# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 8482 | 0 | 0.8611 | Potential roles of IFI44 genes in high resistance to Vibrio in hybrids of Argopecten scallops. Vibrio bacteria are often fatal to aquatic organisms and selection of Vibrio-resistant strains is warranted for aquaculture animals. In this study, we found that hybrids between bay scallops and Peruvian scallops exhibited significantly higher resistance to Vibrio challenge, but little is available on its mechanism. Interferon induced protein 44 (IFI44), a member of the type I interferon (IFN) family, plays an important role in the IFN immune response in invertebrates, which may also participate in the resistance to Vibrio in scallops. To explore the roles of IFI44 genes in the resistance to Vibrio, they were identified and characterized in the bay scallop (designated as AiIFI44), the Peruvian scallop (designated as ApIFI44), and their reciprocal hybrids (designated as AipIFI44 and ApiIFI44, respectively). Their open reading frame (ORF) sequences were all 1434 bp, encoding 477 amino acids, but with large variations among the four genes. The AipIFI44 and ApiIFI44 exhibited higher similarity with ApIFI44 than with AiIFI44. All four genes have a TLDc structural domain with significant variations in sequences among them. Predicted differences in conformation and posttranslational modifications may lead to altered protein activity. We further demonstrated that the AiIFI44, AipIFI44 and ApiIFI44 expressed in all the tested tissues, with the highest expression in the gills and hepatopancreas. In response to Vibrio anguillarum challenge, the profile of mRNA expression of IFI44 gene differed among the bay scallops and the two hybrids. In the bay scallops, it increased at 6 h but dramatically decreased after 12-48 h. However, the mRNA expression of both AipIFI44 and ApiIFI44 decreased at 6 h but continuously increased thereafter and reached the highest value at 48 h. The results in the present study suggest the immune responds of IFI44 in scallops and it may be related to the higher resistance to Vibrio bacterial in hybrids. | 2023 | 36948367 |
| 804 | 1 | 0.8412 | Cloning, mutagenesis, and characterization of the microalga Parietochloris incisa acetohydroxyacid synthase, and its possible use as an endogenous selection marker. Parietochloris incisa is an oleaginous fresh water green microalga that accumulates an unusually high content of the valuable long-chain polyunsaturated fatty acid (LC-PUFA) arachidonic acid within triacylglycerols in cytoplasmic lipid bodies. Here, we describe cloning and mutagenesis of the P. incisa acetohydroxyacid synthase (PiAHAS) gene for use as an herbicide resistance selection marker for transformation. Use of an endogenous gene circumvents the risks and regulatory difficulties of cultivating antibiotic-resistant organisms. AHAS is present in plants and microorganisms where it catalyzes the first essential step in the synthesis of branched-chain amino acids. It is the target enzyme of the herbicide sulfometuron methyl (SMM), which effectively inhibits growth of bacteria and plants. Several point mutations of AHAS are known to confer herbicide resistance. We cloned the cDNA that encodes PiAHAS and introduced a W605S point mutation (PimAHAS). Catalytic activity and herbicide resistance of the wild-type and mutant proteins were characterized in the AHAS-deficient E. coli, BUM1 strain. Cloned PiAHAS wild-type and mutant genes complemented AHAS-deficient bacterial growth. Furthermore, bacteria expressing the mutant PiAHAS exhibited high resistance to SMM. Purified PiAHAS wild-type and mutant proteins were assayed for enzymatic activity and herbicide resistance. The W605S mutation was shown to cause a twofold decrease in enzymatic activity and in affinity for the Pyruvate substrate. However, the mutant exhibited 7 orders of magnitude higher resistance to the SMM herbicide than that of the wild type. | 2012 | 22488216 |
