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81.
Juan Wang Yanwen Yu Zhijin Zhang Ruidang Quan Haiwen Zhang Ligeng Ma Xing Wang Deng Rongfeng Huang 《The Plant cell》2013,25(2):625-636
Light regulates ascorbic acid (AsA) synthesis, which increases in the light, presumably reflecting a need for antioxidants to detoxify reactive molecules produced during photosynthesis. Here, we examine this regulation in Arabidopsis thaliana and find that alterations in the protein levels of the AsA biosynthetic enzyme GDP-Man pyrophosphorylase (VTC1) are associated with changes in AsA contents in light and darkness. To find regulatory factors involved in AsA synthesis, we identified VTC1-interacting proteins by yeast two-hybrid screening of a cDNA library from etiolated seedlings. This screen identified the photomorphogenic factor COP9 signalosome subunit 5B (CSN5B), which interacted with the N terminus of VTC1 in yeast and plants. Gel filtration profiling showed that VTC1-CSN5B also associated with the COP9 signalosome complex, and this interaction promotes ubiquitination-dependent VTC1 degradation through the 26S proteasome pathway. Consistent with this, csn5b mutants showed very high AsA levels in both light and darkness. Also, a double mutant of csn5b with the partial loss-of-function mutant vtc1-1 contained AsA levels between those of vtc1-1 and csn5b, showing that CSN5B modulates AsA synthesis by affecting VTC1. In addition, the csn5b mutant showed higher tolerance to salt, indicating that CSN5B regulation of AsA synthesis affects the response to salt stress. Together, our data reveal a regulatory role of CSN5B in light-dark regulation of AsA synthesis. 相似文献
82.
Ke Xing Guang-Kai Bian Sheng Qin Hans-Peter Klenk Bo Yuan Yue-Ji Zhang Wen-Jun Li Ji-Hong Jiang 《Antonie van Leeuwenhoek》2013,104(6):1245-1245
83.
Peng Xing Jiuwen Zheng Huabing Li Qing Liu 《World journal of microbiology & biotechnology》2013,29(2):373-377
The main goal of this work was to determine which methanogens were present during the anaerobic degradation of Microcystis biomass in the water columns of freshwater lakes. Simulation experiments were performed in which 30 ml Microcystis slurries were anaerobically incubated in 60 ml airtight bottles at three temperatures (15, 25, and 35 °C) for over 90 days. The production of CH4 was monitored, and the methanogenic community was analyzed by cloning and sequencing the mcrA genes in samples incubated at the three different temperatures. In total, four clusters were detected at different temperatures by phylogenetic analysis of mcrA genes; these included members of Methanomicrobiales, Methanobacteriaceae, and Methanosarcina. An apparent linkage between temperature and phylogeny of the methanogenic community was observed: Methanomicrobiales and Methanobacteriaceae dominated the incubation system at the lower temperatures of 15 and 25 °C, whereas Methanosarcina prevailed at 35 °C. The dominance of these hydrogenotrophic methanogens suggested that, at least at lower temperatures, H2 and CO2 might be the primary substrates for CH4 production during Microcystis anaerobic decomposition. 相似文献
84.
