Resistance to maize southern leaf spot disease was induced by the low-concentration filtrate of Bipolaris maydis race T cultivation in an experiment. The nuclear neterogeny corn C103 was used as the test material. The...Resistance to maize southern leaf spot disease was induced by the low-concentration filtrate of Bipolaris maydis race T cultivation in an experiment. The nuclear neterogeny corn C103 was used as the test material. The lesion area on the leaves was significant difference by connalysis. The lesion areas on pretreated leaves were （0.3±0.05）- （0.9±0.5） mm^2, but those on the control were （23.1±8.7） mm^2. At the same time, the changes in peroxidase, phenylalanine, ammonialyase, and malondialdehvde activities were determined. During 0-96 h of inspection, phenylalanine and ammonialyase （PAL） activities increased by 64.2%, peroxidase （POD） activities increased by 41.2%, but the malondialdenvde （MDA） content decreased by 29.7% compared with the control. It seems that the low-concentration filtrate of Bipolaris maydis race T cultivation itself can be used as an elicitor to enhance the induced resistance.展开更多
Bipolaris oryzae is a severe rice disease,resulting in significant economic losses.MYB73 gene of Arabidopsis was isolated based on T-DNA insertion mutants whose lose-of-function mutant increased susceptibility to B.or...Bipolaris oryzae is a severe rice disease,resulting in significant economic losses.MYB73 gene of Arabidopsis was isolated based on T-DNA insertion mutants whose lose-of-function mutant increased susceptibility to B.oryzae.Results of staining for H2O2 revealed that infection of incompatible B.oryzae caused much more strong brown patches on the leaves of myb73 mutant than those on the leaves of wild type.Expression of MYB73 gene was induced by B.oryzae.Its increased expression was severely impaired in the myb73 mutant.Expression of MYB73 was severely decreased in the npr1,jar1,eds5,and sid2 mutants,suggesting MYB73 gene participates in the jasmonate （JA） and salicylic acid （SA） signaling pathways.Expression of MYB73 who encoded an R2R3 MYB transcription factor was increased by SA,JA,and ethylene （ET） treatments.The cDNA full-length sequence of MYB73 was 960 bp and a protein with 320 amino acids was encoded.The predicted molecular weight of MYB73 was 34.85 kDa.The expression of MYB73 gene was induced within 24 h of the inoculation,however,the expression of PR1,PDF1.2 and NPR1 weren＇t changed.When B.oryzae successfully infected myb73 mutant plants,the expression of PR1,PDF1.2 and NPR1 were increased.Collectively,our results suggested that MYB73 is involved in NPR1-mediated SA and JA signaling pathways.展开更多
Bipolarins A–H(1–8), eight new tetracyclic ophiobolin-type sesterterpenes featuring a rare oxaspiro[4.4]nonane moiety, were isolated from cultures of fungus Bipolaris sp. TJ403-B1. Their structures and absolute conf...Bipolarins A–H(1–8), eight new tetracyclic ophiobolin-type sesterterpenes featuring a rare oxaspiro[4.4]nonane moiety, were isolated from cultures of fungus Bipolaris sp. TJ403-B1. Their structures and absolute configurations were elucidated by comprehensive spectroscopic analyses, single-crystal X-ray diffraction experiments, electronic circular dichroism and 13 C NMR calculations. Additionally, compound 5 exhibited significant selective antimicrobial activity against Enterococcus faecalis with an MIC value 8 μg·mL^-1.展开更多
A series of terpenoids(1-17),comprising six new compounds designated bipolariterpenes A-F(1-6)and eleven rec-ognized compounds(7-17),were isolated from the wheat culture of the potato endophytic fungus Bipolaris eleus...A series of terpenoids(1-17),comprising six new compounds designated bipolariterpenes A-F(1-6)and eleven rec-ognized compounds(7-17),were isolated from the wheat culture of the potato endophytic fungus Bipolaris eleusines.Their structures and stereochemistry were clarified by HRESIMS,NMR,DP4+probability analyses,and computations for electronic circular dichroism(ECD).All compounds are made up of six meroterpenoids,four sesterterpenes and seven sesquiterpenes.Among them,four sesterterpenes(4,5,10,11)were investigated for their antifungal,antibacterial and cytotoxic properties,and six meroterpenoids(1-3,7-9)were evaluated for their antifungal properties.The compounds 7,9,and 10 had substantial antifungal activity against Epidermophyton floccosum at a concentration of 100μM.No antibacterial and cytotoxic activities were observed.展开更多
