# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 8729 | 0 | 0.9302 | Protein S-Acyl Transferase GhPAT27 Was Associated with Verticillium wilt Resistance in Cotton. Protein palmitoylation is an ability of the frame of the cell marker protein is one of the most notable reversible changes after translation. However, studies on protein palmitoylation in cotton have not yet been performed. In our current research, the PAT gene family was systematically identified and bioinformatically analyzed in G. arboreum, G. raimondii, G. barbadense and G. hirsutum, and 211 PAT genes were authenticated and classified into six subfamilies. Sixty-nine PAT genes were identified in upland cotton, mainly at the ends of its the 26 chromosomes of upland cotton. The majority of these genes are located in the nucleus of the plant. Gene structure analysis revealed that each member encodes a protein that which contains at least one DHHC structural domain. Cis-acting element analysis indicated that GhPATs genes are mainly involved in hormone production, light response and stress response. Gene expression pattern analysis indicated that most GhPATs genes were differentially expressed upon induction by pathogenic bacteria, drought, salt, hot and cold stresses, and some GhPATs could be induced by multiple abiotic stresses simultaneously. GhPATs genes showed different expression patterns in tissue-specific assays and were found to be preferentially expressed in roots, followed by expression in stems and leaves. Virus-induced gene silencing (VIGS) experiments showed that cotton was significantly less resistant to Verticillium dahliae when GhPAT27 was silenced. We conclude that the GhPAT27 gene, which mediates S-palmitoylation acetylation, may be involved in the regulation of upland cotton resistance to Verticillium wilt (VW). Overall, this work has provided a fundamental framework for understanding the latent capabilities of GhPATs and a solid foundation for molecular breeding and plant pathogen resistance in cotton. | 2022 | 36297782 |
| 540 | 1 | 0.9276 | Effect of ogt expression on mutation induction by methyl-, ethyl- and propylmethanesulphonate in Escherichia coli K12 strains. We have previously reported the isolation of an Escherichia coli K12 mutant that is extremely sensitive to mutagenesis by low doses of ethylating agents. We now show by Southern analysis that the mutation involves a gross deletion covering at least the ogt and fnr genes and that no O6-alkylguanine-DNA-alkyltransferase activity is present in cell-free extracts of an ada::Tn10 derivative of these bacteria. Confirmation that sensitisation to ethylation-induced mutagenesis was attributable to ogt and not to any other loci covered by the deletion was obtained by constructing derivatives. Thus an ogt::kanr disruption mutation was introduced into the parental ogt+ bacteria, and the ogt::kanr mutation was then eliminated by cotransduction of ogt+ with the closely linked Tetr marker (zcj::Tn10). The delta(ogt-fnr) deletion or ogt::kanr disruption mutants were highly sensitive to ethyl methanesulphonate-induced mutagenesis, as measured by the induction of forward mutations to L-arabinose resistance (Arar). Furthermore, the number of Arar mutants increased linearly with dose, unlike the case in ogt+ bacteria, which had a threshold dose below which no mutants accumulated. Differences in mutability were even greater with propyl methanesulphonate. Overproduction of the ogt alkyltransferase from a multicopy plasmid reduced ethylmethanesulphonate-induced mutagenesis in the ogt- mutant strains and also methylmethanesulphonate mutagenesis in ada- bacteria. A sample of AB1157 obtained from the E. coli K12 genetic stock centre also had a deletion covering the ogt and fnr genes. Since such deletions greatly influence the mutagenic responses to alkylating agents, a survey of the presence of the ogt gene in the E. coli K12 strain being used is advisable. | 1994 | 8152424 |
| 574 | 2 | 0.9275 | Pyrroloquinoline quinone and a quinoprotein kinase support γ-radiation resistance in Deinococcus radiodurans and regulate gene expression. Deinococcus radiodurans is known for its extraordinary resistance to various DNA damaging agents including γ-radiation and desiccation. The pqqE:cat and Δdr2518 mutants making these cells devoid of pyrroloquinoline quinone (PQQ) and a PQQ inducible Ser/Thr protein kinase, respectively, became sensitive to γ-radiation. Transcriptome analysis of these mutants showed differential expression of the genes including those play roles in oxidative stress tolerance and (DSB) repair in D. radiodurans and in genome maintenance and stress response in other bacteria. Escherichia coli cells expressing DR2518 and PQQ showed improved resistance to γ-radiation, which increased further when both DR2518 and PQQ were present together. Although, profiles of genes getting affected in these mutants were different, there were still a few common genes showing similar expression trends in both the mutants and some others as reported earlier in oxyR and pprI mutant of this bacterium. These results suggested that PQQ and DR2518 have independent roles in γ-radiation resistance of D. radiodurans but their co-existence improves radioresistance further, possibly by regulating differential expression of the genes important for bacterial response to oxidative stress and DNA damage. | 2013 | 22961447 |
