scholarly journals A Sclerotinia sclerotiorum Transcription Factor Involved in Sclerotial Development and Virulence on Pea

mSphere ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Hyunkyu Sang ◽  
Hao-Xun Chang ◽  
Martin I. Chilvers
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Sclerotinia Sclerotiorum ◽  
Culture Medium ◽  
Expression Patterns ◽  
White Mold ◽  
In Planta ◽  
Content Type ◽  
Sclerotial Development

ABSTRACT Sclerotinia sclerotiorum is a plant-pathogenic ascomycete fungus and infects over 400 host plants, including pea (Pisum sativum L.). The fungus causes white mold on pea, and substantial yield loss is attributed to the disease. To improve white mold management, further understanding of S. sclerotiorum pathogenicity is crucial. In this study, 389 transcription factors (TFs) were mined from the complete genome sequence of S. sclerotiorum and their in planta expression patterns were determined in susceptible and partially resistant pea lines and compared to in vitro expression patterns on culture medium. One of the transcription factors was significantly induced in planta at 24 and 48 h postinfection compared to the expression in vitro. This putative C6 transcription factor of S. sclerotiorum (SsC6TF1) was knocked down using a gene-silencing approach to investigate its functions in vegetative growth and sclerotial development as well as its virulence and pathogenicity in pea. While the SsC6TF1 knockdown mutants had hyphal growth rates identical to those of the wild-type strain and were capable of infection, the knockdown mutants produced no sclerotia or significantly fewer and smaller sclerotia on the culture medium and exhibited reduced virulence on both pea lines. This study profiled genome-wide expression for S. sclerotiorum transcription factors in planta and in vitro and functionally characterized a novel transcription factor, SsC6TF1, which positively regulates sclerotial development and virulence on pea. The finding provides molecular insights into S. sclerotiorum biology and interaction with pea and other economically important crops. IMPORTANCE White mold, caused by Sclerotinia sclerotiorum, is a destructive disease on important legume species such as soybean, dry bean, and pea. This study investigated expression levels of transcription factors in S. sclerotiorum in planta (pea lines) and in vitro (culture medium). One transcription factor displaying high expression in planta was found to be involved in sclerotial development and virulence on pea. This report provides a new understanding regarding transcription factors of S. sclerotiorum in development and virulence.

scholarly journals Expression of Adhesive Pili and the Collagen-Binding Adhesin Ace Is Activated by ArgR Family Transcription Factors inEnterococcus faecalis

2018 ◽  
Vol 200 (18) ◽  
Author(s):  
Dawn A. Manias ◽  
Gary M. Dunny
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Enterococcus Faecalis ◽  
Opportunistic Infections ◽  
Structural Genes ◽  
Gene Encoding ◽  
Collagen Binding ◽  
Content Type ◽  
Surface Adhesins

ABSTRACTIt was shown previously that the disruption of theahrCgene encoding a predicted ArgR family transcription factor results in a severe defect in biofilm formationin vitro, as well as a significant attenuation of virulence ofEnterococcus faecalisstrain OG1RF in multiple experimental infection models. Using transcriptome sequencing (RNA-seq), we observedahrC-dependent changes in the expression of more than 20 genes. AhrC-repressed genes included predicted determinants of arginine catabolism and several other metabolic genes and predicted transporters, while AhrC-activated genes included determinants involved in the production of surface protein adhesins. Most notably, the structural and regulatory genes of theebplocus encoding adhesive pili were positively regulated, as well as theacegene, encoding a collagen-binding adhesin. UsinglacZtranscription reporter fusions, we determined thatahrCand a secondargRtranscription factor gene,argR2, both function to activate the expression ofebpR, which directly activates the transcription of the pilus structural genes. Our data suggest that in the wild-typeE. faecalis, the low levels of EbpR limit the expression of pili and that biofilm biomass is also limited by the amount of pili expressed by the bacteria. The expression ofaceis similarly enhanced by AhrC and ArgR2, butaceexpression is not dependent on EbpR. Our results demonstrate the existence of novel regulatory cascades controlled by a pair of ArgR family transcription factors that might function as a heteromeric protein complex.IMPORTANCECell surface adhesins play critical roles in the formation of biofilms, host colonization, and the pathogenesis of opportunistic infections byEnterococcus faecalis. Here, we present new results showing that the expression of two major enterococcal surface adhesins,ebppili, and the collagen-binding protein Ace is positively regulated at the transcription level by twoargRfamily transcription factors, AhrC and ArgR2. In the case of pili, the direct target of regulation is theebpRgene, previously shown to activate the transcription of the pilus structural genes, while the activation ofacetranscription appears to be directly impacted by the two ArgR proteins. These transcription factors may represent new targets for blocking enterococcal infections.

