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71.
A cytosolic glucosyltransferase is required for conversion of starch to sucrose in Arabidopsis leaves at night 总被引:7,自引:0,他引:7
Chia T Thorneycroft D Chapple A Messerli G Chen J Zeeman SC Smith SM Smith AM 《The Plant journal : for cell and molecular biology》2004,37(6):853-863
Maltose is exported from the Arabidopsis chloroplast as the main product of starch degradation at night. To investigate its fate in the cytosol, we characterised plants with mutations in a gene encoding a putative glucanotransferase (disproportionating enzyme; DPE2), a protein similar to the maltase Q (MalQ) gene product involved in maltose metabolism in bacteria. Use of a DPE2 antiserum revealed that the DPE2 protein is cytosolic. Four independent mutant lines lacked this protein and displayed a decreased capacity for both starch synthesis and starch degradation in leaves. They contained exceptionally high levels of maltose, and elevated levels of glucose, fructose and other malto-oligosaccharides. Sucrose levels were lower than those in wild-type plants, especially at the start of the dark period. A glucosyltransferase activity, capable of transferring one of the glucosyl units of maltose to glycogen or amylopectin and releasing the other, was identified in leaves of wild-type plants. Its activity was sufficient to account for the rate of starch degradation. This activity was absent from dpe2 mutant plants. Based on these results, we suggest that DPE2 is an essential component of the pathway from starch to sucrose and cellular metabolism in leaves at night. Its role is probably to metabolise maltose exported from the chloroplast. We propose a pathway for the conversion of starch to sucrose in an Arabidopsis leaf. 相似文献
72.
High throughput T-DNA insertion mutagenesis in rice: a first step towards in silico reverse genetics 总被引:23,自引:0,他引:23
73.
Popov VF Iunasova TN Gaĭderova LA Aksenov LA Averina OB Shitikova OIu 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2004,(6):41-43
The work was aimed at the evaluation of the antigenic activity and reactogenicity of antirubella vaccine, manufactured by the Serum Institute of India, on the basis of the active observation of 373 children. Vaccinal reactions were registered in 8.8% of the vaccinees. Seroconversion after the injection of the vaccine was 100%. The results of the epidemiological trial demonstrated that the Indian antirubella vaccine was faintly reactogenic and had high antigenic activity. 相似文献
74.
Gataullin AG Mikhaĭlova NA Blinkova LP Romanenko EE Elkina SI Gaĭderov AA Kalina NG 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2004,(2):91-94
The cultural, physiologo-biochemical adhesive and antagonistic properties of B. subtilis strains with good prospects for use as biotherapeutic preparations were studied. For further studies B. subtilis strain No. 1719 was chosen. In experiments on non-inbred white mice the animals were treated by the preparation Cifran used for their selective decontamination from opportunistic microflora and for the creation of the state of dysbiosis. The influence of the spore-forming microbe on the parietal microflora of the large intestine of the animals was shown. Reliable data on the changes in the number of microorganisms (CFU/ml) per 1 cm of the surface of the large intestine were established. As markers making it possible to evaluate the action of biotherapeutic and other medicinal remedies, easily determinable ratios of lac+/lac- of bacteria and Staphylococcus aureus/Staphylococcus spp. was proposed. 相似文献
75.
Gaĭnutdinova TKh Tagirova RR Ismailova AI Muranova LN Gaĭnutdinov KhL Balaban PM 《Zhurnal vysshe? nervno? deiatelnosti imeni I P Pavlova》2004,54(6):795-800
We investigated influence of anisomycine injection on reconsolidation of contextual memory after development of environmental conditioned reflex in terrestrial snail Helix. Testing the amplitude of behavioral reactions (tentacle withdrawal) in response to standard tactile stimulation of the skin in two contexts: a) when the snail was fixed by the shell and was moving on the surface of the ball floating in water, or b) was moving on the flat surface of glass terrarium, has shown no difference in response amplitudes. After a session of electric shocks (5 days) in one context only (ball) the associative learning was clearly observed as the significant difference of response amplitudes in two contexts. On the other day following testing was performed a session of "reminding", immediately after which the snails were injected by anisomycine (control snails were injected by saline solution). Testing has shown that injection of anisomycine led to impairment of the context conditioning. Results suggest that the mechanisms of consolidation of new memory and memory reconsolidation after retrieval are not identical. 相似文献
76.
