The Experts below are selected from a list of 1224 Experts worldwide ranked by ideXlab platform

Jing Fan - One of the best experts on this subject based on the ideXlab platform.

  • The False Smut pathogen Ustilaginoidea virens requires rice stamens for False Smut ball formation
    Environmental microbiology, 2019
    Co-Authors: Jing Fan, Jie Liu, Zhi-you Gong, Juan Yang, Yu-qiu Wang, Yu-feng Zhou
    Abstract:

    Rice False Smut has emerged as a serious grain disease in rice production worldwide. The disease is characterized by the transformation of individual rice florets into False Smut balls, which is caused by the fungal pathogen Ustilaginoidea virens. To date, little is known about the host factors required for False Smut ball formation by U. virens. In this study, we identified histological determinants for the formation of False Smut balls by inoculating U. virens into rice floral mutants defective with respect to individual floral parts. The results showed that U. virens could form mature False Smut balls in rice floral mutants with defective pistils, but failed to develop False Smut balls in the superwoman mutant lacking stamens, identifying that U. virens requires rice stamens to complete its infection cycle. Comparative transcriptome analysis indicated a list of candidate host genes that may facilitate nutrient acquisition by U. virens from the rice stamens, such as SWEET11, SWEET14 and SUT5, and genes involved in the biosynthesis of trehalose and raffinose family sugars. These data pinpoint rice stamens as the key target organ of U. virens infection and provide a valuable starting point for dissecting the molecular mechanism of False Smut ball formation.

  • current understanding on villosiclava virens a unique flower infecting fungus causing rice False Smut disease
    Molecular Plant Pathology, 2016
    Co-Authors: Jing Fan, Juan Yang, Yu-qiu Wang, Fu Huang, Wenming Wang
    Abstract:

    Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes False Smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a False Smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the False Smut ball. This profile provides a general overview of the rice False Smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely False Smut balls. When maturing, the False Smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the False Smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces False Smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of False Smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice False Smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

  • Current understanding on Villosiclava virens, a unique flower‐infecting fungus causing rice False Smut disease
    Molecular plant pathology, 2016
    Co-Authors: Jing Fan, Juan Yang, Yu-qiu Wang, Fu Huang, Wenming Wang
    Abstract:

    Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes False Smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a False Smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the False Smut ball. This profile provides a general overview of the rice False Smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely False Smut balls. When maturing, the False Smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the False Smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces False Smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of False Smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice False Smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

  • Stachyose is a preferential carbon source utilized by the rice False Smut pathogen, Villosiclava virens
    Physiological and Molecular Plant Pathology, 2016
    Co-Authors: Yu-qiu Wang, Jing Fan, Zhi-you Gong, Fu Huang, Wenming Wang
    Abstract:

    Abstract Villosiclava virens is the causal pathogen of rice False Smut (RFS) disease. RFS is an emerging panicle disease, concerning rice production worldwide. However, the biology and pathogenicity of V. virens are still not well-understood. In this study, we investigated the sugar preference of V. virens and the underlying mechanism on how the favored sugar promoted the fungal growth. The results demonstrated that V. virens preferentially utilized stachyose over sucrose that is previously reported to be the best carbon source for V. virens . Stachyose could promote conidia germination, hyphae elongation and mycelium growth of V. virens . Transcriptome and qRT-PCR analyses showed that genes involved in transporting carbohydrate, amino acid, inorganic ion and secondary metabolites were mostly up-regulated by stachyose than by sucrose. Moreover, Uv8b_6977 encoding a putative major facilitator superfamily (MFS) transporter was highly and specifically induced by stachyose, indicating that it may be a stachyose transporter. Expression levels of several stachyose-inducible MFS genes were also highly induced in V. virens -infected rice spikelets especially when early False Smut balls appeared, implicating that these genes may play important roles in the formation of False Smut balls. Collectively, this work identifies stachyose as a preferential carbon source for V. virens , and provides gene candidates for investigation of the sugar utilization mechanism of V. virens .

Wenming Wang - One of the best experts on this subject based on the ideXlab platform.