scholarly journals Transfection of Sclerotinia sclerotiorum withIn VitroTranscripts of a Naturally Occurring Interspecific Recombinant of Sclerotinia sclerotiorum Hypovirus 2 Significantly Reduces Virulence of the Fungus

2015 ◽  
Vol 89 (9) ◽  
pp. 5060-5071 ◽  
Author(s):  
Shin-Yi Lee Marzano ◽  
Houston A. Hobbs ◽  
Berlin D. Nelson ◽  
Glen L. Hartman ◽  
Darin M. Eastburn ◽  
...  
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Plant Pathogens ◽  
High Throughput Sequencing ◽  
Infectious Clone ◽  
White Mold ◽  
Content Type ◽  
Fungal Plant Pathogens ◽  
Rapid Amplification ◽  
Valsa Ceratosperma

ABSTRACTA recombinant strain ofSclerotinia sclerotiorumhypovirus 2 (SsHV2) was identified from a North AmericanSclerotinia sclerotiorumisolate (328) from lettuce (Lactuca sativaL.) by high-throughput sequencing of total RNA. The 5′- and 3′-terminal regions of the genome were determined by rapid amplification of cDNA ends. The assembled nucleotide sequence was up to 92% identical to two recently reported SsHV2 strains but contained a deletion near its 5′ terminus of more than 1.2 kb relative to the other SsHV2 strains and an insertion of 524 nucleotides (nt) that was distantly related toValsa ceratospermahypovirus 1. This suggests that the new isolate is a heterologous recombinant of SsHV2 with a yet-uncharacterized hypovirus. We named the new strainSclerotinia sclerotiorumhypovirus 2 Lactuca (SsHV2L) and deposited the sequence in GenBank with accession numberKF898354.Sclerotinia sclerotiorumisolate 328 was coinfected with a strain ofSclerotinia sclerotiorumendornavirus 1 and was debilitated compared to cultures of the same isolate that had been cured of virus infection by cycloheximide treatment and hyphal tipping. To determine whether SsHV2L alone could induce hypovirulence inS. sclerotiorum, a full-length cDNA of the 14,538-nt viral genome was cloned. Transcripts corresponding to the viral RNA were synthesizedin vitroand transfected into a virus-free isolate ofS. sclerotiorum, DK3. Isolate DK3 transfected with SsHV2L was hypovirulent on soybean and lettuce and exhibited delayed maturation of sclerotia relative to virus-free DK3, completing Koch's postulates for the association of hypovirulence with SsHV2L.IMPORTANCEA cosmopolitan fungus,Sclerotinia sclerotioruminfects more than 400 plant species and causes a plant disease known as white mold that produces significant yield losses in major crops annually. Mycoviruses have been used successfully to reduce losses caused by fungal plant pathogens, but definitive relationships between hypovirus infections and hypovirulence inS. sclerotiorumwere lacking. By establishing a cause-and-effect relationship betweenSclerotinia sclerotiorumhypovirus Lactuca (SsHV2L) infection and the reduction in host virulence, we showed direct evidence that hypoviruses have the potential to reduce the severity of white mold disease. In addition to intraspecific recombination, this study showed that recent interspecific recombination is an important factor shaping viral genomes. The construction of an infectious clone of SsHV2L allows future exploration of the interactions between SsHV2L andS. sclerotiorum, a widespread fungal pathogen of plants.

scholarly journals Information-dependent Enrichment Analysis Reveals Time-dependent Transcriptional Regulation of the Estrogen Pathway of Toxicity

2016 ◽  
Author(s):  
Salil N. Pendse ◽  
Alexandra Maertens ◽  
Michael Rosenberg ◽  
Dipanwita Roy ◽  
Rick A. Fasani ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcription Factors ◽  
Expression Patterns ◽  
Enrichment Analysis ◽  
Fold Change ◽  
Gene Set Enrichment Analysis ◽  
High Dose ◽  
Functional Responses ◽  
Pathways Of Toxicity

