Brassica clubroot caused by Plasmodiophora brassicae has been identified as a severe soil-borne disease that poses a significant threat to plants root systems.The disease results in the formation of tumorous enlargeme...Brassica clubroot caused by Plasmodiophora brassicae has been identified as a severe soil-borne disease that poses a significant threat to plants root systems.The disease results in the formation of tumorous enlargements in the roots,leading to wilting and eventual plant death.Consequently,crop yield is drastically reduced,causing substantial economic losses in agriculture.The current study aims to provide a comprehensive overview of recent research process on Brassica clubroot,focusing on the biological characteristics,physiological race identification,and pathogenic mechanism of P.brassicae.Furthermore,it covers the latest advancements in the comprehensive prevention and clubroot control.The insights gained from this study are expected to contribute to the future research on clubroot and the development of resistance breeding strategies.展开更多
Clubroot caused by Plasmodiophora brassicae is a devastating disease of Cruciferous crops.Developing cultivars with clubroot resistance(CR)is the most effective control measure.For the two major Brassica vegetable spe...Clubroot caused by Plasmodiophora brassicae is a devastating disease of Cruciferous crops.Developing cultivars with clubroot resistance(CR)is the most effective control measure.For the two major Brassica vegetable species B.rapa and B.oleracea,several commercial cultivars with unclear CR pedigrees have been intensively used as CR donors in breeding.However,the continuous occurrence of CR-breaking makes the CR pedigree underlying these cultivars one of the breeders'most urgent concerns.The complex intraspecific diversity of these two major Brassica vegetables has also limited the applicability of CR markers in different breeding programs.Here we first traced the pedigree underlying two kinds of CR that have been widely applied in breeding by linkage and introgression analyses based on public resequencing data.In B.rapa,a major locus CRzi8 underlying the CR of the commercial CR donor‘DegaoCR117’was identified.CRzi8 was further shown to have been introgressed from turnip(B.rapa ssp.rapifera)and that it carried a potential functional allele of Crr1a.The turnip introgression carried CRb^(c),sharing the same coding sequence with the CRb that was also identified from chromosome C07 of B.oleracea CR cultivars with different morphotypes.Within natural populations,variation analysis of linkage intervals of CRzi8,PbBa8.1,CRb,and CRb^(c)yielded easily resolved InDel markers(>20 bp)for these fundamental CR genes.The specificity of these markers was tested in diverse cultivars panels,and each exhibited high reliability in breeding.Our research demonstrates the value of the practice of applying resequencing big data to solve urgent concerns in breeding programs.展开更多
Clubroot disease is a severe threat to Brassica crops globally,particularly in western Canada.Genetic resistance,achieved through pyramiding clubroot resistance(CR)genes with different modes of action,is the most impo...Clubroot disease is a severe threat to Brassica crops globally,particularly in western Canada.Genetic resistance,achieved through pyramiding clubroot resistance(CR)genes with different modes of action,is the most important strategy for managing the disease.However,studies on the CR gene functions are quite limited.In this study,we have conducted investigations into the temporal,structural,and interacting features of a newly cloned CR gene,Rcr1,using CRISPR/Cas9 technology.For temporal functionality,we developed a novel CRISPR/Cas9-based binary vector,pHHIGR-Hsp18.2,to deliver Rcr1 into a susceptible canola line(DH12075)and observed that early expression of Rcr1 is critical for conferring resistance.For structural functionality,several independent mutations in specific domains of Rcr1 resulted in loss-offunction,highlighting their importance for CR phenotype.In the study of the interacting features of Rcr1,a cysteine protease gene and its homologous allele in canola were successfully disrupted via CRISPR/Cas9 as an interacting component with Rcr1 protein,resulting in the conversion from clubroot resistant to susceptible in plants carrying intact Rcr1.These results indicated an indispensable role of these two cysteine proteases in Rcr1-mediated resistance response.This study,the first of its kind,provides valuable insights into the functionality of Rcr1.Further,the new vector p HHIGR-Hsp18.2 demonstrated an inducible feature on the removal of add-on traits,which should be useful for functional genomics and other similar research in brassica crops.展开更多
