The plant pathogenic fungus Sclerotinia sclerotiorum is the causative agent of Sclerotinia stem rot(SSR)disease in most dicotyledons.Among the various proteins involved in drug efflux or substance transport,ATP-bindin...The plant pathogenic fungus Sclerotinia sclerotiorum is the causative agent of Sclerotinia stem rot(SSR)disease in most dicotyledons.Among the various proteins involved in drug efflux or substance transport,ATP-binding cassette(ABC)transporters constitute a superfamily of membrane-bound proteins that may play a crucial role in the survival of S.sclerotiorum.However,the expression patterns and functions of ABC transporter genes in S.sclerotiorum remain largely uncharacterized.This study characterized a highly expressed S.sclerotiorum ABC transporter gene during inoculation on host plants,Ss BMR1.Silencing Ss BMR1 resulted in a significant reduction in hyphal growth,infection cushion development,sclerotia formation,and virulence.Moreover,host-induced gene silencing(HIGS)of Ss BMR1 significantly enhanced plant resistance.Transcriptome and metabolomics analyses suggested that Ss BMR1 is involved in antioxidant and toxin transport,thereby influencing fungal defense and cell rescue mechanisms.In comparison to the wild-type strain,Ss BMR1 gene-silenced transformants exhibited a diminished response to extracellar oxidative stress and a decreased exporting of antioxidant glutathione.Tolerance assays further demonstrated the crucial role of Ss BMR1 in conferring resistance to the plant antifungal substances,camalexin and brassinin,as well as certain fungicides.Furthermore,Ss BMR1 gene-silenced transformants showed enhanced repression on virulence when sprayed with camalexin and brassinin on the leaves.Thus,Ss BMR1 likely contributes to virulence by facilitating the export of antioxidant and providing resistance against antifungal agents.The findings of this study provide valuable insights that could contribute to the development of novel management techniques for SSR.展开更多
White mold of pea caused by Sclerotinia sclerotiorum is a common disease in China.However,we discovered that the diverse Sclerotinia species could cause white mold on pea plants in Chongqing and Sichuan of China durin...White mold of pea caused by Sclerotinia sclerotiorum is a common disease in China.However,we discovered that the diverse Sclerotinia species could cause white mold on pea plants in Chongqing and Sichuan of China during recent disease surveys.Thus,the objective of this study was to confirm the causal agents from diseased pea plants.The obtained isolates of white mold from Chongqing and Sichuan were identified by morphological characters and molecular characterization to determine the pathogen species,and their pathogenicity was confirmed on pea through completing Koch’s postulates.Fungal isolates of Sclerotinia-like were obtained from diseased plants or sclerotia.Based on morphological characteristics and molecular characterization,30 isolates were identified to three species,six isolates as S.minor,seven as S.sclerotiorum,and 17 as S.trifoliorum.In pathogenicity tests on pea cultivars Zhongwan 4 and Longwan 1,all 30 isolates caused typical symptoms of white mold on the inoculated plants,and the inoculated pathogens were re-isolated from the diseased plants.This study confirmed that white mold of pea was caused by three Sclerotinia species,S.sclerotiorum,S.minor and S.trifoliorum in Chongqing and Sichuan.It is the first report that S.minor and S.trifoliorum cause white mold of pea in Southwest China.展开更多
[Objective] The study was to investigate roles of Brassica napus EINB in （ BnEIN3 ） resistance to Sclerotinia sclerotiorum. [ Methods] Genomic PCR and RT-PCR were carded out to isolate genomic DNA and cDNA sequences...[Objective] The study was to investigate roles of Brassica napus EINB in （ BnEIN3 ） resistance to Sclerotinia sclerotiorum. [ Methods] Genomic PCR and RT-PCR were carded out to isolate genomic DNA and cDNA sequences of BnEIN3 from oilseed rape, based on the highly conserved region of EIN3 gene from Arabidopsis thaliana and the homologous sequences of oilseed rape ESTs. Expression levels of BnEIN3 were detected in three varieties of oilseed rape inoculated with S. sclerotiorum by real-time quantitative PCR.[Results] A 1 947 bp DNA fragment was obtained from oilseed rape. The fragment shared 82% identity to A. thaliana EIIV3, encoded 614 amino acids containing an EIN3 domain, and was named as BnEIN3. Real-time PCR results showed that expression patterns of BnEIN3 were drastically different in different varieties. In highly resistant oilseed rape variety D083, BnEIN3 expression level was significantly increased 72 h after S. sclerotiorum inoculation whereas in middle resistant and susceptible varieties Zhongshuang 9 and 84039, BnEIN3 expression was suppressed. [ Conclusion ] BnEIIV3 may play an important role in oilseed rape resistance to S. sclerotiorum.展开更多