Wenliang Xiang Ke Li Seng Liu Yage Xing Mingyuan Li Zhenming Che 《World journal of microbiology & biotechnology》2013,29(3):559-567
The community succession of microbes inhabited in the fermenting lees of Luzhou-flavor liquor was investigated based on small-subunit rRNA culture independent method. All sequences recovered from fermenting lees respectively fell into the genera of Lactobacillus, Streptococcus, Bacillus, Staphylococcus, Clostridium, Pelobacter, Actobacter, Serratia, Burkholderia, Rhodoccous, Corynebacterium, Arthrobacter, Microbacterium, Curtobacterium, Leptotrichia, Methanocuuleus, Saccharomyces, Zygosaccharomyces, Saccharomycopsis, Pichia, Talaromyces, Aspergillus, Eurotium, Fomitopsis and Trichosporon. The fungal Pichia, Saccharomycopsis and Talaromyces were most abundant in the lees fermented for 1 day, the fungal Eurotium and the bacteria Burkholderia, Streptococcus and Lactobacillus were dominant in the lees fermented for 7 days, only the bacteria Lactobacillus, Burkholderia were prevalent in the lees fermented for 60 days. Most genera almost existed in the fermenting lees, while their distributions were significantly different in 1, 7 and 60 days fermented lees. The prokaryotic community similarity coefficient was from 0.5000 to 0.5455 and followed to 0.1523, and that of eukaryotic community was from 0.5466 to 0.5259 and to 0.3750 when compared at species level. These results suggested that many microbes in lees have community successions associated with fermenting and that such successions maybe contribute the fermentation process of Luzhou-flavor liquor and is main reasons that the characteristic flavor factors are produced. 相似文献
85.
Xing Wu Qunying Mao Xin Yao Pan Chen Xiangmei Chen Jie Shao Fan Gao Xiang Yu Fengcai Zhu Rongcheng Li Wenhui Li Zhenglun Liang Junzhi Wang Fengmin Lu 《PloS one》2013,8(6)
The level of neutralizing antibodies (NtAb) induced by vaccine inoculation is an important endpoint to evaluate the efficacy of EV71 vaccine. In order to evaluate the efficacy of EV71 vaccine, here, we reported the development of a novel pseudovirus system expression firefly luciferase (PVLA) for the quantitative measurement of NtAb. We first evaluated and validated the sensitivity and specificity of the PVLA method. A total of 326 serum samples from an epidemiological survey and 144 serum specimens from 3 clinical trials of EV71 vaccines were used, and the level of each specimen''s neutralizing antibodies (NtAb) was measured in parallel using both the conventional CPE-based and PVLA-based assay. Against the standard neutralization assay based on the inhibition of the cytopathic effect (CPE), the sensitivity and specificity of the PVLA method are 98% and 96%, respectively. Then, we tested the potential interference of NtAb against hepatitis A virus, Polio-I, Polio-II, and Polio-III standard antisera (WHO) and goat anti-G10/CA16 serum, the PVLA based assay showed no cross-reactivity with NtAb against other specific sera. Importantly, unlike CPE based method, no live replication-competent EV71 is used during the measurement. Taken together, PVLA is a rapid and specific assay with higher sensitivity and accuracy. It could serve as a valuable tool in assessing the efficacy of EV71 vaccines in clinical trials and disease surveillance in epidemiology studies. 相似文献
86.
Juan Chen Li-Chun Zhang Yong-Mei Xing Yun-Qiang Wang Xiao-Ke Xing Da-Wei Zhang Han-Qiao Liang Shun-Xing Guo 《PloS one》2013,8(3)
Dendrobium spp. are traditional Chinese medicinal plants, and the main effective ingredients (polysaccharides and alkaloids) have pharmacologic effects on gastritis infection, cancer, and anti-aging. Previously, we confirmed endophytic xylariaceous fungi as the dominant fungi in several Dendrobium species of tropical regions from China. In the present study, the diversity, taxonomy, and distribution of culturable endophytic xylariaceous fungi associated with seven medicinal species of Dendrobium (Orchidaceae) were investigated. Among the 961 endophytes newly isolated, 217 xylariaceous fungi (morphotaxa) were identified using morphological and molecular methods. The phylogenetic tree constructed using nuclear ribosomal internal transcribed spacer (ITS), large subunit of ribosomal DNA (LSU), and beta-tubulin sequences divided these anamorphic xylariaceous isolates into at least 18 operational taxonomic units (OTUs). The diversity of the endophytic xylariaceous fungi in these seven Dendrobium species was estimated using Shannon and evenness indices, with the results indicating that the dominant Xylariaceae taxa in each Dendrobium species were greatly different, though common xylariaceous fungi were found in several Dendrobium species. These findings implied that different host plants in the same habitats exhibit a preference and selectivity for their fungal partners. Using culture-dependent approaches, these xylariaceous isolates may be important sources for the future screening of new natural products and drug discovery. 相似文献
87.
