# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 320 | 0 | 1.0000 | Monitoring Azospirillum-wheat interactions using the gfp and gusA genes constitutively expressed from a new broad-host range vector. To monitor the colonization of wheat roots by Azospirillum brasilense, we constructed several plasmids based on the pBBR1 replicon expressing the gfp and gusA genes constitutively. Both genes were placed under control of the gentamycin resistance gene promoter resulting in high levels of expression in Escherichia coli and A. brasilense. The constructed plasmids were stably maintained in A. brasilense strains even in the absence of selective pressure. The colonization of wheat plants grown under controlled conditions in sterilized vermiculite by A. brasilense strain FP2 (a Sp7-derivative) transconjugants containing these plasmids was monitored. Bacteria expressing GFP were easily observed in fresh plant material by fluorescence microscopy. Cell aggregates and single bacteria were visualized on the surfaces of young root zones, such as roots hairs and lateral roots. Large cellular clumps were observed at the points of lateral root emergence or at intercellular spaces of root epidermal cells 30 days after inoculation. Although we failed to detected bacteria in internal cortical and xylem tissues of wheat roots, the initial stage of endophytic colonization by A. brasilense may involve the sites detected in this work. | 2002 | 12084480 |
| 445 | 1 | 0.9991 | Selection of Shigella flexneri candidate virulence genes specifically induced in bacteria resident in host cell cytoplasm. We describe an in vivo expression technology (IVET)-like approach, which uses antibiotic resistance for selection, to identify Shigella flexneri genes specifically activated in bacteria resident in host cell cytoplasm. This procedure required construction of a promoter-trap vector containing a synthetic operon between the promoterless chloramphenicol acetyl transferase (cat) and lacZ genes and construction of a library of plasmids carrying transcriptional fusions between S. flexneri genomic fragments and the cat-lacZ operon. Clones exhibiting low levels (<10 micro g ml-1) of chloramphenicol (Cm) resistance on laboratory media were analysed for their ability to induce a cytophatic effect--plaque--on a cell monolayer, in the presence of Cm. These clones were assumed to carry a plasmid in which the cloned fragment acted as a promoter/gene which is poorly expressed under laboratory conditions. Therefore, only strains harbouring fusion-plasmids in which the cloned promoter was specifically activated within host cytoplasm could survive within the cell monolayer in the presence of Cm and give a positive result in the plaque assay. Pai (plaque assay induced) clones, selected following this procedure, were analysed for intracellular (i) beta-galactosidase activity, (ii) proliferation in the presence of Cm, and (iii) Cm resistance. Sequence analysis of Pai plasmids revealed genes encoding proteins of three functional classes: external layer recycling, adaptation to microaerophilic environment and gene regulation. Sequences encoding unknown functions were also trapped and selected by this new IVET-based protocol. | 2002 | 12390353 |
| 383 | 2 | 0.9991 | Construction of improved vectors and cassettes containing gusA and antibiotic resistance genes for studies of transcriptional activity and bacterial localization. Broad-host-range, conjugative vectors with a constitutively expressed gusA gene combined with different antibiotic resistance (tetracycline, gentamicin, kanamycin) genes have been constructed. These plasmids are designed for tracking Gram-negative bacterial strains without the risk of random mutagenesis. We also constructed a set of cassettes containing a promoterless gusA gene linked with different antibiotic resistance genes for making transcriptional fusions and for cassette mutagenesis. New plasmids and cassettes can be useful tools for studying gene expression, interaction of bacteria with plants and monitoring bacteria in the environment. | 2001 | 11348677 |
| 6303 | 3 | 0.9991 | Induction of AmpC-Mediated β-Lactam Resistance Requires a Single Lytic Transglycosylase in Agrobacterium tumefaciens. The remarkable ability of Agrobacterium tumefaciens to transfer DNA to plant cells has allowed the generation of important transgenic crops. One challenge of A. tumefaciens-mediated transformation is eliminating the bacteria after plant transformation to prevent detrimental effects to plants and the release of engineered bacteria to the environment. Here, we use a reverse-genetics approach to identify genes involved in ampicillin resistance, with the goal of utilizing these antibiotic-sensitive strains for plant transformations. We show that treating A. tumefaciens C58 with ampicillin led to increased β-lactamase production, a response dependent on the broad-spectrum β-lactamase AmpC and its transcription factor, AmpR. Loss of the putative ampD orthologue atu2113 led to constitutive production of AmpC-dependent