| 8481 | 2 | 0.8411 | Universal stress proteins contribute Edwardsiella piscicida adversity resistance and pathogenicity and promote blocking host immune response. Universal stress proteins (Usps) exist ubiquitously in bacteria and other organisms. Usps play an important role in adaptation of bacteria to a variety of environmental stresses. There is increasing evidence that Usps facilitate pathogens to adapt host environment and are involved in pathogenicity. Edwardsiella piscicida (formerly included in E. tarda) is a severe fish pathogen and infects various important economic fish including tilapia (Oreochromis niloticus). In E. piscicida, a number of systems and factors that are involved in stress resistance and pathogenesis were identified. However, the function of Usps in E. piscicida is totally unknown. In this study, we examined the expressions of 13 usp genes in E. piscicida and found that most of these usp genes were up-regulated expression under high temperature, oxidative stress, acid stress, and host serum stress. Particularly, among these usp genes, usp13, exhibited dramatically high expression level upon several stress conditions. To investigate the biological role of usp13, a markerless usp13 in-frame mutant strain, TX01Δusp13, was constructed. Compared to the wild type TX01, TX01Δusp13 exhibited markedly compromised tolerance to high temperature, hydrogen peroxide, and low pH. Deletion of usp13 significantly retarded bacterial biofilm growth and decreased resistance against serum killing. Pathogenicity analysis showed that the inactivation of usp13 significantly impaired the ability of E. piscicida to invade into host cell and infect host tissue. Introduction of a trans-expressed usp13 gene restored the lost virulence of TX01Δusp13. In support of these results, host immune response induced by TX01 and TX01Δusp13 was examined, and the results showed reactive oxygen species (ROS) levels in TX01Δusp13-infected macrophages were significantly higher than those in TX01-infected cells. The expression level of several cytokines (IL-6, IL-8, IL-10, TNF-α, and CC2) in TX01Δusp13-infected fish was significantly higher than that in TX01-infected fish. These results suggested that the deletion of usp13 attenuated the ability of bacteria to overcome the host immune response to pathogen infection. Taken together, our study indicated Usp13 of E. piscicida was not only important participant in adversity resistance, but also was essential for E. piscicida pathogenicity and contributed to block host immune response to pathogen infection. | 2019 | 31654767 |
| 516 | 3 | 0.8409 | Role of Iron-Containing Alcohol Dehydrogenases in Acinetobacter baumannii ATCC 19606 Stress Resistance and Virulence. Most bacteria possess alcohol dehydrogenase (ADH) genes (Adh genes) to mitigate alcohol toxicity, but these genes have functions beyond alcohol degradation. Previous research has shown that ADH can modulate quorum sensing in Acinetobacter baumannii, a rising opportunistic pathogen. However, the number and nature of Adh genes in A. baumannii have not yet been fully characterized. We identified seven alcohol dehydrogenases (NAD(+)-ADHs) from A. baumannii ATCC 19606, and examined the roles of three iron-containing ADHs, ADH3, ADH4, and ADH6. Marker-less mutation was used to generate Adh3, Adh4, and Adh6 single, double, and triple mutants. Disrupted Adh4 mutants failed to grow in ethanol-, 1-butanol-, or 1-propanol-containing mediums, and recombinant ADH4 exhibited strongest activity against ethanol. Stress resistance assays with inorganic and organic hydroperoxides showed that Adh3 and Adh6 were key to oxidative stress resistance. Virulence assays performed on the Galleria mellonella model organism revealed that Adh4 mutants had comparable virulence to wild-type, while Adh3 and Adh6 mutants had reduced virulence. The results suggest that ADH4 is primarily involved in alcohol metabolism, while ADH3 and ADH6 are key to stress resistance and virulence. Further investigation into the roles of other ADHs in A. baumannii is warranted. | 2021 | 34576087 |
| 8722 | 4 | 0.8406 | 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 |
| 648 | 5 | 0.8389 | SpoVG Is a Conserved RNA-Binding Protein That Regulates Listeria monocytogenes Lysozyme Resistance, Virulence, and Swarming Motility. In this study, we sought to characterize the targets of the abundant Listeria monocytogenes noncoding RNA Rli31, which is required for L. monocytogenes lysozyme resistance and pathogenesis. Whole-genome sequencing of lysozyme-resistant suppressor strains identified loss-of-expression mutations in the promoter of spoVG, and deletion of spoVG rescued lysozyme sensitivity and attenuation in vivo of the rli31 mutant. SpoVG was demonstrated to be an RNA-binding protein that interacted with Rli31 in vitro. The relationship