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Stephen E Strelkov - One of the best experts on this subject based on the ideXlab platform.
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pathotypes of Plasmodiophora brassicae collected from clubroot resistant canola brassica napus l cultivars in western canada in 2017 2018
2021Co-Authors: K B Hollman, V. P. Manolii, Sheaufang Hwang, Stephen E StrelkovAbstract:Clubroot, caused by Plasmodiophora brassicae Woronin, is an important soilborne disease of canola (oilseed rape; Brassica napus L.). In Canada, clubroot management relies heavily on the planting of...
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Development of molecular markers to identify distinct populations of Plasmodiophora brassicae
2021Co-Authors: Michael D. Holtz, V. P. Manolii, Sheaufang Hwang, Ileana S. Strelkov, Stephen E StrelkovAbstract:Clubroot, caused by Plasmodiophora brassicae , has become a serious production problem for canola ( Brassica napus ) on the Canadian prairies. Recently, clubroot-resistant (CR) canola cultivars have begun to show susceptibility to particular strains of P. brassicae . Using next generation sequencing data, a search was undertaken to identify genomic insertions unique to Canadian P. brassicae isolates belonging to two distinct populations. A total of 1353 candidate loci were detected that were present in Canadian P. brassicae isolates and were not homologous to sequences from any other species. Of these candidate loci, 600 appeared to be unique to isolates from the first population, which has been known to be present in Alberta for the longest period of time, while 85 appeared to be unique to isolates from the second population, in which virulence on CR canola cultivars was first detected. From these loci, 11 PCR markers were developed to identify P. brassicae isolates from these two populations. The primers did not amplify DNA from uninfected canola plants, soil samples, bacteria or fungal samples when tested. Assays Pb_pop1_52, Pb_pop1_60, Pb_pop1_255, Pb_pop1_327, Pb_pop1_595, Pb_pop1_673 were specific to population one, whereas primers Pb_pop2_2, Pb_pop2_26, Pb_pop2_33, Pb_pop2_57, and Pb_pop2_94 were specific to population two. The PCR assays were highly sensitive and could detect < 1 pg of target DNA. These methods should be useful for rapid diagnosis and identification of P. brassicae -infected canola plants.
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characterization of clubroot Plasmodiophora brassicae from canola brassica napus in the peace country of alberta canada
2021Co-Authors: Stephen E Strelkov, V. P. Manolii, Sheaufang Hwang, George D Turnbull, Rudolph Freduaagyeman, Keisha Hollman, Sheila KausAbstract:Clubroot of canola (Brassica napus L.), caused by Plasmodiophora brassicae Woronin, has spread to more than 3000 fields in Alberta, Canada, since it was first identified in 2003, but the disease ha...
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effect of canola brassica napus cultivar rotation on Plasmodiophora brassicae pathotype composition
2020Co-Authors: Tiesen Cao, V. P. Manolii, Sheaufang Hwang, Qixing Zhou, Stephen E StrelkovAbstract:In Canada, clubroot (Plasmodiophora brassicae) disease is managed mainly by planting clubroot resistant (CR) canola (Brassica napus). New pathotypes of P. brassicae have emerged recently, however, ...
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identification of winter and spring brassica napus genotypes with partial resistance to canadian isolates of Plasmodiophora brassicae
2020Co-Authors: Yoann Aigu, V. P. Manolii, Stephen E Strelkov, Ileana S. Strelkov, Tiesen Cao, Jocelyne Lemoine, Maria J Manzanaresdauleux, Antoine GravotAbstract:Clubroot is an important root disease of canola/oilseed rape (Brassica napus L.) caused by Plasmodiophora brassicae. To cope with the emergence of new virulent pathotypes of P. brassicae that threa...
Sheaufang Hwang - One of the best experts on this subject based on the ideXlab platform.
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pathotypes of Plasmodiophora brassicae collected from clubroot resistant canola brassica napus l cultivars in western canada in 2017 2018
2021Co-Authors: K B Hollman, V. P. Manolii, Sheaufang Hwang, Stephen E StrelkovAbstract:Clubroot, caused by Plasmodiophora brassicae Woronin, is an important soilborne disease of canola (oilseed rape; Brassica napus L.). In Canada, clubroot management relies heavily on the planting of...