[ Objective] The paper was to study ISSR molecular makers of resistant gene against Sclerotinia trifoliorum in Medicago sativa L. [ Method] Using mi- crosatellite markers （ISSR） molecular maker technology, combined ...[ Objective] The paper was to study ISSR molecular makers of resistant gene against Sclerotinia trifoliorum in Medicago sativa L. [ Method] Using mi- crosatellite markers （ISSR） molecular maker technology, combined with bulked-segregant analysis （BSA） method, the molecular makers for gene linkage with re- sistance against S. trifoliorum were screened from five resistant plants and seven susceptible plants. Leaf in vitro inoculation method was used to carry out resistant verification on 94 hybrid plants in Ft generation of high resistant No. 83 ~ high susceptible No. 4. [ Result] Among 93 ISSR primers, 35 primers could produce clear and stable amplification bands, and six of them could produce 9 specific bands between resistant and susceptible DNA pools. Resistance verification result showed that 825 - 1400, 831 - 1480, 850 - 1800, 858 - 1600, 866 - 1900, 888 - 1400 could be used as ISSR molecular makers of the resistant gene against S. trifoliorum in M. sativa. [Conclusion] The results provided basis for the further research on mapping,, cloning and genetically modified of resistant gene against S. trifoliorum in M. sativa.展开更多
Zhongshuang9, a new semi-winter Brassica napus variety with high resistance to Sclerotinia sclerotiorum and lodging, high-yield, double-low quality and extensive adaptability, was bred by multiple crossing and microsp...Zhongshuang9, a new semi-winter Brassica napus variety with high resistance to Sclerotinia sclerotiorum and lodging, high-yield, double-low quality and extensive adaptability, was bred by multiple crossing and microspore culture technique. It was registered and released in China in 2002. In regional trial of Hubei Province in China, Zhongshuang9 yielded 2 482. 2 kg ha-1 averagely in 2000 - 2002, 15. 33% higher than the control variety Zhongyou821. Erucic acid, glucosinolates and oil contents of Zhongshuang9 were 0.23%, 22.69 μmol g-1(in meal)and 42%, respectively. In field assessment of resistance to S. Sclerotiorum , the disease incidence and disease index of Zhongshuang9 averaged 13.31 % and 6.47, respectively, which were lower than those of Zhongyou821 by 28% and 36%, respectively. After inoculation of detached leaves with mycelia, the lesion size of Zhongshuang9 was 4. 709 cm2, which was significantly smaller than that of the mid-resistant variety Zhongyou821(5. 933 cm2). The stem lesion length of Zhongshuang9 after match-stick inoculation was 1.275 cm, which was significantly lower than that of Zhongyou821(1.943 cm). The possible mechanism of resistance to S. sclerotiorum was studied through comparing the activities of phenylalanine ammonia lyase(PAL), exo-chitinase, β-1, 3-glucanase, peroxidase(POD)and polyphenoloxidase(PPO)in Zhongshuang9 with those in other resistant, mid-resistant and susceptible cultivars.展开更多
Sclerotinia stem rot(SSR) caused by Sclerotinia sclerotiorum(Lib.) de Bary is one of the most devastating diseases of Brassica napus worldwide. Both SSR resistance and flowering time(FT) adaptation are major breeding ...Sclerotinia stem rot(SSR) caused by Sclerotinia sclerotiorum(Lib.) de Bary is one of the most devastating diseases of Brassica napus worldwide. Both SSR resistance and flowering time(FT) adaptation are major breeding goals in B. napus. However, early maturing rapeseed varieties, which are important for rice-rapeseed rotation in China, are often highly susceptible to SSR. Here, we found that SSR resistance was significantly negatively correlated with FT in a natural population containing 521 rapeseed inbred lines and a double haploid(DH) population with 150 individual lines, both of which had great variation in FT. Four chromosomal regions on A2, A6, C2, and C8 affecting both SSR resistance and FT were identified using quantitative trait loci(QTL) mapping after constructing a high-density genetic map based on single nucleotide polymorphism markers in the DH population.Furthermore, we aligned QTL for the two traits identified in the present and previous studies to the B. napus reference genome, and identified four colocalized QTL hotspots of SSR resistance and FT on A2(0–7.7 Mb), A3(0.8–7.5 Mb), C2(0–15.2 Mb), and C6(20.2–36.6 Mb). Our results revealed a genetic link between SSR resistance and FT in B.napus, which should facilitate the development of effective strategies in both early maturing and SSR resistance breeding and in map-based cloning of SSR resistance QTL.展开更多
