[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
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
Conidiation is the primary mode of reproduction in filamentous fungi and is essential for the dispersal of pathogenic species.However,the fundamental cellular mechanisms regulating conidiation in plant pathogenic fung...Conidiation is the primary mode of reproduction in filamentous fungi and is essential for the dispersal of pathogenic species.However,the fundamental cellular mechanisms regulating conidiation in plant pathogenic fungi remain largely unexplored.Here,using Verticillium dahliae as a model,we investigated the dynamic assembly and function of the contractile actomyosin ring(CAR)and septins during conidiation through live-cell imaging.We show that septins,visualized via VdCdc11-GFP,first accumulate at the tip of budding hyphae during the transition from hyphal elongation to apical budding,and undergo an hourglass-to-double-ring transition at the bud neck.Following mitosis,myosin Ⅱ and actin assemble simultaneously into a contractile ring to drive cytokinesis.Disruption of core septin function results in defective nuclear segregation and aberrant nuclear migration during mitosis,as well as delayed recruitment of myosin Ⅱ to the bud neck,indicating that septins scaffold cytokinetic machinery and coordinate nuclear division during conidiation.In contrast,during hyphal septation,myosin Ⅱ,actin,and septins appear simultaneously as a diffuse cortical band,with septin organization dependent on actin.Collectively,these findings reveal distinct spatial and temporal coordination between actomyosin and septins in two cytokinetic contexts-conidiation and hyphal septation-and define apical budding as a specialized cytokinesis mode in V.dahliae.Our study broadens the understanding of fungal cytokinesis beyond yeast models to multicellular filamentous fungi.展开更多
Aspergillus niger is an efficient cell factory for organic acids production,particularly l-malic acid,through genetic manipulation.However,the traditional method of collecting A.niger spores for inoculation is labor-i...Aspergillus niger is an efficient cell factory for organic acids production,particularly l-malic acid,through genetic manipulation.However,the traditional method of collecting A.niger spores for inoculation is labor-intensive and resource-consuming.In our study,we used the CRISPR-Cas9 system to replace the promoter of brlA,a key gene in Aspergillus conidiation,with a xylose-inducible promoter xylP in l-malic acid-producing A.niger strain RG0095,generating strain brlAxylP.When induced with xylose in submerged liquid culture,brlAxylP exhibited significant upregulation of conidiation-related genes.This induction allowed us to easily collect an abundance of brlAxylP spores(>7.1×106/mL)in liquid xylose medium.Significantly,the submerged conidiation approach preserves the substantial potential of A.niger as a foundational cellular platform for the biosynthesis of organic acids,including but not limited to l-malic acid.In summary,our study offers a simplified submerged conidiation strategy to streamline the preparation stage and reduce labor and material costs for industrial organic acid production using Aspergillus species.展开更多
C_(2)H_(2)zinc finger transcription factors such as FlbC and Msn2,have broad regulatory roles in fungal growth and conidiation.In the present study,we cloned and characterized a C_(2)H_(2)zinc finger transcription fac...C_(2)H_(2)zinc finger transcription factors such as FlbC and Msn2,have broad regulatory roles in fungal growth and conidiation.In the present study,we cloned and characterized a C_(2)H_(2)zinc finger transcription factor gene,FpCzf14,in the wheat pathogen Fusarium pseudograminearum.FpCzf14 was localized to the nuclei.The expression of FpCzf14 was significantly upregulated in conidia,suggesting that FpCzf14 might contribute to conidiation.Further analysis of the fpczf14-deleted mutant(Δfpczf14)demonstrated that it exhibited defect in conidiation,and this defect was restored in the complemented strainΔfpczf14-C expressing FpCzf14,demonstrating that FpCzf14 was essential for conidiation.Moreover,FpCzf14 was required for mycelial growth and pathogenicity of F.pseudograminearum.Microscopic observation results showed thatΔfpczf14 produced only very few penetration pegs and invasive hyphae inside host tissues compared with WT andΔfpczf14-C.Additionally,results of reverse transcription quantitative PCR(RT-qPCR)showed that FpCzf14 regulated expression of several conidiation-related genes in F.pseudograminearum.In conclusion,FpCzf14,as a core regulatory gene in conidiation,provides new insights into the mechanism of conidiation in F.pseudograminearum.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
