Colletotrichum orbiculare MTF4 Is a Key Transcription Factor Downstream of MOR Essential for Plant Signal-Dependent Appressorium Development and Pathogenesis

2019 ◽  
Vol 32 (3) ◽  
pp. 313-324 ◽  
Author(s):  
Sayo Kodama ◽  
Takumi Nishiuchi ◽  
Yasuyuki Kubo
Keyword(s):  
Transcription Factor ◽  
In Planta ◽  
Colletotrichum Orbiculare ◽  
Appressorium Formation ◽  
Constitutive Overexpression ◽  
Plant Signals ◽  
Biochemical Signals ◽  
Kinase Pathway ◽  
Appressorium Development

The cucumber anthracnose fungus Colletotrichum orbiculare forms a specialized infection structure, called an appressorium. Appressorium differentiation relies on fungal perception of physical and biochemical signals at the plant surface. Our previous report showed that the morphogenesis-related NDR (nuclear Dbf2-related) kinase pathway (MOR) is crucial for translating plant-derived signals for appressorium development. Here, we focused on identifying transcriptional regulators downstream of MOR that are involved in plant signal sensing and transduction for appressorium development. Based on whole-genome transcript profiling, we identified a Zn(II)2Cys6 transcription factor, CoMTF4, as a potential downstream factor of MOR. CoMTF4 was expressed in planta rather than in vitro under the control of the NDR kinase CoCbk1. Phenotypes of comtf4 mutants, strains with constitutively active CoCbk1 and strains with constitutive overexpression of CoMTF4 suggested that CoMtf4 acts downstream of MOR. Furthermore, nuclear localization of CoMtf4 was dependent on the MOR and responsive to plant-derived signals that lead to appressorium morphogenesis. Thus, we conclude that CoMtf4 is a transcription factor downstream of MOR that is essential for appressorium morphogenesis and pathogenesis and is regulated in response to plant-derived signals. This study provides insights into fungal sensing of plant signals and subsequent responses critical for appressorium formation.

scholarly journals Role for the Ran Binding Protein, Mog1p, in Saccharomyces cerevisiae SLN1-SKN7 Signal Transduction

2004 ◽  
Vol 3 (6) ◽  
pp. 1544-1556 ◽  
Author(s):  
Jade Mei-Yeh Lu ◽  
Robert J. Deschenes ◽  
Jan S. Fassler
Keyword(s):  
Signal Transduction ◽  
Transcription Factor ◽  
Osmotic Stress ◽  
Kinase Activity ◽  
Mitogen Activated Protein Kinase ◽  
Osmotic Response ◽  
Mitogen Activated Protein ◽  
Kinase Pathway

ABSTRACT Yeast Sln1p is an osmotic stress sensor with histidine kinase activity. Modulation of Sln1 kinase activity in response to changes in the osmotic environment regulates the activity of the osmotic response mitogen-activated protein kinase pathway and the activity of the Skn7p transcription factor, both important for adaptation to changing osmotic stress conditions. Many aspects of Sln1 function, such as how kinase activity is regulated to allow a rapid response to the continually changing osmotic environment, are not understood. To gain insight into Sln1p function, we conducted a two-hybrid screen to identify interactors. Mog1p, a protein that interacts with the yeast Ran1 homolog, Gsp1p, was identified in this screen. The interaction with Mog1p was characterized in vitro, and its importance was assessed in vivo. mog1 mutants exhibit defects in SLN1-SKN7 signal transduction and mislocalization of the Skn7p transcription factor. The requirement for Mog1p in normal localization of Skn7p to the nucleus does not fully account for the mog1-related defects in SLN1-SKN7 signal transduction, raising the possibility that Mog1p may play a role in Skn7 binding and activation of osmotic response genes.

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.

scholarly journals Different Regulation and Roles of Lactonases AiiB and AttM in Agrobacterium tumefaciens C58

2009 ◽  
Vol 22 (5) ◽  
pp. 529-537 ◽  
Author(s):  
Elise Haudecoeur ◽  
Mélanie Tannières ◽  
Amélie Cirou ◽  
Aurélie Raffoux ◽  
Yves Dessaux ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Selective Advantage ◽  
In Planta ◽  
Host Interaction ◽  
Plant Tumors ◽  
Plant Signals ◽  
Polymerase Chain ◽  
Agrobacterium Tumefaciens C58 ◽  
Regulated Functions

The phytopathogen Agrobacterium tumefaciens C58 expresses two lactonases, AttM and AiiB. We showed that expression of the aiiB gene was controlled by agrocinopines A and B and required the agrocinopine-ABC transporter Acc, but was not affected by the level of quorum-sensing (QS) signal 3-oxo-octanoylhomoserine lactone (OC8-HSL). In the presence of agrocinopines, a constructed aiiB mutant accumulated OC8-HSL at a level 10-fold higher than that of the wild-type strain, and showed an exacerbated expression of a key QS-regulated function, conjugation of Ti plasmid (in vitro and in planta), as well as an increase of the number of emerging tumors on the host plant. The expression and acyl-HSL-degrading activity of AttM were evident in the presence of wounded tissues; however, in unwounded plant tumors, the QS-regulated functions were weakly affected in an attM mutant. By contrast, we observed that attM conferred a selective advantage in the course of colonization of plant tumors. Finally, polymerase chain reaction survey of genes attM and aiiB showed that they were not strictly conserved in the genus Agrobacterium. This work proved that the lactonases AttM and AiiB are regulated by different plant signals and are implicated in different functions in the course of the A. tumefaciens C58–host interaction.