β-lactamase activity and ampicillin resistance. Finally, one cell wall remodeling enzyme, MltB3, was necessary for the AmpC-dependent β-lactamase activity, and its loss elicited ampicillin and carbenicillin sensitivity in the A. tumefaciens C58 and GV3101 strains. Furthermore, GV3101 ΔmltB3 transforms plants with efficiency comparable to that of the wild type but can be cleared with sublethal concentrations of ampicillin. The functional characterization of the genes involved in the inducible ampicillin resistance pathway of A. tumefaciens constitutes a major step forward in efforts to reduce the intrinsic antibiotic resistance of this bacterium. IMPORTANCE Agrobacterium tumefaciens, a significant biotechnological tool for production of transgenic plant lines, is highly resistant to a wide variety of antibiotics, posing challenges for various applications. One challenge is the efficient elimination of A. tumefaciens from transformed plant tissue without using levels of antibiotics that are toxic to the plants. Here, we present the functional characterization of genes involved in β-lactam resistance in A. tumefaciens. Knowledge about proteins that promote or inhibit β-lactam resistance will enable the development of strains to improve the efficiency of Agrobacterium-mediated plant genetic transformations. Effective removal of Agrobacterium from transformed plant tissue has the potential to maximize crop yield and food production, improving the outlook for global food security. | 2022 | 35638841 |
| 446 | 4 | 0.9990 | Identification of Lactobacillus reuteri genes specifically induced in the mouse gastrointestinal tract. Lactobacilli are common inhabitants of the gastrointestinal tracts of mammals and have received considerable attention due to their putative health-promoting properties. Little is known about the traits that enhance the ability of these bacteria to inhabit the gastrointestinal tract. In this paper we describe the development and application of a strategy based on in vivo expression technology (IVET) that enables detection of Lactobacillus reuteri genes specifically induced in the murine gut. A plasmid-based system was constructed containing 'ermGT (which confers lincomycin resistance) as the primary reporter gene for selection of promoters active in the gastrointestinal tract of mice treated with lincomycin. A second reporter gene, 'bglM (beta-glucanase), allowed differentiation between constitutive and in vivo inducible promoters. The system was successfully tested in vitro and in vivo by using a constitutive promoter. Application of the IVET system with chromosomal DNA of L. reuteri 100-23 and reconstituted lactobacillus-free mice revealed three genes induced specifically during colonization. Two of the sequences showed homology to genes encoding xylose isomerase (xylA) and peptide methionine sulfoxide reductase (msrB), which are involved in nutrient acquisition and stress responses, respectively. The third locus showed homology to the gene encoding a protein whose function is not known. Our IVET system has the potential to identify genes of lactobacilli that have not previously been functionally characterized but which may be essential for growth of these bacteria in the gastrointestinal ecosystem. | 2003 | 12676681 |
| 322 | 5 | 0.9990 | Resistance inducers modulate Pseudomonas syringae pv. tomato strain DC3000 response in tomato plants. The efficacy of hexanoic acid (Hx) as an inducer of resistance in tomato plants against Pseudomonas syringae pv. tomato DC3000 was previously demonstrated, and the plant response was characterized. Because little is known about the reaction of the pathogen to this effect, the goal of the present work was to determine whether the changes in the plant defence system affect the pathogen behaviour. This work provides the first demonstration of the response of the pathogen to the changes observed in plants after Hx application in terms of not only the population size but also the transcriptional levels of genes involved in quorum sensing establishment and pathogenesis. Therefore, it is possible that Hx treatment attenuates the virulence and survival of bacteria by preventing or diminishing the appearance of symptoms and controlling the growth of the bacteria in the mesophyll. It is interesting to note that the gene transcriptional changes in the bacteria from the treated plants occur at the same time as the changes in the plants. Hx is able to alter bacteria pathogenesis and survival only when it is applied as a resistance inducer because the changes that it promotes in plants affect the bacteria. | 2014 | 25244125 |
