Crypt1, an active Ac-like transposon from the chestnut blight fungus, Cryphonectria parasitica

2001 ◽  
Vol 265 (4) ◽  
pp. 730-738 ◽  
Author(s):  
D. Linder-Basso ◽  
R. Foglia ◽  
P. Zhu ◽  
B.I. Hillman
Keyword(s):  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Chestnut Blight Fungus

scholarly journals Hard Mast Production Before and After the Chestnut Blight

2000 ◽  
Vol 24 (4) ◽  
pp. 196-201 ◽  
Author(s):  
Seth J. Diamond ◽  
Robert H. Giles ◽  
Roy L. Kirkpatrick ◽  
Gary J. Griffin
Keyword(s):  
Carrying Capacity ◽  
Basal Area ◽  
Cryphonectria Parasitica ◽  
Castanea Dentata ◽  
Chestnut Blight ◽  
Wildlife Species ◽  
Chestnut Blight Fungus ◽  
Southern Appalachian ◽  
Before And After ◽  
Mast Production

Abstract We estimated hard mast production of a Southern Appalachian forest for two 10 yr intervals: one before and one, 35 yr after, the chestnut blight fungus (Cryphonectria parasitica) (Murr.) Barr, had killed all mature chestnut trees. The basal area of hard mast-producing trees in the postblight forest was 28% less than in the preblight forest. The estimate of hard mast output was 34% less after the chestnut blight. Postblight production was less than preblight production for 8 of 10 yr. During 5 of these years, postblight production was only 5-27% of preblight production. Annual preblight mast production was relatively stable, whereas annual postblight production fluctuated substantially. Our findings suggest that the loss of mature chestnuts (Castanea dentata) markedly reduced the Southern Appalachian forest's carrying capacity for certain wildlife species. South. J. Appl. For 24(4):196-201.

scholarly journals Characterization of Hypovirus-Derived Small RNAs Generated in the Chestnut Blight Fungus by an Inducible DCL-2-Dependent Pathway

2008 ◽  
Vol 82 (6) ◽  
pp. 2613-2619 ◽  
Author(s):  
Xuemin Zhang ◽  
Gert C. Segers ◽  
Qihong Sun ◽  
Fuyou Deng ◽  
Donald L. Nuss
Keyword(s):  
Small Rnas ◽  
Rna Silencing ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Fungal Host ◽  
Chestnut Blight Fungus ◽  
Mutant Strains ◽  
Suppressor Of Rna Silencing ◽  
Dependent Pathway

ABSTRACT The disruption of one of two dicer genes, dcl-2, of the chestnut blight fungus Cryphonectria parasitica was recently shown to increase susceptibility to mycovirus infection (G. C. Segers, X. Zhang, F. Deng, Q. Sun, and D. L. Nuss, Proc. Natl. Acad. Sci. USA 104:12902-12906, 2007). We now report the accumulation of virus-derived small RNAs (vsRNAs) in hypovirus CHV1-EP713-infected wild-type and dicer gene dcl-1 mutant C. parasitica strains but not in hypovirus-infected dcl-2 mutant and dcl-1 dcl-2 double-mutant strains. The CHV1-EP713 vsRNAs were produced from both the positive and negative viral RNA strands at a ratio of 3:2 in a nonrandom distribution along the viral genome. We also show that C. parasitica responds to hypovirus and mycoreovirus infections with a significant increase (12- to 20-fold) in dcl-2 expression while the expression of dcl-1 is increased only modestly (2-fold). The expression of dcl-2 is further increased (∼35-fold) following infection with a hypovirus CHV1-EP713 mutant that lacks the p29 suppressor of RNA silencing. The combined results demonstrate the biogenesis of mycovirus-derived small RNAs in a fungal host through the action of a specific dicer gene, dcl-2. They also reveal that dcl-2 expression is significantly induced in response to mycovirus infection by a mechanism that appears to be repressed by the hypovirus-encoded p29 suppressor of RNA silencing.

scholarly journals Investigation of Host Range of and Host Defense against a Mitochondrially Replicating Mitovirus

2019 ◽  
Vol 93 (6) ◽  
Author(s):  
Sabitree Shahi ◽  
Ana Eusebio-Cope ◽  
Hideki Kondo ◽  
Bradley I. Hillman ◽  
Nobuhiro Suzuki
Keyword(s):  
Rna Polymerase ◽  
Host Range ◽  
Protoplast Fusion ◽  
Rna Silencing ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Rna Dependent Rna Polymerase ◽  
Content Type ◽  
Host Interactions ◽  
Chestnut Blight Fungus

