Covered smut, which is caused by Ustilago hordei（Pers.） Lagerh., is one of the most damaging diseases of highland barley（Hordeum vulgare Linn. var. nudum Hook. f） in Tibetan areas of China. To understand the molec...Covered smut, which is caused by Ustilago hordei（Pers.） Lagerh., is one of the most damaging diseases of highland barley（Hordeum vulgare Linn. var. nudum Hook. f） in Tibetan areas of China. To understand the molecular diversity of U. hordei, a total of 27 isolates, which were collected from highland barley plants from Tibet, Sichuan, Qinghai, and Gansu provinces/autonomous region, were analyzed using random amplified polymorphic DNA（RAPD） and simple sequence repeat（SSR） markers. Among the 100 RAPD primers used, 24 primers exhibited polymorphism. A total of 111 fragments were amplified, of which 103 were polymorphic with a polymorphic rate of 92.79%. The average observed number of alleles（Na）, effective number of alleles（Ne）, Nei＇s genetic diversity（H）, Shannon＇s information index（I） and polymorphism information content（PIC） value in the RAPD markers were 1.9279, 1.5016, 0.2974, 0.4503 and 0.6428, respectively. For the SSR markers, 40 of the 111 primer pairs exhibited polymorphism and provided a total of 119 bands, of which 109 were polymorphic and accounted for 91.60% of the total bands. The Na, Ne, H, I and PIC values of the SSR markers were 1.9160, 1.4639, 0.2757, 0.4211 and 0.4340, respectively. The similarity coefficients ranged from 0.4957 to 0.9261 with an average of 0.7028 among all the 27 isolates used. The dendrogram, which was developed based on the RAPD and SSR combined marker dataset showed that the 27 U. hordei isolates were divided into 3 clusters at similarity coefficient of 0.7314. We determined that RAPD and SSR markers can be successfully used to assess the genetic variation among U. hordei isolates. The RAPD markers revealed higher levels of genetic polymorphism than did the SSR markers in this study. There existed a moderate genetic difference among isolates. The molecular variation and differentiation was somewhat associated with geographical origin but not for all of the isolates.展开更多
The smut Ustilago esculenta is an endophytic fungus that invades Zizania latifolia(Jiaobai)and plays an important role in inducing the host stem to form a swollen gall.The aims of this study were to investigate isolat...The smut Ustilago esculenta is an endophytic fungus that invades Zizania latifolia(Jiaobai)and plays an important role in inducing the host stem to form a swollen gall.The aims of this study were to investigate isolation,identification and inoculation methods of U.esculenta from Jiaobai.The spore suspension culturing method was the best method of isolating U.esculenta,and yeast-like fungal strains and septate hyphal strains were obtained.The universal primers ITS1 and ITS4 amplified a ribosomal DNA spacer element from all tested strains,while specific primers for Lam16A gene generated a 442 bp product only with septate hyphae strains.De novo transcriptome assembly results showed that the yeast-like fungal strains did not match Ustilago,and genomic analysis suggested the septate hyphae strains were highly similar to known smut fungi.Therefore,the septate hyphae strains were identified as U.esculenta,which indicated that the ITS primers were not species-specific but that Lam16A-specific primers can distinguish U.esculenta accurately and easily.In vitro,U.esculenta grew quickly on PDA medium at 28°C in darkness.Furthermore,an inoculation method was established to produce swollen stems by injecting a spore suspension of U.esculenta at OD600=2.5 into the basal culm internode of male Jiaobai.展开更多
The Central region of Kenya which is the second largest market oriented dairy zone, faces a threat in milk production. The challenge is a disease known as the napier head smut caused by Ustilago kamerunensis. This fun...The Central region of Kenya which is the second largest market oriented dairy zone, faces a threat in milk production. The challenge is a disease known as the napier head smut caused by Ustilago kamerunensis. This fungal microorganism is a facultative pathogen which has been reported to cause yield losses in napier grass (Pennisetum purpureum) ranging from 25% to 46% across the affected areas. Additionally, there are reports of the continual spread of the disease into neighbouring county of Nakuru in Rift-Valley region which is the leading milk producing zone in the country. This scenario of spread is worrying combined with observation of variations in damage levels of napier grass clones across the five counties of Central Kenya. These observations led to the hypothesis that possible differences might be existing among the Ustilago kamerunensis variants