Bipolaris sorokiniana is an important disease causing wheat root rot. Different biocontrol strains were screened with the pathogen as the target. A total of 210 strains of bacteria and fungi preserved in the laborator...Bipolaris sorokiniana is an important disease causing wheat root rot. Different biocontrol strains were screened with the pathogen as the target. A total of 210 strains of bacteria and fungi preserved in the laboratory were preliminarily and secondarily screened by plate confrontation culture. The 17 strains of bacteria and 36 strains of fungi with good bicontrol effect were screened. Eventually, the best fungal strain and the best bacterial strain were obtained. The ITS fragments of fungi were amplified by PCR, and the target band of 571 bp was obtained. The 16 S gene frag-ments of bacteria were amplified by PCR, and the target band of 1 455 bp was obtained. Through morphological observation, the screened strains were identified. Finally, the bicontrol fungus was confirmed as Trichoderma asperellum and the bacterium was Bacillus amylofaciens.展开更多
Two new seco-sativene sesquiterpenoids,bipolenins D(1)and E(2),a new seco-longifolene sesquiterpenoid,bipolenin F(3),together with three known analogues(4–6),were obtained from cultures of endophytic fungus Bipolaris...Two new seco-sativene sesquiterpenoids,bipolenins D(1)and E(2),a new seco-longifolene sesquiterpenoid,bipolenin F(3),together with three known analogues(4–6),were obtained from cultures of endophytic fungus Bipolaris eleusines.Their structures were established by MS and NMR data.Compounds 1–6 showed no activity to five human cancer cell lines.展开更多
Bipolaris oryzae is the causal agent of brown leaf spot disease in rice, and its asexual spore (conidium) formation is known to be induced by near-ultraviolet (NUV) irradiation. In order to reveal the photomorphogenic...Bipolaris oryzae is the causal agent of brown leaf spot disease in rice, and its asexual spore (conidium) formation is known to be induced by near-ultraviolet (NUV) irradiation. In order to reveal the photomorphogenic response and to identify new genes upregulated by NUV irradiation, suppression subtractive hybridization (SSH) was carried out in B. oryzae. To confirm the differential gene expression in NUV-irradiated mycelia, quantitative real-time PCR (qRT-PCR) analysis was performed among 301 genes arbitrarily chosen from 1170 cDNA clones. The expression of 46 genes (named NUV01 to NUV46) was found to be significantly enhanced (>4-fold) by NUV irradiation. Sequence analysis revealed that 23 out of the 46 sequences (50%) showed significant matches to known fungal genes. The 46 genes were categorized as either BLR1-dependent or BLR1-independent expression groups using the BLR1-deficient mutant, which presumably lacks the blue/UVA-absorbing photoreceptor. This finding demonstrates that NUV irradiation can induce gene regulation, and that this response may be mediated by both a blue/UVA-absorbing photoreceptor and an as-yet-unidentified photoreceptor in B. oryzae.展开更多
Bipolaris oryzae is the causal agent of brown spot disease in rice and produces the dark pigment melanin. We isolated and characterized T4HR1 gene encoding 1,3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) reductase, whic...Bipolaris oryzae is the causal agent of brown spot disease in rice and produces the dark pigment melanin. We isolated and characterized T4HR1 gene encoding 1,3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) reductase, which converted 1,3,6,8-THN to scytalone in the melanin biosynthesis from B. oryzae. A sequence analysis showed that the T4HR1 gene encoded a putative protein of 268 amino acids showing 50% - 99% sequence identity to other fungal 1,3,6,8-THN reductases. Targeted disruption of the T4HR1 gene showed a different phenotype of mycelial color due to an accumulation of shunt products compared to those of wild-type on PDA plates using tricyclazole as a melanin biosynthesis inhibitor. A quantitative real-time PCR analysis showed that the expression of T4HR1 transcripts was enhanced by near-ultraviolet (NUV) irradiation and regulated by transcriptional factor BMR1, similar to three other melanin biosynthesis genes (polyketide synthase gene [PKS1], scytalone dehydratase gene [SCD1], and 1,3,8-THN reductase gene [THR1]) in the melanin biosynthesis of B. oryzae. These results suggested that common transcriptional mechanisms could regulate the enhanced gene expression of these melanin biosynthesis genes by NUV irradiation in B. oryzae.展开更多
