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Dehydrins are proteins associated with conditions affecting the water status of plant cells, such as drought, salinity, freezing and seed maturation. Although the function of dehydrins remains unknown, it is hypothesized that they stabilize membranes and macromolecules during cellular dehydration. Red-osier dogwood (Cornus sericea L.), an extremely freeze-tolerant woody plant, accumulates dehydrin-like proteins during cold acclimation and the presence of these proteins is correlated with increased freeze tolerance (Karlson 2001, Sarnighausen et al. 2002, Karlson et al. 2003). Our objective was to determine the location of dehydrins in cold-acclimated C. sericea stems in an effort to provide insight into their potential role in the freeze tolerance of this extremely cold hardy species. Abundant labeling was observed in the nucleus and cytoplasm of cold-acclimated C. sericea stem cells. In addition, labeling was observed in association with plasmodesmata of cold-acclimated vascular cambium cells. The unique association of dehydrin-like proteins with plasmodesmata has not been reported previously. 相似文献
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Effect of Oil Overlay on Inhibition Potential of Roscovitine in Sheep Cumulus‐Oocyte Complexes 
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下载免费PDF全文 LF Crocomo WC Marques Filho CMV Ulian NS Branchini DT Silva CL Ackermann FC Landim‐Alvarenga SD Bicudo 《Reproduction in domestic animals》2015,50(3):410-416
Inhibitors of cyclin‐dependent kinases, as roscovitine, have been used to prevent the spontaneous resumption of meiosis in vitro and to improve the oocyte developmental competence. In this study, the interference of oil overlay on the reversible arrest capacity of roscovitine in sheep oocytes as well as its effects on cumulus expansion was evaluated. For this, cumulus‐oocyte complexes (COCs) were cultured for 20 h in TCM 199 with 10% foetal bovine serum (Control) containing 75 μm roscovitine (Rosco). Subsequently, they were in vitro matured (IVM) for further 18 h in inhibitor‐free medium with LH and FSH. The culture was performed in Petri dishes under mineral oil (+) or in 96 well plates without oil overlay (?) at 38.5°C and 5% CO2. At 20 and 38 h, the cumulus expansion and nuclear maturation were evaluated under stereomicroscope and by Hoechst 33342 staining, respectively. No group presented cumulus expansion at 20 h. After additional culture with gonadotrophins, a significant rate of COCs from both Control groups (+/?) exhibited total expansion while in both Rosco groups (+/?) the partial expansion prevailed. Among the oocytes treated with roscovitine, 65.2% were kept at GV in the absence of oil overlay while 40.6% of them reached MII under oil cover (p < 0.05). This meiotic arrest was reversible, and proper meiosis progression also occurred in the Control groups (+/?). So, the culture system without oil overlay improved the meiotic inhibition promoted by roscovitine without affecting the cumulus expansion rate or the subsequent meiosis progression. 相似文献
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N. Kusumoto T. Zhao G. Swedjemark T. Ashitani K. Takahashi A.‐K. Borg‐Karlson 《Forest Pathology》2014,44(5):353-361
The antifungal properties of 14 major oleoresin‐constitutive terpenoids of Norway spruce (Picea abies) against Heterobasidion parviporum were evaluated in vitro at three gradient concentrations, 0.1, 0.2 and 0.4 μmol/cm2, on potato dextrose agar medium. Eight monoterpene hydrocarbons (+)‐ and (?)‐α‐pinene, (?)‐β‐pinene, (+)‐3‐carene, myrcene, (+)‐ and (?)‐limonene, terpinolene; four oxygenated monoterpenes α‐terpineol, terpinen‐4‐ol, 1,8‐cineole, bornyl acetate; and two resin acids abietic acid and dehydroabietic acid were selected. Abietic and dehydroabietic acids showed the highest antifungal activities at all concentrations. Among oxygenated monoterpenes, bornyl acetate and α‐terpineol showed antifungal activity at the highest concentration. Among monoterpene hydrocarbons, (+)‐α‐pinene showed similar activity to terpinen‐4‐ol and 1,8‐cineole at the highest concentration; however, it was lower than α‐terpineol and bornyl acetate. Other monoterpene hydrocarbons inhibited mycelial growth by <10%. Re‐extraction of medium surfaces after the test period revealed that most α‐terpineol and terpinen‐4‐ol remained unchanged on the surface but monoterpene hydrocarbons completely disappeared. However, notable fungal transformed products were observed on surfaces applied with 1,8‐cineole and bornyl acetate. Thus, mycelial growth inhibition of monoterpenoids might be caused by complex functions such as biodegradation and/or detoxification by interaction between mycelium and compound. These results provide a basis for future studies considering the role of chemodiversity in the comprehensive chemical defence of P. abies. 相似文献
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Atrial natriuretic peptide inhibits a cation channel in renal inner medullary collecting duct cells 总被引：18，自引：0，他引：18