Objective] This study was conducted to investigate the genetic inheritance of clubroot resistance in Chinese non-heading cabbage （Brassica campestris ssp. chinensis）. [Method] The clubroot resistance gene was introd...Objective] This study was conducted to investigate the genetic inheritance of clubroot resistance in Chinese non-heading cabbage （Brassica campestris ssp. chinensis）. [Method] The clubroot resistance gene was introduced from a Brassica campestris ssp. pekinensis cultivar to non-heading Chinese cabbage, and the inheri-tance and molecular markers of clubroot resistance gene in parental lines, F1, F2 and BC1 of non-heading Chinese cabbage were studied through pathogen inoculation at seedling stage and ISSR-PCR. [Result] Clubroot resistance in non-heading Chi-nese cabbage was control ed by a single dominant gene. ISSR molecular markers with Bulk segregant analysis （BSA） found that primer-873 was linked to resistance gene, named CR-873, and the genetic distance between the marker and the resis-tance gene was 9.72 cM. [Conclusion] The results provide references for the molecular marker assisted breeding of non-heading Chinese cabbage.展开更多
[Objective] The paper was to study the relationship between cytokinin and Chinese cabbage clubroot, and to explore the incidence mechanism of clubroot. [Method]The spores were extracted from the tumors of diseased pla...[Objective] The paper was to study the relationship between cytokinin and Chinese cabbage clubroot, and to explore the incidence mechanism of clubroot. [Method]The spores were extracted from the tumors of diseased plant, and their DNA was extracted for PCR test. The diagnosed spores were inoculated to the culture soils in erlenmeyer flask at seeding stage, at seed germination and 21 d after sowing, and 0.08 μmol/L 6-BA was added to the soil at germination. Spores were extracted from the root tumors developed in inoculated plants and examined by scanning electronic microscope （ SEM）, and the incidence rate of clubroot in 6-BA treatment and control was recorded. [ Result] Plasmodiophora brassicae Woron could cause the clubroot incidence of Chinese cabbage planted in erlenmeyer flasks, the incidence rate of chibroot in the treatment adding with 0.08 μmol/L 6-BA was 100%, while that in the treatment without 6-BA was 57%, and the volume of former tumor was much larger than the latter. SEM showed that the size of resting spore of P. brassicae was 1.5 -4.3μm. [ Conduslon] 6-BA applied at germination could significantly promote the formation of tumor of Chinese cabbage clubroot.展开更多
Clubroot disease, caused by Plasmodiophora brassicae, is one of the most destructive soil-borne diseases in cruciferous crops worldwide. New strategies are urgently needed to control this disease, as no effective dise...Clubroot disease, caused by Plasmodiophora brassicae, is one of the most destructive soil-borne diseases in cruciferous crops worldwide. New strategies are urgently needed to control this disease, as no effective disease-resistant varieties or chemical control agents exist. Previously, we found that the incidence rate and disease index of clubroot in oilseed rape decreased by 50 and 40%, respectively, when oilseed rape was planted after soybean. In order to understand how different rotation patterns affect the occurrence of clubroot in oilseed rape, high-throughput sequencing was used to analyze the rhizosphere microbial community of oilseed rape planted after leguminous (soybean, clover), gramineous (rice, maize) and cruciferous (oilseed rape, Chinese cabbage) crops. Results showed that planting soybeans before oilseed rape significantly increased the population density of microbes that could inhibit P. brassicae (e.g., Sphingomonas, Bacillus, Streptomyces and Trichoderma). Conversely, consecutive cultivation of cruciferous crops significantly accumulated plant pathogens, including P. brassicae, Olpidium and Colletotrichum (P<0.05). These results will help to develop the most effective rotation pattern for reducing clubroot damage.展开更多
Clubroot and herbicide resistance,high oleic acid(OA)content,and early maturity are targets of rapeseed(Brassica napus L.)breeding.The objective of this study was to develop new male-fertility restorer lines by pyrami...Clubroot and herbicide resistance,high oleic acid(OA)content,and early maturity are targets of rapeseed(Brassica napus L.)breeding.The objective of this study was to develop new male-fertility restorer lines by pyramiding favorable genes to improve these traits simultaneously.Seven elite alleles for the four traits were introduced into the restorer line 621R by speed breeding with marker-assisted and phenotypic selection.Six introgression lines(ILs)were developed with four-to seven-gene combinations and crossed with two elite parents to develop hybrids.All ILs and their corresponding hybrids displayed high resistance to both clubroot pathotype 4 and sulfonylurea herbicides.Three ILs and their hybrids showed large increases in OA contents and four showed earlier maturity.These new ILs may be useful in rapeseed hybrid breeding for the target traits.展开更多