between Rli31 and SpoVG is multifaceted, as both the spoVG-encoded protein and the spoVG 5′-untranslated region interacted with Rli31. In addition, we observed that spoVG-deficient bacteria were nonmotile in soft agar and suppressor mutations that restored swarming motility were identified in the gene encoding a major RNase in Gram-positive bacteria, RNase J1. Collectively, these findings suggest that SpoVG is similar to global posttranscriptional regulators, a class of RNA-binding proteins that interact with noncoding RNA, regulate genes in concert with RNases, and control pleiotropic aspects of bacterial physiology. IMPORTANCE: spoVG is widely conserved among bacteria; however, the function of this gene has remained unclear since its initial characterization in 1977. Mutation of spoVG impacts various phenotypes in Gram-positive bacteria, including methicillin resistance, capsule formation, and enzyme secretion in Staphylococcus aureus and also asymmetric cell division, hemolysin production, and sporulation in Bacillus subtilis. Here, we demonstrate that spoVG mutant strains of Listeria monocytogenes are hyper-lysozyme resistant, hypervirulent, nonmotile, and misregulate genes controlling carbon metabolism. Furthermore, we demonstrate that SpoVG is an RNA-binding protein. These findings suggest that SpoVG has a role in L. monocytogenes, and perhaps in other bacteria, as a global gene regulator. Posttranscriptional gene regulators help bacteria adapt to various environments and coordinate differing aspects of bacterial physiology. SpoVG may help the organism coordinate environmental growth and virulence to survive as a facultative pathogen. | 2016 | 27048798 |
| 543 | 6 | 0.8389 | 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 |
| 584 | 7 | 0.8388 | Cadmium and iron transport by members of a plant metal transporter family in Arabidopsis with homology to Nramp genes. Metal cation homeostasis is essential for plant nutrition and resistance to toxic heavy metals. Many plant metal transporters remain to be identified at the molecular level. In the present study, we have isolated AtNramp cDNAs from Arabidopsis and show that these genes complement the phenotype of a metal uptake deficient yeast strain, smf1. AtNramps show homology to the Nramp gene family in bacteria, yeast, plants, and animals. Expression of AtNramp cDNAs increases Cd(2+) sensitivity and Cd(2+) accumulation in yeast. Furthermore, AtNramp3 and AtNramp4 complement an iron uptake mutant in yeast. This suggests possible roles in iron transport in plants and reveals heterogeneity in the functional properties of Nramp transporters. In Arabidopsis, AtNramps are expressed in both roots and aerial parts under metal replete conditions. Interestingly, AtNramp3 and AtNramp4 are induced by iron starvation. Disruption of the AtNramp3 gene leads to slightly enhanced cadmium resistance of root growth. Furthermore, overexpression of AtNramp3 results in cadmium hypersensitivity of Arabidopsis root growth and increased accumulation of Fe, on Cd(2+) treatment. Our results show that Nramp genes in plants encode metal transporters and that AtNramps transport both the metal nutrient Fe and the toxic metal cadmium. | 2000 | 10781110 |
| 16 | 8 | 0.8375 | A glycoside hydrolase 30 protein BpXynC of Bacillus paralicheniformis NMSW12 recognized as A MAMP triggers plant immunity response. Bacillus spp. has been widely used as a biocontrol agent to control plant diseases. However, little is known about mechanisms of the protein MAMP secreted by Bacillus spp. Herein, our study reported a glycoside hydrolase family 30 (GH30) protein, BpXynC, produced by the biocontrol bacteria Bacillus paralicheniformis NMSW12, that can induce cell death in several plant species. The results revealed that the recombinant protein triggers cell death in Nicotiana benthamiana in a BAK1-dependent manner and elicits an early defense response, including ROS burst, activation of MAPK cascades, and upregulation of plant immunity marker genes. BpXynC was also found to be a glucuronoxylanase that exhibits hydrolysis activity on xlyan. Two mutants of BpXynC which lost the glucuronoxylanase activity still retained the elicitor activity. The qRT-PCR results of defense-related genes showed that BpXynC induces plant immunity responses via an SA-mediated pathway. BpXynC and its mutants could induce resistance in N. benthamiana against infection by Sclerotinia sclerotiorum and tobacco mosaic virus (TMV). Furthermore, BpXynC-treated tomato fruits exhibited strong resistance to the infection of Phytophthora capsica. Overall, our study revealed that GH30 protein BpXynC can induce plant immunity response as MAMP, which can be further applied as a biopesticide to control plant diseases. | 2024 | 38286384 |