| 543 | 3 | 0.9274 | OxyR2 Modulates OxyR1 Activity and Vibrio cholerae Oxidative Stress Response. Bacteria have developed capacities to deal with different stresses and adapt to different environmental niches. The human pathogen Vibrio cholerae, the causative agent of the severe diarrheal disease cholera, utilizes the transcriptional regulator OxyR to activate genes related to oxidative stress resistance, including peroxiredoxin PrxA, in response to hydrogen peroxide. In this study, we identified another OxyR homolog in V. cholerae, which we named OxyR2, and we renamed the previous OxyR OxyR1. We found that OxyR2 is required to activate its divergently transcribed gene ahpC, encoding an alkylhydroperoxide reductase, independently of H(2)O(2) A conserved cysteine residue in OxyR2 is critical for this function. Mutation of either oxyR2 or ahpC rendered V. cholerae more resistant to H(2)O(2) RNA sequencing analyses indicated that OxyR1-activated oxidative stress-resistant genes were highly expressed in oxyR2 mutants even in the absence of H(2)O(2) Further genetic analyses suggest that OxyR2-activated AhpC modulates OxyR1 activity by maintaining low intracellular concentrations of H(2)O(2) Furthermore, we showed that ΔoxyR2 and ΔahpC mutants were less fit when anaerobically grown bacteria were exposed to low levels of H(2)O(2) or incubated in seawater. These results suggest that OxyR2 and AhpC play important roles in the V. cholerae oxidative stress response. | 2017 | 28138024 |
| 606 | 4 | 0.9272 | Coexistence of SOS-Dependent and SOS-Independent Regulation of DNA Repair Genes in Radiation-Resistant Deinococcus Bacteria. Deinococcus bacteria are extremely resistant to radiation and able to repair a shattered genome in an essentially error-free manner after exposure to high doses of radiation or prolonged desiccation. An efficient, SOS-independent response mechanism to induce various DNA repair genes such as recA is essential for radiation resistance. This pathway, called radiation/desiccation response, is controlled by metallopeptidase IrrE and repressor DdrO that are highly conserved in Deinococcus. Among various Deinococcus species, Deinococcus radiodurans has been studied most extensively. Its genome encodes classical DNA repair proteins for error-free repair but no error-prone translesion DNA polymerases, which may suggest that absence of mutagenic lesion bypass is crucial for error-free repair of massive DNA damage. However, many other radiation-resistant Deinococcus species do possess translesion polymerases, and radiation-induced mutagenesis has been demonstrated. At least dozens of Deinococcus species contain a mutagenesis cassette, and some even two cassettes, encoding error-prone translesion polymerase DnaE2 and two other proteins, ImuY and ImuB-C, that are probable accessory factors required for DnaE2 activity. Expression of this mutagenesis cassette is under control of the SOS regulators RecA and LexA. In this paper, we review both the RecA/LexA-controlled mutagenesis and the IrrE/DdrO-controlled radiation/desiccation response in Deinococcus. | 2021 | 33923690 |
| 8419 | 5 | 0.9269 | The uncultured luminous symbiont of Anomalops katoptron (Beryciformes: Anomalopidae) represents a new bacterial genus. Flashlight fishes (Beryciformes: Anomalopidae) harbor luminous symbiotic bacteria in subocular light organs and use the bacterial light for predator avoidance, feeding, and communication. Despite many attempts anomalopid symbionts have not been brought into laboratory culture, which has restricted progress in understanding their phylogenetic relationships with other luminous bacteria, identification of the genes of their luminescence system, as well as the nature of their symbiotic interactions with their fish hosts. To begin addressing these issues, we used culture-independent analysis of the bacteria symbiotic with the anomalopid fish, Anomalops katoptron, to characterize the phylogeny of the bacteria and to identify the genes of their luminescence system including those involved in the regulation of luminescence. Analysis of the 16S rRNA, atpA, gapA, gyrB, pyrH, recA, rpoA, and