The twenty-first century vision for toxicology involves a transition away from high-dose animal studies and into in vitro and computational models. This movement requires mapping pathways of toxicity through an understanding of how in vitro systems respond to chemical perturbation. Uncovering transcription factors responsible for gene expression patterns is essential for defining pathways of toxicity, and ultimately, for determining chemical mode of action, through which a toxicant acts. Traditionally this is achieved via chromatin immunoprecipitation studies and summarized by calculating, which transcription factors are statistically associated with the up- and down-regulated genes. These lists are commonly determined via statistical or fold-change cutoffs, a procedure that is sensitive to statistical power and may not be relevant to determining transcription factor associations. To move away from an arbitrary statistical or fold-change based cutoffs, we have developed in the context of the Mapping the Human Toxome project, a novel enrichment paradigm called Information Dependent Enrichment Analysis (IDEA) to guide identification of the transcription factor network. We used the test case of endocrine disruption of MCF-7 cells activated by 17β estradiol (E2). Using this new approach, we were able to establish a time course for transcriptional and functional responses to E2. ERα and ERβ are associated with short-term transcriptional changes in response to E2. Sustained exposure leads to the recruitment of an additional ensemble of transcription factors and alteration of cell-cycle machinery. TFAP2C and SOX2 were the transcription factors most highly correlated with dose. E2F7, E2F1 and Foxm1, which are involved in cell proliferation, were enriched only at 24h. IDEA is, therefore, a novel tool to identify candidate pathways of toxicity, clearly outperforming Gene-set Enrichment Analysis but with similar results as Weighted Gene Correlation Network Analysis, which helps to identify genes not annotated to pathways.

scholarly journals White Mold on Pea Caused by Sclerotinia sclerotiorum: A New Threat for Pea Cultivation in Bangladesh

2020 ◽  
Author(s):  
Md. Rabiul Islam ◽  
Ananya Prova ◽  
Md. Tanbir Rubayet ◽  
Md. Mahidul Islam Masum ◽  
Md. Motaher Hossain
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Foliar Application ◽  
Management Strategies ◽  
Carbon Sources ◽  
Hyphal Growth ◽  
White Mold ◽  
In Planta ◽  
Severity Rating ◽  
Internal Transcribed Spacer Sequences ◽  
Sclerotial Development

A new disease causing the tan to light brown blighted stems and pods has occurred in 2.6% pea (Pisum sativum L.) plants with an average disease severity rating of 3.7 in Chapainawabganj district, Bangladesh. A fungus with white appressed mycelia and large sclerotia was consistently isolated from symptomatic tissues. The fungus formed funnel-shaped apothecia with sac-like ascus and endogenously formed ascospores. Healthy pea plants inoculated with the fungus produced typical white mold symptoms. The internal transcribed spacer sequences of the fungus were 100% similar to that recovered from an epitype of Sclerotinia sclerotiorum, considering the fungus to be the causative agent of white mold. Mycelial growth and sclerotial development of S. sclerotiorum were favored at 20°C and pH 5.0. Glucose was the best carbon sources to support hyphal growth and sclerotia formation. Bavistin and Amistar Top inhibited the radial growth of the fungus completely at the lowest concentration. In planta, foliar application of Amistar Top showed the considerable potential to control the disease at 1.0% concentration until 7 days after spraying, while Bavistin prevented infection significantly until 15 days after spraying. A large majority (70.93%) of genotypes including tested released pea cultivars were susceptible, while six genotypes (6.98%) appeared resistant to the disease. These results could be important for management strategies aiming to control the incidence of S. Sclerotinia and eliminate yield loss in pea.

Subnuclear compartmentalization of sequence-specific transcription factors and regulation of eukaryotic gene expression

2005 ◽  
Vol 83 (4) ◽  
pp. 535-547 ◽  
Author(s):  
Gareth N Corry ◽  
D Alan Underhill
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Transcriptional Activation ◽  
Current Knowledge ◽  
Nuclear Architecture ◽  
Subnuclear Localization ◽  
Modular Structures

To date, the majority of the research regarding eukaryotic transcription factors has focused on characterizing their function primarily through in vitro methods. These studies have revealed that transcription factors are essentially modular structures, containing separate regions that participate in such activities as DNA binding, protein–protein interaction, and transcriptional activation or repression. To fully comprehend the behavior of a given transcription factor, however, these domains must be analyzed in the context of the entire protein, and in certain cases the context of a multiprotein complex. Furthermore, it must be appreciated that transcription factors function in the nucleus, where they must contend with a variety of factors, including the nuclear architecture, chromatin domains, chromosome territories, and cell-cycle-associated processes. Recent examinations of transcription factors in the nucleus have clarified the behavior of these proteins in vivo and have increased our understanding of how gene expression is regulated in eukaryotes. Here, we review the current knowledge regarding sequence-specific transcription factor compartmentalization within the nucleus and discuss its impact on the regulation of such processes as activation or repression of gene expression and interaction with coregulatory factors.Key words: transcription, subnuclear localization, chromatin, gene expression, nuclear architecture.