| 8784 | 6 | 0.9990 | Bacillus firmus Strain I-1582, a Nematode Antagonist by Itself and Through the Plant. Bacillus firmus I-1582 is approved in Europe for the management of Meloidogyne on vegetable crops. However, little information about its modes of action and temperature requirements is available, despite the effect of these parameters in its efficacy. The cardinal temperatures for bacterial growth and biofilm formation were determined. The bacteria was transformed with GFP to study its effect on nematode eggs and root colonization of tomato (Solanum lycopersicum) and cucumber (Cucumis sativus) by laser-scanning confocal microscopy. Induction of plant resistance was determined in split-root experiments and the dynamic regulation of genes related to jasmonic acid (JA) and salicylic acid (SA) by RT-qPCR at three different times after nematode inoculation. The bacteria was able to grow and form biofilms between 15 and 45°C; it degraded egg-shells and colonized eggs; it colonized tomato roots more extensively than cucumber roots; it induced systemic resistance in tomato, but not in cucumber; SA and JA related genes were primed at different times after nematode inoculation in tomato, but only the SA-related gene was up-regulated at 7 days after nematode inoculation in cucumber. In conclusion, B. firmus I-1582 is active at a wide range of temperatures; its optimal growth temperature is 35°C; it is able to degrade Meloidogyne eggs, and to colonize plant roots, inducing systemic resistance in a plant dependent species manner. | 2020 | 32765537 |
| 318 | 7 | 0.9990 | Overexpression of an Arabidopsis thaliana ABC transporter confers kanamycin resistance to transgenic plants. Selectable markers of bacterial origin such as the neomycin phosphotransferase type II gene, which can confer kanamycin resistance to transgenic plants, represent an invaluable tool for plant engineering. However, since all currently used antibiotic-resistance genes are of bacterial origin, there have been concerns about horizontal gene transfer from transgenic plants back to bacteria, which may result in antibiotic resistance. Here we characterize a plant gene, Atwbc19, the gene that encodes an Arabidopsis thaliana ATP binding cassette (ABC) transporter and confers antibiotic resistance to transgenic plants. The mechanism of resistance is novel, and the levels of resistance achieved are comparable to those attained through expression of bacterial antibiotic-resistance genes in transgenic tobacco using the CaMV 35S promoter. Because ABC transporters are endogenous to plants, the use of Atwbc19 as a selectable marker in transgenic plants may provide a practical alternative to current bacterial marker genes in terms of the risk for horizontal transfer of resistance genes. | 2005 | 16116418 |
| 324 | 8 | 0.9990 | Capillary electrophoresis-based profiling and quantitation of total salicylic acid and related phenolics for analysis of early signaling in Arabidopsis disease resistance. A capillary electrophoresis-based method for quantitation of total salicylic acid levels in Arabidopsis leaves was developed. Direct comparison to previous high-performance liquid chromatography (HPLC)-based measurements showed similar levels of salicylic acid. Simultaneous quantitation of trans-cinnamic acid, benzoic acid, sinapic acid, and an internal recovery standard was achieved. A rapid, streamlined protocol with requirements for plant tissue reduced relative to those of HPLC-based protocols is presented. Complicated, multiparameter experiments were thus possible despite the labor-intensive nature of inoculating plants with bacterial pathogens. As an example of this sort of experiment, detailed time course studies of total salicylic acid accumulation by wild-type Arabidopsis and two lines with mutations affecting salicylic acid accumulation in response to either of two avirulent bacterial strains were performed. Accumulation in the first 12h was biphasic. The first phase was partially SID2 and NDR1 dependent with both bacterial strains. The second phase was largely independent of both genes with bacteria carrying avrB, but dependent upon both genes with bacteria carrying avrRpt2. Virulent bacteria did not elicit salicylic acid accumulation at these time points. Application of this method to various Arabidopsis pathosystems and the wealth of available disease resistance signaling mutants will refine knowledge of disease resistance and associated signal transduction. | 2003 | 12927828 |
| 6305 | 9 | 0.9990 | Antimicrobial genes from Allium sativum and Pinellia ternata revealed by a Bacillus subtilis expression system. Antimicrobial genes are found in all classes of life. To efficiently isolate these genes, we used Bacillus subtilis and Escherichia coli as target indicator bacteria and transformed them with cDNA libraries. Among thousands of expressed proteins, candidate proteins played antimicrobial roles from the inside of the indicator bacteria (internal effect), contributing to the sensitivity (much more sensitivity than the external effect from antimicrobial proteins working from outside of the cells) and the high throughput ability of screening. We found that B. subtilis is more efficient and reliable than E. coli. Using the B. subtilis expression system, we identified 19 novel, broad-spectrum antimicrobial genes. Proteins expressed by these genes were extracted and tested, exhibiting strong external antibacterial, antifungal and nematicidal activities. Furthermore, these newly isolated proteins could control plant diseases. Application of these proteins secreted by engineered B. subtilis in soil could inhibit the growth of pathogenic bacteria. These proteins are thermally stable and suitable for clinical medicine, as they exhibited no haemolytic activity. Based on our findings, we speculated that plant, animal and human pathogenic bacteria, fungi or even cancer cells might be taken as the indicator target cells for screening specific resistance genes. | 2018 | 30266995 |