topA genes resolved the A. katoptron symbionts as a clade nested within and deeply divergent from other members of Vibrionaceae. The bacterial luminescence (lux) genes were identified as a contiguous set (luxCDABEG), as found for the lux operons of other luminous bacteria. Phylogenetic analysis based on the lux genes confirmed the housekeeping gene phylogenetic placement. Furthermore, genes flanking the lux operon in the A. katoptron symbionts differed from those flanking lux operons of other genera of luminous bacteria. We therefore propose the candidate name Candidatus Photodesmus (Greek: photo = light, desmus = servant) katoptron for the species of bacteria symbiotic with A. katoptron. Results of a preliminary genomic analysis for genes regulating luminescence in other bacteria identified only a Vibrio harveyi-type luxR gene. These results suggest that expression of the luminescence system might be continuous in P. katoptron. | 2011 | 21864694 |
| 10 | 6 | 0.9269 | YODA Kinase Controls a Novel Immune Pathway of Tomato Conferring Enhanced Disease Resistance to the Bacterium Pseudomonas syringae. Mitogen-activated protein kinases (MAPK) play pivotal roles in transducing developmental cues and environmental signals into cellular responses through pathways initiated by MAPK kinase kinases (MAP3K). AtYODA is a MAP3K of Arabidopsis thaliana that controls stomatal development and non-canonical immune responses. Arabidopsis plants overexpressing a constitutively active YODA protein (AtCA-YDA) show broad-spectrum disease resistance and constitutive expression of defensive genes. We tested YDA function in crops immunity by heterologously overexpressing AtCA-YDA in Solanum lycopersicum. We found that these tomato AtCA-YDA plants do not show developmental phenotypes and fitness alterations, except a reduction in stomatal index, as reported in Arabidopsis AtCA-YDA plants. Notably, AtCA-YDA tomato plants show enhanced resistance to the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 and constitutive upregulation of defense-associated genes, corroborating the functionality of YDA in tomato immunity. This function was further supported by generating CRISPR/Cas9-edited tomato mutants impaired in the closest orthologs of AtYDA [Solyc08g081210 (SlYDA1) and Solyc03g025360 (SlYDA2)]. Slyda1 and Slyda2 mutants are highly susceptible to P. syringae pv. tomato DC3000 in comparison to wild-type plants but only Slyda2 shows altered stomatal index. These results indicate that tomato orthologs have specialized functions and support that YDA also regulates immune responses in tomato and may be a trait for breeding disease resistance. | 2020 | 33154763 |
| 133 | 7 | 0.9268 | Determinants of Copper Resistance in Acidithiobacillus Ferrivorans ACH Isolated from the Chilean Altiplano. The use of microorganisms in mining processes is a technology widely employed around the world. Leaching bacteria are characterized by having resistance mechanisms for several metals found in their acidic environments, some of which have been partially described in the Acidithiobacillus genus (mainly on ferrooxidans species). However, the response to copper has not been studied in the psychrotolerant Acidithiobacillus ferrivorans strains. Therefore, we propose to elucidate the response mechanisms of A. ferrivorans ACH to high copper concentrations (0-800 mM), describing its genetic repertoire and transcriptional regulation. Our results show that A. ferrivorans ACH can grow in up to 400 mM of copper. Moreover, we found the presence of several copper-related makers, belonging to cop and cus systems, as well as rusticyanins and periplasmatic acop protein in the genome. Interestingly, the ACH strain is the only one in which we find three copies of copB and copZ genes. Moreover, transcriptional expression showed an up-regulation response (acop, copZ, cusA, rusA, and rusB) to high copper concentrations. Finally, our results support the important role of these genes in A. ferrivorans copper stress resistance, promoting the use of the ACH strain in industrial leaching under low temperatures, which could decrease the activation times of oxidation processes and the energy costs. | 2020 | 32722087 |
