scholarly journals Comparative Transcriptomics and Gene Knockout Reveal Virulence Factors of Arthrinium phaeospermum in Bambusa pervariabilis × Dendrocalamopsis grandis

2021 ◽  
Vol 7 (12) ◽  
pp. 1001
Author(s):  
Xinmei Fang ◽  
Peng Yan ◽  
Mingmin Guan ◽  
Shan Han ◽  
Tianmin Qiao ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Gene Knockout ◽  
Disease Index ◽  
Economic Losses ◽  
Rna Seq ◽  
Wild Type ◽  
Relative Growth ◽  
Rice Tissue ◽  
Arthrinium Phaeospermum ◽  
Type Strains

Arthrinium phaeospermum can cause branch wilting of Bambusa pervariabilis × Dendrocalamopsis grandis, causing great economic losses and ecological damage. A. phaeospermum was sequenced in sterile deionized water (CK), rice tissue (T1) and B. pervariabilis × D. grandis (T2) fluid by RNA-Seq, and the function of Ctf1β 1 and Ctf1β 2 was verified by gene knockout. There were 424, 471 and 396 differentially expressed genes between the T2 and CK, T2 and T1, and CK and T1 groups, respectively. Thirty DEGs had verified the change in expression by fluorescent quantitative PCR. Twenty-nine DEGs were the same as the expression level in RNA-Seq. In addition, ΔApCtf1β 1 and ΔApCtf1β 2 showed weaker virulence by gene knockout, and the complementary strains Ctf1β 1 and Ctf1β 2 showed the same virulence as the wild-type strains. Relative growth inhibition of ΔApCtf1β 1 and ΔApCtf1β was significantly decreased by 21.4% and 19.2%, respectively, by adding H2O2 compared to the estimates from the wild-type strain and decreased by 25% and 19.4%, respectively, by adding Congo red. The disease index of B. pervariabilis × D. grandis infected by two mutants was significantly lower than that of wild type. This suggested that Ctf1β genes are required for the stress response and virulence of A. phaeospermum.

Development of mutants of Gliocladium virens tolerant to benomyl

1990 ◽  
Vol 36 (7) ◽  
pp. 484-489 ◽  
Author(s):  
G. C. Papavizas ◽  
D. P. Roberts ◽  
K. K. Kim
Keyword(s):  
Carbon Source ◽  
Type Strain ◽  
Wild Type Strain ◽  
Carbon Sources ◽  
Sclerotium Rolfsii ◽  
Wild Type ◽  
Gliocladium Virens ◽  
Rhizosphere Competence ◽  
Filter Paper Cellulase ◽  
Type Strains

Aqueous suspensions of conidia of Gliocladium virens strains Gl-3 and Gl-21 were exposed to both ultraviolet radiation and ethyl methanesulfonate. Two mutants of Gl-3 and three of Gl-21 were selected for tolerance to benomyl at 10 μg∙mL−1, as indicated by growth and conidial germination on benomyl-amended potato dextrose agar. The mutants differed considerably from their respective wild-type strains in appearance, growth habit, sporulation, carbon-source utilization, and enzyme activity profiles. Of 10 carbon sources tested, cellobiose, xylose, and xylan were the best for growth, galactose and glucose were intermediate, and arabinose, ribose, and rhamnose were poor sources of carbon. The wild-type strains and the mutants did not utilize cellulose as the sole carbon source for growth. Two benomyl-tolerant mutants of Gl-3 produced less cellulase (β-1,4-glucosidase, carboxymethylcellulase, filter-paper cellulase) than Gl-3. In contrast, mutants of Gl-21 produced more cellulase than the wild-type strain. Only Gl-3 provided control of blight on snapbean caused by Sclerotium rolfsii. Wild-type strain Gl-21 and all mutants from both strains were ineffective biocontrol agents. Key words: Gliocladium, benomyl tolerance, Sclerotium, rhizosphere competence.

scholarly journals Growth optimization and identification of an ω-transaminase by a novel native PAGE activity staining method in a Bacillus sp. strain BaH isolated from Iranian soil