Phototropism, the induction of carotenogenesis and reproductive structures, and resetting of the circadian rhythm are controlled by blue light. Trichoderma is used as a photomorphogenetic model due to its ability to c...Phototropism, the induction of carotenogenesis and reproductive structures, and resetting of the circadian rhythm are controlled by blue light. Trichoderma is used as a photomorphogenetic model due to its ability to conidiate upon exposure to light. In total darkness, T. atroviride grows indefinitely as a mycelium provided that nutrients are not limiting. However, nutrient deprivation and light trigger the conidiation process. A pulse of blue light given to a radially growing colony induces synchronous sporulation. A ring of conidiophores bearing green conidia is produced at what had been the colony perimeter at the time of the light pulse. All known responses to blue light in N. crassa are initiated by a couple of transcription factors encoded by the white-collar genes (wc -1 and wc-2). WC-1 and WC-2 bind to the promoters of light regulated genes to rapidly activate transcription in response to light. In T. atroviride the photolyase encoding gene phr1 undergoes fast transcriptional activation in response to light. The presence of putative WCC binding boxes in the promoter of phr1, suggested that light responses in Trichoderma could be under the control of white-collar homologues. We cloned two genes and demonstrated by gene replacement that both are essential for photoconidiation and photolyase gene expression. Therefore, they were named blue-light regulator one and two (blr1 and blr2). The BLR1 protein has all the characteristics of a blue-light photoreceptor. The generation of subtractive cDNA libraries allowed us to identify novel, BLR independent, light responses including the regulation of gene expression by blue-light. In addition, we recently initiated a Trichoderma ESTs sequencing project. Until now, we have sequenced above 3000 ESTs, from which we have obtained approximately 1800 unigenes. This unigene set was printed in microarrays and used to search for light induced genes. Twenty five clearly induced and around thirty repressed genes have been detected. Among this set we have found both blr dependent and independent blue light induced genes, strengthening our view of the existence of alternative light perception pathways. We also show the first evidence for the entry of Trichoderma into the conidiation process caused by mechanical injury, which remains unaltered in the mutants. Finally, an unprecedented crosstalk between light and glucose sensing was found involving the BLR1 and BLR2 proteins in the control of carbon deprivation induced conidiation.展开更多
Magnaporthe oryzae, a filamentous ascomycete fungus, is well known as the causal agent of rice blast. With the technology of suppression subtractive hybridization （SSH）, it was previously found that MGG_06001 （or n...Magnaporthe oryzae, a filamentous ascomycete fungus, is well known as the causal agent of rice blast. With the technology of suppression subtractive hybridization （SSH）, it was previously found that MGG_06001 （or named MoNEM1）, a gene of M. oryzae homologous to the NEM1 （nuclear envelope morphology protein 1） gene of baker＇s yeast （Saccharomyces cerevisiae）, is differentially expressed between the mature appressium and the conidium and mycelium. This study aimed to characterize the function of MoNEM1 gene by knocking it out using the method of target gene replacement. The AMoneml mutants exhibited reduced mycelial growth and conidiation. However, disruption of MoNEM1 gene does not affect the pathogenicity of M. oryzae on barley and rice.展开更多
Systemic studies on the effects of mitogen-activated protein kinase(MAPK)signal transduction pathway on the growth and development of Setosphaeria turcica is helpful not only in understanding the molecular mechanism o...Systemic studies on the effects of mitogen-activated protein kinase(MAPK)signal transduction pathway on the growth and development of Setosphaeria turcica is helpful not only in understanding the molecular mechanism of pathogenhost interaction but also in the effective control of the diseases caused by S.turcica.U0126,the specific MEK inhibitor,is used to treat S.turcica before the observation of the conidial germination,appressorium production,and pathogenicity of the pathogen.There is no significant effect of U0126 on the colony morphology and mycelium growth of the pathogen.After treatment with U0126,the growth of mycelium and conidia are normal,but the conidial germination,appressorium production,and pathogenicity of S.turcica on susceptible corn leaves are significantly inhibited.Under the definite concentration scope,an increase in U0126 concentration increases the inhibition degree of conidial germination and appressorium production,but the inhibition degree decreases with elongation of treatment time.The conidial germination,appressorium production,and pathogenicity of S.turcica on susceptible corn leaves are regulated by the MAPK pathway inhibited by U0126.展开更多