Sclerotinia sclerotiorum is generally considered one of the most economically damaging pathogens in oilseed rape(Brassica napus).Breeding for Sclerotinia resistance is challenging,as no immune germplasm available in B...Sclerotinia sclerotiorum is generally considered one of the most economically damaging pathogens in oilseed rape(Brassica napus).Breeding for Sclerotinia resistance is challenging,as no immune germplasm available in B.napus.It is desirable to develop new breeding strategies.In the present study,hostinduced gene silencing(HIGS),developed based on RNA interference(RNAi),was applied to protect B.napus from S.sclerotiorum infection.Three pathogenicity genes,the endo-polygalacturonase gene(Ss PG1),cellobiohydrolase gene(Ss CBH),and oxaloacetate acetylhydrolase gene(Ss OAH1),were chosen as HIGS targets.Co-incubation of synthesized double-stranded RNAs(ds RNAs)with S.sclerotiorum in liquid medium significantly reduced the transcript levels of the target genes.Application to plant surfaces of ds RNA targeting the three genes conferred effective protection against S.sclerotiorum.Stable transgenic B.napus plants expressing small interfering RNAs with sequence identity to Ss PG1,Ss CBH,and Ss OAH1 were generated.HIGS transgenic B.napus prevented the expression of S.sclerotiorum target genes,slowed pathogenicity-factor accumulation,impeded fungal growth,and suppressed appressorium formation,thereby conferring resistance to S.sclerotiorum.Simultaneous silencing of Ss PG1,Ss CBH,and Ss OAH1 by stable expression of a chimeric hairpin RNAi construct in B.napus led to enhanced protection phenotypes(with disease lesion size reduced by 36.8%–43.7%).We conclude that HIGS of pathogenic-factor genes of S.sclerotiorum is a promising strategy for controlling Sclerotinia rot in oilseed rape.展开更多
A dry flowable formulation of Clonostachys rosea with fungicidal activity against Sclerotinia sclerotiorum was prepared by spray drying. The formulation was optimized by a four-factor, three-level orthogonal experimen...A dry flowable formulation of Clonostachys rosea with fungicidal activity against Sclerotinia sclerotiorum was prepared by spray drying. The formulation was optimized by a four-factor, three-level orthogonal experiment to screen inert ingredients and spray-drying conditions. The optimal dry flowable formulation of C. rosea included 30% C. rosea （ratio of conidia powder and its fermentation broth is 1：3）, 3% Morwet EFW, 4% K12, 10% Morwet D425, 9% sodium salt of polynaphthalene sulphonic acid （NNO）, 5% croscarmellose sodium, 5% （NH4）2SO4, 0.5% carboxymethyl cellulose sodium （CMC-Na）, 1% oxalic acid and palygorskite （carrier） up to 100%. The formulation exhibited good physical characteristics, such as high dispersibility, viability and a long shelf life. Plate antagonism tests and pot trials indicated that the dry flowable formulation was very effective against S. sclerotiorum, with control efficiency of up to 88.30%. This dry flowable formulation of C. rosea is a new potential commercial fungicide for spray drying to control S. sclerotiorum.展开更多
Sclerotinia sclerotiorum is one of the most devastating necrotrophic phytopathogens. Virulence of the hyphae of this fungus at different ages varies significantly. Molecular mechanisms underlying this functional disti...Sclerotinia sclerotiorum is one of the most devastating necrotrophic phytopathogens. Virulence of the hyphae of this fungus at different ages varies significantly. Molecular mechanisms underlying this functional distinction are largely unknown. In this study, we confirmed the effect of mycelial culture time/age on virulence in two host plants and elucidated its molecular and morphological basis. The virulence of the S. sclerotiorum mycelia in plants dramatically decreases along with the increase of the mycelial age. Three-day-old mycelia lost the virulence in plants. Comparative proteomics analyses revealed that metabolism pathways were comprehensively reprogrammed to suppress the oxalic acid（OA） accumulation in old mycelia. The oxaloacetate acetylhydrolase（OAH）, which