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Najme Gord Noshahri ◽  
Jamshid Fooladi ◽  
Ulrike Engel ◽  
Delphine Muller ◽  
Michaela Kugel ◽  
...  
Keyword(s):  
Wild Type Strain ◽  
Colorimetric Assay ◽  
Protein Band ◽  
Wild Type ◽  
Direct Identification ◽  
Native Page ◽  
Crude Extracts ◽  
Amino Donor ◽  
Bioreactor System ◽  
Type Strains

Abstractω-Transaminases’ (ω-TAs) importance for synthesizing chiral amines led to the development of different methods to quickly identify and characterize new sources of these enzymes. Here we describe the optimization of growth and induction of such an enzyme in a wild type strain of Bacillus sp. strain BaH (IBRC-M 11337) isolated from Iranian soil in shaking flasks by the response surface methodology (RSM). Optimum conditions were set in a multiplexed bench-top bioreactor system (Sixfors). ω-TA activity of obtained biomass was checked by an innovative efficient colorimetric assay for localizing ω-TAs in crude extracts on acrylamide gel by using ortho-xylylenediamine (OXD) as amino donor. The application of the established OXD assay is thereby expanded from high-throughput activity screenings and colony-based screenings of heterologously expressed mutants to a direct identification of ω-TAs in wild-type strains: This assay can be used to detect the protein band of the respective enzyme in crude extracts of novel isolates by visual inspection of native PAGEs without any upstream protein purification, thus enabling subsequent further investigations of a newly discovered enzyme directly from the crude extract.

scholarly journals Infection Components of Wild-Type and Mutant Strains of Colletotrichum gloeosporioides f. sp. aeschynomene on Northern Jointvetch

Plant Disease ◽  
1997 ◽  
Vol 81 (4) ◽  
pp. 404-409 ◽  
Author(s):  
Y. Luo ◽  
D. O. TeBeest
Keyword(s):  
Fungal Pathogens ◽  
Wild Type Strain ◽  
Colletotrichum Gloeosporioides ◽  
Wild Type ◽  
Biological Control Of Weeds ◽  
Lesion Number ◽  
Mutant Strains ◽  
Controlled Environments ◽  
Resistant Strains ◽  
Type Strains

Colletotrichum gloeosporioides f. sp. aeschynomene causes an anthracnose of northern jointvetch, Aeschynomene virginica. Infection components, including lesion number, latent period, lesion expansion rate, and sporulation, were measured in experiments conducted in controlled environments. Two wild-type strains (3-1-3 and CLA 5A), four benomyl-resistant strains (B13, B15, B18 and B21), and four nitrate nonutilizing mutant strains (Nit A, Nit R, Nit L, and Nit T) of the pathogen were tested. Nitrate nonutilizing strains caused significantly fewer lesions on northern jointvetch than did wild-type and benomyl-resistant strains. Latent periods were significantly shorter for the wild-type strain CLA 5A than for most other strains. Lesion expansion rates of all benomyl-resistant strains were significantly slower than those of the wild- type strains. Large variations in sporulation were observed for most strains, and no differences in sporulation were found between wild-type and mutant strains. The usefulness of infection component analysis for the identification of competitiveness of strains of fungal pathogens for biological control of weeds is discussed.

scholarly journals Role of aspartate ammonia-lyase in Pasteurella multocida

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zui Wang ◽  
Li Li ◽  
Peng Liu ◽  
Chen Wang ◽  
Qin Lu ◽  
...  
Keyword(s):  
Mutant Strain ◽  
Bacterial Growth ◽  
Type Strain ◽  
Pasteurella Multocida ◽  
Wild Type Strain ◽  
Luria Bertani ◽  
Economic Losses ◽  
Wild Type ◽  
Mueller Hinton ◽  
Significant Difference