Aiming at the climatic characteristics of more rain and high humidity and cultivation habits of rapeseed in Tongren area,in terms of rapeseed and Morchella spp.interplanting,excellent varieties suitable for the local ...Aiming at the climatic characteristics of more rain and high humidity and cultivation habits of rapeseed in Tongren area,in terms of rapeseed and Morchella spp.interplanting,excellent varieties suitable for the local climate were selected,the formulas of culture substrate and nutrition bag were optimized to produce high-quality strains,soil pests were prevented and controlled,rapeseed was transplanted in time,Morchella spp.were sown in ditches,nutrition bags were placed simultaneously,thick soil was covered and fruiting ditches were left,and stress was arranged to promote growth of mycelia.The production cycle was 90-100 d.The yield of Morchella spp.reached 2250-3375 kg/ha,with a net profit of 6000-10000 yuan.展开更多
A Cordyceps specimen was collected in Anhui, China, a strain of Beauveria bassiana, an important ento-mopathogenic fungus for biological pest control, was isolated and their relationship was demonstrated by microcycle...A Cordyceps specimen was collected in Anhui, China, a strain of Beauveria bassiana, an important ento-mopathogenic fungus for biological pest control, was isolated and their relationship was demonstrated by microcycle co-nidiation. The teleomorph is an undescribed species and is named Cordyceps bassiana.展开更多
Verticillium dahliae is a soil-borne phytopathogenic fungus that causes vascular wilt disease in a broad range of hosts. This pathogen survives for many years in soil in the form ofmelanized microsclerotia. To investi...Verticillium dahliae is a soil-borne phytopathogenic fungus that causes vascular wilt disease in a broad range of hosts. This pathogen survives for many years in soil in the form ofmelanized microsclerotia. To investigate the melanin synthesis in V.. dahliae, we identified a polyketide synthase gene in V. dahliae, namely VdPKS1. PKS1 is known to involve in the dihydroxynaphthalene melanin synthesis pathway in many fungi. We found that VdPKS1 was required for melanin formation but not for microsclerotial production in E dahliae. The VdPKS1 gene-disruption mutant （vdpksl） formed melanin-deficient albino microsclerotia, which did not affect the fungal colonization in host tissues but significantly reduced the disease severity. Gene transcription analysis in the wild-type and the vdpks1 strains suggested that VdPKS1 gene-disruption influenced the expression of a series of genes involved in ethylene biosynthesis, microsclerotial formation and pathogenesis. Our results suggest that the VdPKS1-mediated melanin synthesis is important for virulence and developmental traits of E dahliae.展开更多
Predatory fungi possess intricate signal transduction systems that regulate their development and support successful infection of the host.Herein,we characterized three components of the cell wall integrity-controllin...Predatory fungi possess intricate signal transduction systems that regulate their development and support successful infection of the host.Herein,we characterized three components of the cell wall integrity-controlling pathway,namely protein kinase C(Ao PKC),SLT2-MAPK(Ao SLT2),and SWI6(Ao SWI6),in a representative nematode-trapping fungus Arthrobotrys oligospora,using gene disruption and multi-omics approaches.The phenotypic traits(such as mycelia development,conidiation,stress response,and trap morphogenesis) and metabolic profiles of ΔAopkc and ΔAoswi6 mutants were similar but differed from those of the ΔAoslt2 mutants.Transcriptomic analysis indicated that the genes differentially expressed in the absence of Aoswi6 were involved in DNA replication,repair,and recombination during trap formation.Moreover,the yeast two-hybrid assay showed that Ao PKC interacted with Ao SWI6,suggesting that in A.oligospora,PKC can directly regulate SWI6,bypassing the SLT2signaling cascade.Conclusively,our findings deepen our understanding of the regulatory mechanism of asexual development and lifestyle switching in nematode-trapping fungi.展开更多