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Development of molecular markers to identify distinct populations of Plasmodiophora brassicae
2021Co-Authors: Michael D. Holtz, V. P. Manolii, Sheaufang Hwang, Ileana S. Strelkov, Stephen E StrelkovAbstract:Clubroot, caused by Plasmodiophora brassicae , has become a serious production problem for canola ( Brassica napus ) on the Canadian prairies. Recently, clubroot-resistant (CR) canola cultivars have begun to show susceptibility to particular strains of P. brassicae . Using next generation sequencing data, a search was undertaken to identify genomic insertions unique to Canadian P. brassicae isolates belonging to two distinct populations. A total of 1353 candidate loci were detected that were present in Canadian P. brassicae isolates and were not homologous to sequences from any other species. Of these candidate loci, 600 appeared to be unique to isolates from the first population, which has been known to be present in Alberta for the longest period of time, while 85 appeared to be unique to isolates from the second population, in which virulence on CR canola cultivars was first detected. From these loci, 11 PCR markers were developed to identify P. brassicae isolates from these two populations. The primers did not amplify DNA from uninfected canola plants, soil samples, bacteria or fungal samples when tested. Assays Pb_pop1_52, Pb_pop1_60, Pb_pop1_255, Pb_pop1_327, Pb_pop1_595, Pb_pop1_673 were specific to population one, whereas primers Pb_pop2_2, Pb_pop2_26, Pb_pop2_33, Pb_pop2_57, and Pb_pop2_94 were specific to population two. The PCR assays were highly sensitive and could detect < 1 pg of target DNA. These methods should be useful for rapid diagnosis and identification of P. brassicae -infected canola plants.
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characterization of clubroot Plasmodiophora brassicae from canola brassica napus in the peace country of alberta canada
2021Co-Authors: Stephen E Strelkov, V. P. Manolii, Sheaufang Hwang, George D Turnbull, Rudolph Freduaagyeman, Keisha Hollman, Sheila KausAbstract:Clubroot of canola (Brassica napus L.), caused by Plasmodiophora brassicae Woronin, has spread to more than 3000 fields in Alberta, Canada, since it was first identified in 2003, but the disease ha...
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effect of canola brassica napus cultivar rotation on Plasmodiophora brassicae pathotype composition
2020Co-Authors: Tiesen Cao, V. P. Manolii, Sheaufang Hwang, Qixing Zhou, Stephen E StrelkovAbstract:In Canada, clubroot (Plasmodiophora brassicae) disease is managed mainly by planting clubroot resistant (CR) canola (Brassica napus). New pathotypes of P. brassicae have emerged recently, however, ...
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genotyping of Plasmodiophora brassicae reveals the presence of distinct populations
2018Co-Authors: Michael D. Holtz, Sheaufang Hwang, Stephen E StrelkovAbstract:Plasmodiophora brassicae is a soilborne pathogen of the family Brassicaceae and the causal agent of clubroot disease. In Canada, P. brassicae is now one of the most important constraints to canola (Brassica napus) production, and is managed mainly by the deployment of resistant cultivars. In recent years, however, new strains of the pathogen have emerged that are capable of overcoming host resistance, posing new challenges for disease management. Despite its economic significance, molecular studies of P. brassicae are rare, mainly because this microorganism cannot be cultured outside of its host. Restriction site-associated DNA sequencing (RADseq) was used to examine the genetic diversity within P. brassicae single-spore and field isolates collected from across Canada. The isolates included individuals that were either capable or incapable of causing disease on clubroot resistant canola cultivars. Over 8750 variants were identified through RADseq. Population analysis indicated that most isolates belonged to one of two distinct populations, corresponding with the ability of isolates to cause disease on resistant cultivars. Within each population, there were low levels of genetic diversity. One thousand and fifty of the genetic variants that distinguished the two populations were nonsynonymous, altering the coding sequences of genes. The application of RADseq revealed two distinct populations of P. brassicae in Canada, suggesting multiple introductions of the pathogen into the country. The genetic variation found here will be important for future research and monitoring of the pathogen.