  • current understanding on villosiclava virens a unique flower infecting fungus causing rice False Smut disease
    Molecular Plant Pathology, 2016
    Co-Authors: Jing Fan, Juan Yang, Yu-qiu Wang, Fu Huang, Wenming Wang
    Abstract:

    Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes False Smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a False Smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the False Smut ball. This profile provides a general overview of the rice False Smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely False Smut balls. When maturing, the False Smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the False Smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces False Smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of False Smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice False Smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

  • Current understanding on Villosiclava virens, a unique flower‐infecting fungus causing rice False Smut disease
    Molecular plant pathology, 2016
    Co-Authors: Jing Fan, Juan Yang, Yu-qiu Wang, Fu Huang, Wenming Wang
    Abstract:

    Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes False Smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a False Smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the False Smut ball. This profile provides a general overview of the rice False Smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely False Smut balls. When maturing, the False Smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the False Smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces False Smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of False Smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice False Smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

  • Stachyose is a preferential carbon source utilized by the rice False Smut pathogen, Villosiclava virens
    Physiological and Molecular Plant Pathology, 2016
    Co-Authors: Yu-qiu Wang, Jing Fan, Zhi-you Gong, Fu Huang, Wenming Wang
    Abstract:

    Abstract Villosiclava virens is the causal pathogen of rice False Smut (RFS) disease. RFS is an emerging panicle disease, concerning rice production worldwide. However, the biology and pathogenicity of V. virens are still not well-understood. In this study, we investigated the sugar preference of V. virens and the underlying mechanism on how the favored sugar promoted the fungal growth. The results demonstrated that V. virens preferentially utilized stachyose over sucrose that is previously reported to be the best carbon source for V. virens . Stachyose could promote conidia germination, hyphae elongation and mycelium growth of V. virens . Transcriptome and qRT-PCR analyses showed that genes involved in transporting carbohydrate, amino acid, inorganic ion and secondary metabolites were mostly up-regulated by stachyose than by sucrose. Moreover, Uv8b_6977 encoding a putative major facilitator superfamily (MFS) transporter was highly and specifically induced by stachyose, indicating that it may be a stachyose transporter. Expression levels of several stachyose-inducible MFS genes were also highly induced in V. virens -infected rice spikelets especially when early False Smut balls appeared, implicating that these genes may play important roles in the formation of False Smut balls. Collectively, this work identifies stachyose as a preferential carbon source for V. virens , and provides gene candidates for investigation of the sugar utilization mechanism of V. virens .

Yu-qiu Wang - One of the best experts on this subject based on the ideXlab platform.

  • The False Smut pathogen Ustilaginoidea virens requires rice stamens for False Smut ball formation
    Environmental microbiology, 2019
    Co-Authors: Jing Fan, Jie Liu, Zhi-you Gong, Juan Yang, Yu-qiu Wang, Yu-feng Zhou
    Abstract:

    Rice False Smut has emerged as a serious grain disease in rice production worldwide. The disease is characterized by the transformation of individual rice florets into False Smut balls, which is caused by the fungal pathogen Ustilaginoidea virens. To date, little is known about the host factors required for False Smut ball formation by U. virens. In this study, we identified histological determinants for the formation of False Smut balls by inoculating U. virens into rice floral mutants defective with respect to individual floral parts. The results showed that U. virens could form mature False Smut balls in rice floral mutants with defective pistils, but failed to develop False Smut balls in the superwoman mutant lacking stamens, identifying that U. virens requires rice stamens to complete its infection cycle. Comparative transcriptome analysis indicated a list of candidate host genes that may facilitate nutrient acquisition by U. virens from the rice stamens, such as SWEET11, SWEET14 and SUT5, and genes involved in the biosynthesis of trehalose and raffinose family sugars. These data pinpoint rice stamens as the key target organ of U. virens infection and provide a valuable starting point for dissecting the molecular mechanism of False Smut ball formation.

  • current understanding on villosiclava virens a unique flower infecting fungus causing rice False Smut disease
    Molecular Plant Pathology, 2016
    Co-Authors: Jing Fan, Juan Yang, Yu-qiu Wang, Fu Huang, Wenming Wang
    Abstract:

    Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes False Smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a False Smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the False Smut ball. This profile provides a general overview of the rice False Smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely False Smut balls. When maturing, the False Smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the False Smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces False Smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of False Smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice False Smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

  • Current understanding on Villosiclava virens, a unique flower‐infecting fungus causing rice False Smut disease
    Molecular plant pathology, 2016
    Co-Authors: Jing Fan, Juan Yang, Yu-qiu Wang, Fu Huang, Wenming Wang
    Abstract:

    Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes False Smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a False Smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the False Smut ball. This profile provides a general overview of the rice False Smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely False Smut balls. When maturing, the False Smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the False Smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces False Smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of False Smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice False Smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