The patch-clamp technique was used to examine the effects of atrial natriuretic peptide (ANP) and its second messenger guanosine 3',5'-monophosphate (cGMP) on an amiloride-sensitive cation channel in the apical membrane of renal inner medullary collecting duct cells. Both ANP (10(-11) M) and dibutyryl guanosine 3',5'-monophosphate (10(-4) M) inhibited the channel in cell-attached patches, and cGMP (10(-5) M) inhibited the channel in inside-out patches. The inner medullary collecting duct is the first tissue in which ANP, via its second messenger cGMP, has been shown to regulate single ion channels. The results suggest that the natriuretic action of ANP is related in part to cGMP-mediated inhibition of electrogenic Na+ absorption by the inner medullary collecting duct. 相似文献
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Aspects of phytoremediation of organic pollutants 总被引：1，自引：0，他引：1
Phytoremediation is a quite novel technique to clean polluted soils using plants. In theory, phytoremediation methods are
cheap, are accepted by the public and, compared to physical or chemical approaches, are ecologically advantageous. Until today,
however, there are only a few examples of successful applications. One reason is that the processes involved are complex,
and a full clean up may require many years. Plants affect the water balance of a site, they change redox potential and pH,
and stimulate microbial activity of the soil. These indirect influences may accelerate degradation in the root zone or reduce
leaching of compounds to groundwater. Compounds taken up into plants may be metabolised, accumulated, or volatilised into
air. Based on these processes, several phytoremediation methods have been developed: Phytoextraction, rhizofiltra-tion, phytostabilisation,
rhizo and phytodegradation, pump and tree, land farming, phytovolatilisation, hydraulic control and more. Already in use are
plants (and here willow, poplar and grass) for the degradation of petroleum products, aromatic hydrocarbons (BTEX), chlorinated
solvents, explosives and cyanides. However, phytotoxicity and pollutant mass balances were rarely documented. Often, the success
of the projects was not controlled, and only estimates can be made about the applicability and the potential of phytoremediation.
This lack of experience about possibilities and limitations seems to be a hindrance for a broader use of these techniques. 相似文献
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DT Rodbell GO Seltzer DM Anderson MB Abbott DB Enfield JH Newman 《Science (New York, N.Y.)》1999,283(5401):516-520
Debris flows have deposited inorganic laminae in an alpine lake that is 75 kilometers east of the Pacific Ocean, in Ecuador. These storm-induced events were dated by radiocarbon, and the age of laminae that are less than 200 years old matches the historic record of El Nino events. From about 15,000 to about 7000 calendar years before the present, the periodicity of clastic deposition is greater than or equal to 15 years; thereafter, there is a progressive increase in frequency to periodicities of 2 to 8.5 years. This is the modern El Nino periodicity, which was established about 5000 calendar years before the present. This may reflect the onset of a steeper zonal sea surface temperature gradient, which was driven by enhanced trade winds. 相似文献
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K Pittman A Pittman S Karlson T Cieplinska P Sourd K Redmond B Ravnøy E Sweetman 《Journal of fish diseases》2013,36(2):115-127
Mucous cell size and distribution were investigated in the skin of five salmon using a novel stereology‐based methodology: one (48 cm) fish to test 15 tissue treatment combinations on measures of cell area and density on the dorsolateral region and, using the most suitable treatment, we mapped mucous cell differences between body regions on four (52 cm) salmon, comprising a male and a female on each of two diets. The section site, decalcification, embedding medium and plane of sectioning all impacted significantly on mucous cell size, whereas mucous cell density is more robust. There were highly significant differences in both mucosal density and mean mucous cell size depending on body site: the dorsolateral skin of the four salmon had significantly denser (about 8% of skin area) and larger (mean about 160 μm2) mucous cells, whereas the lowest mean density (about 4%) and smallest mean area (115 μm2) were found on the head. We found that 100 random measurements may be sufficient to distinguish differences >7 μm2 in mean mucous cell areas. The results further suggest that salmon exhibit a dynamic repeatable pattern of mucous cell development influenced by sex, diet and possibly strain and season. 相似文献
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Distributions of numerical abundance and resource use among species are fundamental aspects of community structure. Here we characterize these patterns for tropical reef fishes and corals across a 10,000-kilometer biodiversity gradient. Numerical abundance and resource-use distributions have similar shapes, but they emerge at markedly different scales. These results are consistent with a controversial null hypothesis regarding community structure, according to which abundance distributions arise from the interplay of multiple stochastic environmental and demographic factors. Our findings underscore the importance of robust conservation strategies that are appropriately scaled to the broad suite of environmental processes that help sustain biodiversity. 相似文献