The symptoms of petal response to ethylene, including petal in-rolling and increase in ion leakage through cell membrane, were completely inhibited by treatment of transcription inhibitor a-amanitin as well as protein...The symptoms of petal response to ethylene, including petal in-rolling and increase in ion leakage through cell membrane, were completely inhibited by treatment of transcription inhibitor a-amanitin as well as protein synthesis inhibitor--cycloheximide. It was observed in Dianthus caryophyllus L. cv. White Sim that protein synthesis in flowers declined and the responsiveness to ethylene increased as the flowers became matured. However, when the flowers were pre-treated with aminooxyacetic acid (AOA), an inhibitor of ethylene synthesis, the observed responsiveness to ethylene in flowers declined with age. These results suggested that responsiveness to ethylene in flowers may be due to a declination in the capacity of protein synthesis in flowers.展开更多
The strain LWYZ003, which can restrain multiple pathogens, was screened from the sediment of the ocean and identified as Bacillus amyloliquefaciens. Large-scale fermentation and modern chromatographic separation techn...The strain LWYZ003, which can restrain multiple pathogens, was screened from the sediment of the ocean and identified as Bacillus amyloliquefaciens. Large-scale fermentation and modern chromatographic separation technologies(macroporous resin column chromatography, silica gel column chromatography, thin-layer chromatography and high-performance liquid chromatography) were used to separate antimicrobial products from the fermentation broth of marine-derived Bacillus amyloliquefaciens LWYZ003. Bioactive-guided separation was used in the term of seeking antimicrobial products from the secondary metabolites of Bacillus amyloliquefaciens LWYZ003. As a result, two natural products cycloheximide( 1) and trehalose( 2) were obtained. Their structures were elucidated by Fourier transform infrared spectroscopy, high-resolution mass spectrometry, ~1 H and ^(13) C nuclear magnetic resonance analysis. In the cylinder plate method, compound 1 exhibited stronger antimicrobial activities than compound 2 against Micrococcus luteus, and also exhibited wider antimicrobial spectrum than compound 2. In conclusion, isolation of bioactive secondary metabolites from marine Bacillus sp. has enormous potentials in finding suitable antibiotics to inhibit multiple pathogens.展开更多
IM To undergo apoptosis during negative and positive selection processes in rat mucosal immune system which are implicated in the pathogenesis of various mucosal diseases. METHODS Female SpragueDawley rats were g...IM To undergo apoptosis during negative and positive selection processes in rat mucosal immune system which are implicated in the pathogenesis of various mucosal diseases. METHODS Female SpragueDawley rats were given protein synthesis inhibitor, cycloheximide, intravenously or intraperitoneally, an apoptosis was recognized by morphological hallmark under light and electronmicroscopy, and the expression of proliferating cell nuclear antigen was visualized immunohistochemically. RESULTS The apoptosis of mucosal lymphocytes in the digestive tract, as well as in trachea, uterus and lacrimal gland was induced by cycloheximide (>10mg·kg-1 body weight), which were located mainly in lamina propria and germinal centers of lymphoid nodules. At the same time, a portion of crypt epithelial cells of proliferating zone in small and large intestine, and the epithelial cells in genital tract were also found to undergo apoptosis. Immunostainings showed that apoptotic cells expressed proliferating cell nuclear antigen. CONCLUSION Apoptosis of lymphocytes in mucosal immune system can be induced by cycloheximide. This model will facilitate the understanding of normal mucosal immune system and its role in the pathogenesis of related diseases such as inflammatory bowel diseases.展开更多
文摘The symptoms of petal response to ethylene, including petal in-rolling and increase in ion leakage through cell membrane, were completely inhibited by treatment of transcription inhibitor a-amanitin as well as protein synthesis inhibitor--cycloheximide. It was observed in Dianthus caryophyllus L. cv. White Sim that protein synthesis in flowers declined and the responsiveness to ethylene increased as the flowers became matured. However, when the flowers were pre-treated with aminooxyacetic acid (AOA), an inhibitor of ethylene synthesis, the observed responsiveness to ethylene in flowers declined with age. These results suggested that responsiveness to ethylene in flowers may be due to a declination in the capacity of protein synthesis in flowers.
基金supported by the National Basic Research Program of China ("973" Program) (no. 2012CB721105)the Major Research Plan of Tianjin, China (no. 16YFXTSF00460)
文摘The strain LWYZ003, which can restrain multiple pathogens, was screened from the sediment of the ocean and identified as Bacillus amyloliquefaciens. Large-scale fermentation and modern chromatographic separation technologies(macroporous resin column chromatography, silica gel column chromatography, thin-layer chromatography and high-performance liquid chromatography) were used to separate antimicrobial products from the fermentation broth of marine-derived Bacillus amyloliquefaciens LWYZ003. Bioactive-guided separation was used in the term of seeking antimicrobial products from the secondary metabolites of Bacillus amyloliquefaciens LWYZ003. As a result, two natural products cycloheximide( 1) and trehalose( 2) were obtained. Their structures were elucidated by Fourier transform infrared spectroscopy, high-resolution mass spectrometry, ~1 H and ^(13) C nuclear magnetic resonance analysis. In the cylinder plate method, compound 1 exhibited stronger antimicrobial activities than compound 2 against Micrococcus luteus, and also exhibited wider antimicrobial spectrum than compound 2. In conclusion, isolation of bioactive secondary metabolites from marine Bacillus sp. has enormous potentials in finding suitable antibiotics to inhibit multiple pathogens.
文摘IM To undergo apoptosis during negative and positive selection processes in rat mucosal immune system which are implicated in the pathogenesis of various mucosal diseases. METHODS Female SpragueDawley rats were given protein synthesis inhibitor, cycloheximide, intravenously or intraperitoneally, an apoptosis was recognized by morphological hallmark under light and electronmicroscopy, and the expression of proliferating cell nuclear antigen was visualized immunohistochemically. RESULTS The apoptosis of mucosal lymphocytes in the digestive tract, as well as in trachea, uterus and lacrimal gland was induced by cycloheximide (>10mg·kg-1 body weight), which were located mainly in lamina propria and germinal centers of lymphoid nodules. At the same time, a portion of crypt epithelial cells of proliferating zone in small and large intestine, and the epithelial cells in genital tract were also found to undergo apoptosis. Immunostainings showed that apoptotic cells expressed proliferating cell nuclear antigen. CONCLUSION Apoptosis of lymphocytes in mucosal immune system can be induced by cycloheximide. This model will facilitate the understanding of normal mucosal immune system and its role in the pathogenesis of related diseases such as inflammatory bowel diseases.