ABSTRACT Mitoviruses (genus Mitovirus, family Narnaviridae) are mitochondrially replicating viruses that have the simplest positive-sense RNA genomes of 2.2 to 4.4 kb with a single open reading frame (ORF) encoding an RNA-dependent RNA polymerase. Cryphonectria parasitica mitovirus 1 (CpMV1) from U.S. strain NB631 of the chestnut blight fungus, Cryphonectria parasitica, was the first virus identified as a mitochondrially replicating virus. Despite subsequent discovery of many other mitoviruses from diverse fungi, no great advances in understanding mitovirus biology have emerged, partly because of the lack of inoculation methods. Here we developed a protoplast fusion-based protocol for horizontal transmission of CpMV1 that entailed fusion of recipient and donor protoplasts, hyphal anastomosis, and single-conidium isolation. This method allowed expansion of the host range to many other C. parasitica strains. Species within and outside the family Cryphonectriaceae, Cryphonectria radicalis and Valsa ceratosperma, also supported the replication of CpMV1 at a level comparable to that in the natural host. No stable maintenance of CpMV1 was observed in Helminthosporium victoriae. PCR-based haplotyping of virus-infected fungal strains confirmed the recipient mitochondrial genetic background. Phenotypic comparison between CpMV1-free and -infected isogenic strains revealed no overt effects of the virus. Taking advantage of the infectivity to the standard strain C. parasitica EP155, accumulation levels were compared among antiviral RNA silencing-proficient and -deficient strains in the EP155 background. Comparable accumulation levels were observed among these strains, suggesting the avoidance of antiviral RNA silencing by CpMV1, which is consistent with its mitochondrial replication. Collectively, the results of study provide a foundation to further explore the biology of mitoviruses. IMPORTANCE Capsidless mitoviruses, which are ubiquitously detected in filamentous fungi, have the simplest RNA genomes of 2.2 to 4.4 kb, encoding only RNA-dependent RNA polymerase. Despite their simple genomes, detailed biological characterization of mitoviruses has been hampered by their mitochondrial location within the cell, posing challenges to their experimental introduction and study. Here we developed a protoplast fusion-based protocol for horizontal transfer of the prototype mitovirus, Cryphonectria parasitica mitovirus 1 (CpMV1), which was isolated from strain NB631 of the chestnut blight fungus (Cryphonectria parasitica), a model filamentous fungus for studying virus-host interactions. The host range of CpMV1 has been expanded to many different strains of C. parasitica and different fungal species within and outside the Cryphonectriaceae. Comparison of CpMV1 accumulation among various RNA silencing-deficient and -competent strains showed clearly that the virus was unaffected by RNA silencing. This study provides a solid foundation for further exploration of mitovirus-host interactions.

scholarly journals Saprophytic Activity and Sporulation of Cryphonectria parasitica on Dead Chestnut Wood in Forests with Naturally Established Hypovirulence

2006 ◽  
Vol 96 (12) ◽  
pp. 1337-1344 ◽  
Author(s):  
S. Prospero ◽  
M. Conedera ◽  
U. Heiniger ◽  
D. Rigling
Keyword(s):  
Biological Control ◽  
Dead Wood ◽  
Transmission Rate ◽  
Virus Transmission ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Chestnut Blight Fungus ◽  
The Mean ◽  
Chestnut Wood

Sustainable biological control of the chestnut blight fungus Crypho-nectria parasitica with hypovirulence depends on the production and dissemination of hypovirus-infected propagules of the pathogen. We investigated the ability of C. parasitica to sporulate and produce hypo-virus-infected spores on recently dead chestnut wood in coppice stands in southern Switzerland where hypovirulence has been naturally established. The number and type (active, inactive, or none) of cankers was assessed on experimentally cut and stacked stems, firewood stacks, and natural dead wood. Hypovirus-free and hypovirus-infected strains readily survived for more than 1 year in the chestnut blight cankers of the stacked stems. Sporulation of C. parasitica was observed on the surface of preexisting inactive and active cankers, as well as on newly colonized bark areas and was significantly more abundant than on comparable cankers on living stems. On all types of dead wood, we observed more stromata with perithecia than with pycnidia; however, a large proportion of the stromata was not differentiated. All perithecia examined yielded only hypovirus-free ascospores. The incidence of pycnidia that produced hypovirus-infected conidia ranged from 5% on natural dead wood to 41% on the experimental stacks. The mean virus transmission rate into conidia was 69%. Our study demonstrates a considerable saprophytic activity of C. parasitica on recently dead chestnut wood and supports the hypothesis of a role of this saprophytic phase in the epidemiology of hypovirulence.