Black point of wheat caused by Bipolaris sorokiniana (Bs) is very destructive disease of wheat in Bangladesh and all over the world. The symptoms of diseases caused by Bipolaris sorokiniana can vary depending on the h...Black point of wheat caused by Bipolaris sorokiniana (Bs) is very destructive disease of wheat in Bangladesh and all over the world. The symptoms of diseases caused by Bipolaris sorokiniana can vary depending on the host plant and environmental conditions. The conidia of Bs germinate from two poles, which differ physiologically as indicated by the rate, growth character, of length, breadth and number of septa on different media. The aim of this study was to evaluate the efficacy of selected plant extracts on the morphology and cultural characteristics of the fungus Bipolaris sorokiniana causing black point disease in wheat crops in Bangladesh. The efficacy of fifteen plant extracts on the growth and characteristics of Bs was conducted in vitro in 2019-2020. The treatments were: Untreated control, T<sub>1</sub>—Black berry Leaves, T<sub>2</sub>—Guava Leaves, T<sub>3</sub>—Lantena camera leaves, T<sub>4</sub>—Eucalyptus Leaves, T<sub>5</sub>— Turmeric Leaves, T<sub>6</sub>—Khoksha Leaves, T<sub>7</sub>—Papaya leaves, T<sub>8</sub>-Gurlic Bulb, T<sub>9</sub>—Chili dust, T<sub>10</sub>—Nigella seeds, T<sub>11</sub>—Turmeric dust, T<sub>12</sub>—Cloves, T<sub>13</sub>— Bohera fruits, T<sub>14</sub>—Black pepper and T<sub>15</sub>—Neem leaves. After 15 days of inoculation of Bipolaris sorokiniana, colony color and shapes were Gerrish blackish, greenish blackish, greyish blackish and shapes were round or irregular. In our study, conidia color was dark brown to light brown, conidiophore color was brown, dark brown, grayish brown, dark olivaceous, light brown and conidia shapes were elliptical, oblong or slightly curved. The septation of conidia was 2 - 5 and highest septation was seen in T<sub>4</sub> and T<sub>14</sub> treatments. The highest conidial length was 17.79 μm recorded in T<sub>2</sub> treatment and lowest was 6.62 μm T<sub>9</sub> treatment where conidial breath was 8.27 μm in control and lowest was 3.79 μm in T<sub>8</sub> treatment. Mycelial growth rate of Bipolaris sorokiniana was different in different treatments in different days after inoculation (DAI) where at 7 DAI, % reduction of mycelial growth over control was highest in Bohera and Neem Leaves treatments respectively.展开更多
Bipolarpenoids A–J(1–10),ten undescribed ophiobolin-derived sesterterpenoids,were identified from the fungus Bipolaris oryzae.Their structures were elucidated by high resolution electrospray ionization mass spectrom...Bipolarpenoids A–J(1–10),ten undescribed ophiobolin-derived sesterterpenoids,were identified from the fungus Bipolaris oryzae.Their structures were elucidated by high resolution electrospray ionization mass spectrometry(HRESIMS),spectroscopic analyses,quantum chemical ^(13)C nuclear magnetic resonance(NMR),electronic circular dichroism(ECD)calculations,and single-crystal X-ray diffraction analyses.Notably,compounds 1 and 2 were uniquely characterized by a multicyclic caged pentacyclo[8.4.0.0^(1,5).0^(4,9).0^(7,11)]tetradecane-bridged system;compounds 4–6 featured unprecedented5/8/5/6 and 5/8/5/5 fused cores,respectively;compound 7 represented the first example of 3,4-secoophiobolin-alkaloid hybrid with a modified 5/6/8/5/5 fused carbon skeleton.Compound 9 showed potential anti-inflammatory effect in RAW264.7 macrophages and ulcerative colitis mice.展开更多
The fungal pathogen Bipolaris maydis invades by direct penetration into maize leaf veins. In order to understand the resistance mechanism of maize to B. maydis strain 523, cDNA-AFLP (amplified fragment length polymorp...The fungal pathogen Bipolaris maydis invades by direct penetration into maize leaf veins. In order to understand the resistance mechanism of maize to B. maydis strain 523, cDNA-AFLP (amplified fragment length polymorphism) analysis was conducted to compare the changes in mRNA transcripts hi response to B. maydis infection between a highly disease-resistant (HDR) line and a susceptible (S) line. 13 cDNA fragments derived from the genes showing enhanced expression after fungal infection, named HDR genes, were isolated from the HDR line. Northern blot analysis showed that 5 HDR genes were induced by fungal infection in the HDR, but not the S lines. The 5 HDR genes showed homology to previously characterized genes involved in disease resistance. A full-length HDR10 cDNA was isolated. It had a capacity to encode a protein of 284 amino acids. The deduced amino acid sequence of the HDR10 gene was homologous to a fungal infection-induced protein from Cicer arietinum and a hypersensitive response protein from展开更多