catalyzes OA biosynthesis, was identified in the S. sclerotiorum genome. Both gene expression and protein accumulation of OAH in old mycelia were strongly repressed. Moreover, in planta OA accumulation was strikingly reduced in old mycelia-inoculated plants compared with young vegetative mycelia-inoculated plants. Furthermore, supply with 10 mmol L^（-1） OA enabled the old mycelia infect the host plants, demonstrating that loss of virulence of old mycelia is mainly caused by being unable to accumulate OA. Additionally, aerial mycelia started to develop from 0.5-day-old vegetative mycelia and dominated over 1-day-old mycelia grown on potato dextrose agar plates. They were much smaller in hypha diameter and grew significantly slower than young vegetative mycelia when subcultured, which did not maintain to progenies. Collectively, our results reveal that S. sclerotiorum aerial hyphae-dominant old mycelia fail to accumulate OA and thereby lose the virulence in host plants.展开更多
基金received financial support from the Natural Science Foundation of Chongqing,China(CSTB2023NSCQMSX0355)the Fundamental Research Funds for the Central Universities,China(SWU120075)the National Natural Science Foundation of China(32372077)。
文摘The plant pathogenic fungus Sclerotinia sclerotiorum is the causative agent of Sclerotinia stem rot(SSR)disease in most dicotyledons.Among the various proteins involved in drug efflux or substance transport,ATP-binding cassette(ABC)transporters constitute a superfamily of membrane-bound proteins that may play a crucial role in the survival of S.sclerotiorum.However,the expression patterns and functions of ABC transporter genes in S.sclerotiorum remain largely uncharacterized.This study characterized a highly expressed S.sclerotiorum ABC transporter gene during inoculation on host plants,Ss BMR1.Silencing Ss BMR1 resulted in a significant reduction in hyphal growth,infection cushion development,sclerotia formation,and virulence.Moreover,host-induced gene silencing(HIGS)of Ss BMR1 significantly enhanced plant resistance.Transcriptome and metabolomics analyses suggested that Ss BMR1 is involved in antioxidant and toxin transport,thereby influencing fungal defense and cell rescue mechanisms.In comparison to the wild-type strain,Ss BMR1 gene-silenced transformants exhibited a diminished response to extracellar oxidative stress and a decreased exporting of antioxidant glutathione.Tolerance assays further demonstrated the crucial role of Ss BMR1 in conferring resistance to the plant antifungal substances,camalexin and brassinin,as well as certain fungicides.Furthermore,Ss BMR1 gene-silenced transformants showed enhanced repression on virulence when sprayed with camalexin and brassinin on the leaves.Thus,Ss BMR1 likely contributes to virulence by facilitating the export of antioxidant and providing resistance against antifungal agents.The findings of this study provide valuable insights that could contribute to the development of novel management techniques for SSR.
基金supported by the China Agriculture Research System of MOF and MARA(CARS-08)the National Crop Germplasm Resources Center of China(NCGRC-2020-09)the Scientific Innovation Program of the Chinese Academy of Agricultural Sciences。
文摘White mold of pea caused by Sclerotinia sclerotiorum is a common disease in China.However,we discovered that the diverse Sclerotinia species could cause white mold on pea plants in Chongqing and Sichuan of China during recent disease surveys.Thus,the objective of this study was to confirm the causal agents from diseased pea plants.The obtained isolates of white mold from Chongqing and Sichuan were identified by morphological characters and molecular characterization to determine the pathogen species,and their pathogenicity was confirmed on pea through completing Koch’s postulates.Fungal isolates of Sclerotinia-like were obtained from diseased plants or sclerotia.Based on morphological characteristics and molecular characterization,30 isolates were identified to three species,six isolates as S.minor,seven as S.sclerotiorum,and 17 as S.trifoliorum.In pathogenicity tests on pea cultivars Zhongwan 4 and Longwan 1,all 30 isolates caused typical symptoms of white mold on the inoculated plants,and the inoculated pathogens were re-isolated from the diseased plants.This study confirmed that white mold of pea was caused by three Sclerotinia species,S.sclerotiorum,S.minor and S.trifoliorum in Chongqing and Sichuan.It is the first report that S.minor and S.trifoliorum cause white mold of pea in Southwest China.