Daohong Jiang - One of the best experts on this subject based on the ideXlab platform.
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two new biocontrol agents against clubroot caused by Plasmodiophora brassicae
2020Co-Authors: Manli Zhu, Daohong Jiang, Tirong Ren, Hao Liu, Junbin Huang, Tom Hsiang, Lu ZhengAbstract:Clubroot disease caused by Plasmodiophora brassicae can lead to serious yield losses in crucifers such as Brassica napus. In this study, 323 bacterial strains were isolated from the rhizosphere of severely diseased B. napus in Dangyang county, Hubei province, China. Antagonistic strains were first identified based on dual culture inhibition zones with Fusarium oxysporum and Magnaporthe oryzae. These were then further screened in germination inhibition and viability assays of resting spores of P. brassicae. Finally, eight of the antagonistic strains were found to significantly reduce the disease severity of clubroot by more than 40% under greenhouse conditions, and two strains, F85 and T113, were found to have efficacy of more than 80%. Root hair infection experiments showed that F85 and T113 can inhibit early infection of root hairs, reduce the differentiation of primary plasmodia of P. brassicae, and inhibit formation of secondary zoosporangia. Based on sequence analysis of 16S rDNA gene, gyrA gene and 22 housekeeping genes as well as carbon source utilization analysis, the F85 was identified as Bacillus velezensis and T113 as Bacillus amyloliquefaciens. Genome analysis, PCR and RT-PCR detection revealed that both F85 and T113 harbor various antibiotic biosynthesis gene clusters required to form peptides with antimicrobial activity. To our knowledge, this is the first report of B. velezensis as a biocontrol agent against clubroot disease.
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Additional file 4: of Comparative genomics reveals the unique evolutionary status of Plasmodiophora brassicae and the essential role of GPCR signaling pathways
2019Co-Authors: Tao Chen, Zhixiao Gao, Ying Zhao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Daohong JiangAbstract:Table S4. Gene information of GPCR signaling pathway in Plasmodiophora brassicae ZJ-1 (XLSX 17 kb
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Additional file 3: of Comparative genomics reveals the unique evolutionary status of Plasmodiophora brassicae and the essential role of GPCR signaling pathways
2019Co-Authors: Tao Chen, Zhixiao Gao, Ying Zhao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Daohong JiangAbstract:Table S3. The enrichment of GO terms of Plasmodiophora brassicae-expanded and P. brassicae-specific genes (DOCX 32 kb
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Additional file 2: of Comparative genomics reveals the unique evolutionary status of Plasmodiophora brassicae and the essential role of GPCR signaling pathways
2019Co-Authors: Tao Chen, Zhixiao Gao, Ying Zhao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Daohong JiangAbstract:Table S2. Comparative analysis of gene density of genome between Plasmodiophora brassicae ZJ-1 and other plant pathogens (DOCX 29 kb
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endosphere microbiome comparison between symptomatic and asymptomatic roots of brassica napus infected with Plasmodiophora brassicae
2017Co-Authors: Ying Zhao, Tao Chen, Zhixiao Gao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Binnian Tian, Daohong JiangAbstract:Clubroot caused by Plasmodiophora brassicae, is a severe disease of cruciferous crops that causes large hypertrophic galls in the roots. The plant microbiome is important for growth promotion and disease suppression. In this study, using 16S rRNA and internal transcribed spacer (ITS) sequencing techniques, we compared the endosphere microbiome of symptomatic and asymptomatic B. napus roots infected with P. brassicae collected from the same natural clubroot field. The results showed that the microbial population and its relative abundance in the asymptomatic roots was far higher than that in the symptomatic roots, and that many microorganisms in asymptomatic roots have biological control and plant growth promotion functions that may be related to clubroot symptoms. These results suggest the importance of the endosphere microbiome in clubroot disease and provide potential bio-control resources for its prevention.
Mary Ruth Mcdonald - One of the best experts on this subject based on the ideXlab platform.
