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271.
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273.
Regulation of gene expression in plant mitochondria 总被引:9,自引:0,他引:9
274.
Jiuyuan Bai Xin Wang Hao Wu Fei Ling Yun Zhao Yongjun Lin Rui Wang 《Plant biotechnology journal》2020,18(3):668-678
Bidirectional green tissue‐specific promoters have important application prospects in genetic engineering and crop genetic improvement. However, there is no report on the application of them, mainly due to undiscovered natural bidirectional green tissue‐specific promoters and the lack of a comprehensive approach for the synthesis of these promoters. In order to compensate for this vacancy, the present study reports a novel strategy for the expression regulatory sequence selection and the bidirectional green tissue‐specific synthetic promoter construction. Based on this strategy, seven promoters were synthesized and introduced into rice by agrobacterium‐mediated transformation. The functional identification of these synthetic promoters was performed by the expression pattern of GFP and GUS reporter genes in two reverse directions in transgenic rice. The results indicated that all the synthetic promoters possessed bidirectional expression activities in transgenic rice, and four synthetic promoters (BiGSSP2, BiGSSP3, BiGSSP6, BiGSSP7) showed highly bidirectional expression efficiencies specifically in green tissues (leaf, sheath, panicle, stem), which could be widely applied to agricultural biotechnology. Our study provided a feasible strategy for the construction of synthetic promoters, and we successfully created four bidirectional green tissue‐specific synthetic promoters. It is the first report on bidirectional green tissue‐specific promoters that could be efficiently applied in genetic engineering. 相似文献
275.
Standard Chromatin immunoprecipitation protocols have been designed to suit studies performed on cell line cultures or yeast
cells growing in liquid cultures. In these cases cross-linking/fixation takes place directly in the growing medium of the
cells by the addition of a general fixation reagent. When applied on whole isolated silkmoth follicles, this procedure results
in poor release of follicular cells from the basal membrane and lower yield of cross-linked chromatin. We present a modification
to the standard protocol, where detachment of follicular cells from the basal membrane of the egg and nuclei isolation precedes
formaldehyde-mediated cross-linking. We also discuss application of the modified method for the identification of distinct
BmC/EBP and BmGATAβ binding modes on a chorion gene promoter from the Er1.A/B early gene pair. 相似文献
276.
Bifidobacteria play an important role in human health including the enhancement of resistance against infection in infants.
To develop an inexpensive whey-based medium for Bifidobaterium bifidum, potential growth promoters — yeast extract, casein, bovine casein digest, tryptone, peptone and glucosamine — singly or
in combinations, were evaluated for their bifidus growth-promoting activity. The effect of environmental conditions on growth
in cheese whey was also evaluated. A whey-based medium for B. bifidum was formulated. Cheese whey supplemented with N-acetylglucosamine (1 mg/ml) and yeast extract (10 mg/ml) in the presence of sodium thioglycolate (0.1%) at pH 6.8 promoted
the growth of B. bifidum at 37°C. Journal of Industrial Microbiology & Biotechnology (2000) 25, 177–179.
Received 20 May 2000/ Accepted in revised form 20 July 2000 相似文献
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278.
Extracts of cold stored chestnut cuttings ( Castanea sativa Mill.) were examined for the inhibitory effect on the stimulation of rooting by 1AA which has been detected previously in extracts from freshly collected cuttings. The extracts were fractionated by paper chromatography and the different zones of the chromatograms were bioassayed together with 1AA by the bean rooting test. The bean rooting test showed that the inhibitory effect decreased with the length of cold storage period, so that after 5 months of storage, the inhibitory effect had disappeared, and a root promoting zone was found on the chromatograms. A comparative study of phenolics in this zone, before and after cold storage, revealed the formation of vanillyl and salicyl alcohols in the chilled material. Vanillyl and salicyl alcohols are rooting stimulators and increase the effect of 1AA on rooting in bean cuttings. 相似文献
279.
280.
Delsol AA Randall L Cooles S Woodward MJ Sunderland J Roe JM 《Journal of applied microbiology》2005,98(3):564-571
AIM: To assess the effect of the growth promoter avilamycin on emergence and persistence of resistance in enteric bacteria in the pig. METHODS AND RESULTS: Pigs (treated with avilamycin for 3 months and controls) were challenged with multi-resistant Salmonella Typhimurium DT104 and faecal counts were performed for enterococci, Escherichia coli, S. Typhimurium and Campylobacter (before, during and 5 weeks post-treatment). Representative isolates were tested for antibiotic resistance and for the presence of resistance genes. Avilamycin-resistant Enterococci faecalis (speciated by PCR) were isolated from the treated pigs and continued to be detected for the first week after treatment had ceased. The avilamycin-resistance gene was characterized by PCR as the emtA gene and speciation by PCR. MIC profiling confirmed that more than one strain of Ent. faecalis carried this gene. There was no evidence of increased antimicrobial resistance in the E. coli, Salmonella and Campylobacter populations, although there was a higher incidence of tetB positive E. coli in the treated pigs than the controls. CONCLUSION: Although avilamycin selects for resistance in the native enterococci population of the pig, no resistant isolates were detected beyond 1 week post-treatment. This suggests that resistant isolates were unable to persist once selective pressure was removed and were out-competed by the sensitive microflora. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data suggest the risk of resistant isolates becoming carcass contaminants and infecting humans could be minimized by introducing a withdrawal period after using avilamycin and prior to slaughter. 相似文献