Glucosylceramides are a class of membrane lipids that serve as vital structural and signaling molecules in eukaryotes.In this study,we explored the function of FocGCS,a glucosylceramide synthase(GCS)in Fusarium oxyspo...Glucosylceramides are a class of membrane lipids that serve as vital structural and signaling molecules in eukaryotes.In this study,we explored the function of FocGCS,a glucosylceramide synthase(GCS)in Fusarium oxysporum f.sp.cubense tropical race 4(Foc TR4)that causes Fusarium wilt in banana plants.FocGCS is highly expressed in germinating conidia and during early infection stage of Foc TR4.Disruption of FocGCS resulted in severely retarded vegetative growth,reduced conidiation,and production of morphologically abnormal conidia.Sphingolipid profiling revealed that the FocGCS null mutant lacks glucosylceramide.Pathogenicity assays on banana plants revealed substantial loss of virulence in the FocGCS null mutant.Moreover,biochemical analyses indicated that FocGCS is involved in cell wall integrity but is not required for oxidative and osmotic stress tolerance in Foc TR4.Transcriptome analysis suggested that disruption of FocGCS strongly affects transmembrane transport in Foc TR4.Our findings show that GCS is essential for normal fungal growth and pathogenesis in Foc TR4.展开更多
Rice blast is a serious threat to the safe production of grain crops such as rice and wheat.Sporulation,appressorium formation,and invasive growth of Magnaporthe oryzae are the key stages of the development and spread...Rice blast is a serious threat to the safe production of grain crops such as rice and wheat.Sporulation,appressorium formation,and invasive growth of Magnaporthe oryzae are the key stages of the development and spread of rice blast epidemics.M.oryzae is a hemibiotrophic fungus that undergoes changes in available carbon sources during the infection cycle.Lipid is a major storage for M.oryzae spores and a major carbon source used in glycerol synthesis and turgor pressure generation in appressoria.The formation of a dense cell wall melanin layer is necessary for an appressorium to produce turgor and to be pathogenic.The plant cell wall is an important carbon source during the infection stage of M.oryzae.Transcription factors regulate gene expression in fungi and are key intermediates between the reception of external environmental signals and the control of development and pathogenicity in M.oryzae.The disease cycle of M.oryzae is controlled by some key transcription factors,such as sporulation by Cos1 and Hox2,appressorium formation by Sfl1,Hox7,and Vrf1,invasive growth by Mst12 and Mig1,and resistance to host basal immunity by Ap1 and Atf1.This review focuses on describing the key transcription factors of M.oryzae that regulate sporulation,appressorium formation,invasive growth,lipid metabolism,carbohydrate metabolism,melanin synthesis,oxidative response,and host basal immunity,as well as the working mechanism of the transcription factors.展开更多
More than twenty species of lichenicolous fungi have been described in Phoma,a large anamorphic genus of primarily plant-associated pathogens with broad geographic distributions.We obtained nuclear and mitochondrial r...More than twenty species of lichenicolous fungi have been described in Phoma,a large anamorphic genus of primarily plant-associated pathogens with broad geographic distributions.We obtained nuclear and mitochondrial rDNA sequences from 19 fungal cultures isolated from specimens representing four described and two undescribed lichenicolous species in the genus.Our multilocus phylogeny indicates that lichenicolous Phoma species represent at least two phylogenetically distinct clades in the Phaeosphaeriaceae,one including a new species,Phoma puncteliae,isolated from a specimen of Punctelia rudecta collected inMaryland,USA,and another group of primarily lichenicolous species.This latter group includes four described lichenicolous Phoma species,an unidentified melanized rock fungus,and a new lichenicolous Phoma species isolated from Xanthomendoza species collected in Canada that we are naming P.xanthomendozae.Some specimens in this clade collected from different lichen genera and species were found to be very similar genetically,which calls into question the recent practice of recognizing lichenicolous Phoma species mainly by differences in host preference.展开更多
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.
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 Science Foundation of China(Grant No.32370204)the State Key Laboratory of Microbial Diversity and Innovative Utilization.