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Virulence and pathotype classification of Plasmodiophora brassicae populations collected from clubroot resistant canola (Brassica napus) in Canada
2018Co-Authors: Stephen E Strelkov, Bruce D. Gossen, V. P. Manolii, Gary Peng, Sheaufang Hwang, Mary Ruth Mcdonald, Tiesen Cao, Rudolph Fredua-agyeman, Michael W. Harding, David FeindelAbstract:Clubroot, caused by Plasmodiophora brassicae Wor., is an important soilborne disease of canola (Brassica napus L.) in Canada that is managed mainly by planting clubroot-resistant (CR) cultivars. Po...
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first report of clubroot Plasmodiophora brassicae on canola in ontario
2018Co-Authors: Fadi Aldaoud, B D Gossen, Meghan Moran, Mary Ruth McdonaldAbstract:Clubroot, caused by Plasmodiophora brassicae Woronin, is endemic on Brassica vegetables in many regions of Ontario. It has not been previously reported on canola (Brassica napus L.) in Ontario, pos...
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propidium monoazide improves quantification of resting spores of Plasmodiophora brassicae with qpcr
2017Co-Authors: Fadi Aldaoud, B D Gossen, Justin Robson, Mary Ruth McdonaldAbstract:Plasmodiophora brassicae, which causes clubroot of Brassica crops, persists in soil as long-lived resting spores. Quantitative polymerase chain reaction (qPCR) analysis is often used to quantify resting spores but does not distinguish between DNA of viable and nonviable spores. The impact of pretreating spores with propidium monoazide (PMA), which inhibits amplification of DNA from nonviable microorganisms, was assessed in several experiments. Spore suspensions from immature and mature clubs were heat treated; then, PMA-PCR analyses and bioassays were performed to assess spore viability. Prior to heat treatment, assessments comparing PMA-PCR to qPCR for mature spores were similar, indicating that most of these spores were viable. However, only a small proportion (<26%) of immature spores were amplified in PMA-PCR. Bioassays demonstrated that clubroot severity was much higher in plants inoculated with mature spores than with immature spores. Heat treatment produced little or no change in estimates of mature spores from qPCR but spore estimates from PMA-PCR and clubroot severity in bioassays were both substantially reduced. Estimates of spore concentration with PMA-PCR were less consistent for immature spores. To facilitate use of PMA-PCR on infested soil, a protocol for extracting spores from soil was developed that provided higher extraction efficiency than the standard methods.
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spread of Plasmodiophora brassicae on canola in canada 2003 2014 old pathogen new home
2015Co-Authors: B D Gossen, V. P. Manolii, Gary Peng, Sheaufang Hwang, Stephen E Strelkov, Tiesen Cao, D C Rennie, Mary Ruth McdonaldAbstract:AbstractClubroot caused by Plasmodiophora brassicae has been reported at sites across North America on brassica vegetables for more than 50 years. However, it had not been reported on canola (Brassica napus) on the Canadian prairies until the initial discovery of a cluster of 12 infested fields near Edmonton AB in 2003. The purpose of this review is to consolidate and summarize the data on the spread of P. brassicae on canola in Canada since 2003, to compare this pattern of distribution with observations from an infested site in Ontario, and to draw inferences about the relative importance of short- and long-distance transmission of the pathogen on clubroot distribution in the prairie region. Over the last decade, P. brassicae has spread across central Alberta, with the leading edge of the epidemic moving at about 20 km per year, resulting in more than 1850 fields confirmed infested. DNA of the pathogen has also been detected from soil collected at sites across Saskatchewan and Manitoba, and very slight c...
