核仁和核仁蛋白

核仁是位于细胞核内的非膜结构。电子显微镜下的核仁从形态上可以分为三层结构包括纤维中心区(FC)、高密度纤维区(DFC)和颗粒区(GC)。核仁内的蛋白有核糖体蛋白和非核糖体蛋白两种。利用蛋白质组学方法已经鉴定了350多种核仁蛋白,其中包括80多种核糖体蛋白。核仁是核糖体合成的场所,核仁中的非核糖体蛋白对核糖体的生物合成起关键调控作用。核仁不仅是细胞内通讯和核糖体：RNA加工的中心,而且在细胞周期、细胞增殖和衰老中起重要调控作用;核仁也是tRNA、mRNA和其它类型小分子RNA加工的场所。因此核仁是一个多功能的细胞生命活动中心。     

Establishment of Plantago lanceolata L. and Plantago major L. among grass

Summary Establishment of Plantago lanceolata and P. major ssp major among grass was studied in a field experiment in which survival and selection on date of seedling emergence and plant size was investigated in relation to the vegetation structure. P. major — in contrast to P. lanceolata — was not able to establish itself in grass because of its lower competitive ability caused by later germination, smaller seedling size, and shorter leaves. In both species there was selection for early germination. For P. lanceolata a significant correlation was found between the strength of selection and the light climate, determined by the structure of the grass sward. Plants that germinated early were at an advantage because they were larger, especially the leaves, when compared with plants that germinated late. It seems likely that selection was mainly by competition for light. Contrary to expectation P. major-seedlings had a higher shade tolerance than those of P. lanceolata. The performance of both species is discussed in relation to their different life strategies.Grassland species research group publication no 142     

Comparison of the Respiratory Metabolism of Plantago lanceolata L. and Plantago major L.

Bryce, J. H. and ap Rees, T. 1985. Comparison of the respiratorymetabolism of Plantago lanceolata L. and Plantago major L.—J.exp. Bot. 36 1559–1565. The aim of this work was to discover if the respiratory metabolismof the roots of Plantago lanceolata L. differed from that ofthe roots of Plantago major L. Measurements of oxygen uptakeand dry weight of excised root systems during growth of seedlingsprovided evidence that the two species differed in the amountof respiration needed to support a given increase in dry weight.Excised root systems were given a 6-h pulse in [U-¹⁴C]sucrosefollowed by a 16.5-h chase in sucrose. The detailed distributionof ¹⁴C amongst the major components of the roots at the endof the pulse and the chase revealed no significant differencebetween the two species. Patterns of ¹⁴CO₂ production from [1-¹⁴C],[2-¹⁴C], [3,4-¹⁴C], and [6-¹⁴C]glucose of excised root systemsfrom plants of three ages were similar for the two species.It is suggested that there is no conclusive evidence for anysignificant inherent difference in the respiratory metabolismof the roots of the two species. Key words: ¹⁴C sugar metabolism, respiration, roots, Plantago     

Chemotaxonomy and evolution of Plantago L.

In continuation of our investigations of the genus Plantago L. (Plantaginaceae), sixteen species were investigated with respect to water-soluble glycosides. The iridoids auroside, strictoloside and globularicisin, as well as poliumoside, 3-[(4--D-glucopyranosyloxy)phenyl]propionic acid and 2-[4-(-D-glucopyranosyloxy)phenyl]acetic acid were isolated from Plantago for the first time. The latter compound has not previously been isolated as a natural product. Sorbitol was the main carbohydrate in all the species investigated. The distribution of iridoids correlates well with the morphological classification of Rahn and also with a recently published molecular phylogenetic study of nuclear ribosomal and plastid DNA sequences. A new chemotaxonomic finding is an abundance of iridoid glucosides present in one of the two groups within subgenus Coronopus section Coronopus, while the other group lacks iridoids, supporting a subdivision of this section. Moreover, in subgenus Albicans, 10-benzoylcatalpol is a characteristic constituent of section Gnaphaloides, while the corresponding cinnamoyl ester globularin occurs in section Lanceifolia. In biosynthetic experiments, labelled epideoxyloganic acid and deoxygeniposidic acid were incorporated into aucubin and geniposidic acid in Plantago ovata, consistent with earlier findings, but no incorporation into asperuloside was observed. The evolution of biosynthetic pathways in Plantago is discussed.     