Bipolaris maydis race C strain 523 (C523) induces severer leaf blight on cytoplasmic male sterility (CMS)-C maize than on normal (N) maize. Previously, a pathotoxin isolated from C523 (C-toxin) was shown to be respons...Bipolaris maydis race C strain 523 (C523) induces severer leaf blight on cytoplasmic male sterility (CMS)-C maize than on normal (N) maize. Previously, a pathotoxin isolated from C523 (C-toxin) was shown to be responsible for the disease. To understand the basis of the differential responses between CMS-C and N maizes to this fungus, protein synthesis in vitro by mitochondria from N and CMS-C cytoplasms was monitored after their incubation in a solution containing the toxin (0.3%). Similar protein products were detected between the two alloplasmic lines, indicating that the toxin does not directly act on the mitochondrial membrane, nor inhibits the expression of mitochondrial genes. To further locate the action site of the toxin, intact leaves from both N and several subtypes of CMS-C lines were treated by 0.3% toxin. Analysis of electrolyte leakage of leaf cells showed that the leakage rates were similar to one another among the alloplasmic maize lines. In contrast, at a lower concentration of the展开更多
Six new meroterpe no ids,bipolarinoids A-F(1-6),and two known congen ers(7-8)were isolated from a soil-derived fungus Bipolaris zeicola.Their structures were elucidated based on extensive spectroscopic techniques(inel...Six new meroterpe no ids,bipolarinoids A-F(1-6),and two known congen ers(7-8)were isolated from a soil-derived fungus Bipolaris zeicola.Their structures were elucidated based on extensive spectroscopic techniques(ineluding HRESIMS and ID and 2D NMR data),and the absolute configurations of 1-4 were further confirmed viasingle-crystal X-ray diffraction an alysis and comparis on of experimental electronic circular dichroism(ECD)data.Structurally,compound 1 represents the first case of cochlioquinone derivatives featuring a formaldehyde group at C-11, and compou nd 3 features a rareamino group at C-11.In the immunosuppressive activity assay,compounds 5-8 showed potent inhibitory activity against concanavalin A(ConA)-induced T lymphocyte proliferation with IC50 values of 78.3,81.1,48.3,and 48.0 nmol/L,respectively,which provided promising leads for designing and developing new im-muno suppressive agents to treat auto-immunological diseases.展开更多
Plant immunity is a multilayered process that includes recognition of patterns or effectors from pathogens to elicit defense responses.These include the induction of a cocktail of defense metabolites that typically re...Plant immunity is a multilayered process that includes recognition of patterns or effectors from pathogens to elicit defense responses.These include the induction of a cocktail of defense metabolites that typically restrict pathogen virulence.Here,we investigate the interaction between barley roots and the fungal pathogens Bipolaris sorokiniana(Bs)and Fusarium graminearum(Fg)at the metabolite level.We identify hordedanes,a previously undescribed set of labdane-related diterpenoids with antimicrobial properties,as critical players in these interactions.Infection of barley roots by Bs and Fg elicits hordedane synthesis from a 60o-kb gene cluster.Heterologous reconstruction of the biosynthesis pathway in yeast and Nicotiana benthamiana produced several hordedanes,including one of the most functionally decorated products 19-β-hydroxy-hordetrienoic acid(19-OH-HTA).Barley mutants in the diterpene synthase genes of this cluster are unable to produce hordedanes but,unexpectedly,show reduced Bs colonization.By contrast,colonization by Fusarium graminearum,another fungal pathogen of barley and wheat,is 4-fold higher in the mutants completely lacking hordedanes.Accordingly,19-OH-HTA enhances both germination and growth of Bs,whereas it inhibits other pathogenic fungi,including Fg.Analysis of microscopy and transcriptomics data suggest that hordedanes delay the necrotrophic phase of Bs.Taken together,these results show that adapted pathogens such as Bs can subvert plant metabolic defenses to facilitate root colonization.展开更多
文摘Resistance to maize southern leaf spot disease was induced by the low-concentration filtrate of Bipolaris maydis race T cultivation in an experiment. The nuclear neterogeny corn C103 was used as the test material. The lesion area on the leaves was significant difference by connalysis. The lesion areas on pretreated leaves were （0.3±0.05）- （0.9±0.5） mm^2, but those on the control were （23.1±8.7） mm^2. At the same time, the changes in peroxidase, phenylalanine, ammonialyase, and malondialdehvde activities were determined. During 0-96 h of inspection, phenylalanine and ammonialyase （PAL） activities increased by 64.2%, peroxidase （POD） activities increased by 41.2%, but the malondialdenvde （MDA） content decreased by 29.7% compared with the control. It seems that the low-concentration filtrate of Bipolaris maydis race T cultivation itself can be used as an elicitor to enhance the induced resistance.