| 106 | 8 | 0.9264 | Genomic evidence of the illumination response mechanism and evolutionary history of magnetotactic bacteria within the Rhodospirillaceae family. BACKGROUND: Magnetotactic bacteria (MTB) are ubiquitous in natural aquatic environments. MTB can produce intracellular magnetic particles, navigate along geomagnetic field, and respond to light. However, the potential mechanism by which MTB respond to illumination and their evolutionary relationship with photosynthetic bacteria remain elusive. RESULTS: We utilized genomes of the well-sequenced genus Magnetospirillum, including the newly sequenced MTB strain Magnetospirillum sp. XM-1 to perform a comprehensive genomic comparison with phototrophic bacteria within the family Rhodospirillaceae regarding the illumination response mechanism. First, photoreceptor genes were identified in the genomes of both MTB and phototrophic bacteria in the Rhodospirillaceae family, but no photosynthesis genes were found in the MTB genomes. Most of the photoreceptor genes in the MTB genomes from this family encode phytochrome-domain photoreceptors that likely induce red/far-red light phototaxis. Second, illumination also causes damage within the cell, and in Rhodospirillaceae, both MTB and phototrophic bacteria possess complex but similar sets of response and repair genes, such as oxidative stress response, iron homeostasis and DNA repair system genes. Lastly, phylogenomic analysis showed that MTB cluster closely with phototrophic bacteria in this family. One photoheterotrophic genus, Phaeospirillum, clustered within and displays high genomic similarity with Magnetospirillum. Moreover, the phylogenetic tree topologies of magnetosome synthesis genes in MTB and photosynthesis genes in phototrophic bacteria from the Rhodospirillaceae family were reasonably congruent with the phylogenomic tree, suggesting that these two traits were most likely vertically transferred during the evolution of their lineages. CONCLUSION: Our new genomic data indicate that MTB and phototrophic bacteria within the family Rhodospirillaceae possess diversified photoreceptors that may be responsible for phototaxis. Their genomes also contain comprehensive stress response genes to mediate the negative effects caused by illumination. Based on phylogenetic studies, most of MTB and phototrophic bacteria in the Rhodospirillaceae family evolved vertically with magnetosome synthesis and photosynthesis genes. The ancestor of Rhodospirillaceae was likely a magnetotactic phototrophic bacteria, however, gain or loss of magnetotaxis and phototrophic abilities might have occurred during the evolution of ancestral Rhodospirillaceae lineages. | 2019 | 31117953 |
| 339 | 9 | 0.9261 | Multiple mechanisms of resistance to cisplatin toxicity in an Escherichia coli K12 mutant. The mechanisms underlying cellular resistance to the antitumor drug cis-diamminedichloro-platinum(II) (CDDP) were studied in Escherichia coli K12. A bacterial strain (MC4100/DDP) was selected from the MC4100 wild-type strain after growth for four cycles in CDDP. MC4100/DDP bacteria showed a high level of resistance and exhibited various modifications including (1) a decrease in drug uptake and platinum/DNA binding which only partly contributed to resistance, (2) an increase in glutathione content not involved in the resistant phenotype, (3) an increase in DNA repair capacity. Resistance was unmodified by introducing a uvrA mutation which neutralizes the excision-repair pathway. In contrast, it was abolished by deletion of the recA gene which abolishes recombination and SOS repair but also by a mutation in the recA gene leading to RecA co-protease minus (no SOS induction). RecA protein was unchanged in MC4100/DDP but the expression of RecA-dependent gene(s) was required for CDDP resistance. The regulation of genes belonging to the SOS regulon was analysed in MC4100/DDP by monitoring the expression of sfiA and recA::lacZ gene fusions after UV irradiation. These gene fusions were derepressed faster and the optimal expression was obtained for a lower number of UV lesions in MC4100/DDP, suggesting a role of RecA co-protease activity in the mechanism of resistance to CDDP in this E. coli strain. | 1994 | 7974517 |
| 333 | 10 | 0.9254 | Mutants of Escherichia coli altered in both genes coding for the elongation factor Tu. Genetic analysis of a mutant of Escherichia coli resistant to the antibiotic mocimycin is presented. This resistance is due to alterations in both tuf genes coding for the elongation factor Tu. Mocimycin resistance is recessive. Bacteria carryong only one tuf gene from the resistant mutant are still mocimycin sensitive. If the mutant gene is the tufA gene, the seisitive cells can be made resistant through inactivation of the tufB gene by insertion of the bacteriophage milliunits genome. Conditional mocimycin-resistant mutants ban also be isolated when the tufB gene is altered by an amber or a temperature-sensitive mutation. When only the tufB allele from the original mocimycin-resistant mutant is present, inactivation of the wild-type tufA gene fails to give viable mocimycin-resistant progeny. We conclude that the tufA mutant allele codes for a functional mocimycin-resistant EF-Tu, whereas the mutant tufB gene does not code for a functional product. | 1978 | 360222 |