Studies on Amino Acids. XI.

As a part of the studies intending to clarify biological significance of the presence of acylase, enzymatic activity which hydrolyzes acyl amino acids, its activity in yeast was investigated. As a results, the occurrence in yeast of acylase activity was confirmed for the first time.

In order to study the enzymatic properties of this acylase activity, experiments were carried out with the enzyme preparation from brewer’s yeast. As a result of the investigation, yeast acylase was found to be able to hydrolyze a number of acyl amino acids, of these chloroacetyl derivatives especially readily, as in the case of previously studied acylase activity in other sources such as mold acylase. Several observations on the influence of metal ions and inhibitors, optical specificity and others were also presented.     

洋葱细胞核仁内DNA的结构变化及排布过程(英文)

以洋葱 (AlliumcepaL .)细胞为研究材料 ,应用DNA细胞化学特异染色方法 (NAMA_Ur)及常规电子显微镜技术 ,观察了洋葱细胞核仁FC(纤维中心 )内DNA的超微结构 ,发现FC内DNA存在着一个介于集缩到解集缩之间的变化过程 ,并揭示了DNA在核仁内的连续排布过程 ,即核仁外DNA经过核仁通道进入到FC后 ,继续沿FC的边缘或DFC(致密纤维成分 )与FC的交界处环绕FC而排布 ,再经FC之间的核仁通道 ,延伸到另外的FC区域     

早熟凝集染色体和诱导凝集的染色体扫描电镜研究

应用细胞融合技术和扫描电镜研究了ＢＫ（牛肾）细胞早熟凝集染色体（ＰＣＣ）和诱导ＰＣＣ的ＣＨＯ中期染色体的超微结构。所用电镜标本制备方法,尽可能使之减少人工效应,故首次观察到ＰＣＣ超微结构,特别是早、中、晚Ｓ－ＰＣＣ超微结构的自然状态,从早、中、晚Ｓ－ＰＣＣ的染色体片段所显示的ＰＣＣ的多级亚结构,进一步了解了ＢＫ细胞染色体的超微结构。诱导ＰＣＣ的ＣＨＯ中期染色体表面显示出整齐的小毛样由螺旋纤维形成的环状突起。     

Direct and correlated responses to selection on iridoid glycosides in Plantago lanceolata L.

Plantago lanceolata L. (ribwort plantain) produces two costly terpenoid secondary plant compounds, the iridoid glycosides aucubin and catalpol. We performed an artificial selection experiment to investigate direct and correlated responses to selection on the constitutive level of iridoid glycosides in the leaves for four generations. Estimated realized heritabilities (±SE) were 0.23 ± 0.07 and 0.23 ± 0.04 for upward and downward selection, respectively. The response to upward selection was caused by selection for a developmental pattern characterized by the production of fewer leaves that on average contain more iridoids, and by selection for a development‐independent increase in the level of these compounds. Significant correlated responses were observed for plant growth form. Upward selection resulted in plants with larger sized, but fewer leaves, fewer side rosettes, and fewer spikes, corresponding to a previously distinguished ‘hayfield’ ecotype, whereas downward selection produced the opposite pattern, corresponding to a ‘pasture’ ecotype. This indicates that the level of iridoid glycosides is genetically correlated with morphological traits in P. lanceolata, and is part of the complex of genetically correlated traits underlying the two ecotypes. The genetic association between iridoid level and growth forms suggests that there may be constraints to the simultaneous evolution of resistance to generalist insects (by iridoid glycosides) and to larger grazers (by a high production rate of prostrate leaves and inflorescences) in open grazed habitats where the ‘pasture’ ecotype is found.     