| 444 | 10 | 0.9990 | The indigenous Pseudomonas plasmid pQBR103 encodes plant-inducible genes, including three putative helicases. Plasmid pQBR103 ( approximately 400 kb) is representative of many self-transmissible, mercury resistant plasmids observed in the Pseudomonas community colonising the phytosphere of sugar beet. A promoter trapping strategy (IVET) was employed to identify pQBR103 genes showing elevated levels of expression on plant surfaces. Thirty-seven different plant-inducible gene fusions were isolated that were silent in laboratory media, but active in the plant environment. Three of the fusions were to DNA sequences whose protein products show significant homology to DNA-unwinding helicases. The three helicase-like genes, designated helA, helB and helC, are restricted to a defined group of related Pseudomonas plasmids. They are induced in both the root and shoot environments of sugar beet seedlings. Sequence analysis of the three plasmid-encoded helicase-like genes shows that they are phylogenetically distinct and likely to have independent evolutionary histories. The helA gene is predicted to encode a protein of 1121 amino acids, containing conserved domains found in the ultraviolet (UV) resistance helicase, UvrD. A helA knockout mutant was constructed and no phenotypic changes were found with plasmid-conferred UV resistance or plasmid conjugation. The other 34 fusions are unique with no homologues in the public gene databases, including the Pseudomonas genomes. These data demonstrate the presence of plant responsive genes in plasmid DNA comprising a component of the genomes of plant-associated bacteria. | 2004 | 16329852 |
| 6312 | 11 | 0.9990 | D-serine deaminase is a stringent selective marker in genetic crosses. The presence of the locus for D-serine deaminase (dsd) renders bacteria resistant to growth inhibition by D-serine and enables them to grow with D-serine as the sole nitrogen source. The two properties permit stringent selection in genetic crosses and make the D-serine deaminase gene an excellent marker, especially in the construction of strains for which the use of antibiotic resistance genes as selective markers is not allowed. | 1995 | 7814336 |
| 388 | 12 | 0.9990 | Improved bacterial hosts for regulated expression of genes from lambda pL plasmid vectors. The construction and use of a set of Escherichia coli strains with defective lambda prophages that facilitate expression of genes cloned in lambda pL-plasmid vectors is described. These bacteria allow high and regulated expression of such genes, whereas a kanamycin-resistance marker (KmR) on the prophage allows easy identification and genetic transfer from strain to strain. Optimal conditions for examining gene expression with the pL-vector systems using these strains are discussed. | 1993 | 8406046 |
| 314 | 13 | 0.9990 | Characterization of mercury bioremediation by transgenic bacteria expressing metallothionein and polyphosphate kinase. BACKGROUND: The use of transgenic bacteria has been proposed as a suitable alternative for mercury remediation. Ideally, mercury would be sequestered by metal-scavenging agents inside transgenic bacteria for subsequent retrieval. So far, this approach has produced limited protection and accumulation. We report here the development of a transgenic system that effectively expresses metallothionein (mt-1) and polyphosphate kinase (ppk) genes in bacteria in order to provide high mercury resistance and accumulation. RESULTS: In this study, bacterial transformation with transcriptional and translational enhanced vectors designed for the expression of metallothionein and polyphosphate kinase provided high transgene transcript levels independent of the gene being expressed. Expression of polyphosphate kinase and metallothionein in transgenic bacteria provided high resistance to mercury, up to 80 μM and 120 μM, respectively. Here we show for the first time that metallothionein can be efficiently expressed in bacteria without being fused to a carrier protein to enhance mercury bioremediation. Cold vapor atomic absorption spectrometry analyzes revealed that the mt-1 transgenic bacteria accumulated up to 100.2 ± 17.6 μM of mercury from media containing 120 μM Hg. The extent of mercury remediation was such that the contaminated media remediated by the mt-1 transgenic bacteria supported the growth of untransformed bacteria. Cell aggregation, precipitation and color changes were visually observed in mt-1 and ppk transgenic bacteria when these cells were grown in high mercury concentrations. CONCLUSION: The transgenic bacterial system described in this study presents a viable technology for mercury bioremediation from liquid matrices because it provides high mercury resistance and accumulation while inhibiting elemental mercury volatilization. This is the first report that shows that metallothionein expression provides mercury resistance and accumulation in recombinant bacteria. The high accumulation of mercury in the transgenic cells could present the possibility of retrieving the accumulated mercury for further industrial applications. | 2011 | 21838857 |