  • Stachyose is a preferential carbon source utilized by the rice False Smut pathogen, Villosiclava virens
    Physiological and Molecular Plant Pathology, 2016
    Co-Authors: Yu-qiu Wang, Jing Fan, Zhi-you Gong, Fu Huang, Wenming Wang
    Abstract:

    Abstract Villosiclava virens is the causal pathogen of rice False Smut (RFS) disease. RFS is an emerging panicle disease, concerning rice production worldwide. However, the biology and pathogenicity of V. virens are still not well-understood. In this study, we investigated the sugar preference of V. virens and the underlying mechanism on how the favored sugar promoted the fungal growth. The results demonstrated that V. virens preferentially utilized stachyose over sucrose that is previously reported to be the best carbon source for V. virens . Stachyose could promote conidia germination, hyphae elongation and mycelium growth of V. virens . Transcriptome and qRT-PCR analyses showed that genes involved in transporting carbohydrate, amino acid, inorganic ion and secondary metabolites were mostly up-regulated by stachyose than by sucrose. Moreover, Uv8b_6977 encoding a putative major facilitator superfamily (MFS) transporter was highly and specifically induced by stachyose, indicating that it may be a stachyose transporter. Expression levels of several stachyose-inducible MFS genes were also highly induced in V. virens -infected rice spikelets especially when early False Smut balls appeared, implicating that these genes may play important roles in the formation of False Smut balls. Collectively, this work identifies stachyose as a preferential carbon source for V. virens , and provides gene candidates for investigation of the sugar utilization mechanism of V. virens .

Juan Yang - One of the best experts on this subject based on the ideXlab platform.

  • The False Smut pathogen Ustilaginoidea virens requires rice stamens for False Smut ball formation
    Environmental microbiology, 2019
    Co-Authors: Jing Fan, Jie Liu, Zhi-you Gong, Juan Yang, Yu-qiu Wang, Yu-feng Zhou
    Abstract:

    Rice False Smut has emerged as a serious grain disease in rice production worldwide. The disease is characterized by the transformation of individual rice florets into False Smut balls, which is caused by the fungal pathogen Ustilaginoidea virens. To date, little is known about the host factors required for False Smut ball formation by U. virens. In this study, we identified histological determinants for the formation of False Smut balls by inoculating U. virens into rice floral mutants defective with respect to individual floral parts. The results showed that U. virens could form mature False Smut balls in rice floral mutants with defective pistils, but failed to develop False Smut balls in the superwoman mutant lacking stamens, identifying that U. virens requires rice stamens to complete its infection cycle. Comparative transcriptome analysis indicated a list of candidate host genes that may facilitate nutrient acquisition by U. virens from the rice stamens, such as SWEET11, SWEET14 and SUT5, and genes involved in the biosynthesis of trehalose and raffinose family sugars. These data pinpoint rice stamens as the key target organ of U. virens infection and provide a valuable starting point for dissecting the molecular mechanism of False Smut ball formation.

  • current understanding on villosiclava virens a unique flower infecting fungus causing rice False Smut disease
    Molecular Plant Pathology, 2016
    Co-Authors: Jing Fan, Juan Yang, Yu-qiu Wang, Fu Huang, Wenming Wang
    Abstract:

    Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes False Smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a False Smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the False Smut ball. This profile provides a general overview of the rice False Smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely False Smut balls. When maturing, the False Smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the False Smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces False Smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of False Smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice False Smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

  • Current understanding on Villosiclava virens, a unique flower‐infecting fungus causing rice False Smut disease
    Molecular plant pathology, 2016
    Co-Authors: Jing Fan, Juan Yang, Yu-qiu Wang, Fu Huang, Wenming Wang
    Abstract:

    Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes False Smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a False Smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the False Smut ball. This profile provides a general overview of the rice False Smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely False Smut balls. When maturing, the False Smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the False Smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces False Smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of False Smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice False Smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.

Ligang Zhou - One of the best experts on this subject based on the ideXlab platform.