scholarly journals Arsenic Directly Binds to and Activates the Yeast AP-1-Like Transcription Factor Yap8

2015 ◽  
Vol 36 (6) ◽  
pp. 913-922 ◽  
Author(s):  
Nallani Vijay Kumar ◽  
Jianbo Yang ◽  
Jitesh K. Pillai ◽  
Swati Rawat ◽  
Carlos Solano ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Transcriptional Activation ◽  
Transcriptional Response ◽  
Transcriptional Regulator ◽  
Yeast Protein ◽  
Content Type ◽  
Arsenic Tolerance ◽  
Arsenic Sensing

The AP-1-like transcription factor Yap8 is critical for arsenic tolerance in the yeastSaccharomyces cerevisiae. However, the mechanism by which Yap8 senses the presence of arsenic and activates transcription of detoxification genes is unknown. Here we demonstrate that Yap8 directly binds to trivalent arsenite [As(III)]in vitroandin vivoand that approximately one As(III) molecule is bound per molecule of Yap8. As(III) is coordinated by three sulfur atoms in purified Yap8, and our genetic and biochemical data identify the cysteine residues that form the binding site as Cys132, Cys137, and Cys274. As(III) binding by Yap8 does not require an additional yeast protein, and Yap8 is regulated neither at the level of localization nor at the level of DNA binding. Instead, our data are consistent with a model in which a DNA-bound form of Yap8 acts directly as an As(III) sensor. Binding of As(III) to Yap8 triggers a conformational change that in turn brings about a transcriptional response. Thus, As(III) binding to Yap8 acts as a molecular switch that converts inactive Yap8 into an active transcriptional regulator. This is the first report to demonstrate how a eukaryotic protein couples arsenic sensing to transcriptional activation.

scholarly journals Biocontrol of Sclerotinia sclerotiorum and white mold of soybean using saprobic fungi from semi-arid areas of Northeastern Brazil

2015 ◽  
Vol 41 (4) ◽  
pp. 251-255 ◽  
Author(s):  
Daiane Cristina Martins Barros ◽  
Inês Cristina de Batista Fonseca ◽  
Maria Isabel Balbi-Peña ◽  
Sérgio Florentino Pascholati ◽  
Douglas Casaroto Peitl
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Culture Medium ◽  
Antagonistic Effect ◽  
Northeastern Brazil ◽  
White Mold ◽  
Lesion Length ◽  
Fungal Culture ◽  
Saprobic Fungi ◽  
Previously Treated

ABSTRACTThe incidence and the levels of yield loss caused by the white mold of soybean (caused by the fungus Sclerotinia sclerotiorum) have increased in areas of higher altitude at Cerrado and Southern Brazil, causing yield losses of up to 60%. The aim of this study was to select saprobic fungi with the potential to control the white mold of soybean. First, in vitroantagonism screening was carried out to test eight saprobic fungi against S. sclerotiorum. Assessment of S. sclerotiorum mycelial growth was done at four and seven days after its placement on the culture medium. The isolate showing greatest antagonistic effect in all tests/assessments was Myrothecium sp. An in vivo experiment was conducted in a greenhouse and growth chamber, where plants previously treated with eight saprobic fungi were artificially inoculated with S. sclerotiorum. The fungal culture medium (potato-dextrose) and the commercial resistance inducer acibenzolar-S-methyl were used as controls. In the in vivotests, severity of the white mold was assessed at 8, 14 and 21 days after inoculation. The highest reduction percentage in the lesion length was observed for the treatment with Myrothecium sp. (70%), which has the greater potential to be used as biocontrol agent of soybean under the conditions of this experiment.

scholarly journals Selection of Trichoderma spp. strains for the control of Sclerotinia sclerotiorum in soybean

2017 ◽  
Vol 52 (12) ◽  
pp. 1140-1148 ◽  
Author(s):  
Patrícia Elias Haddad ◽  
Luis Garrigós Leite ◽  
Cleusa Maria Mantovanello Lucon ◽  
Ricardo Harakava
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Culture Medium ◽  
Harmful Effect ◽  
Soybean Seeds ◽  
Trichoderma Spp ◽  
Negative Effect ◽  
Soybean Plants ◽  
Selection Of