Abstract Background Pasteurella multocida is responsible for a highly infectious and contagious disease in birds, leading to heavy economic losses in the chicken industry. However, the pathogenesis of this disease is poorly understood. We recently identified an aspartate ammonia-lyase (aspA) in P. multocida that was significantly upregulated under iron-restricted conditions, the protein of which could effectively protect chicken flocks against P. multocida. However, the functions of this gene remain unclear. In the present study, we constructed aspA mutant strain △aspA::kan and complementary strain C△aspA::kan to investigate the function of aspA in detail. Result Deletion of the aspA gene in P. multocida resulted in a significant reduction in bacterial growth in LB (Luria-Bertani) and MH (Mueller-Hinton) media, which was rescued by supplementation with 20 mM fumarate. The mutant strain △aspA::kan showed significantly growth defects in anaerobic conditions and acid medium, compared with the wild-type strain. Moreover, growth of △aspA::kan was more seriously impaired than that of the wild-type strain under iron-restricted conditions, and this growth recovered after supplementation with iron ions. AspA transcription was negatively regulated by iron conditions, as demonstrated by quantitative reverse transcription-polymerase chain reaction. Although competitive index assay showed the wild-type strain outcompetes the aspA mutant strain and △aspA::kan was significantly more efficient at producing biofilms than the wild-type strain, there was no significant difference in virulence between the mutant and the wild-type strains. Conclusion These results demonstrate that aspA is required for bacterial growth in complex medium, and under anaerobic, acid, and iron-limited conditions.

A Stable 44S Intermediate in the Autodigestion of 50S Ribosomal Subunits

1971 ◽  
Vol 29 ◽  
pp. 430-431
Author(s):  
John H. Nisbet ◽  
Henry S. Slayter
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Ribosomal Rna ◽  
Gel Electrophoresis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Ribosomal Subunit ◽  
Wild Type ◽  
Ribosomal Subunits ◽  
Type Strains

Wild - type strains of Escherichia coli are known to contain as many as four endogenous nucleases (Ref. 1). These are commonly found associated with the ribosomes after extraction from the cell, but may be removed, with the exception of RNase IV, by washing the ribosomes in NH4Cl (at 0.2 M and higher concentrations). We have examined the effect of these nucleases on the 50S ribosomal subunit of one wild-type strain, K12 (Hfr 3000), by incubating the unwashed particles at 37° in the presence of varying magnesium concentrations.At 10-4 molar magnesium (slower at 10-3 molar), the 50S particle is converted to a species sedimenting at about 44S. About 20% of the total O.D260 is liberated at the same time. Continued incubation leads to the release of more O.D260 material while the RNA remaining in the 44S (Fig. 1) particle is progressively cleaved, eventually to the point where it consists of one principal fragment of molecular weight 0.42 x 106 daltons and several lesser fragments. The ribosomal RNA and proteins have been characterized by acrylamide gel electrophoresis.

scholarly journals The Secreted Esterase of Propionibacterium freudenreichii Has a Major Role in Cheese Lipolysis

2013 ◽  
Vol 80 (2) ◽  
pp. 751-756 ◽  
Author(s):  
María Claudia Abeijón Mukdsi ◽  
Hélène Falentin ◽  
Marie-Bernadette Maillard ◽  
Victoria Chuat ◽  
Roxana Beatriz Medina ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Type Strain ◽  
Wild Type Strain ◽  
Lipolytic Activity ◽  
Premature Stop Codon ◽  
Propionibacterium Freudenreichii ◽  
Wild Type ◽  
Swiss Cheese ◽  
Content Type ◽  
Type Strains

ABSTRACTFree fatty acids are important flavor compounds in cheese.Propionibacterium freudenreichiiis the main agent of their release through lipolysis in Swiss cheese. Our aim was to identify the esterase(s) involved in lipolysis byP. freudenreichii. We targeted two previously identified esterases: one secreted esterase, PF#279, and one putative cell wall-anchored esterase, PF#774. To evaluate their role in lipolysis, we constructed overexpression and knockout mutants ofP. freudenreichiiCIRM-BIA1Tfor each corresponding gene. The sequences of both genes were also compared in 21 wild-type strains. All strains were assessed for their lipolytic activity on milk fat. The lipolytic activity observed matched data previously reported in cheese, thus validating the relevance of the method used. The mutants overexpressing PF#279 or PF#774 released four times more fatty acids than the wild-type strain, demonstrating that both enzymes are lipolytic esterases. However, inactivation of thepf279gene induced a 75% reduction in the lipolytic activity compared to that of the wild-type strain, whereas inactivation of thepf774gene did not modify the phenotype. Two of the 21 wild-type strains tested did not display any detectable lipolytic activity. Interestingly, these two strains exhibited the same single-nucleotide deletion at the beginning of thepf279gene sequence, leading to a premature stop codon, whereas they harbored apf774gene highly similar to that of the other strains. Taken together, these results clearly demonstrate that PF#279 is the main lipolytic esterase inP. freudenreichiiand a key agent of Swiss cheese lipolysis.