Comparative proteomic analysis of chestnut blight fungus,Cryphonectria parasitica, under tannic-acid-inducing and hypovirus-regulating conditions

2012 ◽  
Vol 58 (7) ◽  
pp. 863-871 ◽  
Author(s):  
Jung-Mi Kim ◽  
Jin-Ah Park ◽  
Dae-Hyuk Kim
Keyword(s):  
Tannic Acid ◽  
Proteomic Analysis ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Gene Products ◽  
Glutathione S Transferase ◽  
Chestnut Blight Fungus ◽  
Shock Proteins ◽  
Related Proteins ◽  
Hypothetical Genes

Chestnut blight fungus, Cryphonectria parasitica , and its hypovirus present a useful model system for investigating the mechanisms of hypoviral infection. To identify gene products associated with fungal pathogenicity and hypoviral regulation, we attempted a proteomic analysis of the virus-free EP155/2 strain and its isogenic virus-infected UEP1 strain in response to tannic acid (TA), which is abundant in the bark of chestnut trees. In this study, pretreatment of mycelia grown on TA-supplemented media was developed for proteomic analysis. Approximately 704 proteins from the mycelia of the EP155/2 strain were reproducibly present in 3 independent extractions. Among these, 111 and 79 spots were found to be responsive to hypovirus infection and TA supplementation, respectively. The TA-grown UEP1 strain yielded 28 spots showing an expression pattern different from that of untreated UEP1. Thirty protein spots showing considerable differences in spot density were selected for further analysis. Hybrid tandem LC-MS/MS spectrometry of the 30 selected protein spots revealed that 29 were identified while 1 was unidentified. Among the identified 29 proteins, 15 were metabolic enzymes; 5 were stress-related, of which 4 were heat-shock proteins and 1 was glutathione S-transferase; 5 were signaling and cellular process-related proteins; 2 were structural proteins; and 2 matched proteins of hypothetical genes.

scholarly journals Specific and Common Alterations in Host Gene Transcript Accumulation following Infection of the Chestnut Blight Fungus by Mild and Severe Hypoviruses

2004 ◽  
Vol 78 (8) ◽  
pp. 4145-4155 ◽  
Author(s):  
Todd D. Allen ◽  
Donald L. Nuss
Keyword(s):  
Transcriptional Response ◽  
Cryphonectria Parasitica ◽  
Chestnut Blight ◽  
Gene Transcript ◽  
Transcript Accumulation ◽  
Transcriptional Responses ◽  
Chestnut Blight Fungus ◽  
Reverse Transcription Pcr ◽  
Initial Assignment ◽  
Severe Isolate

ABSTRACT We report the use of a cDNA microarray to monitor global transcriptional responses of the chestnut blight fungus, Cryphonectria parasitica, to infection by mild and severe isolates of virulence-attenuating hypoviruses that share 87 to 93% and 90 to 98% identity at the nucleotide and amino acid levels, respectively. Infection by the mild hypovirus isolate CHV1-Euro7 resulted in differential expression of 166 of the ca. 2,200 genes represented on the microarray (90 upregulated and 76 downregulated). This is roughly half the number of genes scored as differentially expressed after infection by the severe isolate, CHV1-EP713 (295 genes; 132 upregulated and 163 downregulated). Comparison of the lists of genes responsive to infection by the two hypovirus isolates revealed 80 virus-common responsive genes. Infection by CHV1-EP713 also caused changes in gene transcript accumulation that were, in general, of greater magnitude than those observed with CHV1-Euro7 infections. Thus, the host transcriptional response to infection by severe hypovirus CHV1-EP713 appears to be considerably more dynamic than the response to infection by the mild isolate CHV1-Euro7. Real-time reverse transcription-PCR was performed on 39 different clones, with false-positive rates of 3 and 8% observed for the microarray-predicted list of genes responsive to CHV1-EP713 and CHV1-Euro7 infections, respectively. This analysis has allowed an initial assignment for ca. 2,200 unique C. parasitica-expressed genes as being unresponsive to hypovirus infection, selectively responsive to a specific hypovirus, or generally responsive to hypovirus infection.

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