| 122 | 9 | 0.8375 | Functional characterization of ORCTL2--an organic cation transporter expressed in the renal proximal tubules. Chromosome 11p15.5 harbors a gene or genes involved in Beckwith-Wiedemann syndrome that confer(s) susceptibility to Wilms' tumor, rhabdomyosarcoma, and hepatoblastoma. We have previously identified a transcript at 11p15.5 which encodes a putative membrane transport protein, designated organic cation transporter-like 2 (ORCTL2), that shares homology with tetracycline resistance proteins and bacterial multidrug resistance proteins. In this report, we have investigated the transport properties of ORCTL2 and show that this protein can confer resistance to chloroquine and quinidine when overexpressed in bacteria. Immunohistochemistry analyses performed with anti-ORCTL2 polyclonal antibodies on human renal sections indicate that ORCTL2 is localized on the apical membrane surface of the proximal tubules. These results suggest that ORCTL2 may play a role in the transport of chloroquine and quinidine related compounds in the kidney. | 1998 | 9744804 |
| 42 | 10 | 0.8373 | Suppression of the rice fatty-acid desaturase gene OsSSI2 enhances resistance to blast and leaf blight diseases in rice. Fatty acids and their derivatives play important signaling roles in plant defense responses. It has been shown that suppressing a gene for stearoyl acyl carrier protein fatty-acid desaturase (SACPD) enhances the resistance of Arabidopsis (SSI2) and soybean to multiple pathogens. In this study, we present functional analyses of a rice homolog of SSI2 (OsSSI2) in disease resistance of rice plants. A transposon insertion mutation (Osssi2-Tos17) and RNAi-mediated knockdown of OsSSI2 (OsSSI2-kd) reduced the oleic acid (18:1) level and increased that of stearic acid (18:0), indicating that OsSSI2 is responsible for fatty-acid desaturase activity. These plants displayed spontaneous lesion formation in leaf blades, retarded growth, slight increase in endogenous free salicylic acid (SA) levels, and SA/benzothiadiazole (BTH)-specific inducible genes, including WRKY45, a key regulator of SA/BTH-induced resistance, in rice. Moreover, the OsSSI2-kd plants showed markedly enhanced resistance to the blast fungus Magnaporthe grisea and leaf-blight bacteria Xanthomonas oryzae pv. oryzae. These results suggest that OsSSI2 is involved in the negative regulation of defense responses in rice, as are its Arabidopsis and soybean counterparts. Microarray analyses identified 406 genes that were differentially expressed (>or=2-fold) in OsSSI2-kd rice plants compared with wild-type rice and, of these, approximately 39% were BTH responsive. Taken together, our results suggest that induction of SA-responsive genes, including WRKY45, is likely responsible for enhanced disease resistance in OsSSI2-kd rice plants. | 2009 | 19522564 |
| 8727 | 11 | 0.8367 | Transcriptome Analysis of Rice Near-Isogenic Lines Inoculated with Two Strains of Xanthomonas oryzae pv. oryzae, AH28 and PXO99(A). Rice bacterial blight (BB), caused by Xanthomonas oryzae pv. oryzae (Xoo), is a major threat to rice production and food security. Exploring new resistance genes and developing varieties with broad-spectrum and high resistance has been a key focus in rice disease resistance research. In a preliminary study, rice cultivar Fan3, exhibiting high resistance to PXO99(A) and susceptibility to AH28, was developed by enhancing the resistance of Yuehesimiao (YHSM) to BB. This study performed a transcriptome analysis on the leaves of Fan3 and YHSM following inoculation with Xoo strains AH28 and PXO99(A). The analysis revealed significant differential expression of 14,084 genes. Among the transcription factor (TF) families identified, bHLH, WRKY, and ERF were prominent, with notable differences in the expression of OsWRKY62, OsWRKY76, and OsbHLH6 across samples. Over 100 genes were directly linked to disease resistance, including nearly 30 NBS-LRR family genes. Additionally, 11 SWEET family protein genes, over 750 protein kinase genes, 63 peroxidase genes, and eight phenylalanine aminolysase genes were detected. Gene ontology (GO) analysis showed significant enrichment in pathways related to defense response to bacteria and oxidative stress response. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis indicated that differentially expressed genes (DEGs) were enriched in phenylpropanoid biosynthesis and diterpenoid biosynthesis pathways. Gene expression results from qRT-PCR were consistent with those from RNA-Seq, underscoring the reliability of the findings. Candidate genes identified in this study that may be resistant to BB, such as NBS-LRR family genes LOC_Os11g11960 and LOC_Os11g12350, SWEET family genes LOC_Os01g50460 and LOC_Os01g12130, and protein kinase-expressing genes LOC_Os01g66860 and LOC_Os02g57700, will provide a theoretical basis for further experiments. These results suggest that the immune response of rice to the two strains may be more concentrated in the early stage, and there are more up-regulated genes in the immune response of the high-resistant to PXO99A and medium-resistant to AH28, respectively, compared with the highly susceptible rice. This study offers a foundation for further research on resistance genes and the molecular mechanisms in Fan3 and YHSM. | 2024 | 39599338 |
| 8419 | 12 | 0.8366 | 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 |
| 8475 | 13 | 0.8365 | Antibacterial Activity of Endophytic Bacteria Against Sugar Beet Root Rot Agent by Volatile Organic Compound Production and Induction of Systemic Resistance. The volatile organic compounds (VOCs) produced by endophytic bacteria have a significant role in the control of phytopathogens. In this research, the VOCs produced by the endophytic bacteria Streptomyces sp. B86, Pantoea sp. Dez632, Pseudomonas sp. Bt851, and Stenotrophomonas sp. Sh622 isolated from healthy sugar beet (Beta vulgaris) and sea beet (Beta maritima) were evaluated for their effects on the virulence traits of Bacillus pumilus Isf19, the causal agent of harvested sugar beet root rot disease. The gas chromatographymass spectrometry (GC-MS) analysis revealed that B86, Dez632, Bt851, and Sh622 produced 15, 28, 30, and 20 VOCs, respectively, with high quality. All antagonistic endophytic bacteria produced VOCs that significantly reduced soft root symptoms and inhibited the growth of B. pumilus Isf19 at different levels. The VOCs produced by endophytic bacteria significantly reduced swarming, swimming, and twitching motility by B. pumilus Isf19, which are important to pathogenicity. Our results revealed that VOCs produced by Sh622 and Bt851 significantly reduced attachment of B. pumilus Isf19 cells to sugar beetroots, and also all endophytic bacteria tested significantly reduced chemotaxis motility of the pathogen toward root extract. The VOCs produced by Dez632 and Bt851 significantly upregulated the expression levels of defense genes related to soft rot resistance. Induction of PR1 and NBS-LRR2 genes in sugar beetroot slices suggests the involvement of SA and JA pathways, respectively, in the induction of resistance against pathogen attack. Based on our results, the antibacterial VOCs produced by endophytic bacteria investigated in this study can reduce soft rot incidence. | 2022 | 35722285 |
| 545 | 14 | 0.8365 | Characterization of the organic hydroperoxide resistance system of Brucella abortus 2308. The organic hydroperoxide resistance protein Ohr has been identified in numerous bacteria where it functions in the detoxification of organic hydroperoxides, and expression of ohr is often regulated by a MarR-type regulator called OhrR. The genes annotated as BAB2_0350 and BAB2_0351 in the Brucella abortus 2308 genome sequence are predicted to encode OhrR and Ohr orthologs, respectively. Using isogenic ohr and ohrR mutants and lacZ promoter fusions, it was determined that Ohr contributes to resistance to organic hydroperoxide, but not hydrogen peroxide, in B. abortus 2308 and that OhrR represses the transcription of both ohr and ohrR in this strain. Moreover, electrophoretic mobility shift assays and DNase I footprinting revealed that OhrR binds directly to a specific region in the intergenic region between ohr and ohrR that shares extensive nucleotide sequence similarity with so-called "OhrR boxes" described in other bacteria. While Ohr plays a prominent role in protecting B. abortus 2308 from organic hydroperoxide stress in in vitro assays, this protein is not required for the wild-type virulence of this strain in cultured murine macrophages or experimentally infected mice. | 2012 | 22821968 |
