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612300.9345Genomic analysis of a hop-resistance Lactobacillus brevis strain responsible for food spoilage and capable of entering into the VBNC state. BACKGROUND: Lactobacillus brevis is a major contaminant of spoiled beer. And it was able to enter VBNC state and cause false negative detection, which poses a major challenge to the brewing industry. METHODS: The genomic DNA of L. brevis BM-LB13908 was extracted and purified to form a sequencing library that meets the quality requirements and was sequenced. The sequencing results were then screened and assembled to obtain the entire genome sequence of L. brevis. Predicted genes were annotated by GO database, KEGG pathway database and COG functional classification system. RESULTS: The final assembly yielded 275 scaffolds of a total length of 2 840 080 bp with a G + C content of 53.35%. There were 2357, 701, 1519 predicted genes with corresponding GO functional, COG functional, and KEGG biological pathway annotations, respectively. The genome of L. brevis BM-LB13908 contains hop resistance gene horA and multiple genes related to the formation of VBNC state. CONCLUSIONS: This report describes the draft genome sequence of L. brevis BM-LB13908, a spoilage strain isolated from finished beer sample. This study may support further study on L. brevis and other beer spoilage bacteria, and prevent and control beer spoilage caused by microorganisms.202032272213
56010.9334A general genetic approach in Escherichia coli for determining the mechanism(s) of action of tumoricidal agents: application to DMP 840, a tumoricidal agent. We describe here a simple and easily manipulatable Escherichia coli-based genetic system that permits us to identify bacterial gene products that modulate the sensitivity of bacteria to tumoricidal agents, such as DMP 840, a bisnaphthalimide drug. To the extent that the action of these agents is conserved, these studies may expand our understanding agents is conserved, these studies may expand our understanding of how the agents work in mammalian cells. The approach briefly is to use a library of E. coli genes that are overexpressed in a high copy number vector to select bacterial clones that are resistant to the cytotoxic effects of drugs. AtolC bacterial mutant is used to maximize permeability of cells to hydrophobic organic molecules. By using DMP 840 to model the system, we have identified two genes, designated mdaA and mdaB, that impart resistance to DMP 840 when they are expressed at elevated levels. mdaB maps to E. coli map coordinate 66, is located between the parE and parC genes, and encodes a protein of 22 kDa. mdaA maps to E. coli map coordinate 18, is located adjacent to the glutaredoxin (grx) gene, and encodes a protein of 24 kDa. Specific and regulatable overproduction of both of these proteins correlates with DMP 840 resistance. Overproduction of the MdaB protein also imparts resistance to two mammalian topoisomerase inhibitors, Adriamycin and etoposide. In contrast, overproduction of the MdaA protein produces resistance only to Adriamycin. Based on its drug-resistance properties and its location between genes that encode the two subunits of the bacterial topoisomerase IV, we suggest that mdaB acts by modulating topoisomerase IV activity. The location of the mdaA gene adjacent to grx suggests it acts by a drug detoxification mechanism.19957568050
55820.9308Thiamine pyrophosphate riboswitches are targets for the antimicrobial compound pyrithiamine. Thiamine metabolism genes are regulated in numerous bacteria by a riboswitch class that binds the coenzyme thiamine pyrophosphate (TPP). We demonstrate that the antimicrobial action of the thiamine analog pyrithiamine (PT) is mediated by interaction with TPP riboswitches in bacteria and fungi. For example, pyrithiamine pyrophosphate (PTPP) binds the TPP riboswitch controlling the tenA operon in Bacillus subtilis. Expression of a TPP riboswitch-regulated reporter gene is reduced in transgenic B. subtilis or Escherichia coli when grown in the presence of thiamine or PT, while mutant riboswitches in these organisms are unresponsive to these ligands. Bacteria selected for PT resistance bear specific mutations that disrupt ligand binding to TPP riboswitches and derepress certain TPP metabolic genes. Our findings demonstrate that riboswitches can serve as antimicrobial drug targets and expand our understanding of thiamine metabolism in bacteria.200516356850