| 8866 | 11 | 0.9254 | Contribution of rpoS and bolA genes in biofilm formation in Escherichia coli K-12 MG1655. Flexibility of gene expression in bacteria permits its survival in varied environments. The genetic adaptation of bacteria through systematized gene expression is not only important, but also clinically relevant in their ability to grow biofilms in stress environments. Stress responses enable their survival under more severe conditions, enhanced resistance and/or virulence. In Escherichia coli (E. coli), two of the possible important genes for biofilm growth are rpoS and bolA gene. RpoS is also called as a master regulator of general stress response. Even though many studies have revealed the importance of rpoS in planktonic cells, little is known about the functions of rpoS in biofilms. In contrast, bolA which is a morphogene in E. coli is overexpressed under stressed environments resulting in round morphology. The hypothesis is that bolA could be implicated in biofilm development. This study reviewed the literature with the aim of understanding the stress tolerance response of E. coli in relation with rpoS and bolA genes in different environmental conditions including heat shock, cold shock, and stress in response to oxidation, acidic condition and in presence of cadmium. Knowledge of the genetic regulation of biofilm formation may lead to the understanding of the factors that drive the bacteria to switch to the biofilm mode of growth. | 2010 | 20480211 |
| 8722 | 12 | 0.9253 | Symbiotic Fungus Affected the Asian Citrus Psyllid (ACP) Resistance to Imidacloprid and Thiamethoxam. The Asian citrus psyllid (ACP), Diaphorina citri (Kuwayama) (Hemiptera: Liviidae), is a notorious Rutaceae plant pest. Frequent and extensive use of pesticides has resulted in severe insecticide resistance in ACP populations. Fully understanding the mechanism of ACP resistance to pesticides is vital for us to control or delay the development of resistance. Therefore, we compared the difference in resistance to imidacloprid and thiamethoxam between Hunan (Yongzhou, Chenzhou) and Guangdong (Guangzhou) ACP populations and analyzed the correlations between the resistance level and genes and symbiotic fungi. The results showed that the resistance of the Guangdong ACP population to imidacloprid and thiamethoxam was lower than that of Hunan ACP population, and the relative expression of genes associated with P450 mono-oxygenase and acetylcholinesterase was significantly lower in the Guangdong ACP population than in Hunan ACP population. The differences of mean relative abundances of four symbiotic bacteria among three populations were marginally significant; however, the mean relative abundance of 16 fungi among three populations was significantly different, and positive linear correlations were observed between the resistance level and two fungi (Aspergillus niger and Aureobasidium pullulans) and two genes (CYP4C70 and CYP4DB1). Negative correlations were only observed between the resistance level and two fungi (Golubevia pallescens and Acremonium sclerotigenum). Moreover, four fungi were unique to the Chenzhou population which was the highest resistance to imidacloprid and thiamethoxam. These findings suggested the P450 mono-oxygenase and symbiotic fungi together affected ACP resistance to imidacloprid and thiamethoxam. In the future, we may use environmental G. pallescens and A. sclerotigenum to control or delay ACP resistance. | 2020 | 33391190 |
| 8426 | 13 | 0.9253 | Ionizing radiation responses appear incidental to desiccation responses in the bdelloid rotifer Adineta vaga. BACKGROUND: The remarkable resistance to ionizing radiation found in anhydrobiotic organisms, such as some bacteria, tardigrades, and bdelloid rotifers has been hypothesized to be incidental to their desiccation resistance. Both stresses produce reactive oxygen species and cause damage to DNA and other macromolecules. However, this hypothesis has only been investigated in a few species. RESULTS: In this study, we analyzed the transcriptomic response of the bdelloid rotifer Adineta vaga to desiccation and to low- (X-rays) and high- (Fe) LET radiation to highlight the molecular and genetic mechanisms triggered by both stresses. We identified numerous genes encoding antioxidants, but also chaperones, that are constitutively highly expressed, which may contribute to the protection of proteins against oxidative stress during desiccation and ionizing radiation. We also detected a transcriptomic response common to desiccation and ionizing radiation with the over-expression of genes mainly involved in DNA repair and protein modifications but also genes with unknown functions that were bdelloid-specific. A distinct transcriptomic response specific to rehydration was also found, with the over-expression of genes mainly encoding Late Embryogenesis Abundant proteins, specific heat shock proteins, and glucose repressive proteins. CONCLUSIONS: These results suggest that the extreme resistance of bdelloid rotifers to radiation might indeed be a consequence of their capacity to resist complete desiccation. This study paves the way to functional genetic experiments on A. vaga targeting promising candidate proteins playing central roles in radiation and desiccation resistance. | 2024 | 38273318 |
