In this study the MTP1 gene, encoding a type III integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp 1 protein is 520 amino acids long and is comparable to the Ytp 1 pro...In this study the MTP1 gene, encoding a type III integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp 1 protein is 520 amino acids long and is comparable to the Ytp 1 protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP （green fluorescent protein） fusion expression results indicate that Mtp 1 is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily expressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for pathogenicity. The Amtpl mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use.展开更多
[Objective] This study aimed to investigate the regulatory mechanisms of carotenoid biosynthesis in Neurospora crassa. [Method] Gene knockout mutants pro- ducing less carotenoid were screened from 6 087 mutants; the y...[Objective] This study aimed to investigate the regulatory mechanisms of carotenoid biosynthesis in Neurospora crassa. [Method] Gene knockout mutants pro- ducing less carotenoid were screened from 6 087 mutants; the yield of carotenoid and asexual spore was measured; finally fluorescent quantitative real-time PCR was adopted to analyze the transcription of genes related to carotenoid synthesis and asexual sporulation, [Result] Six knockout mutants produced less carotenoid. In one of them, the yield of both carotenoid and asexual spore reduced, because the gene which encodes an ATP-dependent chromatin remodelling complex ATPase chain ISW1 was knocked out. This gene was named /ca-1 in this study. And the /ca-1 deletion result- ed in a reduction of 88% in conidial production and a decrease of 81% in carotenoid production. [Conclusion] The Ica-1 positively regulates the carotenoid syn- thesis and asexual sporulation in N. crassa.展开更多
Rice false smut,which is caused by Ustilaginoidea virens,is an emerging disease of rice spikelets in rice-growing areas worldwide.However,the infection mechanism of U.virens on rice spikelets is still unclear.Here,we ...Rice false smut,which is caused by Ustilaginoidea virens,is an emerging disease of rice spikelets in rice-growing areas worldwide.However,the infection mechanism of U.virens on rice spikelets is still unclear.Here,we characterized a suppressor of mitogen-activated protein kinase kinase or ERK kinase(MEK)null(UvSMEKI)in U.virens that is conserved among filamentous fungi.Compared with wild type U.virens strain P-1,UvSMEKI deletion mutants were defective in pathogenicity and conidial germination.In addition,conidiation of UvSMEKI deletion mutants was significantly reduced on yeast extract tryptone(YT)plates,but inc「eased in YT broth compared with the wild type.Compared with UvSMEKI expression level during the vegetative mycelia and conidiation stages,UvSMEKI dramatically increased during infection of rice florets.Surprisingly,the UvSMEKI deletion mutants exhibited higher tolerance to H_(2)O_(2) and NaCl.In summary,presented evidence suggested that UvSMEKI positively regulated pathogenicity,conidial germination and conidiation in YT broth,and negatively regulated conidiation on YT medium and tolerance to oxidative and osmotic stresses.The results enhanee our understanding of the regulatory mechanism of pathogenicity of U.virens,and present a potential molecular target for blocking rice infection by U.virens.展开更多
Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtrac...Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtractive suppressive cDNA library and functionally analyzed. Sequence analysis showed that the MoFLP1 gene contains an open reading frame (ORF) of 1050 nucleotides encoding 349 amino acids with a calculated molecular weight of 35.85 kDa and a pI of 7.76. The deduced MoFLP1 protein contains a 17-amino acid secretion signal sequence and an 18-amino acid sequence with the characteristics of a glycosylphosphotidylinositol (GPI) anchor additional signal at its N- and C-terminuses, respectively. Potential N-glycosylation sites and domains involving cell adhesion were also identified in MoFLP1. Sequence analysis and subcellular localization by the expression of MoFLP1-GFP fusion construct in M. oryzae indicated that the MoFLP1 protein is probably localized on the vacuole membrane. Two MoFLP1 null mutants generated by targeted gene disruption exhibited marked reduction of conidiation, conidial adhesion, appressorium turgor, and pathogenicity. Our results indicate that fasciclin proteins play important roles in fungal de-velopment and pathogenicity in M. oryzae.展开更多
bZIP proteins are widely distributed in eukaryotic organisms and regulate a diverse range of physiological processes.Several bZIP proteins have previously been identified in Ustilaginoidea virens.However,the biologica...bZIP proteins are widely distributed in eukaryotic organisms and regulate a diverse range of physiological processes.Several bZIP proteins have previously been identified in Ustilaginoidea virens.However,the biological roles of these bZIP proteins in this pathogen are still unknown.Here,one of these bZIP protein coding genes,UvATF21,was functionally characterized.Targeted deletion of UvATF21resulted in reduced conidiation and pathogenicity despite of the increased vegetative growth.The deletion mutants also significantly decreased the sensitivity to osmotic and oxidative stresses.Interestingly,deletion of UvATF21 exhibited different performances to cell wall integrity stress.These results indicated that UvATF21 played crucial roles in vegetative growth,conidiation,stress response,and full virulence in U.virens.展开更多
