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Li R, Bai S, He Y, Chen Q, Yao Y, Wang J, Chen B. Cpvma1, a Vacuolar H +-ATPase Catalytic Subunit of Cryphonectria parasitica, is Essential for Virulence and Hypovirus RNA Accumulation. PHYTOPATHOLOGY 2019; 109:1417-1424. [PMID: 30860430 DOI: 10.1094/phyto-08-18-0289-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The vacuolar H+-ATPases (V-ATPases) are conserved ATP-dependent proton pumps that acidify intracellular compartments in eukaryotic cells. The role of Cpvma1, a V-ATPase catalytic subunit A of Cryphonectria parasitica, was investigated by generating cpvma1-overexpressing and cpvma1-silenced strains. The mutant strains were evaluated for phenotypic characteristics, V-ATPase activity, response to elevated pH and Ca2+ in the medium, virulence on chestnut, and accumulation of hypovirus RNA in the cells. Compared with the wild-type strain, cpvma1-overexpressing strains showed no significant difference in phenotype; however, cpvma1-silenced strains exhibited a phenotype of reduced growth rate, lower level of sporulation, and a marked decrease in V-ATPase activity and virulence. In addition, silencing of cpvma1 increased sensitivity to elevated pH and Ca2+, implicating an important role for Cpvma1 in pH adaptation and Ca2+ homeostasis. Furthermore, silencing of cpvma1 resulted in significantly decreased accumulation of hypoviral RNA. Taken together, our results indicate that Cpvma1 plays an important role in the regulation of phenotypic traits and virulence and the accumulation of hypovirus RNA in C. parasitica.
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Affiliation(s)
- Ru Li
- 1State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, China
- 2College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Shan Bai
- 2College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Yuanyuan He
- 2College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Qi Chen
- 2College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Yanping Yao
- 2College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Jinzi Wang
- 2College of Life Science and Technology, Guangxi University, Nanning 530004, China
| | - Baoshan Chen
- 1State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi University, Nanning 530004, China
- 2College of Life Science and Technology, Guangxi University, Nanning 530004, China
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Turina M, Rossi M, Moretti M. Investigation on the partial resistance of Cpkk2 knock out strain of Cryphonectria parasitica to Cryphonectria hypovirus 1 infection in presence of Geneticin and Geneticin resistance gene. Virus Res 2016; 219:58-61. [PMID: 26643512 DOI: 10.1016/j.virusres.2015.11.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/18/2015] [Accepted: 11/20/2015] [Indexed: 11/19/2022]
Abstract
We have recently characterized the central components of the three MAP kinase cascades present in Cryphonectria parasitica : the MEK genes cpkk1, cpkk2 and cpkk3. When we attempted to infect through anastomosis the three knock out strains with Cryphonectria hypovirus 1 (CHV1), only the deletion strain of Cpkk2, the yeast Ste7 homologue, involved in mating and filamentous growth, could not be infected. We then proceeded to attempt virus infection through transformation of Δcpkk2 protoplasts using an infectious cDNA clone able to establish virus infection through transformation. In this case, a very limited number of strains could be recovered as stable transformants compared to the efficiency of control transformations with plasmid carrying only the antibiotic marker. Furthermore, transformants carrying actively replicating virus could be isolated only if the selection marker Geneticin was used during the very initial selection process, and not maintained throughout the growth of the colonies. Moreover, Δcpkk2 isolates that maintained the virus lost Geneticin resistance. We therefore unveiled a specific negative interaction among virus infection, presence of Geneticin in the growth media, and lack of Cpkk2 MEK in the fungal host.
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Affiliation(s)
- Massimo Turina
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, 10135 Torino, Italy.
| | - Marika Rossi
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, 10135 Torino, Italy
| | - Marino Moretti
- Istituto per la Protezione Sostenibile delle Piante, CNR, Strada delle Cacce 73, 10135 Torino, Italy
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Eusebio-Cope A, Sun L, Tanaka T, Chiba S, Kasahara S, Suzuki N. The chestnut blight fungus for studies on virus/host and virus/virus interactions: From a natural to a model host. Virology 2015; 477:164-175. [DOI: 10.1016/j.virol.2014.09.024] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 09/15/2014] [Accepted: 09/26/2014] [Indexed: 01/03/2023]
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Hypovirus-responsive transcription factor gene pro1 of the chestnut blight fungus Cryphonectria parasitica is required for female fertility, asexual spore development, and stable maintenance of hypovirus infection. EUKARYOTIC CELL 2008; 8:262-70. [PMID: 19114501 DOI: 10.1128/ec.00338-08] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report characterization of the gene encoding putative transcription factor PRO1, identified in transcriptional profiling studies as being downregulated in the chestnut blight fungus Cryphonectria parasitica in response to infection by virulence-attenuating hypoviruses. Sequence analysis confirmed that pro1 encodes a Zn(II)(2)Cys(6) binuclear cluster DNA binding protein with significant sequence similarity to the pro1 gene product that controls fruiting body development in Sordaria macrospora. Targeted disruption of the C. parasitica pro1 gene resulted in two phenotypic changes that also accompany hypovirus infection, a significant reduction in asexual sporulation that could be reversed by exposure to high light intensity, and loss of female fertility. The pro1 disruption mutant, however, retained full virulence. Although hypovirus CHV1-EP713 infection was established in the pro1 disruption mutant, infected colonies continually produced virus-free sectors, suggesting that PRO1 is required for stable maintenance of hypovirus infection. These results complement the recent characterization of the hypovirus-responsive homologue of the Saccharomyces cerevisiae Ste12 C(2)H(2) zinc finger transcription factor gene, cpst12, which was shown to be required for C. parasitica female fertility and virulence.