基金supported by the Natural Science Foundation of Hebei Province,China (08B021)
文摘Bipolaris oryzae is a severe rice disease,resulting in significant economic losses.MYB73 gene of Arabidopsis was isolated based on T-DNA insertion mutants whose lose-of-function mutant increased susceptibility to B.oryzae.Results of staining for H2O2 revealed that infection of incompatible B.oryzae caused much more strong brown patches on the leaves of myb73 mutant than those on the leaves of wild type.Expression of MYB73 gene was induced by B.oryzae.Its increased expression was severely impaired in the myb73 mutant.Expression of MYB73 was severely decreased in the npr1,jar1,eds5,and sid2 mutants,suggesting MYB73 gene participates in the jasmonate （JA） and salicylic acid （SA） signaling pathways.Expression of MYB73 who encoded an R2R3 MYB transcription factor was increased by SA,JA,and ethylene （ET） treatments.The cDNA full-length sequence of MYB73 was 960 bp and a protein with 320 amino acids was encoded.The predicted molecular weight of MYB73 was 34.85 kDa.The expression of MYB73 gene was induced within 24 h of the inoculation,however,the expression of PR1,PDF1.2 and NPR1 weren＇t changed.When B.oryzae successfully infected myb73 mutant plants,the expression of PR1,PDF1.2 and NPR1 were increased.Collectively,our results suggested that MYB73 is involved in NPR1-mediated SA and JA signaling pathways.
基金supported by the Program for Changjiang Scholars of Ministry of Education of the People’s Republic of China(No.T2016088)the National Natural Science Foundation for Distinguished Young Scholars(No.81725021)+2 种基金the Innovative Research Groups of the National Natural Science Foundation of China(No.81721005)the National Natural Science Foundation of China(Nos.81573316,21702067,and 81803387)the Hubei Provincial Natural Science Foundation of China(No.2018CFB152)
文摘Bipolarins A–H(1–8), eight new tetracyclic ophiobolin-type sesterterpenes featuring a rare oxaspiro[4.4]nonane moiety, were isolated from cultures of fungus Bipolaris sp. TJ403-B1. Their structures and absolute configurations were elucidated by comprehensive spectroscopic analyses, single-crystal X-ray diffraction experiments, electronic circular dichroism and 13 C NMR calculations. Additionally, compound 5 exhibited significant selective antimicrobial activity against Enterococcus faecalis with an MIC value 8 μg·mL^-1.
基金the National Natural Science Foundation of China(32000011,82204239)Hubei Provincial Natural Science Foundation of China(2022CFB462)+1 种基金the Fund of State Key Laboratory of Phytochemistry and Plant Resources in West China(P2022-KF03)the Fundamental Research Funds for the Central Universities,South-Central MinZu University(CZY23024).