  • Development of a Monoclonal Antibody-Based icELISA for the Detection of Ustiloxin B in Rice False Smut Balls and Rice Grains.
    Toxins, 2015
    Co-Authors: Ali Wang, Ligang Zhou, Xiaohan Wang, Fengke Lin, Daowan Lai, Yang Liu, Baoming Wang
    Abstract:

    Rice False Smut is an emerging and economically-important rice disease caused by infection by the fungal pathogen Villosiclava virens. Ustiloxin B is an antimitotic cyclopeptide mycotoxin isolated from the rice False Smut balls that formed in the pathogen-infected rice spikelets. A monoclonal antibody (mAb) designated as mAb 1B5A10 was generated with ustiloxin B—ovalbumin conjugate. A highly-sensitive and specific indirect competitive enzyme-linked immunosorbent assay (icELISA) was then developed. The median inhibitory concentration (IC50) of the icELISA was 18.0 ng/mL for the detection of ustiloxin B; the limit of detection was 0.6 ng/mL, and the calibration range was from 2.5 to 107.4 ng/mL. The LOD/LOQ values of the developed ELISA used for the determination of ustiloxin B in rice False Smut balls and rice grains were 12/50 μg/g and 30/125 ng/g, respectively. The mAb 1B5A10 cross-reacted with ustiloxin A at 13.9% relative to ustiloxin B. Average recoveries of ustiloxin B ranged from 91.3% to 105.1% for rice False Smut balls at spiking levels of 0.2 to 3.2 mg/g and from 92.6% to 103.5% for rice grains at spiking levels of 100 to 5000 ng/g. Comparison of ustiloxin B content in rice False Smut balls and rice grains detected by both icELISA and high performance liquid chromatography (HPLC) demonstrated that the developed icELISA can be employed as an effective and accurate method for the detection of ustiloxin B in rice False Smut balls, as well as rice food and feed samples.

  • Optimization of extraction process for ustiloxins A and B from rice False Smut balls using an orthogonal array design
    African Journal of Biotechnology, 2014
    Co-Authors: Tijiang Shan, Weibo Sun, X Wang, J Meng, A Wang, Yanhong Liu, Ligang Zhou
    Abstract:

    Optimization of four factors, namely methanol concentration ( A ), extraction pH value ( B ), material-to-solvent ratio ( C ) and extraction times ( D ), for extraction of ustiloxins A and B from rice False Smut balls was achieved by using an L 18 orthogonal array design with three levels and four factors. The results show that the optimum conditions for ustiloxins A and B extraction should be A 1 B 2 C 2 D 3 corresponding to methanol concentration at 10%, extraction pH value at 6, material-to-solvent ratio at 1:30 (g/mL) and extraction times as 3, respectively. Under the optimum extraction condition, the content of ustiloxins A and B in rice False Smut balls was analyzed to be 0.80 and 0.57 mg/g, respectively, on a dry weight basis. Keywords: Rice False Smut balls, Villosiclava virens , Ustilaginoidea virens , ustiloxins A and B, orthogonal array design, extraction optimization. African Journal of Biotechnology , Vol 13(38) 3912-3918

  • Determination and analysis of ustiloxins A and B by LC-ESI-MS and HPLC in False Smut balls of
    2013
    Co-Authors: Tijiang Shan, Wenxian Sun, Weibo Sun, Hao Liu, Shan Gao, Mingan Wang, Zhiyi Chen, Shu Wang, Ligang Zhou
    Abstract:

    Abstract: Ustiloxins are cyclopeptide mycotoxins produced by the pathogenic fungus Villosiclava virens of rice False Smut. Ustiloxins A and B as two main mycotoxins were determined conveniently by LC-ESI-MS in the water extract from rice False Smut balls which were mostly composed of the chlamydospores and mycelia of the pathogen. Both ustiloxins A and B in the water extract were also quantitatively analyzed by HPLC. This is the first report on the determination and analysis of ustiloxins A and B simultaneously by LC-ESI-MS and HPLC in False Smut balls of rice

  • Determination and analysis of ustiloxins A and B by LC-ESI-MS and HPLC in False Smut balls of rice.
    International journal of molecular sciences, 2012
    Co-Authors: Tijiang Shan, Wenxian Sun, Weibo Sun, Hao Liu, Shan Gao, Mingan Wang, Zhiyi Chen, Shu Wang, Ligang Zhou
    Abstract:

    Ustiloxins are cyclopeptide mycotoxins produced by the pathogenic fungus Villosiclava virens of rice False Smut. Ustiloxins A and B as two main mycotoxins were determined conveniently by LC-ESI-MS in the water extract from rice False Smut balls which were mostly composed of the chlamydospores and mycelia of the pathogen. Both ustiloxins A and B in the water extract were also quantitatively analyzed by HPLC. This is the first report on the determination and analysis of ustiloxins A and B simultaneously by LC-ESI-MS and HPLC in False Smut balls of rice.