616630.9307Intraperitoneal infection with Salmonella abortusovis is partially controlled by a gene closely linked with the Ity gene. The aim of the present study was to determine whether the Ity gene, which controls the resistance to S. typhimurium infection in mice, also governs the resistance to S. abortusovis, a serotype specific for goat and sheep. During either i.v. or i.p. infection, BALB/c mice (Itys) were not able to control the growth of S. abortusovis and eventually died from infection. In contrast CBA (Ityr) or (C.CB)F1 (Ityr/s) mice were able to control the growth of these bacteria. Using congenic C.D2 Ityr mice, we found that the gene controlling resistance to S. abortusovis was tightly linked to the Ity gene on chromosome 1. Furthermore, in the spleen and the liver of backcross BALB/c x (CBA x BALB/c) mice, the S. abortusovis resistance phenotype cosegregated with the two alleles of the Len-1 gene, a gene tightly linked to the Ity gene. By contrast, in these backcross mice, the level of infection of the peritoneal cavity, the site of inoculation, did not correlated with the Len-1 phenotype of the animal. These results provide evidence that after i.p. inoculation the control of S. abortusovis growth in the spleen and the liver is controlled by the Ity gene, but also suggest that additional gene(s) regulate the number of bacteria at the site of inoculation.19921544222
818640.9305Tumor-infiltrating bacteria disrupt cancer epithelial cell interactions and induce cell-cycle arrest. Tumor-infiltrating bacteria are increasingly recognized as modulators of cancer progression and therapy resistance. We describe a mechanism by which extracellular intratumoral bacteria, including Fusobacterium, modulate cancer epithelial cell behavior. Spatial imaging and single-cell spatial transcriptomics show that these bacteria predominantly localize extracellularly within tumor microniches of colorectal and oral cancers, characterized by reduced cell density, transcriptional activity, and proliferation. In vitro, Fusobacterium nucleatum disrupts epithelial contacts, inducing G0-G1 arrest and transcriptional quiescence. This state confers 5-fluorouracil resistance and remodels the tumor microenvironment. Findings were validated by live-cell imaging, spatial profiling, mouse models, and a 52-patient colorectal cancer cohort. Transcriptomics reveals downregulation of cell cycle, transcription, and antigen presentation genes in bacteria-enriched regions, consistent with a quiescent, immune-evasive phenotype. In an independent rectal cancer cohort, high Fusobacterium burden correlates with reduced therapy response. These results link extracellular bacteria to cancer cell quiescence and chemoresistance, highlighting microbial-tumor interactions as therapeutic targets.202541106380
54550.9302Characterization 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.201222821968
52960.9301Crystal structure of the transcriptional repressor PagR of Bacillus anthracis. PagR is a transcriptional repressor in Bacillus anthracis that controls the chromosomal S-layer genes eag and sap, and downregulates the protective antigen pagA gene by direct binding to their promoter regions. The PagR protein sequence is similar to those of members of the ArsR repressor family involved in the repression of arsenate-resistance genes in numerous bacteria. The crystal structure of PagR was solved using multi-wavelength anomalous diffraction (MAD) techniques and was refined with 1.8 A resolution diffraction data. The PagR molecules form dimers, as observed in all SmtB/ArsR repressor family proteins. In the crystal lattice four PagR dimers pack together to form an inactive octamer. Model-building studies suggest that the dimer binds to a DNA duplex with a bend of around 4 degrees.201019926656
634870.9300Overexpression of cold shock protein A of Psychromonas arctica KOPRI 22215 confers cold-resistance. A polar bacterium was isolated from Arctic sea sediments and identified as Psychromonas artica, based on 16S rDNA sequence. Psychromonas artica KOPRI 22215 has an optimal growth temperature of 10 degrees C and a maximum growth temperature of 25 degrees C, suggesting this bacterium is a psychrophile. Cold shock proteins (Csps) are induced upon temperature downshift by more than 10 degrees C. Functional studies have researched mostly Csps of a mesophilic bacterium Escherichia coli, but not on those of psychrophilic bacteria. In an effort to understand the molecular mechanisms of psychrophilic bacteria that allow it withstand freezing environments, we cloned a gene encoding a cold shock protein from P. artica KOPRI 22215 (CspA(Pa)) using the conserved sequences in csp genes. The 204 bp-long ORF encoded a protein of 68 amino acids, sharing 56% homology to previously reported E. coli CspA protein. When CspA(Pa) was overexpressed in E. coli, it caused cell growth-retardation and morphological elongation. Interestingly, overexpression of CspA(Pa) drastically increased the host's cold-resistance by more than ten times, suggesting the protein aids survival in polar environments.201020169403