文摘[Objective] The study was to investigate roles of Brassica napus EINB in （ BnEIN3 ） resistance to Sclerotinia sclerotiorum. [ Methods] Genomic PCR and RT-PCR were carded out to isolate genomic DNA and cDNA sequences of BnEIN3 from oilseed rape, based on the highly conserved region of EIN3 gene from Arabidopsis thaliana and the homologous sequences of oilseed rape ESTs. Expression levels of BnEIN3 were detected in three varieties of oilseed rape inoculated with S. sclerotiorum by real-time quantitative PCR.[Results] A 1 947 bp DNA fragment was obtained from oilseed rape. The fragment shared 82% identity to A. thaliana EIIV3, encoded 614 amino acids containing an EIN3 domain, and was named as BnEIN3. Real-time PCR results showed that expression patterns of BnEIN3 were drastically different in different varieties. In highly resistant oilseed rape variety D083, BnEIN3 expression level was significantly increased 72 h after S. sclerotiorum inoculation whereas in middle resistant and susceptible varieties Zhongshuang 9 and 84039, BnEIN3 expression was suppressed. [ Conclusion ] BnEIIV3 may play an important role in oilseed rape resistance to S. sclerotiorum.
基金Support by Research and Demonstration of Seed Breeding Technology of South Alfalfa(2009AB1183)Development of Fine Germplasm Resources of Pasture and New Variety Breeding(2009AA1008)~~
文摘[ Objective] The paper was to study ISSR molecular makers of resistant gene against Sclerotinia trifoliorum in Medicago sativa L. [ Method] Using mi- crosatellite markers （ISSR） molecular maker technology, combined with bulked-segregant analysis （BSA） method, the molecular makers for gene linkage with re- sistance against S. trifoliorum were screened from five resistant plants and seven susceptible plants. Leaf in vitro inoculation method was used to carry out resistant verification on 94 hybrid plants in Ft generation of high resistant No. 83 ~ high susceptible No. 4. [ Result] Among 93 ISSR primers, 35 primers could produce clear and stable amplification bands, and six of them could produce 9 specific bands between resistant and susceptible DNA pools. Resistance verification result showed that 825 - 1400, 831 - 1480, 850 - 1800, 858 - 1600, 866 - 1900, 888 - 1400 could be used as ISSR molecular makers of the resistant gene against S. trifoliorum in M. sativa. [Conclusion] The results provided basis for the further research on mapping,, cloning and genetically modified of resistant gene against S. trifoliorum in M. sativa.
文摘油菜菌核病(Sclerotinia sclerotiorum)是油菜生产上最重要的病害之一,其致病性可能来源于基因水平转移(Horizontal gene transfer,HGT).为认识其致病原理和寻找新的真菌抑制剂的靶点,首先通过BLASTp发现其基因XM_001585458.1编码蛋白XP_001585508.1与细菌比对结果中出现低E值3.23e-109和高SCORE值436,暗示存在HGT现象;进一步通过系统进化树的建立,发现该蛋白在进化分枝上更接近于细菌中由Streptomyces sp.C的NZ_CM000832.1基因编码的蛋白ZP_07291173;同时核苷酸组成分析也发现该基因与油菜菌核病菌基因组的碱基组成有较大差别,GC含量提高了14.95%.这些结果证明了XM_001585458.1的确存在基因水平转移事件.结构分析和COG蛋白功能分类显示该HGT序列编码蛋白XP_001585508.1具有FA58C_3(Coagulation factors 5/8 type C domain)、Kelch repeat type 1、Galactose-binding domain-like、Galactose oxidase/kelch,beta-propeller等保守结构域,应为一个膜蛋白并参与多糖代谢,推测该水平转移基因与S.sclerotiorum在侵染植物时进行细胞壁水解和致病性有关.