in Kenya. Further, the differences in biomass yield losses that are within a certain percentage range mentioned-above, seemed to support the existence of possible differences. Therefore, to inform effective integrated management strategies of the pathogen in case it’s co-evolving, this study sought to determine the molecular differences of Ustilago kamerunensis isolates in affected counties using ITS 1 and 2 regions which are spanned by 5.8S ribosomal RNA gene. The Ustilago kamerunensis propagules were systematically collected from affected counties’ hot spot areas for sequencing and phylogenetic analysis. The study revealed the most affected areas to be within the mean altitude level of 1988.17 ± 71.97 metres above sea level. Further, differences in the growth in vitro and molecular characteristics of the seemingly altitude restricted isolates were observed. The Kiambu, Nyandarau and Nakuru counties isolates clustered together, whereas those of Murang’a, Nyeri and Kirinyaga formed another clade. The sequences of sixteen Ustilago kamerunensis isolates were deposited in GenBank with accession numbers ranging from MG722754 to MG722769. The results suggest the existence of possible genetic divergence of the isolates which might be reflected in their pathogenic potential too. Effective integration of management strategies is vital towards slowing the phenomenon for an optimal mitigation of the disease in Kenya.展开更多
Ustilago maydis is the causal agent of the disease known as corn smut or Huitlacohe;their natural hosts are maize (Zea mays L.) and its putative ancestor teocintle (Zea mays ssp. parviglumis and ssp. mexicana). In M&#...Ustilago maydis is the causal agent of the disease known as corn smut or Huitlacohe;their natural hosts are maize (Zea mays L.) and its putative ancestor teocintle (Zea mays ssp. parviglumis and ssp. mexicana). In México there is an evidence of its use as human food since pre-hispanic times. Huitlacoche is a typical Mexican food with interesting nutritional properties and distinctive flavor. Its use in cuisine is considered as a culinary delicacy in Mexico and several parts of the world and the current consumption is increasing markedly, mainly due to its exclusive flavor different from any other known food. Huitlacoche contains proteins, carbohydrates, fats, minerals and vitamins that contribute to its nutritional value, also it has been reported that it contains proteins with balanced levels of essential amino acids, something which does not occur in corn having a deficiency mostly in lysine. The fungus also contains compounds with antioxidant properties, consequently it can be included in what are now known as nutraceutical foods. Besides its use in the food, this fungus has been used in different kinds of basic investigation, such as DNA recombination, signaling, cell biology, biotrophic plant-pathogen interactions and others. Its characteristics of dimorphism, and the detailed knowledge we have on its pathogenic development, that we describe in detail, make it an ideal subject for the analysis of fungal differentiation, and for the knowledge of the behavior of the highly aggressive plant pathogens that are members of its taxonomic group, the Ustilaginales. In the present communication we make a thorough review of the nutritional characteristics of U. maydis, its life cycle, and the molecular bases of its differentiation, morpohogenesis and pathogenicity.展开更多
A key aspect of sustainable bioeconomy is the recirculation of renewable,agricultural waste streams as substrates for microbial production of high-value compounds.One approach is the bioconversion of corn stover,an ab...A key aspect of sustainable bioeconomy is the recirculation of renewable,agricultural waste streams as substrates for microbial production of high-value compounds.One approach is the bioconversion of corn stover,an abundant maize crop byproduct,using the fungal maize pathogen Ustilago maydis.U.maydis is already used as a unicellular biocatalyst in the production of several industrially-relevant compounds using plant biomass hydrolysates.In this study,we demonstrate that U.maydis can grow using untreated corn stover as its sole carbon source.We developed a small-scale bioreactor platform to investigate U.maydis processing of corn stover,combining online monitoring of fungal growth and metabolic activity profiles with biochemical analyses of the pre-and post-fermentation residues.Our results reveal that U.maydis primarily utilizes soluble sugars i.e.,glucose,sucrose and fructose present in corn stover,with only limited exploitation of the abundant lignocellulosic carbohydrates.Thus,we further explored the biotechnological potential of enhancing U.maydis´lignocellulosic utilization.Additive performance improvements of up to 120%were achieved when using a maize mutant with increased biomass digestibility,co-fermentation with a commercial cellulolytic enzyme cocktail,and exploiting engineered fungal strains expressing diverse lignocellulose-degrading enzymes.This work represents a key step towards scaling up the production of sustainable compounds from corn stover using U.maydis and provides a tool for the detailed monitoring of the fungal processing of plant biomass substrates.展开更多
