Genomewide Transcriptome Profiles Reveal How Bacillus subtilis Lipopeptides Inhibit Microsclerotia Formation in Verticillium dahliae

Verticillium dahliae is a soilborne fungus and the primary causal agent of vascular wilt diseases worldwide. The fungus produces melanized microsclerotia that are crucially important for the survival and spread of V. dahliae. There are no fungicides available that are both effective and environmentally friendly to suppress the fungus. Previously, Bacillus subtilis C232 was isolated from soil and was demonstrated to suppress microsclerotia formation in V. dahliae. In this study, liquid chromatography coupled with mass spectrometry revealed that the antifungal substance is actually a mixture of lipopeptides. Exposure of V. dahliae to these lipopeptides resulted in hyphal swelling, cell lysis, and downregulation of melanin-related genes. RNA sequencing analyses of the lipopeptide-suppressed transcriptome during microsclerotial development revealed that 5,974 genes (2,131 upregulated and 3,843 downregulated) were differentially expressed versus nonsuppressive conditions. Furthermore, gene ontology enrichment analyses revealed that genes involved in response to stress, cellular metabolic processes, and translation were significantly enriched. Additionally, the lipopeptides inhibited expression of genes associated with secondary metabolism, protein catabolism, and the high-osmolarity glycerol response signaling pathway. Together, these findings provide evidence for the mechanism by which B. subtilis lipopeptides suppress microsclerotia formation. The transcriptomic insight garnered here may facilitate the development of biological agents to combat Verticillium wilt.

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DNA repair and the evolution of transformation in Bacillus subtilis. II. Role of inducible repair.

Genetics ◽

10.1093/genetics/121.3.411 ◽

1989 ◽

Vol 121 (3) ◽

pp. 411-422

Author(s):

M F Wojciechowski ◽

M A Hoelzer ◽

R E Michod

Keyword(s):

Dna Repair ◽

Bacillus Subtilis ◽

Plasmid Dna ◽

Excision Repair ◽

Physiological State ◽

Transformation Rate ◽

Exogenous Dna ◽

Expression Of Genes ◽

Cell Subpopulations ◽

Experimental Treatments

Abstract In Bacillus subtilis, DNA repair and recombination are intimately associated with competence, the physiological state in which the bacterium can bind, take up and recombine exogenous DNA. Previously, we have shown that the homologous DNA transformation rate (ratio of transformants to total cells) increases with increasing UV dosage if cells are transformed after exposure to UV radiation (UV-DNA), whereas the transformation rate decreases if cells are transformed before exposure to UV (DNA-UV). In this report, by using different DNA repair-deficient mutants, we show that the greater increase in transformation rate in UV-DNA experiments than in DNA-UV experiments does not depend upon excision repair or inducible SOS-like repair, although certain quantitative aspects of the response do depend upon these repair systems. We also show that there is no increase in the transformation rate in a UV-DNA experiment when repair and recombination proficient cells are transformed with nonhomologous plasmid DNA, although the results in a DNA-UV experiment are essentially unchanged by using plasmid DNA. We have used din operon fusions as a sensitive means of assaying for the expression of genes under the control of the SOS-like regulon in both competent and noncompetent cell subpopulations as a consequence of competence development and our subsequent experimental treatments. Results indicate that the SOS-like system is induced in both competent and noncompetent subpopulations in our treatments and so should not be a major factor in the differential response in transformation rate observed in UV-DNA and DNA-UV treatments. These results provide further support to the hypothesis that the evolutionary function of competence is to bring DNA into the cell for use as template in the repair of DNA damage.

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Intracellular localization of the mycobacterial stressosome complex

Scientific Reports ◽

10.1038/s41598-021-89069-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Malavika Ramesh ◽

Ram Gopal Nitharwal ◽

Phani Rama Krishna Behra ◽

B. M. Fredrik Pettersson ◽

Santanu Dasgupta ◽

...

Keyword(s):

Bacillus Subtilis ◽

Fluorescence Microscopy ◽

Bacillus Cereus ◽

Intracellular Localization ◽

Sigma Factors ◽

Alternative Sigma Factors ◽

Expression Of Genes ◽

Molecular Machinery ◽

Stress Signals ◽

Activation Pathways

AbstractMicroorganisms survive stresses by alternating the expression of genes suitable for surviving the immediate and present danger and eventually adapt to new conditions. Many bacteria have evolved a multiprotein "molecular machinery" designated the "Stressosome" that integrates different stress signals and activates alternative sigma factors for appropriate downstream responses. We and others have identified orthologs of some of the Bacillus subtilis stressosome components, RsbR, RsbS, RsbT and RsbUVW in several mycobacteria and we have previously reported mutual interactions among the stressosome components RsbR, RsbS, RsbT and RsbUVW from Mycobacterium marinum. Here we provide evidence that "STAS" domains of both RsbR and RsbS are important for establishing the interaction and thus critical for stressosome assembly. Fluorescence microscopy further suggested co-localization of RsbR and RsbS in multiprotein complexes visible as co-localized fluorescent foci distributed at scattered locations in the M. marinum cytoplasm; the number, intensity and distribution of such foci changed in cells under stressed conditions. Finally, we provide bioinformatics data that 17 (of 244) mycobacteria, which lack the RsbRST genes, carry homologs of Bacillus cereus genes rsbK and rsbM indicating the existence of alternative σF activation pathways among mycobacteria.