| 163 | 15 | 0.8365 | Copper resistance in the cold: Genome analysis and characterisation of a P(IB-1) ATPase in Bizionia argentinensis. Copper homeostasis is a fundamental process in organisms, characterised by unique pathways that have evolved to meet specific needs while preserving core resistance mechanisms. While these systems are well-documented in model bacteria, information on copper resistance in species adapted to cold environments is scarce. This study investigates the potential genes related to copper homeostasis in the genome of Bizionia argentinensis (JUB59-T), a psychrotolerant bacterium isolated from Antarctic seawater. We identified several genes encoding proteins analogous to those crucial for copper homeostasis, including three sequences of copper-transport P1B-type ATPases. One of these, referred to as BaCopA1, was chosen for cloning and expression in Saccharomyces cerevisiae. BaCopA1 was successfully integrated into yeast membranes and subsequently extracted with detergent. The purified BaCopA1 demonstrated the ability to catalyse ATP hydrolysis at low temperatures. Structural models of various BaCopA1 conformations were generated and compared with mesophilic and thermophilic homologous structures. The significant conservation of critical residues and structural similarity among these proteins suggest a shared reaction mechanism for copper transport. This study is the first to report a psychrotolerant P1B-ATPase that has been expressed and purified in a functional form. | 2024 | 38943264 |
| 51 | 16 | 0.8365 | A pair of allelic WRKY genes play opposite roles in rice-bacteria interactions. Although allelic diversity of genes has been reported to play important roles in different physiological processes, information on allelic diversity of defense-responsive genes in host-pathogen interactions is limited. Here, we report that a pair of allelic genes, OsWRKY45-1 and OsWRKY45-2, which encode proteins with a 10-amino acid difference, play opposite roles in rice (Oryza sativa) resistance against bacterial pathogens. Bacterial blight caused by Xanthomonas oryzae pv oryzae (Xoo), bacterial streak caused by Xanthomonas oryzae pv oryzicola (Xoc), and fungal blast caused by Magnaporthe grisea are devastating diseases of rice worldwide. OsWRKY45-1-overexpressing plants showed increased susceptibility and OsWRKY45-1-knockout plants showed enhanced resistance to Xoo and Xoc. In contrast, OsWRKY45-2-overexpressing plants showed enhanced resistance and OsWRKY45-2-suppressing plants showed increased susceptibility to Xoo and Xoc. Interestingly, both OsWRKY45-1- and OsWRKY45-2-overexpressing plants showed enhanced resistance to M. grisea. OsWRKY45-1-regulated Xoo resistance was accompanied by increased accumulation of salicylic acid and jasmonic acid and induced expression of a subset of defense-responsive genes, while OsWRKY45-2-regulated Xoo resistance was accompanied by increased accumulation of jasmonic acid but not salicylic acid and induced expression of another subset of defense-responsive genes. These results suggest that both OsWRKY45-1 and OsWRKY45-2 are positive regulators in rice resistance against M. grisea, but the former is a negative regulator and the latter is a positive regulator in rice resistance against Xoo and Xoc. The opposite roles of the two allelic genes in rice-Xoo interaction appear to be due to their mediation of different defense signaling pathways. | 2009 | 19700558 |
| 95 | 17 | 0.8364 | NtPR1a regulates resistance to Ralstonia solanacearum in Nicotiana tabacum via activating the defense-related genes. Pathogenesis-related proteins (PRs) are associated with the development of systemic acquired resistance (SAR) against further infection enforced by fungi, bacteria and viruses. PR1a is the first PR-1 member that could be purified and characterized. Previous studies have reported its role in plants' resistance system against oomycete pathogens. However, the role of PR1a in Solanaceae plants against the bacterial wilt pathogen Ralstonia solanacearum remains unclear. To assess roles of NtPR1a in tobacco responding to R. solanacearum, we performed overexpression experiments in Yunyan 87 plants (a susceptible tobacco cultivar). The results illuminated that overexpression of NtPR1a contributed to improving resistance to R. solanacearum in tobacco Yunyan 87. Specifically speaking, NtPR1a gene could be induced by exogenous hormones like salicylic acid (SA) and pathogenic bacteria R. Solanacearum. Moreover, NtPR1a-overexpressing tobacco significantly reduced multiple of R. solanacearum and inhibited the development of disease symptoms compared with wild-type plants. Importantly, overexpression of NtPR1a activated a series of defense-related genes expression, including the hypersensitive response (HR)-associated genes NtHSR201 and NtHIN1, SA-, JA- and ET-associated genes NtPR2, NtCHN50, NtPR1b, NtEFE26, and Ntacc oxidase, and detoxification-associated gene NtGST1. In summary, our results suggested that NtPR1a-enhanced tobacco resistance to R. solanacearum may be mainly dependent on activation of the defense-related genes. | 2019 | 30545635 |
| 807 | 18 | 0.8363 | Transcriptomic analysis of Saccharomyces cerevisiae upon honokiol treatment. Honokiol (HNK), one of the main medicinal components in Magnolia officinalis, possesses antimicrobial activity against a variety of pathogenic bacteria and fungi. However, little is known of the molecular mechanisms underpinning the antimicrobial activity. To explore the molecular mechanism of its antifungal activity, we determined the effects of HNK on the mRNA expression profile of Saccharomyces cerevisiae using a DNA microarray approach. HNK markedly induced the expression of genes related to iron uptake and homeostasis. Conversely, genes associated with respiratory electron transport were downregulated, mirroring the effects of iron starvation. Meanwhile, HNK-induced growth deficiency was partly rescued by iron supplementation and HNK reacted with iron, producing iron complexes that depleted iron. These results suggest that HNK treatment induced iron starvation. Additionally, HNK treatment resulted in the upregulation of genes involved in protein synthesis and drug resistance networks. Furthermore, the deletion of PDR5, a gene encoding the plasma membrane ATP binding cassette (ABC) transporter, conferred sensitivity to HNK. Overexpression of PDR5 enhanced resistance of WT and pdr5Δ strains to HNK. Taken together, these findings suggest that HNK, which can be excluded by overexpression of Pdr5, functions in multiple cellular processes in S. cerevisiae, particularly in inducing iron starvation to inhibit cell growth. | 2017 | 28499955 |
| 31 | 19 | 0.8363 | miR395-regulated sulfate metabolism exploits pathogen sensitivity to sulfate to boost immunity in rice. MicroRNAs (miRNAs) play important roles in plant physiological activities. However, their roles and molecular mechanisms in boosting plant immunity, especially through the modulation of macronutrient metabolism in response to pathogens, are largely unknown. Here, we report that an evolutionarily conserved miRNA, miR395, promotes resistance to Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc), two destructive bacterial pathogens, by regulating sulfate accumulation and distribution in rice. Specifically, miR395 targets and suppresses the expression of the ATP sulfurylase gene OsAPS1, which functions in sulfate assimilation, and two sulfate transporter genes, OsSULTR2;1 and OsSULTR2;2, which function in sulfate translocation, to promote sulfate accumulation, resulting in broad-spectrum resistance to bacterial pathogens in miR395-overexpressing plants. Genetic analysis revealed that miR395-triggered resistance is involved in both pathogen-associated molecular pattern-triggered immunity and R gene-mediated resistance. Moreover, we found that accumulated sulfate but not S-metabolites inhibits proliferation of pathogenic bacteria, revealing a sulfate-mediated antibacterial defense mechanism that differs from sulfur-induced resistance. Furthermore, compared with other bacteria, Xoo and Xoc, which lack the sulfate transporter CysZ, are sensitive to high levels of extracellular sulfate. Accordingly, miR395-regulated sulfate accumulation impaired the virulence of Xoo and Xoc by decreasing extracellular polysaccharide production and biofilm formation. Taken together, these results suggest that rice miR395 modulates sulfate metabolism to exploit pathogen sensitivity to sulfate and thereby promotes broad-spectrum resistance. | 2022 | 34968734 |