Barley production has been constrained by various factors,of which loose smut(Ustilago nuda)is the main biotic factor.Molecular and agronomical screening analyses were evaluated to study the similarity levels and mark...Barley production has been constrained by various factors,of which loose smut(Ustilago nuda)is the main biotic factor.Molecular and agronomical screening analyses were evaluated to study the similarity levels and marker assisted selection associated with resistance to loose smut among eight barley genotypes using sequence-related amplified polymorphism(SRAP).Agronomical parameters during two consecutive 2021 and 2022 seasons were studied to identify their reaction to loose smut.The results exhibited significant differences among all studied genotypes for all studied characters,and the highest mean values for all studied traits were detected in Giza 136 and Giza 137.Six SRAP selected primer combinations were amplified and gave 56 total fragments,where primer combination me1+em3 gave the highest polymorphism(100%)and the highest polymorphic information content of PIC was 0.96.The dendrogram of SRAP markers had clustered all studied genotypes into two main clusters.Cluster I includes all the resistance genotypes Giza 136,Giza 137,Giza 123,Giza 132,Giza 138 and Line 2.However,cluster II includes only Line 1 and Line 3 as susceptible genotypes.Thus,SRAP marker could be efficiently used to assess genetic variation among barley genotypes and useful for barley germplasm management in terms of biodiversity protection and design of new crosses for loose smut breeding programs,and seed dressings are commonly used to prevent infected seed from developing smutted heads.Some effective seed dressings include Triticonazole,Black seed oil and gamma rays 150,200,250 Gy.The tested fungicide was highly effective in controlling the disease and gave more than 99%disease control with high grain yield while nature product as black seed oil and utilizing radiation gamma ray 250 GY was the most effective.Utilizing radiation and natural ingredients to manage loose barley smut is economical.展开更多
基金sponsored by the National Millet Crops Research and Development System, China (CARS-0712.5-A9)the National Key Technology R&D Program of China, (2014BAD07B03)the National Natural Science Foundation of China (313 71529)
文摘Covered smut, which is caused by Ustilago hordei（Pers.） Lagerh., is one of the most damaging diseases of highland barley（Hordeum vulgare Linn. var. nudum Hook. f） in Tibetan areas of China. To understand the molecular diversity of U. hordei, a total of 27 isolates, which were collected from highland barley plants from Tibet, Sichuan, Qinghai, and Gansu provinces/autonomous region, were analyzed using random amplified polymorphic DNA（RAPD） and simple sequence repeat（SSR） markers. Among the 100 RAPD primers used, 24 primers exhibited polymorphism. A total of 111 fragments were amplified, of which 103 were polymorphic with a polymorphic rate of 92.79%. The average observed number of alleles（Na）, effective number of alleles（Ne）, Nei＇s genetic diversity（H）, Shannon＇s information index（I） and polymorphism information content（PIC） value in the RAPD markers were 1.9279, 1.5016, 0.2974, 0.4503 and 0.6428, respectively. For the SSR markers, 40 of the 111 primer pairs exhibited polymorphism and provided a total of 119 bands, of which 109 were polymorphic and accounted for 91.60% of the total bands. The Na, Ne, H, I and PIC values of the SSR markers were 1.9160, 1.4639, 0.2757, 0.4211 and 0.4340, respectively. The similarity coefficients ranged from 0.4957 to 0.9261 with an average of 0.7028 among all the 27 isolates used. The dendrogram, which was developed based on the RAPD and SSR combined marker dataset showed that the 27 U. hordei isolates were divided into 3 clusters at similarity coefficient of 0.7314. We determined that RAPD and SSR markers can be successfully used to assess the genetic variation among U. hordei isolates. The RAPD markers revealed higher levels of genetic polymorphism than did the SSR markers in this study. There existed a moderate genetic difference among isolates. The molecular variation and differentiation was somewhat associated with geographical origin but not for all of the isolates.