Achieving a balance between vegetative growth and spore production is essential for successful biocontrol by fungi. Low sporulation rates in the field can result in poor establishment and survival, whereas failure of ...Achieving a balance between vegetative growth and spore production is essential for successful biocontrol by fungi. Low sporulation rates in the field can result in poor establishment and survival, whereas failure of conidia to recognise hosts can lead to persistence without efficacy. Commercial biocontrol products involve bulk preparations of conidia, however considerable variability in conidiation rates exists between biocontrol agents, which can restrict choice of strain for production. The majority of studies on Trichoderma conidiation have focused on the species T. viride and T. atroviride. These species form conidia in response to blue and near-UV light and/or nutrient deprivation and conidiation proceeds in a highly co-ordinated fashion, however relatively little is known on the genetic basis of Trichoderma conidiation. In addition, whilst photoconidiation appears to be a general response detailed studies in other Trichoderma species are absent. In this study, conidiation in the lesser known biocontrol species T. hamatum is being investigated using a combined morphological and molecular approach. In contrast to T. atroviride, conidiation in response to blue-light was weaker and variable and suggested that additional triggers may be required for the T. hamatum photoresponse. A series of comparative photoconidiation assays are currently being undertaken investigating the effect of inoculum type and abiotic factors on timing and intensity of the response. Results will be discussed in relation to the current knowledge on conidial morphogenesis in Trichoderma. In addition to these morphological assays, a selection of genes implicated in sporulation and the blue-light responses are currently being isolated and characterised from T. hamatum. Two genes, phr1 and cmp1, which were isolated previously from T. atroviride will be used as early and late markers of gene expression during the photoresponse in T. hamatum in order to define time points for harvesting comparable stage-specific RNA from T. hamatum and T. atroviride. Using degenerate PCR putative sporulation gene orthologues have also been identified in T. hamatum. Work is currently underway to isolate genomic clones of these genes from T. hamatum and T. atroviride. Sequence and expression analysis of orthologues, including expression in response to abiotic factors will be presented and discussed in relation to the current knowledge of the molecular basis of conidiation in Trichoderma and other filamentous fungi.展开更多
[Objective] To study the effects of different culture conditions on the Fusarium oxysporurn SchL f. sp. [Method] Based on species identification of the pathogenic organism of Fusarium oxysporum Schl. f. sp, effects of...[Objective] To study the effects of different culture conditions on the Fusarium oxysporurn SchL f. sp. [Method] Based on species identification of the pathogenic organism of Fusarium oxysporum Schl. f. sp, effects of different cultures and different nutrients on the mycelial growth and conidial production of Fusarium oxysporum SchL f. sp were studied. [Result] The mycelial growth and conidial pro- duction of Fusarium oxysporum SchL f. sp was different under different culture con- ditions. PDA medium was the most suitable medium for the mycelial growth and had the highest conidial production; and the mycelial grew the fastest on the medium with maltose as carbon source or peptone as nitrogen source, which also had the highest conidial production. [Conclusion] This study provided experimental basis for the study of Fusarium oxysporum SchL f. sp and also provided theoretical basis for the study and control of Fusarium oxysporum Schl. f. sp.展开更多
基金the National Natural Science Foundation of China (Nos. 30671351 and 30470064)the Natural Science Foun-dation of Zhejiang Province, China (No. Y304211)
文摘In this study the MTP1 gene, encoding a type III integral transmembrane protein, was isolated from the rice blast fungus Magnaporthe oryzae. The Mtp 1 protein is 520 amino acids long and is comparable to the Ytp 1 protein of Saccharomyces cerevisiae with 46% sequence similarity. Prediction programs and MTP1-GFP （green fluorescent protein） fusion expression results indicate that Mtp 1 is a protein located at several membranes in the cytoplasm. The functions of the MTP1 gene in the growth and development of the fungus were studied using an MTP1 gene knockout mutant. The MTP1 gene was primarily expressed at the hyphal and conidial stages and is necessary for conidiation and conidial germination, but is not required for pathogenicity. The Amtpl mutant grew more efficiently than the wild type strain on non-fermentable carbon sources, implying that the MTP1 gene has a unique role in respiratory growth and carbon source use.