文摘A series of terpenoids(1-17),comprising six new compounds designated bipolariterpenes A-F(1-6)and eleven rec-ognized compounds(7-17),were isolated from the wheat culture of the potato endophytic fungus Bipolaris eleusines.Their structures and stereochemistry were clarified by HRESIMS,NMR,DP4+probability analyses,and computations for electronic circular dichroism(ECD).All compounds are made up of six meroterpenoids,four sesterterpenes and seven sesquiterpenes.Among them,four sesterterpenes(4,5,10,11)were investigated for their antifungal,antibacterial and cytotoxic properties,and six meroterpenoids(1-3,7-9)were evaluated for their antifungal properties.The compounds 7,9,and 10 had substantial antifungal activity against Epidermophyton floccosum at a concentration of 100μM.No antibacterial and cytotoxic activities were observed.
基金Supported by National Natural Science Foundation of China(31400129&31770029)
文摘Bipolaris sorokiniana is an important disease causing wheat root rot. Different biocontrol strains were screened with the pathogen as the target. A total of 210 strains of bacteria and fungi preserved in the laboratory were preliminarily and secondarily screened by plate confrontation culture. The 17 strains of bacteria and 36 strains of fungi with good bicontrol effect were screened. Eventually, the best fungal strain and the best bacterial strain were obtained. The ITS fragments of fungi were amplified by PCR, and the target band of 571 bp was obtained. The 16 S gene frag-ments of bacteria were amplified by PCR, and the target band of 1 455 bp was obtained. Through morphological observation, the screened strains were identified. Finally, the bicontrol fungus was confirmed as Trichoderma asperellum and the bacterium was Bacillus amylofaciens.
基金National Natural Science Foundation of China(31560010,31260342)China Agricultural Research System(CARS-10)Natural Science Fund of Yunnan province(2013ZA007)。
文摘Two new seco-sativene sesquiterpenoids,bipolenins D(1)and E(2),a new seco-longifolene sesquiterpenoid,bipolenin F(3),together with three known analogues(4–6),were obtained from cultures of endophytic fungus Bipolaris eleusines.Their structures were established by MS and NMR data.Compounds 1–6 showed no activity to five human cancer cell lines.
文摘Bipolaris oryzae is the causal agent of brown leaf spot disease in rice, and its asexual spore (conidium) formation is known to be induced by near-ultraviolet (NUV) irradiation. In order to reveal the photomorphogenic response and to identify new genes upregulated by NUV irradiation, suppression subtractive hybridization (SSH) was carried out in B. oryzae. To confirm the differential gene expression in NUV-irradiated mycelia, quantitative real-time PCR (qRT-PCR) analysis was performed among 301 genes arbitrarily chosen from 1170 cDNA clones. The expression of 46 genes (named NUV01 to NUV46) was found to be significantly enhanced (>4-fold) by NUV irradiation. Sequence analysis revealed that 23 out of the 46 sequences (50%) showed significant matches to known fungal genes. The 46 genes were categorized as either BLR1-dependent or BLR1-independent expression groups using the BLR1-deficient mutant, which presumably lacks the blue/UVA-absorbing photoreceptor. This finding demonstrates that NUV irradiation can induce gene regulation, and that this response may be mediated by both a blue/UVA-absorbing photoreceptor and an as-yet-unidentified photoreceptor in B. oryzae.
文摘Bipolaris oryzae is the causal agent of brown spot disease in rice and produces the dark pigment melanin. We isolated and characterized T4HR1 gene encoding 1,3,6,8-tetrahydroxynaphthalene (1,3,6,8-THN) reductase, which converted 1,3,6,8-THN to scytalone in the melanin biosynthesis from B. oryzae. A sequence analysis showed that the T4HR1 gene encoded a putative protein of 268 amino acids showing 50% - 99% sequence identity to other fungal 1,3,6,8-THN reductases. Targeted disruption of the T4HR1 gene showed a different phenotype of mycelial color due to an accumulation of shunt products compared to those of wild-type on PDA plates using tricyclazole as a melanin biosynthesis inhibitor. A quantitative real-time PCR analysis showed that the expression of T4HR1 transcripts was enhanced by near-ultraviolet (NUV) irradiation and regulated by transcriptional factor BMR1, similar to three other melanin biosynthesis genes (polyketide synthase gene [PKS1], scytalone dehydratase gene [SCD1], and 1,3,8-THN reductase gene [THR1]) in the melanin biosynthesis of B. oryzae. These results suggested that common transcriptional mechanisms could regulate the enhanced gene expression of these melanin biosynthesis genes by NUV irradiation in B. oryzae.