In this study, using Japanese radish cytoplasmic sterile line ＂Half Green Cabbage＂ （HGC） and clubfoot-resistant South Korean cabbage variety ＂ CR Cabbage King＂ （CCK） as experimental materials, serf-incompatibl...In this study, using Japanese radish cytoplasmic sterile line ＂Half Green Cabbage＂ （HGC） and clubfoot-resistant South Korean cabbage variety ＂ CR Cabbage King＂ （CCK） as experimental materials, serf-incompatible DH lines were obtained by mierosporo culture. Through five gnerations of backeross, CCR11239, a clubroot-resistant radish cytoplasmic sterile line, was obtained. Through six generations of serf-crossing, CCR11240, the maintainer line of CCR11239, was bred. After the cross of CCK and Luchunbai 1 （83 - 1 ） and five generations of self-crossing, serf-compatible line CCRl1241 was obtained. Through crossing CCR11240 with CCRl1241, the new cabbage variety CCRl1242 was obtained. After variety comparison test, provincial regional test and production demonstration test, the new variety was registered in 2012. The average yield of CCR11242 reached 60 975 kg/hm2, which was improved by 142% compared with Luchunbai 1 （83 - 1 ）. The disease index of CCR11242 was 5.63, which was 88.13 lower than the control, indicating high resistance （HR） to clubfoot.展开更多
[Objective] The paper was to analyze the inheritance of clubroot resistance of miniature Chinese baby cabbage,to shorten identification time and to improve breeding efficacy of new disease-resistant varieties. [Method...[Objective] The paper was to analyze the inheritance of clubroot resistance of miniature Chinese baby cabbage,to shorten identification time and to improve breeding efficacy of new disease-resistant varieties. [Method] Taking clubroot-resistant Chinese cabbage CCR001,disease-susceptible baby cabbage CM002,and their F_1,F_2 and BC_1 offspring as the research objects,the inheritance of clubroot resistance of baby cabbage was studied. [Result]The clubroot-resistance of baby cabbage was controlled by a single dominant gene,which conformed to Mendel＇s Laws of inheritance. The molecular markers-assisted selection combing with bacterial soil inoculation confirmed that the disease-resistance indeed passed on from the parents,and was inherited in F_1 and F_2. [Conclusion]It is feasible to breed clubroot-resistant baby cabbage by using molecular markers-assisted selection.展开更多
The transcriptome-wide gene expression was compared between susceptible and resistant Chinese cabbage cultivars to identify genes that contributed to clubroot resistance. A higher number of differentially expressed ge...The transcriptome-wide gene expression was compared between susceptible and resistant Chinese cabbage cultivars to identify genes that contributed to clubroot resistance. A higher number of differentially expressed genes were detected in susceptible cultivars than in resistant cultivars. Fifty-six genes involved in cell wall modification, hormone signaling, root marphogenesis, nematodes response and cell proliferation were uniquely expressed in the resistant cultivars. Among them, 27 genes were involved in cell wall modification and hormone signaling, indicating that genes in these two types might play a vital role in the defense response to pathogen infection.展开更多
Chinese cabbage is an economically important Brassica vegetable worldwide, and clubroot, which is caused by the soilborne protist plant pathogen Plasmodiophora brassicae is regarded as a destructive disease to Brassic...Chinese cabbage is an economically important Brassica vegetable worldwide, and clubroot, which is caused by the soilborne protist plant pathogen Plasmodiophora brassicae is regarded as a destructive disease to Brassica crops. Previous studies on the gene transcripts related to Chinese cabbage resistance to clubroot mainly employed RNA-seq technology,although it cannot provide accurate transcript assembly and structural information. In this study, PacBio RS II SMRT sequencing was used to generate full-length transcriptomes of mixed roots at 0, 2, 5, 8, 13, and 22 days after P. brassicae infection in the clubroot-resistant line DH40R. Overall, 39 376 high-quality isoforms and 26 270 open reading frames(ORFs) were identified from the SMRT sequencing data. Additionally, 426 annotated long noncoding RNAs(lncRNAs),56 transcription factor(TF) families, 1 883 genes with poly(A) sites and 1 691 alternative splicing(AS) events were identified. Furthermore, 1 201 of the genes had at least one AS event in DH40R. A comparison with RNA-seq data revealed six differentially expressed AS genes(one for disease resistance and five for defensive response) that are potentially involved in P. brassicae resistance. The results of this study provide valuable resources for basic research on clubroot resistance in Chinese cabbage.展开更多