88.
Peng Xu Anling Zhang Rongcai Jiang Mingzhe Qiu Chunsheng Kang Zhifan Jia Guangxiu Wang Lei Han Xing Fan Peiyu Pu 《PloS one》2013,8(1)
It is well known that Notch signaling plays either oncogenic or tumor suppressive role in a variety of tumors, depending on the cellular context. However, in our previous study, we found that Notch1 was overexpressed while Notch2 downregulated in the majority of astrocytic gliomas with different grades as well as in glioblastoma cell lines U251 and A172. We had knocked down Notch1 by siRNA in glioblastoma cells, and identified that the cell growth and invasion were inhibited, whereas cell apoptosis was induced either in vitro or in vivo. For further clarification of the role of Notch2 in pathogenesis of gliomas, enforced overexpression of Notch2 was carried out with transfection of Notch2 expression plasmid in glioma cells and the cell growth, invasion and apoptosis were examined in vitro and in vivo in the present study, and siRNA targeting Notch1 was used as a positive control in vivo. The results showed that upregulating Notch2 had the effect of suppressing cell growth and invasion as well as inducing apoptosis, just the same as the results of knocking down Notch1. Meanwhile, the activity of core signaling pathway–EGFR/PI3K/AKT in astrocytic glioma cells was repressed. Thus, the present study reveals, for the first time, that Notch1 and Notch2 play different roles in the biological processes of astrocytic gliomas. Knocking down the Notch1 or enforced overexpression of Notch2 both modulate the astrocytic glioma phenotype, and the mechanism by which Notch1 and 2 play different roles in the glioma growth should be further investigated. 相似文献
89.
Wei Xing Xiaozhou He Mohammad A. Kassir Jie Chen Jiule Ding Jun Sun Jiani Hu Zishu Zhang E. Mark Haacke Yongming Dai 《PloS one》2013,8(2)
Background
Intratumoral hemorrhage is a frequent occurrence in renal cell carcinoma and is an indicator of tumor subtype. We hypothesize that susceptibility weighted imaging (SWI) is sensitive to hemorrhage in renal cell carcinoma and can give a more diagnostic image when compared to conventional imaging techniques.Materials and Methods
A retrospective review of 32 patients with clear cell renal cell carcinoma was evaluated. All patients underwent magnetic resonance imaging (MRI) and 22 out of 32 patients also underwent a computed tomography (CT) scan. Hemorrhage was classified into 3 different categories according to shape and distribution. Histopathology was obtained from all masses by radical nephrectomy. The ability to detect the presence of hemorrhage using CT, non-contrast conventional MRI and SWI was evaluated, and the patterns of hemorrhage were compared.Results
Using pathologic results as the gold standard, the sensitivities of non-contrast conventional MRI, SWI and CT in detecting hemorrhage in clear cell renal cell carcinoma were 65.6%, 100% and 22.7%, respectively. Accuracy of non-contrast conventional MRI and SWI in evaluating hemorrhagic patterns were 31.3% and 100%, respectively.Conclusion
These results demonstrate that SWI can better reveal hemorrhage and characterize the pattern more accurately than either non-contrast conventional MRI or CT. This suggests that SWI is the technique of choice for detecting hemorrhagic lesions in patients with renal cancer. 相似文献90.
Duo Shan Jiangping Sun Anna Yakusik Zhongdan Chen Jianhua Yuan Tao Li Jeannia Fu Kaveh Khoshnood Xing Yang Mei Wei Song Duan Marc Bulterys Michael Sante Runhua Ye Lifen Xiang Yuecheng Yang 《PloS one》2013,8(6)