文摘Conidiation is the primary mode of reproduction in filamentous fungi and is essential for the dispersal of pathogenic species.However,the fundamental cellular mechanisms regulating conidiation in plant pathogenic fungi remain largely unexplored.Here,using Verticillium dahliae as a model,we investigated the dynamic assembly and function of the contractile actomyosin ring(CAR)and septins during conidiation through live-cell imaging.We show that septins,visualized via VdCdc11-GFP,first accumulate at the tip of budding hyphae during the transition from hyphal elongation to apical budding,and undergo an hourglass-to-double-ring transition at the bud neck.Following mitosis,myosin Ⅱ and actin assemble simultaneously into a contractile ring to drive cytokinesis.Disruption of core septin function results in defective nuclear segregation and aberrant nuclear migration during mitosis,as well as delayed recruitment of myosin Ⅱ to the bud neck,indicating that septins scaffold cytokinetic machinery and coordinate nuclear division during conidiation.In contrast,during hyphal septation,myosin Ⅱ,actin,and septins appear simultaneously as a diffuse cortical band,with septin organization dependent on actin.Collectively,these findings reveal distinct spatial and temporal coordination between actomyosin and septins in two cytokinetic contexts-conidiation and hyphal septation-and define apical budding as a specialized cytokinesis mode in V.dahliae.Our study broadens the understanding of fungal cytokinesis beyond yeast models to multicellular filamentous fungi.
基金This work was financially supported by the National Key Research and Development Program of China(2021YFC2104300)the National Natural Science Foundation of China(32200055 and 22378210)the Natural Science Foundation of Jiangsu Province(BK20202002).
文摘Aspergillus niger is an efficient cell factory for organic acids production,particularly l-malic acid,through genetic manipulation.However,the traditional method of collecting A.niger spores for inoculation is labor-intensive and resource-consuming.In our study,we used the CRISPR-Cas9 system to replace the promoter of brlA,a key gene in Aspergillus conidiation,with a xylose-inducible promoter xylP in l-malic acid-producing A.niger strain RG0095,generating strain brlAxylP.When induced with xylose in submerged liquid culture,brlAxylP exhibited significant upregulation of conidiation-related genes.This induction allowed us to easily collect an abundance of brlAxylP spores(>7.1×106/mL)in liquid xylose medium.Significantly,the submerged conidiation approach preserves the substantial potential of A.niger as a foundational cellular platform for the biosynthesis of organic acids,including but not limited to l-malic acid.In summary,our study offers a simplified submerged conidiation strategy to streamline the preparation stage and reduce labor and material costs for industrial organic acid production using Aspergillus species.
基金supported by grants from the International(Regional)Cooperation and Exchange Program of National Natural Science Foundation of China(31961143018)the National Key R&D Plan of China(2017YFD0301104).
文摘C_(2)H_(2)zinc finger transcription factors such as FlbC and Msn2,have broad regulatory roles in fungal growth and conidiation.In the present study,we cloned and characterized a C_(2)H_(2)zinc finger transcription factor gene,FpCzf14,in the wheat pathogen Fusarium pseudograminearum.FpCzf14 was localized to the nuclei.The expression of FpCzf14 was significantly upregulated in conidia,suggesting that FpCzf14 might contribute to conidiation.Further analysis of the fpczf14-deleted mutant(Δfpczf14)demonstrated that it exhibited defect in conidiation,and this defect was restored in the complemented strainΔfpczf14-C expressing FpCzf14,demonstrating that FpCzf14 was essential for conidiation.Moreover,FpCzf14 was required for mycelial growth and pathogenicity of F.pseudograminearum.Microscopic observation results showed thatΔfpczf14 produced only very few penetration pegs and invasive hyphae inside host tissues compared with WT andΔfpczf14-C.Additionally,results of reverse transcription quantitative PCR(RT-qPCR)showed that FpCzf14 regulated expression of several conidiation-related genes in F.pseudograminearum.In conclusion,FpCzf14,as a core regulatory gene in conidiation,provides new insights into the mechanism of conidiation in F.pseudograminearum.
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.
