排序方式: 共有38条查询结果,搜索用时 46 毫秒
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Andrade Galdino Esteban Eduardo Velasco Leonardo Lorite María J. Bedmar Eulogio J. 《Plant and Soil》1997,197(1):19-23
Four bacterial strains, Pseudomonas stutzeri var. mendocina, Comamonas sp., Agrobacterium tumefaciens biovar. 2 and Sphingobacterium sp., isolated from the rhizosphere of wild-grown caper (Capparis spinosa L.) plants were able to fix N2 as shown by their growth in nitrogen-free medium and by the acetylene reduction test. P. stutzeri var. mendocina and Comamonas sp. contained DNA homologous to the Klebsiella pneumoniae M5a1 nifHDK genes. No hybridization was found with total DNA from either A. tumefaciens biovar. 2 or Sphingobacterium sp. using nifHDK probes from either K. pneumoniae or Rhizobium meliloti. 相似文献
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M. A. Sobrado 《Biologia Plantarum》1997,40(4):633-637
Several pieces of research suggest that leaf liquid-path conductance (K1) may be smaller in evergreen species (EG) than in deciduous species (DC), coexisting in tropical dry forests. This was investigated in four DC and two EG in a tropical dry forest in Venezuela. The K1 (kg m-2 MPa-1 s-1) were consistently lower in EG (8.4 × 10-5) than in DC (12 to 20 × 10-5). Differences in water potential (W) inside the leaves were calculated using K1 values in connection with maximum transpiration rates measured in the field. It was found that W was about 1.9 MPa in EG, intermediate for one DC (Pithecellobium dulce, 1.7 MPa) and minimum for other DC (1.0 to 1.3 MPa). 相似文献
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马槟榔甜味蛋白的研究 Ⅳ.稳定性和变性 总被引:2,自引:0,他引:2
通过对马槟榔甜昧蛋白Ⅰ和Ⅱ热变性试验,发现MaⅠ在80℃水浴中很快失甜味;圆二色谱证明其主链构象中的α螺旋几乎全部消失了。但Ma Ⅱ却能经受长时间保温而不失去甜味;电泳行为亦不发生改变。 在盐酸胍和尿素变性试验中发现,随变性剂浓度加大,蛋白质荧光发射光谱中色氨酸峰发生红移,直至蛋白质发生完全变性为止。以此为指标发现在酸性条件下,马槟榔甜蛋白更稳定;一般情况下3—5M的盐酸胍就足以使它变性;但即使是8M的尿素也不能使它完全变性。此和横向变性剂梯度聚丙烯酰胺凝胶电泳的结果是一致的。当脱掉8M尿素或—6M盐酸胍-MaⅠ溶液中的变性剂后,MaⅠ的甜味可恢复,其二级结构及电泳行为只发生微小的变化。 MaⅠ在SDS聚丙烯酰胺电泳分析中出现了一条双分子聚合体带,但将MaⅠ热变性、还原变性或羧甲基化等后,随MaⅠ甜味的消失,这条聚合体带也消失了。MaⅡ在任何情况下均不出现上述现象,因此认为这条带的形成与MaⅠ本身和甜味相关的一种特殊结构有关。 相似文献
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从马槟榔(Capparis masaikai)种子中曾分离出二种甜味蛋白,称为Mabinlin Ⅰ和Ⅱ,分子量分别为11.6kD和10.4kD。用Edmail降解和反相HPLC鉴定PTH-aa方法测定证明:二者的N末端均因焦谷氨酸环化而封闭。采用1mol/l HCl-甲醇溶液35℃处理24小时的方法可使之开环。二种蛋白N端肽8个氨基酸残基顺序均为:Pyroglutamic acid-Pro-Arg-Gly-Pro-Ala-Leu-Arg-。羧肽酶酶解的动态分析证明MaI羧端的氨基酸顺序为-Phe-Gln-Leu-Ala-Ser,MaⅡ为-Phe-Gln-Leu-Ala。其差别仅在于MaⅡ缺一个Ser,这一结果表明MaⅠ和MaⅡ的主要差异不是在端肽。 相似文献
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《Saudi Journal of Biological Sciences》2022,29(8):103346
The present study examined the phytochemical composition, antioxidant, antimicrobial properties, and molecular docking of different solvents extracts (methanol and water) of two medicinal plants, namely, Capparis spinosa L (CS) and Rumex nervosus (RN). Phytochemical analysis showed that total phenol, flavonoids, alkaloids, and vitamin C were significantly (P ≤ 0.05) higher in the methanolic extract of both plants than in other solvents. However, tannin content was significantly (P ≤ 0.05) high in the water extract for both plants. Chloroform and acetone extracts were significantly lower in phytochemicals than other solvents, therefore excluded in this study. GC–MS analysis showed one dominant compound in CS (isopropyl isothiocyanate) and two in RN (pyrogallol and palmitic acid). The antioxidant methods applied (DPPH, ABTS, β-Carotene/linoleic acid assay, and reducing the power) showed that the methanolic extract of CS exerted higher activity in methanolic extract but lower than that of BHA standard. The methanolic extract of both plants inhibited the bacterial pathogens when a minimum inhibitory concentration (MIC) method was applied, compared to water extract with RN-methanolic extract had a lower inhibition concentration than CS-methanolic extract. The molecular interactions study revealed that the palmitic acid and pyrogallol interacted with the receptors' active site. This work concluded that CS and RN showed a remarkable antioxidant and antibacterial effect with the high antimicrobial activity of RN extract. 相似文献
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Hugh H. Iltis 《Brittonia》2005,57(2):162-166
The new Bolivian endemic,Capparis coimbrana, was first collected by the 22-year-old Edward Palmer while a member of the U.S. Navy’s “Exploration of the River La Plata”
expedition, supervised under Captain T.J. Page from 1853–1856. Since the plant specimen lacks a specific geographic location,
it was necessary to interpret carefully the cryptic, penciled notes that accompany it, and to correlate these with the published
itinerary of the expedition’s sailing vessel, theWater Witch. This historical research revealed that the plant must have been collected on 2 Dec 1853 at Corumbá, Matto Grosso, Brazil,
which was then a tiny village just across the Río Paraguay from Puerto Suárez, Bolivia. This site is at the very edge of the
species' current range. 相似文献
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