基金Supported by the National Natural Science Foundation of China (31000551 30970127)~~
文摘[Objective] This study aimed to investigate the regulatory mechanisms of carotenoid biosynthesis in Neurospora crassa. [Method] Gene knockout mutants pro- ducing less carotenoid were screened from 6 087 mutants; the yield of carotenoid and asexual spore was measured; finally fluorescent quantitative real-time PCR was adopted to analyze the transcription of genes related to carotenoid synthesis and asexual sporulation, [Result] Six knockout mutants produced less carotenoid. In one of them, the yield of both carotenoid and asexual spore reduced, because the gene which encodes an ATP-dependent chromatin remodelling complex ATPase chain ISW1 was knocked out. This gene was named /ca-1 in this study. And the /ca-1 deletion result- ed in a reduction of 88% in conidial production and a decrease of 81% in carotenoid production. [Conclusion] The Ica-1 positively regulates the carotenoid syn- thesis and asexual sporulation in N. crassa.
基金supported by the National Key Research and Development Project in China(Grant No.2016YFD200805)National Natural Science Foundation of China(Grant Nos.31301624 and 31571961).
文摘Rice false smut,which is caused by Ustilaginoidea virens,is an emerging disease of rice spikelets in rice-growing areas worldwide.However,the infection mechanism of U.virens on rice spikelets is still unclear.Here,we characterized a suppressor of mitogen-activated protein kinase kinase or ERK kinase(MEK)null(UvSMEKI)in U.virens that is conserved among filamentous fungi.Compared with wild type U.virens strain P-1,UvSMEKI deletion mutants were defective in pathogenicity and conidial germination.In addition,conidiation of UvSMEKI deletion mutants was significantly reduced on yeast extract tryptone(YT)plates,but inc「eased in YT broth compared with the wild type.Compared with UvSMEKI expression level during the vegetative mycelia and conidiation stages,UvSMEKI dramatically increased during infection of rice florets.Surprisingly,the UvSMEKI deletion mutants exhibited higher tolerance to H_(2)O_(2) and NaCl.In summary,presented evidence suggested that UvSMEKI positively regulated pathogenicity,conidial germination and conidiation in YT broth,and negatively regulated conidiation on YT medium and tolerance to oxidative and osmotic stresses.The results enhanee our understanding of the regulatory mechanism of pathogenicity of U.virens,and present a potential molecular target for blocking rice infection by U.virens.
基金Project supported by the National Natural Science Foundation of China (No. 30870101)the Public Welfare Profession (Agricul-ture) Research Project (No. 200803008), China
文摘Fasciclin family proteins have been identified as cell adhesion molecules in various organisms. In this study, a novel Magnaporthe oryzae fasciclin-like protein encoding gene, named MoFLP1, was isolated from a subtractive suppressive cDNA library and functionally analyzed. Sequence analysis showed that the MoFLP1 gene contains an open reading frame (ORF) of 1050 nucleotides encoding 349 amino acids with a calculated molecular weight of 35.85 kDa and a pI of 7.76. The deduced MoFLP1 protein contains a 17-amino acid secretion signal sequence and an 18-amino acid sequence with the characteristics of a glycosylphosphotidylinositol (GPI) anchor additional signal at its N- and C-terminuses, respectively. Potential N-glycosylation sites and domains involving cell adhesion were also identified in MoFLP1. Sequence analysis and subcellular localization by the expression of MoFLP1-GFP fusion construct in M. oryzae indicated that the MoFLP1 protein is probably localized on the vacuole membrane. Two MoFLP1 null mutants generated by targeted gene disruption exhibited marked reduction of conidiation, conidial adhesion, appressorium turgor, and pathogenicity. Our results indicate that fasciclin proteins play important roles in fungal de-velopment and pathogenicity in M. oryzae.