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a multiplex qpcr assay for detection and quantification of Plasmodiophora brassicae in soil
2015Co-Authors: Abhinandan Deora, B D Gossen, Sasan Amirsadeghi, Mary Ruth McdonaldAbstract:Various physical and chemical factors in soil can inhibit the detection and quantification of soilborne plant pathogens using quantitative polymerase chain reaction (qPCR) assays. A multiplexed TaqMan qPCR assay, including a competitive internal positive control (CIPC), was developed to identify and (where necessary) compensate for inhibition in the quantification of resting spores of Plasmodiophora brassicae from soil. The CIPC amplicon was developed by modifying a sequence coding for green fluorescent protein so that it could be amplified with P. brassicae-specific primers. Addition of CIPC at 5 fg/μl to the singleplex qPCR assay designed to quantify P. brassicae genomic DNA did not reduce the sensitivity, specificity, or reproducibility of the assay. Each of the soil samples, either artificially inoculated or naturally infested with P. brassicae, exhibited no amplification of the CIPC. When the samples were diluted and reassessed, the quantification cycle of the CIPC relative to the control (water only...
Tao Chen - One of the best experts on this subject based on the ideXlab platform.
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Additional file 4: of Comparative genomics reveals the unique evolutionary status of Plasmodiophora brassicae and the essential role of GPCR signaling pathways
2019Co-Authors: Tao Chen, Zhixiao Gao, Ying Zhao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Daohong JiangAbstract:Table S4. Gene information of GPCR signaling pathway in Plasmodiophora brassicae ZJ-1 (XLSX 17 kb
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Additional file 3: of Comparative genomics reveals the unique evolutionary status of Plasmodiophora brassicae and the essential role of GPCR signaling pathways
2019Co-Authors: Tao Chen, Zhixiao Gao, Ying Zhao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Daohong JiangAbstract:Table S3. The enrichment of GO terms of Plasmodiophora brassicae-expanded and P. brassicae-specific genes (DOCX 32 kb
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Additional file 2: of Comparative genomics reveals the unique evolutionary status of Plasmodiophora brassicae and the essential role of GPCR signaling pathways
2019Co-Authors: Tao Chen, Zhixiao Gao, Ying Zhao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Daohong JiangAbstract:Table S2. Comparative analysis of gene density of genome between Plasmodiophora brassicae ZJ-1 and other plant pathogens (DOCX 29 kb
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endosphere microbiome comparison between symptomatic and asymptomatic roots of brassica napus infected with Plasmodiophora brassicae
2017Co-Authors: Ying Zhao, Tao Chen, Zhixiao Gao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Binnian Tian, Daohong JiangAbstract:Clubroot caused by Plasmodiophora brassicae, is a severe disease of cruciferous crops that causes large hypertrophic galls in the roots. The plant microbiome is important for growth promotion and disease suppression. In this study, using 16S rRNA and internal transcribed spacer (ITS) sequencing techniques, we compared the endosphere microbiome of symptomatic and asymptomatic B. napus roots infected with P. brassicae collected from the same natural clubroot field. The results showed that the microbial population and its relative abundance in the asymptomatic roots was far higher than that in the symptomatic roots, and that many microorganisms in asymptomatic roots have biological control and plant growth promotion functions that may be related to clubroot symptoms. These results suggest the importance of the endosphere microbiome in clubroot disease and provide potential bio-control resources for its prevention.
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transcriptome analysis of arabidopsis thaliana in response to Plasmodiophora brassicae during early infection
2017Co-Authors: Ying Zhao, Tao Chen, Zhixiao Gao, Huiquan Liu, Jiatao Xie, Jiasen Cheng, Daohong JiangAbstract:Clubroot disease is a serious threat to cruciferous plants worldwide, especially to oilseed rape. However, knowledge on pathogenic molecular mechanisms and host interaction is limited. We presume that the recognition between Arabidopsis thaliana and Plasmodiophora brassicae occurs at the early stage of infection and within a relatively short period. In this study, we demonstrated changes on gene expression and pathways in A. thaliana during early infection with P. brassicae using transcriptome analysis. We identified 1903 and 1359 DEGs at 24 and 48 hours post inoculation (hpi), respectively. Flavonoids and the lignin synthesis pathways were enhanced, glucosinolates, terpenoids and proanthocyanidins accumulated and many hormonal- and receptor-kinase related genes were expressed, caused by P. brassicae infection during its early phase. Therefore, the early interaction between A. thaliana and P. brassicae plays an important role in the entire infection process. The results provide a new contribution to a better understanding of the interaction between host plants and P. brassicae, as well as the development of future measures for the prevention of clubroot.