scholarly journals Functional Analysis of preA in Aeromonas veronii TH0426 Reveals a Key Role in the Regulation of Virulence and Resistance to Oxidative Stress

2019 ◽  
Vol 21 (1) ◽  
pp. 98
Author(s):  
Bintong Yang ◽  
Haichao Song ◽  
Dingjie An ◽  
Dongxing Zhang ◽  
Sayed Haidar Abbas Raza ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Type Strain ◽  
Wild Type Strain ◽  
Lethal Dose ◽  
Tolerance Test ◽  
Economic Losses ◽  
Cytotoxicity Test ◽  
Test Results ◽  
Wild Type ◽  
Aeromonas Veronii

Aeromonas veronii is one of the main pathogens causing freshwater fish sepsis and ulcer syndrome. This bacterium has caused serious economic losses in the aquaculture industry worldwide, and it has become an important zoonotic and aquatic agent. However, little is known about the molecular mechanism of pathogenesis of A. veronii. In this study, we first constructed an unmarked mutant strain (ΔpreA) by generating an in-frame deletion of the preA gene, which encodes a periplasmic binding protein, to investigate its role in A. veronii TH0426. Our results showed that the motility and biofilm formation ability of ΔpreA were similar to those of the wild-type strain. However, the adhesion and invasion ability in epithelioma papulosum cyprini (EPC) cells were significantly enhanced (2.0-fold). Furthermore, the median lethal dose (LD50) of ΔpreA was 7.6-fold higher than that of the wild-type strain, which illustrates that the virulence of the mutant was significantly enhanced. This finding is also supported by the cytotoxicity test results, which showed that the toxicity of ΔpreA to EPC cells was enhanced 1.3-fold relative to the wild type. Conversely, tolerance test results showed that oxidative stress resistance of ΔpreA decreased 5.9-fold compared to with the wild-type strain. The results suggest that preA may negatively regulate the virulence of A. veronii TH0426 through the regulation of resistance to oxidative stress. These insights will help to further elucidate the function of preA and understand the pathogenesis of A. veronii.

scholarly journals The BfeR Regulator Mediates Enterobactin-Inducible Expression of Bordetella Enterobactin Utilization Genes

2004 ◽  
Vol 186 (21) ◽  
pp. 7302-7311 ◽  
Author(s):  
Mark T. Anderson ◽  
Sandra K. Armstrong
Keyword(s):  
Wild Type Strain ◽  
Transcriptional Regulator ◽  
Sole Source ◽  
Bordetella Bronchiseptica ◽  
Transcriptional Analysis ◽  
Respiratory Pathogens ◽  
Wild Type ◽  
Outer Membrane Receptor ◽  
Reading Frame ◽  
Type Strains

ABSTRACT Utilization of the enterobactin siderophore by the respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica is dependent on the BfeA outer membrane receptor. This study determined that production of BfeA was increased significantly in iron-starved bacteria upon supplementation of cultures with enterobactin. A 1.01-kb open reading frame, designated bfeR, encoding a predicted positive transcriptional regulator of the AraC family was identified upstream and divergently oriented from bfeA. In iron-depleted cultures containing enterobactin, a Bordetella bfeR mutant exhibited markedly decreased BfeA receptor production compared to that of the wild-type strain. Additionally, B. pertussis and B. bronchiseptica bfeR mutants exhibited impaired growth with ferric enterobactin as the sole source of iron, demonstrating that effective enterobactin utilization is bfeR dependent. Transcriptional analysis using bfeA-lacZ reporter fusions in wild-type strains demonstrated that bfeA transcription was stimulated in iron-depleted conditions in the presence of enterobactin, compared to modest expression levels in cultures lacking enterobactin. In contrast, bfeA transcription in B. pertussis and B. bronchiseptica bfeR mutants was completely unresponsive to the enterobactin inducer. bfeA transcriptional analyses of a bfeA mutant demonstrated that induction by enterobactin did not require BfeA receptor-mediated uptake of the siderophore. These studies establish that bfeR encodes an enterobactin-dependent positive regulator of bfeA transcription in these Bordetella species.

