[Objective] we aimed to provide a basis for the prevention of Alternaria leaf spot in sorghum. [Method] One kind of pathogen of leaf spot in sorghum was isolated and identified. [Result] The pathogen grew quickly on P...[Objective] we aimed to provide a basis for the prevention of Alternaria leaf spot in sorghum. [Method] One kind of pathogen of leaf spot in sorghum was isolated and identified. [Result] The pathogen grew quickly on PDA plates. The aeri- al hyphae of the pathogen had white edge and green-grey center. The conidia were, brown and connected into a chain. The shape of conidia was nearly cylindrical or inverted clavate. The conidia had 2-7 diaphragms and 0-4 longitudinal septa. It was identified as Alternaria fungus, [Conclusion] The leaves of sorghum were sus- ceptible to leaf spot. So the infection and healing process and pathogenic mecha- nism of leaf spot were needed to study further.展开更多
AA （Alopecia areata） is the most frequent cause of inflammation-induced hair loss, affecting 0.1 to 0.2% of population worldwide. The development of organ-specific autoimmune reactions directed against anagen hair f...AA （Alopecia areata） is the most frequent cause of inflammation-induced hair loss, affecting 0.1 to 0.2% of population worldwide. The development of organ-specific autoimmune reactions directed against anagen hair follicles seems to play a key role in the pathogenesis of alopecia areata. However, the triggering antigen（s） responsible for inducing autoimmune phenomena in these individuals remain unknown. Viral, bacterial or fungal pathogens have been implied as possible triggering factors of autoimmune reactions. The present study aims to identify the role of dematiaceous fungi in the pathogenesis of alopecia areata. 30 patients diagnosed clinically as alopecia areata and 30 normal age matched persons have undergone mycological examination. Mycology examination of the epidermal scrapings was done by DME （direct microscopic examination）, culture on SDA （sabouraud＇s dextrose agar） and imaging. There is significantly higher percentage of positive results for Alternaria species by culture on sabouraud＇s agar in patients group （20%） compared to controls （13.3%） P-value 〈 0.05. The possible role of Alternaria antigens （e.g. antigens involved in melanin synthesis） in triggering autoimmunity in alopecia areata still needs further research on a wider scale of cases.展开更多
Many different types of toxins are produced by the fungus, Alternaria alternata （Fr.） Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-...Many different types of toxins are produced by the fungus, Alternaria alternata （Fr.） Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography （HPLC） analyses demon- strated that tenuazonic acid （TEA） was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 IJg/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated re- sponses in rose plants to intensively enhance the plant＇s resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants.展开更多
文摘[Objective] we aimed to provide a basis for the prevention of Alternaria leaf spot in sorghum. [Method] One kind of pathogen of leaf spot in sorghum was isolated and identified. [Result] The pathogen grew quickly on PDA plates. The aeri- al hyphae of the pathogen had white edge and green-grey center. The conidia were, brown and connected into a chain. The shape of conidia was nearly cylindrical or inverted clavate. The conidia had 2-7 diaphragms and 0-4 longitudinal septa. It was identified as Alternaria fungus, [Conclusion] The leaves of sorghum were sus- ceptible to leaf spot. So the infection and healing process and pathogenic mecha- nism of leaf spot were needed to study further.
文摘AA （Alopecia areata） is the most frequent cause of inflammation-induced hair loss, affecting 0.1 to 0.2% of population worldwide. The development of organ-specific autoimmune reactions directed against anagen hair follicles seems to play a key role in the pathogenesis of alopecia areata. However, the triggering antigen（s） responsible for inducing autoimmune phenomena in these individuals remain unknown. Viral, bacterial or fungal pathogens have been implied as possible triggering factors of autoimmune reactions. The present study aims to identify the role of dematiaceous fungi in the pathogenesis of alopecia areata. 30 patients diagnosed clinically as alopecia areata and 30 normal age matched persons have undergone mycological examination. Mycology examination of the epidermal scrapings was done by DME （direct microscopic examination）, culture on SDA （sabouraud＇s dextrose agar） and imaging. There is significantly higher percentage of positive results for Alternaria species by culture on sabouraud＇s agar in patients group （20%） compared to controls （13.3%） P-value 〈 0.05. The possible role of Alternaria antigens （e.g. antigens involved in melanin synthesis） in triggering autoimmunity in alopecia areata still needs further research on a wider scale of cases.
基金supported by the National Natural Science Foundation of China(No.31160354)the Foundation of the Education Department of Yunnan Province in China(No.2013Y120)
文摘Many different types of toxins are produced by the fungus, Alternaria alternata （Fr.） Keissler. Little is known, however, regarding the influence of these toxins on insects. In this study, we investigated the toxin-induced inhibitory effects of the toxin produced by A. alternata on the rose aphid, Macrosiphum rosivorum, when the toxin was applied to leaves of the rose, Rosa chinensis. The results demonstrated that the purified crude toxin was non-harmful to rose plants and rose aphids, but had an intensive inhibitory effect on the multiplication of aphids. The inhibitory index against rose aphids reached 87.99% when rose plants were sprayed with the toxin solution at a low concentration. Further results from bioassays with aphids and high performance liquid chromatography （HPLC） analyses demon- strated that tenuazonic acid （TEA） was one of the most important resistance-related active components in the crude toxin. The content of TeA was 0.1199% in the crude toxin under the HPLC method. Similar to the crude toxin, the inhibitory index of pure TeA reached 83.60% 15 d after the rose plants were sprayed with pure TeA solution at the lower concentration of 0.060 IJg/ml, while the contents of residual TeA on the surface and in the inner portion of the rose plants were only 0.04 and 0.00 ng/g fresh weight of TeA-treated rose twigs, respectively, 7 d after the treatment. Our results show that TeA, an active component in the A. alternata toxin, can induce the indirect plant-mediated re- sponses in rose plants to intensively enhance the plant＇s resistances against rose aphids, and the results are very helpful to understand the plant-mediated interaction between fungi and insects on their shared host plants.