| 3789 | 14 | 0.9990 | The fate of antibiotic resistance marker genes in transgenic plant feed material fed to chickens. We have examined the fate of an antibiotic resistance marker, incorporated into transgenic maize when fed to chicks. Plant-derived markers were found in the crops of five birds fed transgenic maize and in the stomach contents of two birds. The plant-derived marker gene was not found in the intestines. The survival of the antibiotic resistance marker gene mirrored that of plant DNA targets, demonstrating that it survives no better than other DNA and indicating that it is very unlikely that bacteria in the gut of chickens will be transformed to ampicillin resistance when the birds are fed transgenic maize. | 2002 | 11751781 |
| 8228 | 15 | 0.9989 | Brucella abortus genes identified following constitutive growth and macrophage infection. The chronicity of Brucella abortus infection in humans and animals depends on the organism's ability to escape host defenses by gaining entry and surviving inside the macrophage. Although no human vaccine exists for Brucella, vaccine development in other bacteria has been based on deletions of selective nutritional as well as regulatory systems. Our goal is to develop a vaccine for Brucella. To further this aim, we have used a green fluorescent protein (GFP) reporter system to identify constitutively and intracellularly induced B. abortus genes. Constitutively producing gfp clones exhibited sequence homology with genes associated with protein synthesis and metabolism (initiation factor-1 and tRNA ribotransferase) and detoxification (organic hydroperoxidase resistance). Of greater interest, clones negative for constitutively produced gfp in agar were examined by fluorescence microscopy to detect promoter activity induced within macrophages 4 and 24 h following infection. Bacterial genes activated in macrophages 4 h postinfection appear to be involved in adapting to intracellular environmental conditions. Included in this group were genes for detoxification (lactoglyglutathione lyase gene), repair (formamidopyrimidine-DNA glycosylase gene), osmotic protection (K(+) transport gene), and site-specific recombination (xerD gene). A gene involved in metabolism and biosynthesis (deoxyxylulose 5' phosphate synthase gene) was also identified. Genes activated 24 h following infection were biosynthesis- and metabolism-associated genes (iron binding protein and rhizopine catabolism). Identification of B. abortus genes that are activated following macrophage invasion provides insight into Brucella pathogenesis and thus is valuable in vaccine design utilizing selective targeted deletions of newly identified Brucella genes. | 2001 | 11705955 |
| 8990 | 16 | 0.9989 | Enhanced virulence of Salmonella enterica serovar typhimurium after passage through mice. The interaction between Salmonella enterica and the host immune system is complex. The outcome of an infection is the result of a balance between the in vivo environment where the bacteria survive and grow and the regulation of fitness genes at a level sufficient for the bacteria to retain their characteristic rate of growth in a given host. Using bacteriological counts from tissue homogenates and fluorescence microscopy to determine the spread, localization, and distribution of S. enterica in the tissues, we show that, during a systemic infection, S. enterica adapts to the in vivo environment. The adaptation becomes a measurable phenotype when bacteria that have resided in a donor animal are introduced into a recipient naïve animal. This adaptation does not confer increased resistance to early host killing mechanisms but can be detected as an enhancement in the bacterial net growth rate later in the infection. The enhanced growth rate is lost upon a single passage in vitro, and it is therefore transient and not due to selection of mutants. The adapted bacteria on average reach higher intracellular numbers in individual infected cells and therefore have patterns of organ spread different from those of nonadapted bacteria. These experiments help in developing an understanding of the influence of passage in a host on the fitness and virulence of S. enterica. | 2011 | 21098099 |