Clubroot is a prevailing soil-borne disease affecting rapeseed production worldwide.However,few clubroot resistant rapeseed accessions were available for breeding.Identification and introgression of new clubroot resis...Clubroot is a prevailing soil-borne disease affecting rapeseed production worldwide.However,few clubroot resistant rapeseed accessions were available for breeding.Identification and introgression of new clubroot resistant genes from closely related species by distant hybridization is an effective strategy.In the present study,9 radish(Raphanus sativus L.,2n=18,RR)lines resistant to Plasmodiophora brassicae pathotype 4 were used as donors to transfer clubroot resistance into a susceptible rapeseed(Brassica napus L.,2n=38,AACC)line by distant hybridization combined with embryo rescue.Nine intergeneric crosses were made but only 1(411×93039)produced F1 plants both from embryo rescue and natural seed-setting.Authenticity of triploid F1 hybrids(2n=28,ACR)were verified by flower color,cytological observation and molecular marker analysis,and 2 genuine F1 hybrids were identified.After chromosome doubling,these synthetic allohexaploid plants(2n=56,AACCRR)became partially fertile(pollen viability rate=35%)and were backcrossed with rapeseed parent to generate a BC1 population(2n=47,AACCR).Totally 178 BC1 plants were obtained,of which the majority(96.1%)were resistant to clubroot.These backcrossing progenies could be used for the breeding of new rapeseed varieties resistant to clubroot.展开更多
Clubroot caused by the protist Plasmodiophora brassicae is a major disease affecting cultivated Brassica-ceae.Using a combination of quantitative trait locus(QTL)fine mapping,CRISPR-Cas9 validation,and extensive analy...Clubroot caused by the protist Plasmodiophora brassicae is a major disease affecting cultivated Brassica-ceae.Using a combination of quantitative trait locus(QTL)fine mapping,CRISPR-Cas9 validation,and extensive analyses of DNA sequence and methylation patterns,we revealed that the two adjacent neigh-boring NLR(nucleotide-binding and leucine-rich repeat)genes AT5G47260 and AT5G47280 cooperate in controlling broad-spectrum quantitative partial resistance to the root pathogen P.brassicae in Arabidopsis and that they are epigenetically regulated.The variation in DNA methylation is not associated with any nucleotide variation or any transposable element presence/absence variants and is stably inherited.Vari-ations in DNA methylation at the Pb-At5.2 QTL are widespread across Arabidopsis accessions and corre-late negatively with variations in expression of the two genes.Our study demonstrates that natural,stable,and transgenerationally inherited epigenetic variations can play an important role in shaping resistance to plant pathogens by modulating the expression of immune receptors.展开更多
根肿病和草害严重威胁油菜的产量和品质。为选育抗根肿病(clubroot-resistant,CR)和抗除草剂(herbicide-resistant,HR)的油菜品种,通过分子标记辅助选择聚合育种策略将抗根肿病位点CRb和PbBa8.1、抗除草剂位点ALS1R和ALS3R导入油菜常规...根肿病和草害严重威胁油菜的产量和品质。为选育抗根肿病(clubroot-resistant,CR)和抗除草剂(herbicide-resistant,HR)的油菜品种,通过分子标记辅助选择聚合育种策略将抗根肿病位点CRb和PbBa8.1、抗除草剂位点ALS1R和ALS3R导入油菜常规品种中双11(ZS11)中,获得3个改良株系ZS11CR(CRb+PbBa8.1)、ZS11HR(ALS1R+ALS3R)和ZS11CHR(CRb+PbBa8.1+ALS1R+ALS3R)。利用根肿菌4号生理小种(湖北枝江)和噻吩磺隆除草剂(45 g a.i.ha^(-1))对ZS11CR、ZS11HR和ZS11CHR的抗性进行评价,结果表明:ZS11CR、ZS11CHR对4号生理小种抗性达到免疫水平,ZS11HR、ZS11CHR对噻吩磺隆除草剂抗性显著。田间农艺性状调查结果表明,ZS11CR、ZS11HR和ZS11CHR的株高较ZS11一定程度增加,而在开花期、分枝数、主花序角果数、角果长、每角果粒数、千粒重等性状上没有显著差异。本研究获得了3个改良株系,其中ZS11CR具有根肿病抗性、ZS11HR具有除草剂抗性、ZS11CHR兼具根肿病抗性和除草剂抗性,这些改良株系不仅目标性状得到了改良,同时维持了ZS11的优良农艺性状,具有一定的应用潜力。展开更多
The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more a...The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more about its pathogenesis, we reported a Nanopore sequencing-derived25.3 Mb high-quality genome sequence of P. brassicae pathotype 4 strain(P.b 4). Comparing the P.b 4 genome with that of the published P.brassicae e3 genome(P.b e3) identified single nucleotide polymorphisms, structural variations, and small insertions and deletions. We then carried out RNA-sequencing of root samples from a clubroot-susceptible line at 5, 14, and 28 days after inoculation(DAI), and classified genes into five categories based on their expression patterns. Interestingly, 158 genes were highly expressed at 14 DAI, which were enriched in budding cell isotropic bud growth, ascospore wall assembly, spore wall assembly, spore wall biogenesis, and ascospore wall biogenesis.Subsequently, we bioinformatically predicted 555 secreted effector candidates, among which only 125 were expressed during infection and had amino acid lengths less than 400. The putative effector Pb010018, which was highly expressed at 14 DAI, was validated to have a signal peptide using a yeast secretion system. Luciferase activity and co-immunoprecipitation assays demonstrated that Pb010018 interacts with serine hydroxymethyltransferase BrSHMT1, and expression analysis showed that SHMT1 was upregulated in both Arabidopsis and B. rapa during infection. Furthermore, after infection, the Arabidopsis shmt1 mutant(atshmt1) showed reduced severity of clubroot disease, together with downregulated expression of Pb010018. Our results offer new insights into plant-pathogen interaction mechanisms, and provide the possibility for improving Brassica resistance to clubroot disease.展开更多
基金supported by the Science and Technology Talent Promotion Project(2023TJ-Z09)Innovation Program(2023RC1077,2023JJ40279)of Hunan Province,China.