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Responses of Bacillus subtilis to Hypotonic Challenges: Physiological Contributions of Mechanosensitive Channels to Cellular Survival

Applied and Environmental Microbiology ◽

10.1128/aem.01573-07 ◽

2008 ◽

Vol 74 (8) ◽

pp. 2454-2460 ◽

Cited By ~ 50

Author(s):

Tamara Hoffmann ◽

Clara Boiangiu ◽

Susanne Moses ◽

Erhard Bremer

Keyword(s):

Bacillus Subtilis ◽

Mutational Analysis ◽

Mechanosensitive Channels ◽

High Osmolarity ◽

Cellular Survival ◽

Genes Encoding ◽

Quadruple Mutant ◽

Rapid Transition ◽

A Minor ◽

Small Conductance

ABSTRACT Mechanosensitive channels are thought to function as safety valves for the release of cytoplasmic solutes from cells that have to manage a rapid transition from high- to low-osmolarity environments. Subsequent to an osmotic down-shock of cells grown at high osmolarity, Bacillus subtilis rapidly releases the previously accumulated compatible solute glycine betaine in accordance with the degree of the osmotic downshift. Database searches suggest that B. subtilis possesses one copy of a gene for a mechanosensitive channel of large conductance (mscL) and three copies of genes encoding proteins that putatively form mechanosensitive channels of small conductance (yhdY, yfkC, and ykuT). Detailed mutational analysis of all potential channel-forming genes revealed that a quadruple mutant (mscL yhdY yfkC ykuT) has no growth disadvantage in high-osmolarity media in comparison to the wild type. Osmotic down-shock experiments demonstrated that the MscL channel is the principal solute release system of B. subtilis, and strains with a gene disruption in mscL exhibited a severe survival defect upon an osmotic down-shock. We also detected a minor contribution of the SigB-controlled putative MscS-type channel-forming protein YkuT to cellular survival in an mscL mutant. Taken together, our data revealed that mechanosensitive channels of both the MscL and MscS types play pivotal roles in managing the transition of B. subtilis from hyper- to hypo-osmotic environments.

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Differential Role of Basal Keratinocytes in UV-Induced Immunosuppression and Skin Cancer

Molecular and Cellular Biology ◽

10.1128/mcb.00807-06 ◽

2006 ◽

Vol 26 (22) ◽

pp. 8515-8526 ◽

Cited By ~ 32

Author(s):

Judith Jans ◽

George A. Garinis ◽

Wouter Schul ◽

Adri van Oudenaren ◽

Michael Moorhouse ◽

...

Keyword(s):

Skin Cancer ◽

Biological Effects ◽

Mouse Skin ◽

Cell Type ◽

Cell Type Specificity ◽

Basal Keratinocytes ◽

Expression Of Genes ◽

Pyrimidine Dimers ◽

Response To Stress

ABSTRACT Cyclobutane pyrimidine dimers (CPDs) and 6-4 photoproducts (6-4PPs) comprise major UV-induced photolesions. If left unrepaired, these lesions can induce mutations and skin cancer, which is facilitated by UV-induced immunosuppression. Yet the contribution of lesion and cell type specificity to the harmful biological effects of UV exposure remains currently unclear. Using a series of photolyase-transgenic mice to ubiquitously remove either CPDs or 6-4PPs from all cells in the mouse skin or selectively from basal keratinocytes, we show that the majority of UV-induced acute effects to require the presence of CPDs in basal keratinocytes in the mouse skin. At the fundamental level of gene expression, CPDs induce the expression of genes associated with repair and recombinational processing of DNA damage, as well as apoptosis and a response to stress. At the organismal level, photolyase-mediated removal of CPDs, but not 6-4PPs, from the genome of only basal keratinocytes substantially diminishes the incidence of skin tumors; however, it does not affect the UVB-mediated immunosuppression. Taken together, these findings reveal a differential role of basal keratinocytes in these processes, providing novel insights into the skin's acute and chronic responses to UV in a lesion- and cell-type-specific manner.