| 336 | 14 | 0.9252 | Genetically engineered termite gut bacteria (Enterobacter cloacae) deliver and spread foreign genes in termite colonies. Indigenous gut bacteria of the Formosan subterranean termite (Coptotermes formosanus Shiraki, Isoptera: Rhinotermitidae) were used as shuttle systems to deliver, express and spread foreign genes in termite colonies. The gut bacterium Enterobacter cloacae was transformed with a recombinant plasmid (pEGFP) containing genes encoding ampicillin resistance and green fluorescent protein (GFP). In laboratory experiments, termite workers and soldiers from three colonies were fed with filter paper inoculated with transformed bacteria. Transformed bacteria were detected in termite guts by growing the entire gut flora under selective conditions and checking the cultures visually for fluorescence. We demonstrated that (1) transformed bacteria were ingested within a few hours and the GFP gene was expressed in the termite gut; (2) transformed bacteria established a persistent population in the termite gut for up to 11 weeks; (3) transformed bacteria were efficiently transferred throughout a laboratory colony, even when the donor (termites initially fed with transformed bacteria) to recipient (not fed) ratio was low; (4) transformed E. cloacae were transferred into soil; however, they did not accumulate over time and the GFP plasmid was not transferred to other soil bacteria. In the future, transgenic bacteria may be used to shuttle detrimental genes into termite colonies for improved pest control. | 2005 | 15742168 |
| 342 | 15 | 0.9251 | Heat-shock-increased survival to far-UV radiation in Escherichia coli is wavelength dependent. Heat-shock-induced resistance to far-UV (FUV) radiation was studied in Escherichia coli. The induction of FUV resistance was shown to be dependent on the products of the genes uvrA and polA in bacteria irradiated at 254 nm. Heat shock increased the resistance to 280 nm radiation in a uvrA6 recA13 mutant. Heat shock lowered the mutation frequency (reversion to tryptophan proficiency) in wild-type or uvrA strains irradiated at 254 nm. When these strains were irradiated at 280 nm, heat shock did not interfere with the mutation frequency in the wild-type strain, but greatly enhanced mutations in the uvrA mutant. After heat-shock treatment, the wild-type strain irradiated at 254 nm showed increased DNA degradation, indicating enhanced repair activity. However, heat shock did not stimulate SOS repair triggered by FUV. An increased survival of bacteriophages irradiated with FUV and inoculated into heat-shock-treated bacteria was not detected. The possibility that heat shock enhances excision repair activity in a wavelength-dependent manner is discussed. | 1994 | 8176549 |
| 713 | 16 | 0.9251 | OxyR-activated expression of Dps is important for Vibrio cholerae oxidative stress resistance and pathogenesis. Vibrio cholerae is the causative agent of cholera, a dehydrating diarrheal disease. This Gram-negative pathogen is able to modulate its gene expression in order to combat stresses encountered in both aquatic and host environments, including stress posed by reactive oxygen species (ROS). In order to further the understanding of V. cholerae's transcriptional response to ROS, we performed an RNA sequencing analysis to determine the transcriptional profile of V. cholerae when exposed to hydrogen hydroperoxide. Of 135 differentially expressed genes, VC0139 was amongst the genes with the largest induction. VC0139 encodes a protein homologous to the DPS (DNA-binding protein from starved cells) protein family, which are widely conserved and are implicated in ROS resistance in other bacteria. Using a promoter reporter assay, we show that during exponential growth, dps is induced by H2O2 in a manner dependent on the ROS-sensing transcriptional regulator, OxyR. Upon entry into stationary phase, the major stationary phase regulator RpoS is required to transcribe dps. Deletion of dps impaired V. cholerae resistance to both inorganic and organic hydroperoxides. Furthermore, we show that Dps is involved in resistance to multiple environmental stresses. Finally, we found that Dps is important for V. cholerae adult mouse colonization, but becomes dispensable in the presence of antioxidants. Taken together, our results suggest that Dps plays vital roles in both V. cholerae stress resistance and pathogenesis. | 2017 | 28151956 |