837280.9299A Plasmid-Encoded Putative Glycosyltransferase Is Involved in Hop Tolerance and Beer Spoilage in Lactobacillus brevis. Lactobacillus brevis beer-spoiling strains harbor plasmids that contain genes such as horA, horC, and hitA which are known to confer hop tolerance. The L. brevis beer-spoiling strain UCCLBBS124, which possesses four plasmids, was treated with novobiocin, resulting in the isolation of UCCLBBS124 derivatives exhibiting hop sensitivity and an inability to grow in beer. One selected derivative was shown to have lost a single plasmid, here designated UCCLBBS124_D, which harbors the UCCLBBS124_pD0015 gene, predicted to encode a glycosyltransferase. Hop tolerance and growth in beer were restored when UCCLBBS124_pD0015 was introduced in one of these hop-sensitive derivatives on a plasmid. We hypothesize that this gene modifies the surface composition of the polysaccharide cell wall, conferring protection against hop compounds. Furthermore, the introduction of this gene in trans in L. brevis UCCLB521, a strain that cannot grow in and spoil beer, was shown to furnish the resulting strain with the ability to grow in beer, while its expression also conferred phage resistance. This study underscores how the acquisition of certain mobile genetic elements plays a role in hop tolerance and beer spoilage for strains of this bacterial species.IMPORTANCELactobacillus brevis is a member of the lactic acid bacteria and is often reported as the causative agent of food or beverage spoilage, in particular, that of beer. Bacterial spoilage of beer may result in product withdrawal or recall, with concomitant economic losses for the brewing industry. A very limited number of genes involved in beer spoilage have been identified and primarily include those involved in hop resistance, such as horA, hitA, and horC However, since none of these genes are universal, it is clear that there are likely (many) other molecular players involved in beer spoilage. Here, we report on the importance of a plasmid-encoded glycosyltransferase associated with beer spoilage by L. brevis that is involved in hop tolerance. The study highlights the complexity of the genetic requirements to facilitate beer spoilage and the role of multiple key players in this process.202031757821
55990.9299Coordinated regulation of chemotaxis and resistance to copper by CsoR in Pseudomonas putida. Copper is an essential enzyme cofactor in bacteria, but excess copper is highly toxic. Bacteria can cope with copper stress by increasing copper resistance and initiating chemorepellent response. However, it remains unclear how bacteria coordinate chemotaxis and resistance to copper. By screening proteins that interacted with the chemotaxis kinase CheA, we identified a copper-binding repressor CsoR that interacted with CheA in Pseudomonas putida. CsoR interacted with the HPT (P1), Dimer (P3), and HATPase_c (P4) domains of CheA and inhibited CheA autophosphorylation, resulting in decreased chemotaxis. The copper-binding of CsoR weakened its interaction with CheA, which relieved the inhibition of chemotaxis by CsoR. In addition, CsoR bound to the promoter of copper-resistance genes to inhibit gene expression, and copper-binding released CsoR from the promoter, leading to increased gene expression and copper resistance. P. putida cells exhibited a chemorepellent response to copper in a CheA-dependent manner, and CsoR inhibited the chemorepellent response to copper. Besides, the CheA-CsoR interaction also existed in proteins from several other bacterial species. Our results revealed a mechanism by which bacteria coordinately regulated chemotaxis and resistance to copper by CsoR.202540197389
605100.9298Conservation 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.201728397370
8357110.9295Identification of novel Legionella genes required for endosymbiosis in Paramecium based on comparative genome analysis with Holospora spp. The relationship between Legionella and protist hosts has a huge impact when considering the infectious risk in humans because it facilitates the long-term replication and survival of Legionella in the environment. The ciliate Paramecium is considered to be a protist host for Legionella in natural environments, but the details of their endosymbiosis are largely unknown. In this study, we determined candidate Legionella pneumophila genes that are likely to be involved in the establishment of endosymbiosis in Paramecium caudatum by comparing the genomes of Legionella spp. and Holospora spp. that are obligate endosymbiotic bacteria in Paramecium spp. Among the candidate genes, each single deletion mutant for five genes (lpg0492, lpg0522, lpg0523, lpg2141 and lpg2398) failed to establish endosymbiosis in P. caudatum despite showing intracellular growth in human macrophages. The mutants exhibited no characteristic changes in terms of their morphology, multiplication rate or capacity for modulating the phagosomes in which they were contained, but their resistance to lysozyme decreased significantly. This study provides insights into novel factors required by L. pneumophila for endosymbiosis in P. caudatum, and suggests that endosymbiotic organisms within conspecific hosts may have shared genes related to effective endosymbiosis establishment.201830124811