El-Sayed NM Ghedin E Song J MacLeod A Bringaud F Larkin C Wanless D Peterson J Hou L Taylor S Tweedie A Biteau N Khalak HG Lin X Mason T Hannick L Caler E Blandin G Bartholomeu D Simpson AJ Kaul S Zhao H Pai G Van Aken S Utterback T Haas B Koo HL Umayam L Suh B Gerrard C Leech V Qi R Zhou S Schwartz D Feldblyum T Salzberg S Tait A Turner CM Ullu E White O Melville S Adams MD Fraser CM Donelson JE 《Nucleic acids research》2003,31(16):4856-4863
77.
Osipova IG Makhaĭlova NA Sorokulova IB Vasil'eva EA Gaĭderov AA 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》2003,(3):113-119
Data on probiotic preparations prepared from spore-forming bacteria is reviewed. Information on indications for use, effectiveness and the mechanism of action is given. Preparations being produced in Russia (Biosporin, Sporobacterin and Bactosporin) are evaluated in detail as well as the prospects of the application of probiotics from spore-forming bacteria. 相似文献
78.
79.
Liu C Gaça MD Swenson ES Vellucci VF Reiss M Wells RG 《The Journal of biological chemistry》2003,278(13):11721-11728
Hepatic stellate cells are the primary cell type responsible for matrix deposition in liver fibrosis, undergoing a process of transdifferentiation into fibrogenic myofibroblasts. These cells, which undergo a similar transdifferentiation process when cultured in vitro, are a major target of the profibrogenic agent transforming growth factor-beta (TGF-beta). We have studied activation of the TGF-beta downstream signaling molecules Smads 2, 3, and 4 in hepatic stellate cells (HSC) cultured in vitro for 1, 4, and 7 days, with quiescent, intermediate, and fully transdifferentiated phenotypes, respectively. Total levels of Smad4, common to multiple TGF-beta superfamily signaling pathways, do not change as HSC transdifferentiate, and the protein is found in both nucleus and cytoplasm, independent of treatment with TGF-beta or the nuclear export inhibitor leptomycin B. TGF-beta mediates activation of Smad2 primarily in early cultured cells and that of Smad3 primarily in transdifferentiated cells. The linker protein SARA, which is required for Smad2 signaling, disappears with transdifferentiation. Additionally, day 7 cells demonstrate constitutive phosphorylation and nuclear localization of Smad 2, which is not affected by pretreatment with TGF-beta-neutralizing antibodies, a type I TGF-beta receptor kinase inhibitor, or activin-neutralizing antibodies. These results demonstrate essential differences between TGF-beta-mediated signaling pathways in quiescent and in vitro transdifferentiated hepatic stellate cells. 相似文献
80.
We conducted laboratory experiments to examine the effects of single versus double exposures of spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae) female larvae to various concentrations of a Bacillus thuringiensis variety kurstaki (Btk) commercial formulation (Foray 48B). Our main objective was to document the vulnerability to Btk and the sublethal responses of fifth-instar larvae that survived from a first ingestion of Btk during their fourth stadium and to compare them with insects treated either during their fifth or fourth stadium only. As reported in the literature, fifth-instar larvae were more vulnerable than fourth-instar larvae, but only at low and medium concentrations. Fifth-instar larvae that had survived Btk ingestion during their fourth stadium were more vulnerable to a high concentration of Btk and had a shorter feeding inhibition period than those that had not been exposed during their fourth stadium. Compared with a single treatment at the fourth stadium, a double exposure to Btk further reduced the population by 20-30%, depending on the concentration applied. The second treatment also induced another feeding inhibition period and increased larval development time by 14%. The impact of the different treatments on pupal weight depended on whether treated insects exhibited supernumerary instars. In the absence of developmental polymorphism, a higher concentration, a late, or a double exposure to Btk significantly reduced pupal weight. 相似文献