Plantago lanceolata L. and Rumex acetosella L. differ in their utilisation of soil phosphorus fractions

To establish relationships between soil phosphorus (P) fractions and leaf P, a mycorrhizal species (Plantago lanceolata L.) was compared with a typically non-mycorrhizal species (Rumex acetosella L.) in a glasshouse experiment. The plants were grown in 40 soils from non-fertilised, abandoned pastures or abandoned arable fields and leaf P concentration were found to be related to various soil P fractions after six weeks of growth. The differences in the P fractions in soil can account for a large share of the variation in leaf P concentration in both species, but the two species differed in their utilisation of P fractions. Leaf P concentration of R. acetosella was more related to extractable soil P than that of P. lanceolata. Rumex acetosella showed a higher maximum P concentration. The P fractions accounting for the largest share of the variation in leaf P concentration was the Bray 1 extractable and the weak oxalate (1 mM) extractable P, and for P. lanceolata also the Na₂SO₄+NaF extractable P fraction. P extracted with these methods accounted for up to 80% of the variation in P concentration in leaves of R. acetosella and 65% of the variation in leaves of P. lanceolata. More P extractable with weak oxalate, Na₂SO₄+NaF and strong oxalate (50 mM) was released from the soil than was taken up by the plants during the experimental period. The Bray 1 extractable P fraction, however, decreased in both unplanted and planted soils. Phosphatase release was not induced in any of the plants during the experimental period, indicating that they were not mobilising soil organic P. However, some of the methods extracted a large share of the organic P and still explained much of the variation in leaf P concentration. Mycorrhizal colonisation of P. lanceolata was inversely related to the extractable soil P. The consistently fast P uptake of R. acetosella indicates that this species have a high demand for P. The differences in P utilisation between R. acetosella and P. lanceolata could be caused by their different mycorrhizal status.     

Iridoid patterns of genus Plantago L. and their systematic significance

The distribution of 14 iridoid glucosides in 14 Plantago L. species (44 samples corresponding to 18 taxa) was shown. P. tenuiflora and P. gentianoides were studied for iridoids for the first time. The iridoid patterns showed a good correlation with morphological and other chemical features of the representatives of genus Plantago. The studied species are grouped together according to the iridoid patterns: species containing mainly aucubin (P. major, P. cornuti, P. gentianoides); species containing aucubin and aucubin derivatives (P. subulata, P. media); species containing aucubin and catalpol (P. lanceolata, P. altissima, P. argentea, P. lagopus, P. atrata); species containing aucubin and plantarenaloside (P. afra, P. scabra).     

Influence of traffic pollution on ecological state of Plantago major L.

The data are presented concerning the amount of mobile compounds of chemical elements (ChE) in soils under various human impact (acetate-ammonium buffer at pH 4.8) and in plants of ripple-seed plantain (Plantago major L.) (extractants such as diluted 1:1 HCl, 10% HCl, distilled H₂O). The content of total ash, mineral impurities of soil origin, water-soluble forms of ChE, polysaccharides and chlorophyll was determined in plants. The obtained data were compared with those for other regions. The ecological state of Plantago major L. was estimated and a conclusion was drawn about its possible use as a medicinal raw material.     

Staining of the Nucleolus with Protein and RNA Stains for Automatic Measurement of Nucleolar Size in Paraffin Sections

In this paper two staining methods for automatic assessment of nucleolar profile area in paraffin sections of breast carcinomas using the IBAS 2000 image analyzer are reported. In the first method, the nucleolar proteins are stained with phloxine B, in the second the nucleolar RNA is stained with methyl green-pyronin. Both methods are fully reproducible. Statistically, the profile areas observed for the same patient by the two methods were found not to differ significantly. Because of their rigidity and their size in relation to section thickness, nucleoli are particularly attractive cell structures for quantitation, for instance in studies of variables that might be useful in establishing the prognosis for carcinoma patients.     

Micropropagation of a medicinal plant, Plantago major L.

An efficient micropropagation protocol was developed for an important medicinal plant, Plantago major L. For this purpose, it is recommended to culture shoot-tips on modified MS medium [412.5 mg dm-3 NH4NO3 and 340 mg dm-3 KH2PO4] supplemented with 50 g dm-3 glucose and 0.5 μM 6-benzylaminopurine. Maximum rooting frequency was obtained at 1 μM naphthaleneacetic acid. This revised version was published online in August 2006 with corrections to the Cover Date.