802120.9295YqhC regulates transcription of the adjacent Escherichia coli genes yqhD and dkgA that are involved in furfural tolerance. Previous results have demonstrated that the silencing of adjacent genes encoding NADPH-dependent furfural oxidoreductases (yqhD dkgA) is responsible for increased furfural tolerance in an E. coli strain EMFR9 [Miller et al., Appl Environ Microbiol 75:4315-4323, 2009]. This gene silencing is now reported to result from the spontaneous insertion of an IS10 into the coding region of yqhC, an upstream gene. YqhC shares homology with transcriptional regulators belonging to the AraC/XylS family and was shown to act as a positive regulator of the adjacent operon encoding YqhD and DkgA. Regulation was demonstrated by constructing a chromosomal deletion of yqhC, a firefly luciferase reporter plasmid for yqhC, and by a direct comparison of furfural resistance and NADPH-dependent furfural reductase activity. Closely related bacteria contain yqhC, yqhD, and dkgA orthologs in the same arrangement as in E. coli LY180. Orthologs of yqhC are also present in more distantly related Gram-negative bacteria. Disruption of yqhC offers a useful approach to increase furfural tolerance in bacteria.201120676725
648130.9294SpoVG 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.201627048798
6124140.9294Comparative analysis of spleen transcriptome detects differences in evolutionary adaptation of immune defense functions in bighead carp and silver carp. The evolutionary divergence of the immune defense functions in bighead carp (A. nobilis) and silver carp (H. molitrix) is still not understood at the molecular level. Here, we obtained 48,821,754 and 55,054,480 clean reads from spleen tissue libraries prepared for bighead carp and silver carp using Illumina paired-end sequencing technology, respectively, and identified 4976 orthologous genes from the transcriptome data sets by comparative analysis. Adaptive evolutionary analysis showed that 212 orthologous genes and 255 Gene Ontology (GO) terms were subjected to positive selection(Ka/Ks values > 1) only in bighead carp, and 195 orthologous genes and 309 GO terms only in silver carp. Among immune defense functions with significant evolutionary divergence, the positively selected biological processes in bighead carp mainly included B cell-mediated immunity, chemokine-mediated signaling pathway, and immunoglobulin mediated immune response, whereas those in silver carp mainly included the antigen processing and presentation, defense response to fungus, and detection of bacteria. Moreover, we found 2974 genes expressed only in spleen of bighead carp and 3494 genes expressed only in spleen of silver carp, where these genes were mostly enriched in the same biological processes or pathways. These results provide a better understanding of the differences in resistance to some diseases by bighead carp and silver carp, and also facilitate the identification of candidate genes related to disease resistance.201930287346
606150.9294Coexistence 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.202133923690
649160.9293The VirAB ABC Transporter Is Required for VirR Regulation of Listeria monocytogenes Virulence and Resistance to Nisin. Listeria monocytogenes is a Gram-positive intracellular pathogen that causes a severe invasive disease. Upon infecting a host cell, L. monocytogenes upregulates the transcription of numerous factors necessary for productive infection. VirR is the response regulator component of a two-component regulatory system in L. monocytogenes In this report, we have identified the putative ABC transporter encoded by genes lmo1746-lmo1747 as necessary for VirR function. We have designated lmo1746-lmo1747 virAB We constructed an in-frame deletion of virAB and determined that the ΔvirAB mutant exhibited reduced transcription of VirR-regulated genes. The ΔvirAB mutant also showed defects in in vitro plaque formation and in vivo virulence that were similar to those of a ΔvirR deletion mutant. Since VirR is important for innate resistance to antimicrobial agents, we determined the MICs of nisin and bacitracin for ΔvirAB bacteria. We found that VirAB expression was necessary for nisin resistance but was dispensable for resistance to bacitracin. This result suggested a VirAB-independent mechanism of VirR regulation in response to bacitracin. Lastly, we found that the ΔvirR and ΔvirAB mutants had no deficiency in growth in broth culture, intracellular replication, or production of the ActA surface protein, which facilitates actin-based motility and cell-to-cell spread. However, the ΔvirR and ΔvirAB mutants produced shorter actin tails during intracellular infection, which suggested that these mutants have a reduced ability to move and spread via actin-based motility. These findings have demonstrated that L. monocytogenes VirAB functions in a pathway with VirR to regulate the expression of genes necessary for virulence and resistance to antimicrobial agents.201829263107