文摘Brassica clubroot caused by Plasmodiophora brassicae has been identified as a severe soil-borne disease that poses a significant threat to plants root systems.The disease results in the formation of tumorous enlargements in the roots,leading to wilting and eventual plant death.Consequently,crop yield is drastically reduced,causing substantial economic losses in agriculture.The current study aims to provide a comprehensive overview of recent research process on Brassica clubroot,focusing on the biological characteristics,physiological race identification,and pathogenic mechanism of P.brassicae.Furthermore,it covers the latest advancements in the comprehensive prevention and clubroot control.The insights gained from this study are expected to contribute to the future research on clubroot and the development of resistance breeding strategies.
基金supported by the China Agriculture Research System(Grant No.CARS-23-A13)Hubei Agrotechnical Major Project(Grant No.2021-620-000-001-01)+1 种基金Wuhan Major Project of Key Technologies in Biological Breeding and New Variety Cultivation(Grant No.2022021302024852)HZAU-AGIS Cooperation Fund(Grant No.SZYJY2023022).
文摘Clubroot caused by Plasmodiophora brassicae is a devastating disease of Cruciferous crops.Developing cultivars with clubroot resistance(CR)is the most effective control measure.For the two major Brassica vegetable species B.rapa and B.oleracea,several commercial cultivars with unclear CR pedigrees have been intensively used as CR donors in breeding.However,the continuous occurrence of CR-breaking makes the CR pedigree underlying these cultivars one of the breeders'most urgent concerns.The complex intraspecific diversity of these two major Brassica vegetables has also limited the applicability of CR markers in different breeding programs.Here we first traced the pedigree underlying two kinds of CR that have been widely applied in breeding by linkage and introgression analyses based on public resequencing data.In B.rapa,a major locus CRzi8 underlying the CR of the commercial CR donor‘DegaoCR117’was identified.CRzi8 was further shown to have been introgressed from turnip(B.rapa ssp.rapifera)and that it carried a potential functional allele of Crr1a.The turnip introgression carried CRb^(c),sharing the same coding sequence with the CRb that was also identified from chromosome C07 of B.oleracea CR cultivars with different morphotypes.Within natural populations,variation analysis of linkage intervals of CRzi8,PbBa8.1,CRb,and CRb^(c)yielded easily resolved InDel markers(>20 bp)for these fundamental CR genes.The specificity of these markers was tested in diverse cultivars panels,and each exhibited high reliability in breeding.Our research demonstrates the value of the practice of applying resequencing big data to solve urgent concerns in breeding programs.
基金supported by the Genomics Initiative of Agriculture and Agri-Food Canada。
文摘Clubroot disease is a severe threat to Brassica crops globally,particularly in western Canada.Genetic resistance,achieved through pyramiding clubroot resistance(CR)genes with different modes of action,is the most important strategy for managing the disease.However,studies on the CR gene functions are quite limited.In this study,we have conducted investigations into the temporal,structural,and interacting features of a newly cloned CR gene,Rcr1,using CRISPR/Cas9 technology.For temporal functionality,we developed a novel CRISPR/Cas9-based binary vector,pHHIGR-Hsp18.2,to deliver Rcr1 into a susceptible canola line(DH12075)and observed that early expression of Rcr1 is critical for conferring resistance.For structural functionality,several independent mutations in specific domains of Rcr1 resulted in loss-offunction,highlighting their importance for CR phenotype.In the study of the interacting features of Rcr1,a cysteine protease gene and its homologous allele in canola were successfully disrupted via CRISPR/Cas9 as an interacting component with Rcr1 protein,resulting in the conversion from clubroot resistant to susceptible in plants carrying intact Rcr1.These results indicated an indispensable role of these two cysteine proteases in Rcr1-mediated resistance response.This study,the first of its kind,provides valuable insights into the functionality of Rcr1.Further,the new vector p HHIGR-Hsp18.2 demonstrated an inducible feature on the removal of add-on traits,which should be useful for functional genomics and other similar research in brassica crops.
基金Supported by Natural Science Foundation of Jiangsu Province(BK20130715)National Science and Technology Program for Rural Development during the 12~(th) Five-Year Plan Period(2013BAD01B04-11)~~
文摘Objective] This study was conducted to investigate the genetic inheritance of clubroot resistance in Chinese non-heading cabbage （Brassica campestris ssp. chinensis）. [Method] The clubroot resistance gene was introduced from a Brassica campestris ssp. pekinensis cultivar to non-heading Chinese cabbage, and the inheri-tance and molecular markers of clubroot resistance gene in parental lines, F1, F2 and BC1 of non-heading Chinese cabbage were studied through pathogen inoculation at seedling stage and ISSR-PCR. [Result] Clubroot resistance in non-heading Chi-nese cabbage was control ed by a single dominant gene. ISSR molecular markers with Bulk segregant analysis （BSA） found that primer-873 was linked to resistance gene, named CR-873, and the genetic distance between the marker and the resis-tance gene was 9.72 cM. [Conclusion] The results provide references for the molecular marker assisted breeding of non-heading Chinese cabbage.
