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Glucose Metabolism and Retention of Glucose Metabolites in the Wheat Embryo during Early Germination
Ginzburg C 《Plant physiology》1978,61(5):757-760
There is a lag period in the growth of excised wheat (Triticum vulgare Host.) embryos extending from 0.5 hour to 4.5 hours of their imbibition in water. During this time there is a sharp increase in the embryos' capability to retain several amino and organic acids, to synthesize cell wall components and starch, and to take up glucose. Their capability to metabolize glucose also increases by 30%. Elevation of the ATP content of 1-hour embryos by incubation in 3 mm adenosine is not sufficient to bring about these changes. These changes may be a part of a metabolic adjustment in the embryos which increases their growth potential. 相似文献
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Oren A Ginzburg M Ginzburg BZ Hochstein LI Volcani BE 《International journal of systematic bacteriology》1990,40(2):209-210
An extremely halophilic red archaebacterium isolated from the Dead Sea (Ginzburg et al., J. Gen. Physiol. 55: 187-207, 1970) belongs to the genus Haloarcula and differs sufficiently from the previously described species of the genus to be designated a new species; we propose the name Haloarcula marismortui (Volcani) sp. nov., nom. rev. because of the close resemblance of this organism to "Halobacterium marismortui," which was first described by Volcani in 1940. The type strain is strain ATCC 43049. 相似文献
15.
Modulation of globin gene expression by a tumor promoter during induced differentiation of Friend erythroleukemic cells 总被引:1,自引:0,他引:1
Friend erythroleukemic cells were induced to differentiate by dimethylsulfoxide (Me2SO) in the absence or presence of the tumor promoter 12-O-tetradecanoyl-phorbol 13-acetate. The effects of the latter on the molecular parameters related to globin mRNA metabolism were examined. When differentiation was scored by benzidine staining, it had an inhibitory effect on Me2SO-treated cells. On the other hand, when differentiation was followed by determination of globin mRNA accumulation, it had a pleiotropic effect on Me2SO-treated cells. At the early phase of differentiation (2--3 days) the rate of globin mRNA accumulation was higher in the promoter-treated cells than in the control. This unexpectedly high level of accumulation was followed by a sharp reduction and most of the globin RNA sequences disappeared at later stages of differentiation (days 4--5). The reduction can be related to the effect of the promoter on the stability of globin RNA in the cytoplasm which was reduced from a half-life of 16 h to that of 8 h only. Other parameters, such as the rate of globin mRNA synthesis and its capability to serve as a template for cell-free protein synthesis were not affected by treatment with the promoter throughout the differentiation process. 相似文献
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Contribution of sea ice microbial production to Antarctic benthic communities is driven by sea ice dynamics and composition of functional guilds 下载免费PDF全文
Stephen R. Wing James J. Leichter Lucy C. Wing Dale Stokes Sal J. Genovese Rebecca M. McMullin Olya A. Shatova 《Global Change Biology》2018,24(8):3642-3653
Organic matter produced by the sea ice microbial community (SIMCo) is an important link between sea ice dynamics and secondary production in near‐shore food webs of Antarctica. Sea ice conditions in McMurdo Sound were quantified from time series of MODIS satellite images for Sept. 1 through Feb. 28 of 2007–2015. A predictable sea ice persistence gradient along the length of the Sound and evidence for a distinct change in sea ice dynamics in 2011 were observed. We used stable isotope analysis (δ13C and δ15N) of SIMCo, suspended particulate organic matter (SPOM) and shallow water (10–20 m) macroinvertebrates to reveal patterns in trophic structure of, and incorporation of organic matter from SIMCo into, benthic communities at eight sites distributed along the sea ice persistence gradient. Mass‐balance analysis revealed distinct trophic architecture among communities and large fluxes of SIMCo into the near‐shore food web, with the estimates ranging from 2 to 84% of organic matter derived from SIMCo for individual species. Analysis of patterns in density, and biomass of macroinvertebrate communities among sites allowed us to model net incorporation of organic matter from SIMCo, in terms of biomass per unit area (g/m2), into benthic communities. Here, organic matter derived from SIMCo supported 39 to 71 per cent of total biomass. Furthermore, for six species, we observed declines in contribution of SIMCo between years with persistent sea ice (2008–2009) and years with extensive sea ice breakout (2012–2015). Our data demonstrate the vital role of SIMCo in ecosystem function in Antarctica and strong linkages between sea ice dynamics and near‐shore secondary productivity. These results have important implications for our understanding of how benthic communities will respond to changes in sea ice dynamics associated with climate change and highlight the important role of shallow water macroinvertebrate communities as sentinels of change for the Antarctic marine ecosystem. 相似文献
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Metabolic Changes in Gladiolus Cormels During the Break of Dormancy: The Role of Dark CO(2) Fixation 下载免费PDF全文
Ginzburg C 《Plant physiology》1981,68(5):1105-1109
Dark CO2 fixation in Gladiolus X gandavensis Van Houtte cormels increases during the break of dormancy by low-temperature storage or by cytokinins. The in vitro activities of phosphoenolpyruvate carboxylase and phosphoenolpyruvate carboxykinase in preparations from dormant and nondormant cormels were compared with dark fixation rates in vivo. The distribution of 14C-label in the carboxylation products in dormant, nondormant, water-imbibed, and benzyladenine- and abscisic acid-treated cormels was compared by pulse-chase experiments. Dormant cormels have more label in malate and less in citrate and amino acids. Malate utilization in dormant cormels is slower than in nondormant ones. Citrate and glutamine accumulate in dormant cormels in inactive pools. Benzyladenine induces in dormant cormels changes similar to cold storage. Dark fixation is among the first reactions which are activated during the break of dormancy by both benzyl adenine and cold storage. 相似文献
19.
M. Ginzburg B. Lepkipfer A. Porath B. Z. Ginzburg 《European biophysics journal : EBJ》1978,4(3):237-249
The electrical conductivity of suspensions of two species of Halobacterium was measured at low A. C. frequency. The results
obtained fromHalobacterium halobium suspensions show that the bacteria act as non-conducting particles. In contrast, the cells of a Halobacterium obtained from
the Dead Sea (Halobacterium marismortui) had an apparently high conductivity which can be explained partly in terms of the cell-membrane being pierced by pores through
which ions can move freely and partly in terms of highly concentrated cell ions, all of which are mobile. 相似文献
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