基金This study was financially supported by the 58th batch of the China Postdoctoral Science Foundation,Jiangsu Agricul-ture Science and Technology Innovation Fund(CX(20)3104)Natural Science Fund Project of Colleges in Jiangsu Province(15KJB210006).
文摘The smut Ustilago esculenta is an endophytic fungus that invades Zizania latifolia(Jiaobai)and plays an important role in inducing the host stem to form a swollen gall.The aims of this study were to investigate isolation,identification and inoculation methods of U.esculenta from Jiaobai.The spore suspension culturing method was the best method of isolating U.esculenta,and yeast-like fungal strains and septate hyphal strains were obtained.The universal primers ITS1 and ITS4 amplified a ribosomal DNA spacer element from all tested strains,while specific primers for Lam16A gene generated a 442 bp product only with septate hyphae strains.De novo transcriptome assembly results showed that the yeast-like fungal strains did not match Ustilago,and genomic analysis suggested the septate hyphae strains were highly similar to known smut fungi.Therefore,the septate hyphae strains were identified as U.esculenta,which indicated that the ITS primers were not species-specific but that Lam16A-specific primers can distinguish U.esculenta accurately and easily.In vitro,U.esculenta grew quickly on PDA medium at 28°C in darkness.Furthermore,an inoculation method was established to produce swollen stems by injecting a spore suspension of U.esculenta at OD600=2.5 into the basal culm internode of male Jiaobai.
文摘The Central region of Kenya which is the second largest market oriented dairy zone, faces a threat in milk production. The challenge is a disease known as the napier head smut caused by Ustilago kamerunensis. This fungal microorganism is a facultative pathogen which has been reported to cause yield losses in napier grass (Pennisetum purpureum) ranging from 25% to 46% across the affected areas. Additionally, there are reports of the continual spread of the disease into neighbouring county of Nakuru in Rift-Valley region which is the leading milk producing zone in the country. This scenario of spread is worrying combined with observation of variations in damage levels of napier grass clones across the five counties of Central Kenya. These observations led to the hypothesis that possible differences might be existing among the Ustilago kamerunensis variants in Kenya. Further, the differences in biomass yield losses that are within a certain percentage range mentioned-above, seemed to support the existence of possible differences. Therefore, to inform effective integrated management strategies of the pathogen in case it’s co-evolving, this study sought to determine the molecular differences of Ustilago kamerunensis isolates in affected counties using ITS 1 and 2 regions which are spanned by 5.8S ribosomal RNA gene. The Ustilago kamerunensis propagules were systematically collected from affected counties’ hot spot areas for sequencing and phylogenetic analysis. The study revealed the most affected areas to be within the mean altitude level of 1988.17 ± 71.97 metres above sea level. Further, differences in the growth in vitro and molecular characteristics of the seemingly altitude restricted isolates were observed. The Kiambu, Nyandarau and Nakuru counties isolates clustered together, whereas those of Murang’a, Nyeri and Kirinyaga formed another clade. The sequences of sixteen Ustilago kamerunensis isolates were deposited in GenBank with accession numbers ranging from MG722754 to MG722769. The results suggest the existence of possible genetic divergence of the isolates which might be reflected in their pathogenic potential too. Effective integration of management strategies is vital towards slowing the phenomenon for an optimal mitigation of the disease in Kenya.
文摘Ustilago maydis is the causal agent of the disease known as corn smut or Huitlacohe;their natural hosts are maize (Zea mays L.) and its putative ancestor teocintle (Zea mays ssp. parviglumis and ssp. mexicana). In México there is an evidence of its use as human food since pre-hispanic times. Huitlacoche is a typical Mexican food with interesting nutritional properties and distinctive flavor. Its use in cuisine is considered as a culinary delicacy in Mexico and several parts of the world and the current consumption is increasing markedly, mainly due to its exclusive flavor different from any other known food. Huitlacoche contains proteins, carbohydrates, fats, minerals and vitamins that contribute to its nutritional value, also it has been reported that it contains proteins with balanced levels of essential amino acids, something which does not occur in corn having a deficiency mostly in lysine. The fungus also contains compounds with antioxidant properties, consequently it can be included in what are now known as nutraceutical foods. Besides its use in the food, this fungus has been used in different kinds of basic investigation, such as DNA recombination, signaling, cell biology, biotrophic plant-pathogen interactions and others. Its characteristics of dimorphism, and the detailed knowledge we have on its pathogenic development, that we describe in detail, make it an ideal subject for the analysis of fungal differentiation, and for the knowledge of the behavior of the highly aggressive plant pathogens that are members of its taxonomic group, the Ustilaginales. In the present communication we make a thorough review of the nutritional characteristics of U. maydis, its life cycle, and the molecular bases of its differentiation, morpohogenesis and pathogenicity.