文摘Phototropism, the induction of carotenogenesis and reproductive structures, and resetting of the circadian rhythm are controlled by blue light. Trichoderma is used as a photomorphogenetic model due to its ability to conidiate upon exposure to light. In total darkness, T. atroviride grows indefinitely as a mycelium provided that nutrients are not limiting. However, nutrient deprivation and light trigger the conidiation process. A pulse of blue light given to a radially growing colony induces synchronous sporulation. A ring of conidiophores bearing green conidia is produced at what had been the colony perimeter at the time of the light pulse. All known responses to blue light in N. crassa are initiated by a couple of transcription factors encoded by the white-collar genes (wc -1 and wc-2). WC-1 and WC-2 bind to the promoters of light regulated genes to rapidly activate transcription in response to light. In T. atroviride the photolyase encoding gene phr1 undergoes fast transcriptional activation in response to light. The presence of putative WCC binding boxes in the promoter of phr1, suggested that light responses in Trichoderma could be under the control of white-collar homologues. We cloned two genes and demonstrated by gene replacement that both are essential for photoconidiation and photolyase gene expression. Therefore, they were named blue-light regulator one and two (blr1 and blr2). The BLR1 protein has all the characteristics of a blue-light photoreceptor. The generation of subtractive cDNA libraries allowed us to identify novel, BLR independent, light responses including the regulation of gene expression by blue-light. In addition, we recently initiated a Trichoderma ESTs sequencing project. Until now, we have sequenced above 3000 ESTs, from which we have obtained approximately 1800 unigenes. This unigene set was printed in microarrays and used to search for light induced genes. Twenty five clearly induced and around thirty repressed genes have been detected. Among this set we have found both blr dependent and independent blue light induced genes, strengthening our view of the existence of alternative light perception pathways. We also show the first evidence for the entry of Trichoderma into the conidiation process caused by mechanical injury, which remains unaltered in the mutants. Finally, an unprecedented crosstalk between light and glucose sensing was found involving the BLR1 and BLR2 proteins in the control of carbon deprivation induced conidiation.
基金supported by the National Natural Science Foundation of China (30671123 and 31000077)
文摘Magnaporthe oryzae, a filamentous ascomycete fungus, is well known as the causal agent of rice blast. With the technology of suppression subtractive hybridization （SSH）, it was previously found that MGG_06001 （or named MoNEM1）, a gene of M. oryzae homologous to the NEM1 （nuclear envelope morphology protein 1） gene of baker＇s yeast （Saccharomyces cerevisiae）, is differentially expressed between the mature appressium and the conidium and mycelium. This study aimed to characterize the function of MoNEM1 gene by knocking it out using the method of target gene replacement. The AMoneml mutants exhibited reduced mycelial growth and conidiation. However, disruption of MoNEM1 gene does not affect the pathogenicity of M. oryzae on barley and rice.
基金supported by the National Natural Science Foundation of China(30471126)Doctoral Foundation Project of Hebei Province,China(05547007D-2).
文摘Systemic studies on the effects of mitogen-activated protein kinase(MAPK)signal transduction pathway on the growth and development of Setosphaeria turcica is helpful not only in understanding the molecular mechanism of pathogenhost interaction but also in the effective control of the diseases caused by S.turcica.U0126,the specific MEK inhibitor,is used to treat S.turcica before the observation of the conidial germination,appressorium production,and pathogenicity of the pathogen.There is no significant effect of U0126 on the colony morphology and mycelium growth of the pathogen.After treatment with U0126,the growth of mycelium and conidia are normal,but the conidial germination,appressorium production,and pathogenicity of S.turcica on susceptible corn leaves are significantly inhibited.Under the definite concentration scope,an increase in U0126 concentration increases the inhibition degree of conidial germination and appressorium production,but the inhibition degree decreases with elongation of treatment time.The conidial germination,appressorium production,and pathogenicity of S.turcica on susceptible corn leaves are regulated by the MAPK pathway inhibited by U0126.
基金Supported by Excellent Youth Talents Project of Guizhou Province Department of Forestry(Qian Lin Ke He J Zi[2021]09)Science and Technology Plan Project of Tongren City([2019]116,[2020]46,[2020]49).
