractDefense responses are a highly conserved behavioral response set across species. Defense responses motivate organisms to detect and react to threats and potential danger as a precursor to anxiety. Accurate measurement of temporal defense responses is important for understanding clinical anxiety and mood disorders, such as post-traumatic stress disorder, obsessive compulsive disorder, and generalized anxiety disorder. Within these conditions, anxiety is defined as a state of prolonged defense response elicitation to a threat that is ambiguous or unspecific. In this study, we aimed to develop a data-driven approach to capture temporal defense response elicitation through a multi-modality data analysis of physiological signals, including electroencephalogram (EEG), electrocardiogram (ECG), and eye-tracking information. A fear conditioning paradigm was adopted to develop a defense response classification model. From a classification model based on 42 feature sets, a higher order crossing feature set-based model was chosen for further analysis with cross-validation loss of 0.0462 (SEM: 0.0077). To validate our model, we compared predicted defense response occurrence ratios from a comprehensive situation that generates defense responses by watching movie clips with fear awareness and threat existence predictability, which have been reported to correlate with defense response elicitation in previous studies. We observed that defense response occurrence ratios are correlated with threat existence predictability, but not with fear awareness. These results are similar to those of previous studies using comprehensive situations. Our study provides insight into measurement of temporal defense responses via a novel approach, which can improve understanding of anxiety and related clinical disorders for neurobiological and clinical researchers.

scholarly journals Chitinase Gene Positively Regulates Hypersensitive and Defense Responses of Pepper to Colletotrichum acutatum Infection

2020 ◽  
Vol 21 (18) ◽  
pp. 6624 ◽  
Author(s):  
Muhammad Ali ◽  
Quan-Hui Li ◽  
Tao Zou ◽  
Ai-Min Wei ◽  
Ganbat Gombojab ◽  
...  
Keyword(s):  
Defense Response ◽  
Defense Responses ◽  
Chitinase Gene ◽  
Colletotrichum Acutatum ◽  
Basal Resistance ◽  
Chitin Binding Domain ◽  
Pepper Leaves ◽  
Defense Response Genes ◽  
Chitinase Genes ◽  
Pepper Plants

Anthracnose caused by Colletotrichum acutatum is one of the most devastating fungal diseases of pepper (Capsicum annuum L.). The utilization of chitin-binding proteins or chitinase genes is the best option to control this disease. A chitin-binding domain (CBD) has been shown to be crucial for the innate immunity of plants and activates the hypersensitive response (HR). The CaChiIII7 chitinase gene has been identified and isolated from pepper plants. CaChiIII7 has repeated CBDs that encode a chitinase enzyme that is transcriptionally stimulated by C. acutatum infection. The knockdown of CaChiIII7 in pepper plants confers increased hypersensitivity to C. acutatum, resulting in its proliferation in infected leaves and an attenuation of the defense response genes CaPR1, CaPR5, and SAR8.2 in the CaChiIII7-silenced pepper plants. Additionally, H2O2 accumulation, conductivity, proline biosynthesis, and root activity were distinctly reduced in CaChiIII7-silenced plants. Subcellular localization analyses indicated that the CaChiIII7 protein is located in the plasma membrane and cytoplasm of plant cells. The transient expression of CaChiIII7 increases the basal resistance to C. acutatum by significantly expressing several defense response genes and the HR in pepper leaves, accompanied by an induction of H2O2 biosynthesis. These findings demonstrate that CaChiIII7 plays a prominent role in plant defense in response to pathogen infection.

scholarly journals Single Molecule Imaging of T-DNA Intermediates Following Agrobacterium tumefaciens Infection in Nicotiana benthamiana

2019 ◽  
Vol 20 (24) ◽  
pp. 6209
Author(s):  
Idan Pereman ◽  
Cathy Melamed-Bessudo ◽  
Tal Dahan-Meir ◽  
Elad Herz ◽  
Michael Elbaum ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Single Molecule ◽  
Nicotiana Benthamiana ◽  
Time Course ◽  
Imaging System ◽  
Laboratory Research ◽  
Type Iv ◽  
Diffusion Analysis ◽  
Dna Foci ◽  
Progressive Accumulation

Plant transformation mediated by Agrobacterium tumefaciens is a well-studied phenomenon in which a bacterial DNA fragment (T-DNA), is transferred to the host plant cell, as a single strand, via type IV secretion system and has the potential to reach the nucleus and to be integrated into its genome. While Agrobacterium-mediated transformation has been widely used for laboratory-research and in breeding, the time-course of its journey from the bacterium to the nucleus, the conversion from single- to double-strand intermediates and several aspects of the integration in the genome remain obscure. In this study, we sought to follow T-DNA infection directly using single-molecule live imaging. To this end, we applied the LacO-LacI imaging system in Nicotiana benthamiana, which enabled us to identify double-stranded T-DNA (dsT-DNA) molecules as fluorescent foci. Using confocal microscopy, we detected progressive accumulation of dsT-DNA foci in the nucleus, starting 23 h after transfection and reaching an average of 5.4 and 8 foci per nucleus at 48 and 72 h post-infection, respectively. A time-course diffusion analysis of the T-DNA foci has demonstrated their spatial confinement.

scholarly journals Application of sonication-assisted Agrobacterium-mediated transformation in Chenopodium rubrum L

2011 ◽  
Vol 49 (No. 6) ◽  
pp. 255-260 ◽  
Author(s):  
J.I. Flores Solís ◽  
P. Mlejnek ◽  
K. Studená ◽  
S. Procházka
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Transient Expression ◽  
Chenopodium Rubrum ◽  
Limiting Factors ◽  
Gus Gene ◽  
Efficient Tool ◽  
Factors Affecting ◽  
Agrobacterium Mediated Transformation ◽  
Glucuronidase Activity ◽  
Gene Coding

Chenopodium rubrum belongs to the plant species in which standard Agrobacterium-mediated transformation procedures remain inefficient. We demonstrate that the employment of sonication-assisted Agrobacterium-mediated transformation (SAAT) effectively enhanced transient expression of GUS gene coding for b-glucuronidase in Chenopodium rubrum. Further the results indicated that the age of seedlings is one of the limiting factors affecting the potency of Agrobacterium tumefaciens infection. Histochemical detection of b-glucuronidase activity revealed that two-days-old seedlings were much more susceptible to infection than ten-days-old ones. According to our results SAAT technology could provide an efficient tool for obtaining stable transformants when applied to two-days-old seedlings of Chenopodium rubrum.

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.

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