文摘Zhongshuang9, a new semi-winter Brassica napus variety with high resistance to Sclerotinia sclerotiorum and lodging, high-yield, double-low quality and extensive adaptability, was bred by multiple crossing and microspore culture technique. It was registered and released in China in 2002. In regional trial of Hubei Province in China, Zhongshuang9 yielded 2 482. 2 kg ha-1 averagely in 2000 - 2002, 15. 33% higher than the control variety Zhongyou821. Erucic acid, glucosinolates and oil contents of Zhongshuang9 were 0.23%, 22.69 μmol g-1(in meal)and 42%, respectively. In field assessment of resistance to S. Sclerotiorum , the disease incidence and disease index of Zhongshuang9 averaged 13.31 % and 6.47, respectively, which were lower than those of Zhongyou821 by 28% and 36%, respectively. After inoculation of detached leaves with mycelia, the lesion size of Zhongshuang9 was 4. 709 cm2, which was significantly smaller than that of the mid-resistant variety Zhongyou821(5. 933 cm2). The stem lesion length of Zhongshuang9 after match-stick inoculation was 1.275 cm, which was significantly lower than that of Zhongyou821(1.943 cm). The possible mechanism of resistance to S. sclerotiorum was studied through comparing the activities of phenylalanine ammonia lyase(PAL), exo-chitinase, β-1, 3-glucanase, peroxidase(POD)and polyphenoloxidase(PPO)in Zhongshuang9 with those in other resistant, mid-resistant and susceptible cultivars.
基金supported by the National Natural Science Foundation of China(31671725,31601330,31330057)the National Key Basic Research Program of China(2015CB150201)+1 种基金Science&Technology Special Project of Guizhou Academy of Agricultural Sciences([2014] 014,[2017] 08)the China Postdoctoral Science Foundation(2015M581867,2016T90514)
文摘Sclerotinia stem rot(SSR) caused by Sclerotinia sclerotiorum(Lib.) de Bary is one of the most devastating diseases of Brassica napus worldwide. Both SSR resistance and flowering time(FT) adaptation are major breeding goals in B. napus. However, early maturing rapeseed varieties, which are important for rice-rapeseed rotation in China, are often highly susceptible to SSR. Here, we found that SSR resistance was significantly negatively correlated with FT in a natural population containing 521 rapeseed inbred lines and a double haploid(DH) population with 150 individual lines, both of which had great variation in FT. Four chromosomal regions on A2, A6, C2, and C8 affecting both SSR resistance and FT were identified using quantitative trait loci(QTL) mapping after constructing a high-density genetic map based on single nucleotide polymorphism markers in the DH population.Furthermore, we aligned QTL for the two traits identified in the present and previous studies to the B. napus reference genome, and identified four colocalized QTL hotspots of SSR resistance and FT on A2(0–7.7 Mb), A3(0.8–7.5 Mb), C2(0–15.2 Mb), and C6(20.2–36.6 Mb). Our results revealed a genetic link between SSR resistance and FT in B.napus, which should facilitate the development of effective strategies in both early maturing and SSR resistance breeding and in map-based cloning of SSR resistance QTL.
基金the National Natural Science Foundation of China(32072020,U20A2028,and 31901504)the Jiangsu Agricultural Science and Technology Innovation Fund(CX(20)3120)+1 种基金the Project of Special Funding for Crop Science Discipline Development(yzuxk202006)the Priority Academic Program Development of Jiangsu Higher Education Institutions and the Qinglan Project of Yangzhou University。
文摘Sclerotinia sclerotiorum is generally considered one of the most economically damaging pathogens in oilseed rape(Brassica napus).Breeding for Sclerotinia resistance is challenging,as no immune germplasm available in B.napus.It is desirable to develop new breeding strategies.In the present study,hostinduced gene silencing(HIGS),developed based on RNA interference(RNAi),was applied to protect B.napus from S.sclerotiorum infection.Three pathogenicity genes,the endo-polygalacturonase gene(Ss PG1),cellobiohydrolase gene(Ss CBH),and oxaloacetate acetylhydrolase gene(Ss OAH1),were chosen as HIGS targets.Co-incubation of synthesized double-stranded RNAs(ds RNAs)with S.sclerotiorum in liquid medium significantly reduced the transcript levels of the target genes.Application to plant surfaces of ds RNA targeting the three genes conferred effective protection against S.sclerotiorum.Stable transgenic B.napus plants expressing small interfering RNAs with sequence identity to Ss PG1,Ss CBH,and Ss OAH1 were generated.HIGS transgenic B.napus prevented the expression of S.sclerotiorum target genes,slowed pathogenicity-factor accumulation,impeded fungal growth,and suppressed appressorium formation,thereby conferring resistance to S.sclerotiorum.Simultaneous silencing of Ss PG1,Ss CBH,and Ss OAH1 by stable expression of a chimeric hairpin RNAi construct in B.napus led to enhanced protection phenotypes(with disease lesion size reduced by 36.8%–43.7%).We conclude that HIGS of pathogenic-factor genes of S.sclerotiorum is a promising strategy for controlling Sclerotinia rot in oilseed rape.