Abstract: The objective of this work was to evaluate, in vitro and in vivo, the potential of Trichoderma spp. strains to control Sclerotinia sclerotiorum in soybeans (Glycine max) and to perform the molecular identification of the best perfoming strains. The effect of 120 strains of Trichoderma spp. on the viability of S. sclerotiorum sclerotia was evaluated in vitro through immersion in suspension of conidia from the antagonists and plating in culture medium. The best performing strains were evaluated in vivo, in a greenhouse, for control of the pathogen inoculated on 'Pintado' soybean seeds and plants. Of the 120 strains tested in vitro, 22 strains of Trichoderma spp. caused 100% inhibition of sclerotia germination. In the greenhouse, five strains inhibited the negative effect of the pathogen on seed germination and two strains increased in up to 67% plant dry matter. The best performing strains were identified as T. koningiopsis (3 strains), T. asperelloides (3), T. atroviride (2), and T. virens (1). Trichoderma strains are able to protect soybean plants from the harmful effect of S. sclerotiorum and, at the same time, they can promote the growth of the aerial part in greenhouse conditions.

scholarly journals Transcription Factor Lbx1 Expression in Mouse Embryonic Stem Cell-Derived Phenotypes

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Stefanie Schmitteckert ◽  
Cornelia Ziegler ◽  
Liane Kartes ◽  
Alexandra Rolletschek
Keyword(s):  
Transcription Factor ◽  
Developmental Stages ◽  
Troponin T ◽  
Es Cells ◽  
Expression Patterns ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cell ◽  
Cardiac Cells ◽  
Cell Stage

Transcription factor Lbx1 is known to play a role in the migration of muscle progenitor cells in limb buds and also in neuronal determination processes. In addition, involvement of Lbx1 in cardiac neural crest-related cardiogenesis was postulated. Here, we used mouse embryonic stem (ES) cells which have the capacity to develop into cells of all three primary germ layers. Duringin vitrodifferentiation, ES cells recapitulate cellular developmental processes and gene expression patterns of early embryogenesis. Transcript analysis revealed a significant upregulation ofLbx1at the progenitor cell stage. Immunofluorescence staining confirmed the expression of Lbx1 in skeletal muscle cell progenitors and GABAergic neurons. To verify the presence of Lbx1 in cardiac cells, triple immunocytochemistry of ES cell-derived cardiomyocytes and a quantification assay were performed at different developmental stages. Colabeling of Lbx1 and cardiac specific markers troponin T, α-actinin, GATA4, and Nkx2.5 suggested a potential role in early myocardial development.

scholarly journals Expression of the ToxA and PtrPf2 genes of the phytopathogenic fungus Pyrenophora tritici-repentis at the beginning of the infection process

2019 ◽  
Author(s):  
Nina V. Mironenko ◽  
Alexandra S. Orina ◽  
Nadezhda M. Kovalenko
Keyword(s):  
Transcription Factor ◽  
Wheat Variety ◽  
Infection Process ◽  
Phytopathogenic Fungus ◽  
In Planta ◽  
Effector Gene ◽  
Pyrenophora Tritici Repentis ◽  
Wheat Leaves ◽  
Necrotrophic Effector

This study shows that the necrotrophic effector gene ToxA is differentially expressed in isolates of P. tritici-repentis fungus at different time periods after inoculation of the wheat variety Glenlea which has the gene Tsn1 controlling sensitivity to the necrosis inducing toxin Ptr ToxA. Two P. tritici-repentis isolates with different ability to cause necrosis on the leaves of Glenlea variety (nec + and nec-) and with different expression level of ToxA and gene of factor transcription PtrPf2 in vitro were used for analysis. Isolates of P. tritici-repentis are characterized by the differential expression of ToxA in planta. The expression of the ToxA gene in P. tritici-repentis ToxA+ isolates significantly increased when infected the wheat leaves compared to ToxA expression results obtained in vitro. The levels of ToxA expression in both isolates differed significantly after 24, 48 and 96 hours after inoculation, however, the dynamics of the trait change over time were similar. However, the highest ToxA expression in the virulent (nec+) isolate in contrast with the avirulent (nec-) isolate was observed at a point of 48 hours. Whereas the expression of regulating transcription factor PtrPf2 in planta differed imperceptibly from expression in vitro throughout the observation period. Obviously, the role of the fungal transcription factor in regulating the effector gene expression weakens in planta, and other mechanisms regulating the expression of pathogen genes at the biotrophic stage of the disease develop.

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