文摘Aiming at the climatic characteristics of more rain and high humidity and cultivation habits of rapeseed in Tongren area,in terms of rapeseed and Morchella spp.interplanting,excellent varieties suitable for the local climate were selected,the formulas of culture substrate and nutrition bag were optimized to produce high-quality strains,soil pests were prevented and controlled,rapeseed was transplanted in time,Morchella spp.were sown in ditches,nutrition bags were placed simultaneously,thick soil was covered and fruiting ditches were left,and stress was arranged to promote growth of mycelia.The production cycle was 90-100 d.The yield of Morchella spp.reached 2250-3375 kg/ha,with a net profit of 6000-10000 yuan.
基金the Program of Research of Biodiversity in the Brazilian Semi-arid(PPBIO Semi-arid/Ministry of Technology and Science-proc.554718/2009-0)for financial supportthe National Council for Scientific and Technological Development for the Postdoctoral Research Fellowships(CNPq proc.163775/2015-0)LFPG for the grant(CNPq proc.303062/2014-2)。
文摘Phaeoisaria triseptata and Spadicoides heterocolorata are described,illustrated and discussed.Both species represent new records for Brazil.
基金This work was supported partly by the National Natural Science Foundation of China (Grant No. 39870013) the Anhui Provincial Natural Science Foundation (Grant No. 98230513) and the Systematic Mycological and Lichenological Laboratory of the Institute
文摘A Cordyceps specimen was collected in Anhui, China, a strain of Beauveria bassiana, an important ento-mopathogenic fungus for biological pest control, was isolated and their relationship was demonstrated by microcycle co-nidiation. The teleomorph is an undescribed species and is named Cordyceps bassiana.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB11040500)the National Natural Science Foundation of China(31160351,311060350)Basic Research Projects of Xingjiang Production and Construction Corps(2016AG001)
文摘Verticillium dahliae is a soil-borne phytopathogenic fungus that causes vascular wilt disease in a broad range of hosts. This pathogen survives for many years in soil in the form ofmelanized microsclerotia. To investigate the melanin synthesis in V.. dahliae, we identified a polyketide synthase gene in V. dahliae, namely VdPKS1. PKS1 is known to involve in the dihydroxynaphthalene melanin synthesis pathway in many fungi. We found that VdPKS1 was required for melanin formation but not for microsclerotial production in E dahliae. The VdPKS1 gene-disruption mutant （vdpksl） formed melanin-deficient albino microsclerotia, which did not affect the fungal colonization in host tissues but significantly reduced the disease severity. Gene transcription analysis in the wild-type and the vdpks1 strains suggested that VdPKS1 gene-disruption influenced the expression of a series of genes involved in ethylene biosynthesis, microsclerotial formation and pathogenesis. Our results suggest that the VdPKS1-mediated melanin synthesis is important for virulence and developmental traits of E dahliae.
基金supported by the National Natural Science Foundation of China(31960556,U1402265,32160665)the Applied Basic Research Foundation of Yunnan Province(202001BB050004)Postdoctoral Science Foundation of Yunnan Province。
文摘Predatory fungi possess intricate signal transduction systems that regulate their development and support successful infection of the host.Herein,we characterized three components of the cell wall integrity-controlling pathway,namely protein kinase C(Ao PKC),SLT2-MAPK(Ao SLT2),and SWI6(Ao SWI6),in a representative nematode-trapping fungus Arthrobotrys oligospora,using gene disruption and multi-omics approaches.The phenotypic traits(such as mycelia development,conidiation,stress response,and trap morphogenesis) and metabolic profiles of ΔAopkc and ΔAoswi6 mutants were similar but differed from those of the ΔAoslt2 mutants.Transcriptomic analysis indicated that the genes differentially expressed in the absence of Aoswi6 were involved in DNA replication,repair,and recombination during trap formation.Moreover,the yeast two-hybrid assay showed that Ao PKC interacted with Ao SWI6,suggesting that in A.oligospora,PKC can directly regulate SWI6,bypassing the SLT2signaling cascade.Conclusively,our findings deepen our understanding of the regulatory mechanism of asexual development and lifestyle switching in nematode-trapping fungi.