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Temple B, Pines PA, Hintz WE. A nine-year genetic survey of the causal agent of Dutch elm disease, Ophiostoma novo-ulmi in Winnipeg, Canada. ACTA ACUST UNITED AC 2006; 110:594-600. [PMID: 16617009 DOI: 10.1016/j.mycres.2006.01.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2004] [Revised: 12/10/2005] [Accepted: 01/01/2006] [Indexed: 11/29/2022]
Abstract
The causal agent of Dutch elm disease, Ophiostoma ulmi s. lat., has been spreading across North America since the 1920s. The population of the pathogen in Winnipeg, Manitoba, Canada was surveyed in 1993 and 2002 using a combination of RAPD marker analysis, vegetative compatibility tests, and surveys for viral double-stranded RNA (dsRNA). The data presented here show that the population, based on the vegetative compatibility and RAPD analysis, was highly genetically uniform, and has remained so for the nine-year duration of the study. The pathogen population was also monitored for the presence and spread of dsRNA molecules that, depending on identity, can be associated with a diseased phenotype and reduction of virulence in the pathogen. The current study found a very low incidence of dsRNA, and did not find any evidence for spread of these molecules through the population, even though there appeared to be no barriers to the transfer of the dsRNA between Winnipeg isolates. Despite the observation that isolates infected with the Winnipeg dsRNA showed no obvious phenotypic differences, the low incidence of dsRNA in general suggests that infected isolates do not compete as successfully as the uninfected isolates. The highly clonal nature of the pathogen population may be exploited in a control strategy.
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Affiliation(s)
- Brad Temple
- Biology Department, University of Victoria, P.O. Box 3020 STN CSC, Victoria, BC, V8W 3N5, Canada
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Zhou T, Boland GJ. Suppression of Dollar Spot by Hypovirulent Isolates of Sclerotinia homoeocarpa. PHYTOPATHOLOGY 1998; 88:788-794. [PMID: 18944884 DOI: 10.1094/phyto.1998.88.8.788] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT Selected hypovirulent isolates of Sclerotinia homoeocarpa were evaluated for efficacy in suppressing dollar spot of turfgrass under growth room and field conditions. Under growth room conditions, hypovirulent isolates Sh12B, Sh09B, or Sh08D of S. homoeocarpa caused 3.4 to 30.4% diseased turf in comparison to virulent isolates Sh48B and Sh14D, which caused 80.2 to 90.2% disease. In treatments that received both virulent and hypovirulent isolates, only hypovirulent isolate Sh12B significantly reduced disease as compared with the control with virulent isolates alone. In a field experiment in 1993 on swards of creeping bentgrass artificially inoculated with a virulent isolate of the pathogen, all treatments containing hypovirulent isolate Sh12B applied as a mycelial suspension, granular mix, or alginate pellets developed significantly less disease (6.3 to 20.8% diseased turf) compared with their respective formulation controls (23.8 to 31.2%). Suppression of dollar spot by treatment with mycelial suspensions of isolate Sh12B was evident up to 45 days postinoculation, and disease suppression was still significant 1 year after application when compared with the water control. Applications of hypovirulent isolate Sh09B did not reduce dollar spot in any treatments. Significant suppression of dollar spot by isolate Sh12B was also observed in the experiment conducted in 1994. In addition, suppression of dollar spot by hypovirulent isolate Sh12B was evaluated on swards with naturally occurring inoculum during 1994. Treatments with a mycelial suspension and alginate pellets of hypovirulent isolate Sh12B significantly reduced dollar spot compared with their respective formulation controls. With few exceptions, there was no statistical difference between treatments with hypovirulent isolate Sh12B and the fungicide chlorothalonil (Daconil 2787). Multiple applications of the hypovirulent isolate did not result in greater suppression of dollar spot as compared with a single application. The results indicate that hypovirulence has potential as an effective strategy for the management of dollar spot.
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Zhou T, Boland GJ. Hypovirulence and Double-Stranded RNA in Sclerotinia homoeocarpa. PHYTOPATHOLOGY 1997; 87:147-153. [PMID: 18945134 DOI: 10.1094/phyto.1997.87.2.147] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT One hundred and thirty-two isolates of Sclerotinia homoeocarpa, the causal agent of dollar spot of turfgrass, were evaluated for virulence on swards and detached leaves of creeping bentgrass and for the presence of double-stranded RNA (dsRNA). In at least four isolates, the hypovirulent phenotype was associated with the presence of specific segments of dsRNA. In addition, these hypovirulent isolates often grew slowly on potato dextrose agar (PDA), formed thin colonies with atypical colony margins, and failed to produce typical black stroma. The hypovirulent phenotype and dsRNA were transmitted from hypovirulent isolate Sh12B to virulent isolate Sh48B, and the converted isolate was hypovirulent and contained dsRNA. The hypovirulent phenotype and dsRNA also were transmitted to at least four other isolates of the pathogen, including the fungicide-resistant, dsRNA isolate KY-7. Converted isolates of KY-7 developed the hypovirulent phenotype, grew on fungicide-amended medium, and contained dsRNA. Subcultures of hypovirulent isolate Sh12B that did not contain dsRNA were obtained through curative treatment using cycloheximide-containing medium and heat. Cured subcultures grew faster on PDA, had more typical colony morphologies, were more virulent on bentgrass leaves, and did not contain dsRNA. No cured subcultures were obtained from hypovirulent isolate Sh09B. Isolates regenerated from protoplasts of hypovirulent isolate Sh12B were not cured, remained hypovirulent, and contained dsRNA. Transmission of hypovirulence and dsRNA in S. homoeocarpa has potential as a novel approach to the management of dollar spot of turfgrass.
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Paoletti MG, Pimentel D. Genetic Engineering in Agriculture and the Environment. Bioscience 1996. [DOI: 10.2307/1312896] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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