scholarly journals Regulation of Biosynthesis of Syringolin A, a Pseudomonas syringae Virulence Factor Targeting the Host Proteasome

2012 ◽  
Vol 25 (9) ◽  
pp. 1198-1208 ◽  
Author(s):  
Christina Ramel ◽  
Nando Baechler ◽  
Michel Hildbrand ◽  
Martin Meyer ◽  
David Schädeli ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Pseudomonas Syringae ◽  
Virulence Factor ◽  
Homoserine Lactone ◽  
Defined Medium ◽  
Lacz Gene ◽  
In Planta ◽  
Phytopathogenic Bacterium ◽  
Promoter Sequences

Many strains of the phytopathogenic bacterium Pseudomonas syringae pv. syringae synthesize the virulence factor syringolin A, which irreversibly inactivates the eukaryotic proteasome. Syringolin A, a peptide derivative, is synthesized by a mixed nonribosomal peptide/polyketide synthetase encoded by five clustered genes, sylA to sylE. Biosynthesis of syringolin A, previously shown to be dependent on the GacS/GacA two-component system, occurs in planta and in vitro but only under still culture conditions in a defined medium. Here, we show that the sylC, sylD, and sylE genes of P. syringae pv. syringae B301D-R form an operon transcribed by promoter sequences located between the sylCDE operon and the sylB gene residing on opposite strands. Assays of overlapping sylB and sylCDE promoter deletions translationally fused to the lacZ gene defined promoter sequences required for gene activity both in vitro and in planta. Activation of both promoters depended on the sylA gene encoding a helix-turn-helix (HTH) LuxR-type transcription factor which was shown to directly bind to the promoters. Activity of the sylA gene, in turn, required a functional salA gene, which also encodes an HTH LuxR-type transcription factor. Furthermore, evidence is presented that acyl-homoserine lactone-mediated quorum-sensing regulation is not involved in syringolin A biosynthesis but that oxygen concentration appears to play a role.

Studies on Graminicolous Species of Phyllachora Fckl. I. Ascospores - their liberation and germination

1963 ◽  
Vol 11 (2) ◽  
pp. 117 ◽  
Author(s):  
DG Parbery
Keyword(s):  
Spore Germination ◽  
Germ Tube ◽  
Leaf Surface ◽  
Individual Species ◽  
Appressorium Formation ◽  
Rain Splash ◽  
First Time ◽  
Germ Tubes ◽  
Appressorium Development

The process of ascospore liberation is a moderately active one. Discharged ascospores collect on the host leaf surface in white, glutinous masses and are believed to be dispersed by rain splash. Ascospores of all species examined germinated in 2-12 hr at 14°C under laboratory conditions, but there were indications that the process was more rapid in the field. The pattern for spore germination and appressorium formation was similar for the six species studied. Each ascospore produced a single germ tube which, in 2-6 hr after germination began, formed an appressorium initial in the form of a swelling at its apex. Appressoria were completely developed 6-12 hr later. The process of appressorium development is described for species of Phyllachora for the first time. The swelling at the apex of the germ tube extended back along the germ tube towards the ascspore. In some species, e.g. P. cornispora, the entire germ tube was converted into an appressorium which consequently was sessile. In other species, such as P. parilis, only approximately half of the germ tube developed into appressorium. In P. parilis, temperatures greater than 26°C inhibited appressorium formation. Instead of producing appressoria, germ tubes continued to grow and became long and flexuous. Germination did not occur at temperatures of 30°C or greater. Evidence suggested that while contact with a surface was not necessary to initiate appressorium formation, contact with a grass leaf surface was required for appressoria to develop normally. The morphology of appressoria of individual species of Phyllachora was usually variable when these structures developed in vitro but constant and distinct when they developed on the host. Among the species examined three basic morphological types of appressoria were recognized.

Homeobox transcription factor CoHox3 is essential for appressorium formation in the plant pathogenic fungus Colletotrichum orbiculare

Mycoscience ◽  
2018 ◽  
Vol 59 (5) ◽  
pp. 353-362 ◽  
Author(s):  
Aya Yokoyama ◽  
Kosuke Izumitsu ◽  
Takuya Sumita ◽  
Chihiro Tanaka ◽  
Toshikazu Irie ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Pathogenic Fungus ◽  
Colletotrichum Orbiculare ◽  
Appressorium Formation ◽  
Plant Pathogenic Fungus ◽  
Homeobox Transcription Factor

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.

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.

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