文摘[Objective] The paper was to study the relationship between cytokinin and Chinese cabbage clubroot, and to explore the incidence mechanism of clubroot. [Method]The spores were extracted from the tumors of diseased plant, and their DNA was extracted for PCR test. The diagnosed spores were inoculated to the culture soils in erlenmeyer flask at seeding stage, at seed germination and 21 d after sowing, and 0.08 μmol/L 6-BA was added to the soil at germination. Spores were extracted from the root tumors developed in inoculated plants and examined by scanning electronic microscope （ SEM）, and the incidence rate of clubroot in 6-BA treatment and control was recorded. [ Result] Plasmodiophora brassicae Woron could cause the clubroot incidence of Chinese cabbage planted in erlenmeyer flasks, the incidence rate of chibroot in the treatment adding with 0.08 μmol/L 6-BA was 100%, while that in the treatment without 6-BA was 57%, and the volume of former tumor was much larger than the latter. SEM showed that the size of resting spore of P. brassicae was 1.5 -4.3μm. [ Conduslon] 6-BA applied at germination could significantly promote the formation of tumor of Chinese cabbage clubroot.
基金This work was supported by the National Key Research and Development Program of China(2017YFD0200600)the Financial Innovation Capacity Enhancement Project in Sichuan Province,China(2019QNJJ-011)the National Modern Agricultural Industry technology System of Sichuan Rape Innovation Team,China(2019-2023).
文摘Clubroot disease, caused by Plasmodiophora brassicae, is one of the most destructive soil-borne diseases in cruciferous crops worldwide. New strategies are urgently needed to control this disease, as no effective disease-resistant varieties or chemical control agents exist. Previously, we found that the incidence rate and disease index of clubroot in oilseed rape decreased by 50 and 40%, respectively, when oilseed rape was planted after soybean. In order to understand how different rotation patterns affect the occurrence of clubroot in oilseed rape, high-throughput sequencing was used to analyze the rhizosphere microbial community of oilseed rape planted after leguminous (soybean, clover), gramineous (rice, maize) and cruciferous (oilseed rape, Chinese cabbage) crops. Results showed that planting soybeans before oilseed rape significantly increased the population density of microbes that could inhibit P. brassicae (e.g., Sphingomonas, Bacillus, Streptomyces and Trichoderma). Conversely, consecutive cultivation of cruciferous crops significantly accumulated plant pathogens, including P. brassicae, Olpidium and Colletotrichum (P<0.05). These results will help to develop the most effective rotation pattern for reducing clubroot damage.
基金supported by the China Agriculture Research System of MOF and MARA(CARS-12)the Open Fund of the National Key Laboratory of Crop Genetic Improvement(ZK201909)。
文摘Clubroot and herbicide resistance,high oleic acid(OA)content,and early maturity are targets of rapeseed(Brassica napus L.)breeding.The objective of this study was to develop new male-fertility restorer lines by pyramiding favorable genes to improve these traits simultaneously.Seven elite alleles for the four traits were introduced into the restorer line 621R by speed breeding with marker-assisted and phenotypic selection.Six introgression lines(ILs)were developed with four-to seven-gene combinations and crossed with two elite parents to develop hybrids.All ILs and their corresponding hybrids displayed high resistance to both clubroot pathotype 4 and sulfonylurea herbicides.Three ILs and their hybrids showed large increases in OA contents and four showed earlier maturity.These new ILs may be useful in rapeseed hybrid breeding for the target traits.
基金Supported by Major Project of New Product Development of Yunnan Provincial Science and Technology Department(2015BB007,2012BB017)International Cooperation Project of Yunnan Provincial Science and Technology Department(2014IA016)+2 种基金Project of Science and Technology to Strengthen the County and Enrich the People of Yunnan Provincial Science and Technology Department(2014EB033)National Bulk Vegetable Industry Technology System of China(CARS-25-G-45)New Vegetable Variety Cooperation Project of Yunnan Provincial Department of Agriculture[YCN(2012)No.58]
文摘In this study, using Japanese radish cytoplasmic sterile line ＂Half Green Cabbage＂ （HGC） and clubfoot-resistant South Korean cabbage variety ＂ CR Cabbage King＂ （CCK） as experimental materials, serf-incompatible DH lines were obtained by mierosporo culture. Through five gnerations of backeross, CCR11239, a clubroot-resistant radish cytoplasmic sterile line, was obtained. Through six generations of serf-crossing, CCR11240, the maintainer line of CCR11239, was bred. After the cross of CCK and Luchunbai 1 （83 - 1 ） and five generations of self-crossing, serf-compatible line CCRl1241 was obtained. Through crossing CCR11240 with CCRl1241, the new cabbage variety CCRl1242 was obtained. After variety comparison test, provincial regional test and production demonstration test, the new variety was registered in 2012. The average yield of CCR11242 reached 60 975 kg/hm2, which was improved by 142% compared with Luchunbai 1 （83 - 1 ）. The disease index of CCR11242 was 5.63, which was 88.13 lower than the control, indicating high resistance （HR） to clubfoot.