文摘Black point of wheat caused by Bipolaris sorokiniana (Bs) is very destructive disease of wheat in Bangladesh and all over the world. The symptoms of diseases caused by Bipolaris sorokiniana can vary depending on the host plant and environmental conditions. The conidia of Bs germinate from two poles, which differ physiologically as indicated by the rate, growth character, of length, breadth and number of septa on different media. The aim of this study was to evaluate the efficacy of selected plant extracts on the morphology and cultural characteristics of the fungus Bipolaris sorokiniana causing black point disease in wheat crops in Bangladesh. The efficacy of fifteen plant extracts on the growth and characteristics of Bs was conducted in vitro in 2019-2020. The treatments were: Untreated control, T<sub>1</sub>—Black berry Leaves, T<sub>2</sub>—Guava Leaves, T<sub>3</sub>—Lantena camera leaves, T<sub>4</sub>—Eucalyptus Leaves, T<sub>5</sub>— Turmeric Leaves, T<sub>6</sub>—Khoksha Leaves, T<sub>7</sub>—Papaya leaves, T<sub>8</sub>-Gurlic Bulb, T<sub>9</sub>—Chili dust, T<sub>10</sub>—Nigella seeds, T<sub>11</sub>—Turmeric dust, T<sub>12</sub>—Cloves, T<sub>13</sub>— Bohera fruits, T<sub>14</sub>—Black pepper and T<sub>15</sub>—Neem leaves. After 15 days of inoculation of Bipolaris sorokiniana, colony color and shapes were Gerrish blackish, greenish blackish, greyish blackish and shapes were round or irregular. In our study, conidia color was dark brown to light brown, conidiophore color was brown, dark brown, grayish brown, dark olivaceous, light brown and conidia shapes were elliptical, oblong or slightly curved. The septation of conidia was 2 - 5 and highest septation was seen in T<sub>4</sub> and T<sub>14</sub> treatments. The highest conidial length was 17.79 μm recorded in T<sub>2</sub> treatment and lowest was 6.62 μm T<sub>9</sub> treatment where conidial breath was 8.27 μm in control and lowest was 3.79 μm in T<sub>8</sub> treatment. Mycelial growth rate of Bipolaris sorokiniana was different in different treatments in different days after inoculation (DAI) where at 7 DAI, % reduction of mycelial growth over control was highest in Bohera and Neem Leaves treatments respectively.
基金financially supported by the National Key Research and Development Program of China(No.2021YFA0910500)the National Natural Science Foundation of China(Nos.U22A20380,82173706,and 82104028)+1 种基金the Fundamental Research Funds for the Central Universities(No.2024BRA018)the Science and Technology Major Project of Hubei Province(No.2021ACA012)。
文摘Bipolarpenoids A–J(1–10),ten undescribed ophiobolin-derived sesterterpenoids,were identified from the fungus Bipolaris oryzae.Their structures were elucidated by high resolution electrospray ionization mass spectrometry(HRESIMS),spectroscopic analyses,quantum chemical ^(13)C nuclear magnetic resonance(NMR),electronic circular dichroism(ECD)calculations,and single-crystal X-ray diffraction analyses.Notably,compounds 1 and 2 were uniquely characterized by a multicyclic caged pentacyclo[8.4.0.0^(1,5).0^(4,9).0^(7,11)]tetradecane-bridged system;compounds 4–6 featured unprecedented5/8/5/6 and 5/8/5/5 fused cores,respectively;compound 7 represented the first example of 3,4-secoophiobolin-alkaloid hybrid with a modified 5/6/8/5/5 fused carbon skeleton.Compound 9 showed potential anti-inflammatory effect in RAW264.7 macrophages and ulcerative colitis mice.