基金supported by grants from the Fundamental Research Funds for the Central Universities, China (2572016DA02)the National Natural Science Foundation of China (31570642)the Science and Technology Innovation and Entrepreneurship Projects of Returned Overseas Personnel in Jilin Province, China (2013-36)
文摘A dry flowable formulation of Clonostachys rosea with fungicidal activity against Sclerotinia sclerotiorum was prepared by spray drying. The formulation was optimized by a four-factor, three-level orthogonal experiment to screen inert ingredients and spray-drying conditions. The optimal dry flowable formulation of C. rosea included 30% C. rosea （ratio of conidia powder and its fermentation broth is 1：3）, 3% Morwet EFW, 4% K12, 10% Morwet D425, 9% sodium salt of polynaphthalene sulphonic acid （NNO）, 5% croscarmellose sodium, 5% （NH4）2SO4, 0.5% carboxymethyl cellulose sodium （CMC-Na）, 1% oxalic acid and palygorskite （carrier） up to 100%. The formulation exhibited good physical characteristics, such as high dispersibility, viability and a long shelf life. Plate antagonism tests and pot trials indicated that the dry flowable formulation was very effective against S. sclerotiorum, with control efficiency of up to 88.30%. This dry flowable formulation of C. rosea is a new potential commercial fungicide for spray drying to control S. sclerotiorum.
基金supported by grants from the Special Fund for Agro-Scientific Research in the Public Interest, China (201103016)the Specialized Research Fund for the Doctoral Program of Higher Education, China (SRFDP) (20110101110092)+2 种基金the National Natural Science Foundation of China (31371892)the Program for New Century Excellent Talents in University (NCET-08-0485)the Program for New Century 151 Talents of Zhejiang Province, China
文摘Sclerotinia sclerotiorum is one of the most devastating necrotrophic phytopathogens. Virulence of the hyphae of this fungus at different ages varies significantly. Molecular mechanisms underlying this functional distinction are largely unknown. In this study, we confirmed the effect of mycelial culture time/age on virulence in two host plants and elucidated its molecular and morphological basis. The virulence of the S. sclerotiorum mycelia in plants dramatically decreases along with the increase of the mycelial age. Three-day-old mycelia lost the virulence in plants. Comparative proteomics analyses revealed that metabolism pathways were comprehensively reprogrammed to suppress the oxalic acid（OA） accumulation in old mycelia. The oxaloacetate acetylhydrolase（OAH）, which catalyzes OA biosynthesis, was identified in the S. sclerotiorum genome. Both gene expression and protein accumulation of OAH in old mycelia were strongly repressed. Moreover, in planta OA accumulation was strikingly reduced in old mycelia-inoculated plants compared with young vegetative mycelia-inoculated plants. Furthermore, supply with 10 mmol L^（-1） OA enabled the old mycelia infect the host plants, demonstrating that loss of virulence of old mycelia is mainly caused by being unable to accumulate OA. Additionally, aerial mycelia started to develop from 0.5-day-old vegetative mycelia and dominated over 1-day-old mycelia grown on potato dextrose agar plates. They were much smaller in hypha diameter and grew significantly slower than young vegetative mycelia when subcultured, which did not maintain to progenies. Collectively, our results reveal that S. sclerotiorum aerial hyphae-dominant old mycelia fail to accumulate OA and thereby lose the virulence in host plants.