基金supported by the National Natural Science Foundation of China(Grant No.31701736)Key Research and Development Program of Hubei Province,China(Grant No.2021BBA236)National Key Research and Development Program,China(Grant No.2016YFD0300700)。
文摘bZIP proteins are widely distributed in eukaryotic organisms and regulate a diverse range of physiological processes.Several bZIP proteins have previously been identified in Ustilaginoidea virens.However,the biological roles of these bZIP proteins in this pathogen are still unknown.Here,one of these bZIP protein coding genes,UvATF21,was functionally characterized.Targeted deletion of UvATF21resulted in reduced conidiation and pathogenicity despite of the increased vegetative growth.The deletion mutants also significantly decreased the sensitivity to osmotic and oxidative stresses.Interestingly,deletion of UvATF21 exhibited different performances to cell wall integrity stress.These results indicated that UvATF21 played crucial roles in vegetative growth,conidiation,stress response,and full virulence in U.virens.
文摘Achieving a balance between vegetative growth and spore production is essential for successful biocontrol by fungi. Low sporulation rates in the field can result in poor establishment and survival, whereas failure of conidia to recognise hosts can lead to persistence without efficacy. Commercial biocontrol products involve bulk preparations of conidia, however considerable variability in conidiation rates exists between biocontrol agents, which can restrict choice of strain for production. The majority of studies on Trichoderma conidiation have focused on the species T. viride and T. atroviride. These species form conidia in response to blue and near-UV light and/or nutrient deprivation and conidiation proceeds in a highly co-ordinated fashion, however relatively little is known on the genetic basis of Trichoderma conidiation. In addition, whilst photoconidiation appears to be a general response detailed studies in other Trichoderma species are absent. In this study, conidiation in the lesser known biocontrol species T. hamatum is being investigated using a combined morphological and molecular approach. In contrast to T. atroviride, conidiation in response to blue-light was weaker and variable and suggested that additional triggers may be required for the T. hamatum photoresponse. A series of comparative photoconidiation assays are currently being undertaken investigating the effect of inoculum type and abiotic factors on timing and intensity of the response. Results will be discussed in relation to the current knowledge on conidial morphogenesis in Trichoderma. In addition to these morphological assays, a selection of genes implicated in sporulation and the blue-light responses are currently being isolated and characterised from T. hamatum. Two genes, phr1 and cmp1, which were isolated previously from T. atroviride will be used as early and late markers of gene expression during the photoresponse in T. hamatum in order to define time points for harvesting comparable stage-specific RNA from T. hamatum and T. atroviride. Using degenerate PCR putative sporulation gene orthologues have also been identified in T. hamatum. Work is currently underway to isolate genomic clones of these genes from T. hamatum and T. atroviride. Sequence and expression analysis of orthologues, including expression in response to abiotic factors will be presented and discussed in relation to the current knowledge of the molecular basis of conidiation in Trichoderma and other filamentous fungi.
文摘[Objective] To study the effects of different culture conditions on the Fusarium oxysporurn SchL f. sp. [Method] Based on species identification of the pathogenic organism of Fusarium oxysporum Schl. f. sp, effects of different cultures and different nutrients on the mycelial growth and conidial production of Fusarium oxysporum SchL f. sp were studied. [Result] The mycelial growth and conidial pro- duction of Fusarium oxysporum SchL f. sp was different under different culture con- ditions. PDA medium was the most suitable medium for the mycelial growth and had the highest conidial production; and the mycelial grew the fastest on the medium with maltose as carbon source or peptone as nitrogen source, which also had the highest conidial production. [Conclusion] This study provided experimental basis for the study of Fusarium oxysporum SchL f. sp and also provided theoretical basis for the study and control of Fusarium oxysporum Schl. f. sp.