文摘The fungal pathogen Bipolaris maydis invades by direct penetration into maize leaf veins. In order to understand the resistance mechanism of maize to B. maydis strain 523, cDNA-AFLP (amplified fragment length polymorphism) analysis was conducted to compare the changes in mRNA transcripts hi response to B. maydis infection between a highly disease-resistant (HDR) line and a susceptible (S) line. 13 cDNA fragments derived from the genes showing enhanced expression after fungal infection, named HDR genes, were isolated from the HDR line. Northern blot analysis showed that 5 HDR genes were induced by fungal infection in the HDR, but not the S lines. The 5 HDR genes showed homology to previously characterized genes involved in disease resistance. A full-length HDR10 cDNA was isolated. It had a capacity to encode a protein of 284 amino acids. The deduced amino acid sequence of the HDR10 gene was homologous to a fungal infection-induced protein from Cicer arietinum and a hypersensitive response protein from
文摘Bipolaris maydis race C strain 523 (C523) induces severer leaf blight on cytoplasmic male sterility (CMS)-C maize than on normal (N) maize. Previously, a pathotoxin isolated from C523 (C-toxin) was shown to be responsible for the disease. To understand the basis of the differential responses between CMS-C and N maizes to this fungus, protein synthesis in vitro by mitochondria from N and CMS-C cytoplasms was monitored after their incubation in a solution containing the toxin (0.3%). Similar protein products were detected between the two alloplasmic lines, indicating that the toxin does not directly act on the mitochondrial membrane, nor inhibits the expression of mitochondrial genes. To further locate the action site of the toxin, intact leaves from both N and several subtypes of CMS-C lines were treated by 0.3% toxin. Analysis of electrolyte leakage of leaf cells showed that the leakage rates were similar to one another among the alloplasmic maize lines. In contrast, at a lower concentration of the
基金supported by the National Natural Science Foundation of China(Nos.81573316 and 32000045)the National Science Fund for Distinguished Young Scholars(No.81725021)+2 种基金the Innovative Research Groups of the National Natural Science Foundation of China(No.81721005)the Tongji-Rongcheng Center for Biomedici ne,Huazhong University of Science and Technology(No.0231514141)the Research and Development Program of Hubei Provinee(No.2020BCA058).
文摘Six new meroterpe no ids,bipolarinoids A-F(1-6),and two known congen ers(7-8)were isolated from a soil-derived fungus Bipolaris zeicola.Their structures were elucidated based on extensive spectroscopic techniques(ineluding HRESIMS and ID and 2D NMR data),and the absolute configurations of 1-4 were further confirmed viasingle-crystal X-ray diffraction an alysis and comparis on of experimental electronic circular dichroism(ECD)data.Structurally,compound 1 represents the first case of cochlioquinone derivatives featuring a formaldehyde group at C-11, and compou nd 3 features a rareamino group at C-11.In the immunosuppressive activity assay,compounds 5-8 showed potent inhibitory activity against concanavalin A(ConA)-induced T lymphocyte proliferation with IC50 values of 78.3,81.1,48.3,and 48.0 nmol/L,respectively,which provided promising leads for designing and developing new im-muno suppressive agents to treat auto-immunological diseases.
基金TI 800/7-1 and TI 800/7-2(SPP 2125 DECRyPT)from the Deutsche Forschungsgemeinschaft,Germany,to A.T.We also acknowledge support from the Cluster of Excellence on Plant Sciences(CEPLAS)the Deutsche Forschungsgemeinschaft under Germany's ExcellenceStrategy-EXC 2048/1-Project ID:390686111and the grant ZU263/11-2(SPP 2125DECRyPT)to A.Z.
文摘Plant immunity is a multilayered process that includes recognition of patterns or effectors from pathogens to elicit defense responses.These include the induction of a cocktail of defense metabolites that typically restrict pathogen virulence.Here,we investigate the interaction between barley roots and the fungal pathogens Bipolaris sorokiniana(Bs)and Fusarium graminearum(Fg)at the metabolite level.We identify hordedanes,a previously undescribed set of labdane-related diterpenoids with antimicrobial properties,as critical players in these interactions.Infection of barley roots by Bs and Fg elicits hordedane synthesis from a 60o-kb gene cluster.Heterologous reconstruction of the biosynthesis pathway in yeast and Nicotiana benthamiana produced several hordedanes,including one of the most functionally decorated products 19-β-hydroxy-hordetrienoic acid(19-OH-HTA).Barley mutants in the diterpene synthase genes of this cluster are unable to produce hordedanes but,unexpectedly,show reduced Bs colonization.By contrast,colonization by Fusarium graminearum,another fungal pathogen of barley and wheat,is 4-fold higher in the mutants completely lacking hordedanes.Accordingly,19-OH-HTA enhances both germination and growth of Bs,whereas it inhibits other pathogenic fungi,including Fg.Analysis of microscopy and transcriptomics data suggest that hordedanes delay the necrotrophic phase of Bs.Taken together,these results show that adapted pathogens such as Bs can subvert plant metabolic defenses to facilitate root colonization.