| 6311 | 17 | 0.9989 | Development of an antibiotic marker-free platform for heterologous protein production in Streptomyces. BACKGROUND: The industrial use of enzymes produced by microorganisms is continuously growing due to the need for sustainable solutions. Nevertheless, many of the plasmids used for recombinant production of proteins in bacteria are based on the use of antibiotic resistance genes as selection markers. The safety concerns and legal requirements surrounding the increased use of antibiotic resistance genes have made the development of new antibiotic-free approaches essential. RESULTS: In this work, a system completely free of antibiotic resistance genes and useful for the production of high yields of proteins in Streptomyces is described. This system is based on the separation of the two components of the yefM/yoeBsl (antitoxin/toxin) operon; the toxin (yoeBsl) gene, responsible for host death, is integrated into the genome and the antitoxin gene (yefMsl), which inactivates the toxin, is located in the expression plasmid. To develop this system, the toxin gene was integrated into the genome of a strain lacking the complete operon, and the antibiotic resistance gene integrated along with the toxin was eliminated by Cre recombinase to generate a final host strain free of any antibiotic resistance marker. In the same way, the antibiotic resistance gene from the final expression plasmid was removed by Dre recombinase. The usefulness of this system was analysed by checking the production of two hydrolases from different Streptomyces. Production of both proteins, with potential industrial use, was high and stable over time after strain storage and after serial subcultures. These results support the robustness and stability of the positive selection system developed. CONCLUSIONS: The total absence of antibiotic resistance genes makes this system a powerful tool for using Streptomyces as a host to produce proteins at the industrial level. This work is the first Streptomyces antibiotic marker-free system to be described. Graphical abstract Antibiotic marker-free platform for protein expression in Streptomyces. The antitoxin gene present in the expression plasmid counteracts the effect of the toxin gene in the genome. In absence of the expression plasmid, the toxin causes cell death ensuring that only plasmid-containing cells persist. | 2017 | 28950904 |
| 319 | 18 | 0.9989 | An Arabidopsis thaliana ABC transporter that confers kanamycin resistance in transgenic plants does not endow resistance to Escherichia coli. Concerns have been raised about potential horizontal gene transfer (HGT) of antibiotic resistance markers (ARMs) from transgenic plants to bacteria of medical and environmental importance. All ARMs used in transgenic plants have been bacterial in origin, but it has been recently shown that an Arabidopsis thaliana ABC transporter, Atwbc19, confers kanamycin resistance when overexpressed in transgenic plants. Atwbc19 was evaluated for its ability to transfer kanamycin resistance to Escherichia coli, a kanamycin-sensitive model bacterium, under simulated HGT, staged by subcloning Atwbc19 under the control of a bacterial promoter, genetically transforming to kanamycin-sensitive bacteria, and assessing if resistance was conferred as compared with bacteria harbouring nptII, the standard kanamycin resistance gene used to produce transgenic plants. NptII provided much greater resistance than Atwbc19 and was significantly different from the no-plasmid control at low concentrations. Atwbc19 was not significantly different from the no-plasmid control at higher concentrations. Even though HGT risks are considered low with nptII, Atwbc19 should have even lower risks, as its encoded protein is possibly mistargeted in bacteria. | 2008 | 21261836 |
| 326 | 19 | 0.9989 | Quantitative nature of Arabidopsis responses during compatible and incompatible interactions with the bacterial pathogen Pseudomonas syringae. We performed large-scale mRNA expression profiling using an Affymetrix GeneChip to study Arabidopsis responses to the bacterial pathogen Pseudomonas syringae. The interactions were compatible (virulent bacteria) or incompatible (avirulent bacteria), including a nonhost interaction and interactions mediated by two different avirulence gene-resistance (R) gene combinations. Approximately 2000 of the approximately 8000 genes monitored showed reproducible significant expression level changes in at least one of the interactions. Analysis of biological variation suggested that the system behavior of the plant response in an incompatible interaction was robust but that of a compatible interaction was not. A large part of the difference between incompatible and compatible interactions can be explained quantitatively. Despite high similarity between responses mediated by the R genes RPS2 and RPM1 in wild-type plants, RPS2-mediated responses were strongly suppressed by the ndr1 mutation and the NahG transgene, whereas RPM1-mediated responses were not. This finding is consistent with the resistance phenotypes of these plants. We propose a simple quantitative model with a saturating response curve that approximates the overall behavior of this plant-pathogen system. | 2003 | 12566575 |