| 8746 | 17 | 0.9250 | Enhanced Resistance to Fungal and Bacterial Diseases Due to Overexpression of BSR1, a Rice RLCK, in Sugarcane, Tomato, and Torenia. Sugarcane smut caused by Sporisorium scitamineum is one of the most devastating sugarcane diseases. Furthermore, Rhizoctonia solani causes severe diseases in various crops including rice, tomato, potato, sugar beet, tobacco, and torenia. However, effective disease-resistant genes against these pathogens have not been identified in target crops. Therefore, the transgenic approach can be used since conventional cross-breeding is not applicable. Herein, the overexpression of BROAD-SPECTRUM RESISTANCE 1 (BSR1), a rice receptor-like cytoplasmic kinase, was conducted in sugarcane, tomato and torenia. BSR1-overexpressing tomatoes exhibited resistance to the bacteria Pseudomonas syringae pv. tomato DC3000 and the fungus R. solani, whereas BSR1-overexpressing torenia showed resistance to R. solani in the growth room. Additionally, BSR1 overexpression conferred resistance to sugarcane smut in the greenhouse. These three BSR1-overexpressing crops exhibited normal growth and morphologies except in the case of exceedingly high levels of overexpression. These results indicate that BSR1 overexpression is a simple and effective tool for conferring broad-spectrum disease resistance to many crops. | 2023 | 36835053 |
| 605 | 18 | 0.9250 | Conservation and diversity of the IrrE/DdrO-controlled radiation response in radiation-resistant Deinococcus bacteria. The extreme radiation resistance of Deinococcus bacteria requires the radiation-stimulated cleavage of protein DdrO by a specific metalloprotease called IrrE. DdrO is the repressor of a predicted radiation/desiccation response (RDR) regulon, composed of radiation-induced genes having a conserved DNA motif (RDRM) in their promoter regions. Here, we showed that addition of zinc ions to purified apo-IrrE, and short exposure of Deinococcus cells to zinc ions, resulted in cleavage of DdrO in vitro and in vivo, respectively. Binding of IrrE to RDRM-containing DNA or interaction of IrrE with DNA-bound DdrO was not observed. The data are in line with IrrE being a zinc peptidase, and indicate that increased zinc availability, caused by oxidative stress, triggers the in vivo cleavage of DdrO unbound to DNA. Transcriptomics and proteomics of Deinococcus deserti confirmed the IrrE-dependent regulation of predicted RDR regulon genes and also revealed additional members of this regulon. Comparative analysis showed that the RDR regulon is largely well conserved in Deinococcus species, but also showed diversity in the regulon composition. Notably, several RDR genes with an important role in radiation resistance in Deinococcus radiodurans, for example pprA, are not conserved in some other radiation-resistant Deinococcus species. | 2017 | 28397370 |
| 722 | 19 | 0.9249 | Evolution of Escherichia coli for maximum HOCl resistance through constitutive expression of the OxyR regulon. Exposure of cells to stress impairs cellular functions and may cause killing or adaptation. Adaptation can be facilitated by stress-induced mutagenesis or epigenetic changes, i.e. phenotypic variation without mutations. Upon exposure to HOCl, which is produced by the innate immune system upon bacterial infection, bacteria trigger stress responses that enable increased survival against the stress. Here, we addressed the question whether bacteria can adapt to high HOCl doses and if so, how the acquired resistance is facilitated. We evolved Escherichia coli cells for maximum HOCl resistance by successively increasing the HOCl concentration in the cultivation medium. HOCl-resistant cells showed broad stress resistance but did not carry any chromosomal mutations as revealed by whole-genome sequencing. According to proteome analysis and analysis of transcript levels of stress-related genes, HOCl resistance was accompanied by altered levels of outer-membrane proteins A, C, F and W, and, most prominently, a constitutively expressed OxyR regulon. Induction of the OxyR regulon is facilitated by a partially oxidized OxyR leading to increased levels of antioxidant proteins such as Dps, AhpC/AhpF and KatG. These changes were maintained in evolved strains even when they were cultivated without stress for a prolonged time, indicating epigenetic changes contributed to stress resistance. This indicated that maximum HOCl resistance was conferred by the accumulated action of the OxyR stress response and other factors such as altered levels of outer-membrane proteins. | 2014 | 24899627 |