基金Supported by Key New Product Plan of Yunnan Provincial Science and Technology Department(2015BB007)International Cooperation Project of Yunnan Provincial Science and Technology Department(2014IA016)+1 种基金Science and Technology Plan for Enriching People and Strengthening County of Yunnan Provincial Science and Technology Department(2014EB033)National Bulk Vegetable Industry Technology System(CARS-23)
文摘[Objective] The paper was to analyze the inheritance of clubroot resistance of miniature Chinese baby cabbage,to shorten identification time and to improve breeding efficacy of new disease-resistant varieties. [Method] Taking clubroot-resistant Chinese cabbage CCR001,disease-susceptible baby cabbage CM002,and their F_1,F_2 and BC_1 offspring as the research objects,the inheritance of clubroot resistance of baby cabbage was studied. [Result]The clubroot-resistance of baby cabbage was controlled by a single dominant gene,which conformed to Mendel＇s Laws of inheritance. The molecular markers-assisted selection combing with bacterial soil inoculation confirmed that the disease-resistance indeed passed on from the parents,and was inherited in F_1 and F_2. [Conclusion]It is feasible to breed clubroot-resistant baby cabbage by using molecular markers-assisted selection.
基金Supported by the National Key Research and Development Project(2017YFD0101803)
文摘The transcriptome-wide gene expression was compared between susceptible and resistant Chinese cabbage cultivars to identify genes that contributed to clubroot resistance. A higher number of differentially expressed genes were detected in susceptible cultivars than in resistant cultivars. Fifty-six genes involved in cell wall modification, hormone signaling, root marphogenesis, nematodes response and cell proliferation were uniquely expressed in the resistant cultivars. Among them, 27 genes were involved in cell wall modification and hormone signaling, indicating that genes in these two types might play a vital role in the defense response to pathogen infection.
基金supported by the National Natural Science Foundation of China (31872945 and 31801874)the earmarked fund for China Agricultural Research System (CARS-23-G15)+1 种基金the Funds for Distinguished Young Scientists from Henan Academy of Agricultural Sciences, China (2021JQ03)the Innovation Team of Henan Academy of Agricultural Sciences, China (2021TD06)。
文摘Chinese cabbage is an economically important Brassica vegetable worldwide, and clubroot, which is caused by the soilborne protist plant pathogen Plasmodiophora brassicae is regarded as a destructive disease to Brassica crops. Previous studies on the gene transcripts related to Chinese cabbage resistance to clubroot mainly employed RNA-seq technology,although it cannot provide accurate transcript assembly and structural information. In this study, PacBio RS II SMRT sequencing was used to generate full-length transcriptomes of mixed roots at 0, 2, 5, 8, 13, and 22 days after P. brassicae infection in the clubroot-resistant line DH40R. Overall, 39 376 high-quality isoforms and 26 270 open reading frames(ORFs) were identified from the SMRT sequencing data. Additionally, 426 annotated long noncoding RNAs(lncRNAs),56 transcription factor(TF) families, 1 883 genes with poly(A) sites and 1 691 alternative splicing(AS) events were identified. Furthermore, 1 201 of the genes had at least one AS event in DH40R. A comparison with RNA-seq data revealed six differentially expressed AS genes(one for disease resistance and five for defensive response) that are potentially involved in P. brassicae resistance. The results of this study provide valuable resources for basic research on clubroot resistance in Chinese cabbage.
基金Financial support from the National Key Research and the Development Program of China (2018YFD0200902, 2016YFD0100202)
文摘Clubroot is a prevailing soil-borne disease affecting rapeseed production worldwide.However,few clubroot resistant rapeseed accessions were available for breeding.Identification and introgression of new clubroot resistant genes from closely related species by distant hybridization is an effective strategy.In the present study,9 radish(Raphanus sativus L.,2n=18,RR)lines resistant to Plasmodiophora brassicae pathotype 4 were used as donors to transfer clubroot resistance into a susceptible rapeseed(Brassica napus L.,2n=38,AACC)line by distant hybridization combined with embryo rescue.Nine intergeneric crosses were made but only 1(411×93039)produced F1 plants both from embryo rescue and natural seed-setting.Authenticity of triploid F1 hybrids(2n=28,ACR)were verified by flower color,cytological observation and molecular marker analysis,and 2 genuine F1 hybrids were identified.After chromosome doubling,these synthetic allohexaploid plants(2n=56,AACCRR)became partially fertile(pollen viability rate=35%)and were backcrossed with rapeseed parent to generate a BC1 population(2n=47,AACCR).Totally 178 BC1 plants were obtained,of which the majority(96.1%)were resistant to clubroot.These backcrossing progenies could be used for the breeding of new rapeseed varieties resistant to clubroot.