6365170.9292The transcriptomic response to cannabidiol of Treponema denticola, a phytocannabinoid-resistant periodontal pathogen. AIM: The use of cannabis, which contains multiple antimicrobials, may be a risk factor for periodontitis. We hypothesized that multiple oral spirochetes would be phytocannabinoid-resistant and that cannabidiol (CBD) would act as an environmental stressor to which Treponema denticola would respond transcriptionally, thereby providing first insights into spirochetal survival strategies. MATERIALS AND METHODS: Oral spirochete growth was monitored spectrophotometrically in the presence and absence of physiologically relevant phytocannabinoid doses, the transcriptional response to phytocannabinoid exposure determined by RNAseq, specific gene activity fluxes verified using qRT-PCR and orthologues among fully sequenced oral spirochetes identified. RESULTS: Multiple strains of oral treponemes were resistant to CBD (0.1-10 μg/mL), while T. denticola ATCC 35405 was resistant to all phytocannabinoids tested (CBD, cannabinol [CBN], tetrahydrocannabinol [THC]). A total of 392 T. denticola ATCC 35405 genes were found to be CBD-responsive by RNAseq. A selected subset of these genes was independently verified by qRT-PCR. Genes found to be differentially activated by both methods included several involved in transcriptional regulation and toxin control. Suppressed genes included several involved in chemotaxis and proteolysis. CONCLUSIONS: Oral spirochetes, unlike some other periodontal bacteria, are resistant to physiological doses of phytocannabinoids. Investigation of CBD-induced transcriptomic changes provided insight into the resistance mechanisms of this important periodontal pathogen. These findings should be considered in the context of the reported enhanced susceptibility to periodontitis in cannabis users.202438105008
8732180.9289RNA-Seq identification of candidate defense genes targeted by endophytic Bacillus cereus-mediated induced systemic resistance against Meloidogyne incognita in tomato. BACKGROUND: The endophytic bacteria Bacillus cereus BCM2 has shown great potential as a defense against the parasitic nematode Meloidogyne incognita. Here, we studied endophytic bacteria-mediated plant defense against M. incognita and searched for defense-related candidate genes using RNA-Seq. RESULTS: The induced systemic resistance of BCM2 against M. incognita was tested using the split-root method. Pre-inoculated BCM2 on the inducer side was associated with a dramatic reduction in galls and egg masses on the responder side, but inoculated BCM2 alone did not produce the same effect. In order to investigate which plant defense-related genes are specifically activated by BCM2, four RNA samples from tomato roots were sequenced, and four high-quality total clean bases were obtained, ranging from 6.64 to 6.75 Gb, with an average of 21 558 total genes. The 34 candidate defense-related genes were identified by pair-wise comparison among libraries, representing the targets for BCM2 priming resistance against M. incognita. Functional characterization revealed that the plant-pathogen interaction pathway (ID: ko04626) was significantly enriched for BCM2-mediated M. incognita resistance. CONCLUSION: This study demonstrates that B. cereus BCM2 maintains a harmonious host-microbe relationship with tomato, but appeared to prime the plant, resulting in more vigorous defense response toward the infection nematode. © 2018 Society of Chemical Industry.201829737595
609190.9289A metazoan ortholog of SpoT hydrolyzes ppGpp and functions in starvation responses. In nutrient-starved bacteria, RelA and SpoT proteins have key roles in reducing cell growth and overcoming stresses. Here we identify functional SpoT orthologs in metazoa (named Mesh1, encoded by HDDC3 in human and Q9VAM9 in Drosophila melanogaster) and reveal their structures and functions. Like the bacterial enzyme, Mesh1 proteins contain an active site for ppGpp hydrolysis and a conserved His-Asp-box motif for Mn(2+) binding. Consistent with these structural data, Mesh1 efficiently catalyzes hydrolysis of guanosine 3',5'-diphosphate (ppGpp) both in vitro and in vivo. Mesh1 also suppresses SpoT-deficient lethality and RelA-induced delayed cell growth in bacteria. Notably, deletion of Mesh1 (Q9VAM9) in Drosophila induces retarded body growth and impaired starvation resistance. Microarray analyses reveal that the amino acid-starved Mesh1 null mutant has highly downregulated DNA and protein synthesis-related genes and upregulated stress-responsible genes. These data suggest that metazoan SpoT orthologs have an evolutionarily conserved function in starvation responses.201020818390