scholarly journals Diffusible Signal Factor–Repressed Extracellular Traits Enable Attachment of Xylella fastidiosa to Insect Vectors and Transmission

2014 ◽  
Vol 104 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Clelia Baccari ◽  
Nabil Killiny ◽  
Michael Ionescu ◽  
Rodrigo P. P. Almeida ◽  
Steven E. Lindow
Keyword(s):  
Type Strain ◽  
Host Plants ◽  
Wild Type Strain ◽  
Culture Supernatant ◽  
Culture Media ◽  
Xylella Fastidiosa ◽  
Xylem Sap ◽  
Wild Type ◽  
Diffusible Signal Factor ◽  
Type Strains

The hypothesis that a wild-type strain of Xylella fastidiosa would restore the ability of rpfF mutants blocked in diffusible signal factor production to be transmitted to new grape plants by the sharpshooter vector Graphocephala atropunctata was tested. While the rpfF mutant was very poorly transmitted by vectors irrespective of whether they had also fed on plants infected with the wild-type strain, wild-type strains were not efficiently transmitted if vectors had fed on plants infected with the rpfF mutant. About 100-fewer cells of a wild-type strain attached to wings of a vector when suspended in xylem sap from plants infected with an rpfF mutant than in sap from uninfected grapes. The frequency of transmission of cells suspended in sap from plants that were infected by the rpfF mutant was also reduced over threefold. Wild-type cells suspended in a culture supernatant of an rpfF mutant also exhibited 10-fold less adherence to wings than when suspended in uninoculated culture media. A factor released into the xylem by rpfF mutants, and to a lesser extent by the wild-type strain, thus inhibits their attachment to, and thus transmission by, sharpshooter vectors and may also enable them to move more readily through host plants.

scholarly journals The Role of Ethylene Production in Virulence of Pseudomonas syringae pvs. glycinea and phaseolicola

2001 ◽  
Vol 91 (5) ◽  
pp. 511-518 ◽  
Author(s):  
Helge Weingart ◽  
Henriette Ullrich ◽  
Klaus Geider ◽  
Beate Völksch
Keyword(s):  
Pseudomonas Syringae ◽  
Ethylene Production ◽  
Type Strain ◽  
Wild Type Strain ◽  
Wild Type ◽  
In Planta ◽  
Population Sizes ◽  
Soybean Plants ◽  
Type Strains

The importance of ethylene production for virulence of Pseudomonas syringae pvs. glycinea and phaseolicola was assayed by comparing bacterial multiplication and symptom development in bean and soybean plants inoculated with ethylene-negative (efe) mutants and wild-type strains. The efe mutants of Pseudomonas syringae pv. glycinea were significantly reduced in their ability to grow in planta. However, the degree of reduction was strain-dependent. Population sizes of efe mutant 16/83-E1 that did not produce the phototoxin coronatine were 10- and 15-fold lower than those of the wild-type strain on soybean and on bean, and 16/83-E1 produced very weak symptoms compared with the wild-type strain. The coronatine-producing efe mutant 7a/90-E1 reached fourfold and twofold lower population sizes compared with the wild-type strain on soybean and bean, respectively, and caused disease symptoms typical of the wild-type strain. Experiments with ethylene-insensitive soybeans confirmed these results. The virulence of the wild-type strains was reduced to the same extent in ethylene-insensitive soybean plants as the virulence of the efe mutants in ethylene-susceptible soybeans. In contrast, the virulence of Pseudomonas syringae pv. phaseolicola was not affected by disruption of the efe gene.

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