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Sphingolipids Regulate the Yeast High-Osmolarity Glycerol Response Pathway

Molecular and Cellular Biology ◽

10.1128/mcb.06111-11 ◽

2012 ◽

Vol 32 (14) ◽

pp. 2861-2870 ◽

Cited By ~ 33

Author(s):

M. Tanigawa ◽

A. Kihara ◽

M. Terashima ◽

T. Takahara ◽

T. Maeda

Keyword(s):

High Osmolarity ◽

High Osmolarity Glycerol

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Fengycins, Cyclic Lipopeptides from MarineBacillus subtilisStrains, Kill the Plant-Pathogenic FungusMagnaporthe griseaby Inducing Reactive Oxygen Species Production and Chromatin Condensation

Applied and Environmental Microbiology ◽

10.1128/aem.00445-18 ◽

2018 ◽

Vol 84 (18) ◽

Cited By ~ 31

Author(s):

Linlin Zhang ◽

Chaomin Sun

Keyword(s):

Mass Spectrometry ◽

Reactive Oxygen Species ◽

Biological Control ◽

Bacillus Subtilis ◽

Rice Blast ◽

Marine Bacterium ◽

Magnaporthe Grisea ◽

Chromatin Condensation ◽

Oxygen Species ◽

Content Type

ABSTRACTRice blast caused by the phytopathogenMagnaporthe griseaposes a serious threat to global food security and is difficult to control.Bacillusspecies have been extensively explored for the biological control of many fungal diseases. In the present study, the marine bacteriumBacillus subtilisBS155 showed a strong antifungal activity againstM. grisea. The active metabolites were isolated and identified as cyclic lipopeptides (CLPs) of the fengycin family, named fengycin BS155, by the combination of high-performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (ESI-MS/MS). Analyses using scanning and transmission electron microscopy revealed that fengycin BS155 caused morphological changes in the plasma membrane and cell wall ofM. griseahyphae. Using comparative proteomic and biochemical assays, fengycin BS155 was demonstrated to reduce the mitochondrial membrane potential (MMP), induce bursts of reactive oxygen species (ROS), and downregulate the expression level of ROS-scavenging enzymes. Simultaneously, fengycin BS155 caused chromatin condensation in fungal hyphal cells, which led to the upregulation of DNA repair-related protein expression and the cleavage of poly(ADP-ribose) polymerase (PARP). Altogether, our results indicate that fengycin BS155 acts by inducing membrane damage and dysfunction of organelles, disrupting MMP, oxidative stress, and chromatin condensation, resulting inM. griseahyphal cell death. Therefore, fengycin BS155 and its parent bacterium are very promising candidates for the biological control ofM. griseaand the associated rice blast and should be further investigated as such.IMPORTANCERice (Oryza sativaL.) is the most important crop and a primary food source for more than half of the world's population. Notably, scientists in China have developed several types of rice that can be grown in seawater, avoiding the use of precious freshwater resources and potentially creating enough food for 200 million people. The plant-affecting fungusMagnaporthe griseais the causal agent of rice blast disease, and biological rather than chemical control of this threatening disease is highly desirable. In this work, we discovered fengycin BS155, a cyclic lipopeptide material produced by the marine bacteriumBacillus subtilisBS155, which showed strong activity againstM. grisea. Our results elucidate the mechanism of fengycin BS155-mediatedM. griseagrowth inhibition and highlight the potential ofB. subtilisBS155 as a biocontrol agent againstM. griseain rice cultivation under both fresh- and saltwater conditions.

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GPD1, which encodes glycerol-3-phosphate dehydrogenase, is essential for growth under osmotic stress in Saccharomyces cerevisiae, and its expression is regulated by the high-osmolarity glycerol response pathway

Molecular and Cellular Biology ◽

10.1128/mcb.14.6.4135-4144.1994 ◽

1994 ◽

Vol 14 (6) ◽

pp. 4135-4144

Author(s):

J Albertyn ◽

S Hohmann ◽

J M Thevelein ◽

B A Prior

Keyword(s):

Saccharomyces Cerevisiae ◽

Osmotic Stress ◽

Yeast Cells ◽

Mrna Levels ◽

Hog Pathway ◽

Hypertonic Medium ◽

High Osmolarity ◽

High Osmolarity Glycerol ◽

Enhanced Production ◽

Glycerol 3 Phosphate Dehydrogenase

The yeast Saccharomyces cerevisiae responds to osmotic stress, i.e., an increase in osmolarity of the growth medium, by enhanced production and intracellular accumulation of glycerol as a compatible solute. We have cloned a gene encoding the key enzyme of glycerol synthesis, the NADH-dependent cytosolic glycerol-3-phosphate dehydrogenase, and we named it GPD1. gpd1 delta mutants produced very little glycerol, and they were sensitive to osmotic stress. Thus, glycerol production is indeed essential for the growth of yeast cells during reduced water availability. hog1 delta mutants lacking a protein kinase involved in osmostress-induced signal transduction (the high-osmolarity glycerol response [HOG] pathway) failed to increase glycerol-3-phosphate dehydrogenase activity and mRNA levels when osmotic stress was imposed. Thus, expression of GPD1 is regulated through the HOG pathway. However, there may be Hog1-independent mechanisms mediating osmostress-induced glycerol accumulation, since a hog1 delta strain could still enhance its glycerol content, although less than the wild type. hog1 delta mutants are more sensitive to osmotic stress than isogenic gpd1 delta strains, and gpd1 delta hog1 delta double mutants are even more sensitive than either single mutant. Thus, the HOG pathway most probably has additional targets in the mechanism of adaptation to hypertonic medium.

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