基金supported by the funds from the National Natural Science Foundation of China(32070196)the Natural Science Foundation of Guangdong Province(2019B1515120088)+1 种基金Department of Science and Technology of Guangdong Province(33000-42021182)by the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(33000-31611238).
文摘Glucosylceramides are a class of membrane lipids that serve as vital structural and signaling molecules in eukaryotes.In this study,we explored the function of FocGCS,a glucosylceramide synthase(GCS)in Fusarium oxysporum f.sp.cubense tropical race 4(Foc TR4)that causes Fusarium wilt in banana plants.FocGCS is highly expressed in germinating conidia and during early infection stage of Foc TR4.Disruption of FocGCS resulted in severely retarded vegetative growth,reduced conidiation,and production of morphologically abnormal conidia.Sphingolipid profiling revealed that the FocGCS null mutant lacks glucosylceramide.Pathogenicity assays on banana plants revealed substantial loss of virulence in the FocGCS null mutant.Moreover,biochemical analyses indicated that FocGCS is involved in cell wall integrity but is not required for oxidative and osmotic stress tolerance in Foc TR4.Transcriptome analysis suggested that disruption of FocGCS strongly affects transmembrane transport in Foc TR4.Our findings show that GCS is essential for normal fungal growth and pathogenesis in Foc TR4.
基金supported by a grant from State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products to JL(2021DG700024-KF202304)by a grant Organism Interaction from Zhejiang Xianghu Laboratory to FLfunded by the National Natural Science Foundation of China to JL(31371891,31671975,and 31871908).
文摘Rice blast is a serious threat to the safe production of grain crops such as rice and wheat.Sporulation,appressorium formation,and invasive growth of Magnaporthe oryzae are the key stages of the development and spread of rice blast epidemics.M.oryzae is a hemibiotrophic fungus that undergoes changes in available carbon sources during the infection cycle.Lipid is a major storage for M.oryzae spores and a major carbon source used in glycerol synthesis and turgor pressure generation in appressoria.The formation of a dense cell wall melanin layer is necessary for an appressorium to produce turgor and to be pathogenic.The plant cell wall is an important carbon source during the infection stage of M.oryzae.Transcription factors regulate gene expression in fungi and are key intermediates between the reception of external environmental signals and the control of development and pathogenicity in M.oryzae.The disease cycle of M.oryzae is controlled by some key transcription factors,such as sporulation by Cos1 and Hox2,appressorium formation by Sfl1,Hox7,and Vrf1,invasive growth by Mst12 and Mig1,and resistance to host basal immunity by Ap1 and Atf1.This review focuses on describing the key transcription factors of M.oryzae that regulate sporulation,appressorium formation,invasive growth,lipid metabolism,carbohydrate metabolism,melanin synthesis,oxidative response,and host basal immunity,as well as the working mechanism of the transcription factors.
基金We thank Peter Scholz for providing us with a copy of the original description of Phoma pisutii,and Walter Obermayer for searching for an isotype of P.pisutii.Sequencing partially supported by grant DEB 0841405 from the National Science FoundationMPN is supported by the Brown Family Graduate Fellowship through the Field Museum.
文摘More than twenty species of lichenicolous fungi have been described in Phoma,a large anamorphic genus of primarily plant-associated pathogens with broad geographic distributions.We obtained nuclear and mitochondrial rDNA sequences from 19 fungal cultures isolated from specimens representing four described and two undescribed lichenicolous species in the genus.Our multilocus phylogeny indicates that lichenicolous Phoma species represent at least two phylogenetically distinct clades in the Phaeosphaeriaceae,one including a new species,Phoma puncteliae,isolated from a specimen of Punctelia rudecta collected inMaryland,USA,and another group of primarily lichenicolous species.This latter group includes four described lichenicolous Phoma species,an unidentified melanized rock fungus,and a new lichenicolous Phoma species isolated from Xanthomendoza species collected in Canada that we are naming P.xanthomendozae.Some specimens in this clade collected from different lichen genera and species were found to be very similar genetically,which calls into question the recent practice of recognizing lichenicolous Phoma species mainly by differences in host preference.