基金Open Access funding enabled and organized by Projekt DEALfunded by the NRW Strategic Project Bioeconomy Science Center(BioSC),Boost Fund 2.0(“NextVegOil”2021_04)+1 种基金The scientific activities of the BioSC were financially supported by the Ministry of Culture and Science within the framework of the NRW Strategieprojekt BioSC(No.313/323-400-00213)Additional funding was provided by Germany’s Federal Ministry of Education and Research(BMBF)grant“Cornwall,”031B1303A and Deutsche Forschun-gsgemeinschaft(DFG,German Research Foundation)under Germany’s Excel-lence Strategy-EXC 2048/1-Project ID:390686111 to M.Pa.,and Marie Curie PIOF-GA-2013-623553 to V.R.
文摘A key aspect of sustainable bioeconomy is the recirculation of renewable,agricultural waste streams as substrates for microbial production of high-value compounds.One approach is the bioconversion of corn stover,an abundant maize crop byproduct,using the fungal maize pathogen Ustilago maydis.U.maydis is already used as a unicellular biocatalyst in the production of several industrially-relevant compounds using plant biomass hydrolysates.In this study,we demonstrate that U.maydis can grow using untreated corn stover as its sole carbon source.We developed a small-scale bioreactor platform to investigate U.maydis processing of corn stover,combining online monitoring of fungal growth and metabolic activity profiles with biochemical analyses of the pre-and post-fermentation residues.Our results reveal that U.maydis primarily utilizes soluble sugars i.e.,glucose,sucrose and fructose present in corn stover,with only limited exploitation of the abundant lignocellulosic carbohydrates.Thus,we further explored the biotechnological potential of enhancing U.maydis´lignocellulosic utilization.Additive performance improvements of up to 120%were achieved when using a maize mutant with increased biomass digestibility,co-fermentation with a commercial cellulolytic enzyme cocktail,and exploiting engineered fungal strains expressing diverse lignocellulose-degrading enzymes.This work represents a key step towards scaling up the production of sustainable compounds from corn stover using U.maydis and provides a tool for the detailed monitoring of the fungal processing of plant biomass substrates.
文摘Barley production has been constrained by various factors,of which loose smut(Ustilago nuda)is the main biotic factor.Molecular and agronomical screening analyses were evaluated to study the similarity levels and marker assisted selection associated with resistance to loose smut among eight barley genotypes using sequence-related amplified polymorphism(SRAP).Agronomical parameters during two consecutive 2021 and 2022 seasons were studied to identify their reaction to loose smut.The results exhibited significant differences among all studied genotypes for all studied characters,and the highest mean values for all studied traits were detected in Giza 136 and Giza 137.Six SRAP selected primer combinations were amplified and gave 56 total fragments,where primer combination me1+em3 gave the highest polymorphism(100%)and the highest polymorphic information content of PIC was 0.96.The dendrogram of SRAP markers had clustered all studied genotypes into two main clusters.Cluster I includes all the resistance genotypes Giza 136,Giza 137,Giza 123,Giza 132,Giza 138 and Line 2.However,cluster II includes only Line 1 and Line 3 as susceptible genotypes.Thus,SRAP marker could be efficiently used to assess genetic variation among barley genotypes and useful for barley germplasm management in terms of biodiversity protection and design of new crosses for loose smut breeding programs,and seed dressings are commonly used to prevent infected seed from developing smutted heads.Some effective seed dressings include Triticonazole,Black seed oil and gamma rays 150,200,250 Gy.The tested fungicide was highly effective in controlling the disease and gave more than 99%disease control with high grain yield while nature product as black seed oil and utilizing radiation gamma ray 250 GY was the most effective.Utilizing radiation and natural ingredients to manage loose barley smut is economical.