文摘Clubroot caused by the protist Plasmodiophora brassicae is a major disease affecting cultivated Brassica-ceae.Using a combination of quantitative trait locus(QTL)fine mapping,CRISPR-Cas9 validation,and extensive analyses of DNA sequence and methylation patterns,we revealed that the two adjacent neigh-boring NLR(nucleotide-binding and leucine-rich repeat)genes AT5G47260 and AT5G47280 cooperate in controlling broad-spectrum quantitative partial resistance to the root pathogen P.brassicae in Arabidopsis and that they are epigenetically regulated.The variation in DNA methylation is not associated with any nucleotide variation or any transposable element presence/absence variants and is stably inherited.Vari-ations in DNA methylation at the Pb-At5.2 QTL are widespread across Arabidopsis accessions and corre-late negatively with variations in expression of the two genes.Our study demonstrates that natural,stable,and transgenerationally inherited epigenetic variations can play an important role in shaping resistance to plant pathogens by modulating the expression of immune receptors.
文摘根肿病和草害严重威胁油菜的产量和品质。为选育抗根肿病(clubroot-resistant,CR)和抗除草剂(herbicide-resistant,HR)的油菜品种,通过分子标记辅助选择聚合育种策略将抗根肿病位点CRb和PbBa8.1、抗除草剂位点ALS1R和ALS3R导入油菜常规品种中双11(ZS11)中,获得3个改良株系ZS11CR(CRb+PbBa8.1)、ZS11HR(ALS1R+ALS3R)和ZS11CHR(CRb+PbBa8.1+ALS1R+ALS3R)。利用根肿菌4号生理小种(湖北枝江)和噻吩磺隆除草剂(45 g a.i.ha^(-1))对ZS11CR、ZS11HR和ZS11CHR的抗性进行评价,结果表明:ZS11CR、ZS11CHR对4号生理小种抗性达到免疫水平,ZS11HR、ZS11CHR对噻吩磺隆除草剂抗性显著。田间农艺性状调查结果表明,ZS11CR、ZS11HR和ZS11CHR的株高较ZS11一定程度增加,而在开花期、分枝数、主花序角果数、角果长、每角果粒数、千粒重等性状上没有显著差异。本研究获得了3个改良株系,其中ZS11CR具有根肿病抗性、ZS11HR具有除草剂抗性、ZS11CHR兼具根肿病抗性和除草剂抗性,这些改良株系不仅目标性状得到了改良,同时维持了ZS11的优良农艺性状,具有一定的应用潜力。
基金supported by the Youth Foundation of Beijing Academy of Agriculture and Forestry Sciences[Grant No.QNJJ202242]the Excellent Young Scholars of Beijing Academy of Agriculture and Forestry Sciences[Grant No.YXQN202205]+3 种基金the Beijing Nova Program[Grant No.20220484052]the National Natural Science Foundation of China[Grant No.31801852]the Collaborative Innovation Center of Beijing Academy of Agriculture and Forestry Sciences[Grant No.KJCX201907-2]the Earmarked Fund for China Agriculture Research System[Grant No.CARS-23-A-05].
文摘The soil-resident pathogen, Plasmodiophora brassicae, infects cruciferous crops, causing obligate parasitic clubroot disease and posing a significant threat to the Brassica vegetable industry in China. To learn more about its pathogenesis, we reported a Nanopore sequencing-derived25.3 Mb high-quality genome sequence of P. brassicae pathotype 4 strain(P.b 4). Comparing the P.b 4 genome with that of the published P.brassicae e3 genome(P.b e3) identified single nucleotide polymorphisms, structural variations, and small insertions and deletions. We then carried out RNA-sequencing of root samples from a clubroot-susceptible line at 5, 14, and 28 days after inoculation(DAI), and classified genes into five categories based on their expression patterns. Interestingly, 158 genes were highly expressed at 14 DAI, which were enriched in budding cell isotropic bud growth, ascospore wall assembly, spore wall assembly, spore wall biogenesis, and ascospore wall biogenesis.Subsequently, we bioinformatically predicted 555 secreted effector candidates, among which only 125 were expressed during infection and had amino acid lengths less than 400. The putative effector Pb010018, which was highly expressed at 14 DAI, was validated to have a signal peptide using a yeast secretion system. Luciferase activity and co-immunoprecipitation assays demonstrated that Pb010018 interacts with serine hydroxymethyltransferase BrSHMT1, and expression analysis showed that SHMT1 was upregulated in both Arabidopsis and B. rapa during infection. Furthermore, after infection, the Arabidopsis shmt1 mutant(atshmt1) showed reduced severity of clubroot disease, together with downregulated expression of Pb010018. Our results offer new insights into plant-pathogen interaction mechanisms, and provide the possibility for improving Brassica resistance to clubroot disease.
