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991.
球毛壳(Chaetomium globosum Kze.)系 Kunze 于1817年报道见于丹麦石竹(Dianthus carthusianorum L.)茎上的毛壳菌属(Chaetomium)的第一个种(模式种)。Cooke and Ellis 在1878年描述了见于飞蓬属(Erigeron L.)腐茎上的橄榄色毛壳(C.oliaceum C.et E.)。在 Chivers(1915)、Skolko and Groves(1953)、Udagawa(1960)、Ames(1963)和 Seth(1972)关于毛壳菌属的专著都曾指出很难划分这两个种的界限。Skolk and Groves(1953)区分此两个种时以橄榄色毛壳具有较大的子囊壳、较宽的顶附属丝和较大的子囊孢子,而 Chivers(1915)则认为橄榄色毛壳是球毛壳的异名,Udagawa(1960)区分此两个种仅根据子囊孢子的长度和宽度,他认为橄榄色毛壳的子囊孢子大于球毛壳的子囊孢子。Seth(1972)在他的专著中虽保留此两个种作为独立种,但他指出限于他镜检过的标本材料及根据 Chivers 专著中的球毛壳的特征辑要概括了橄榄色毛壳的特征,对这两个种的区分界限确实是很难划分的。最近我们在北京采集和分离了来源于不同的植物和动物材料上的毛壳菌种类,以期进行北京地区毛壳菌种类调查研究。我们分离获得许多球毛壳——橄榄色毛壳类的毛壳菌菌株。参考了不同作者对这两个种的子囊壳、顶附属丝、侧附属丝、子囊及子囊孢子的特征记载,对北京的这一类型菌株进行了细致研究,认为球毛壳与橄榄色毛壳确有形态学特征区别,表现在橄榄色毛壳的子囊壳、顶附属丝和子囊孢子较球毛壳的更为粗壮,兼之球毛壳的顶附属丝较橄榄色毛壳的为窄且有分隔和微粗糙,球毛壳的子囊孢子呈浅橄榄褐色至暗橄榄褐色,含两个折光性油滴而橄榄色毛壳的子囊孢子呈暗橄榄褐色,量度亦较大,凭依经验即可鉴别此两个不同种。 相似文献
992.
本文首次将双相电泳(等电聚焦和SDS电泳)技术应用于对棉酚作用机理的研究。实验结果表明,棉酚能够改变大鼠成熟精子的蛋白质组成;同时也证明,双相电泳这一技术对棉酚的研究是有效的。 相似文献
993.
Summary The seed coat of soybean (Glycine max L. Merr.) is of physiological interest for synthesis and transport of amino acids and photosynthates during embryo development. A transmission and scanning electron microscopic study to elucidate the structure of the seed coat disclosed a specialized convex area (antipit) appressed to a concave pit in the center of the abaxial surface of the cotyledon. The antipit, which lies on the inner surface of the seed coat at a medial point in the anterior to posterior direction of the seed, contained specialized secretory cells bounded by loose multi-layered cell walls. These cells were rectangular in the developing seed, varied in length, and contributed directly to the convex morphology of the antipit seen on the ventral surface of the seed coat. At maturity these cells assumed the shape of a cone, extending from the aleurone layer in a perpendicular array. The aleurone and cone cells contained numerous Golgi apparatus, laminated rough endoplasmic reticulum, secretory vesicles, and amyloplasts. Secretory vesicles arose directly from tubules of fenestrated trans cisternae of the Golgi apparatus. Mitochondria were clustered with the amyloplasts; stacks of lamellar cisternae of rough endoplasmic reticulum were associated with the nucleus and Golgi apparatus. The cellular contents, the interconnections by plasmodesmata, and the close physical association with the cotyledon suggested that the aleurone and cone cells may be involved in symplastic transport of nutrients for use by the developing embryo.This paper is dedicated to the memory of my parents, Joseph and Theresa Yaklich, who by their example taught me the value of work and the enjoyment of simple things. 相似文献
994.
Summary Dynamic change of plastid nucleoids (pt nucleoids) was followed by fluorescence microscopy after staining with 46-diamidino-2-phenyl indole (DAPI). The fluorescence image was quantified with a supersensitive photonic microscope system based on photon counting and image analysis. The results showed that small pt nucleoids located in the center of proplastids in the dry seed increased in size after imbibition and formed highly organized ring structures in the dark, which divided into ca. 10 pieces within 3 days. Corresponding to this morphological change, DNA content of a plastid multiplied 7.5 fold. Total increase in DNA content of pt nucleoids per cell was 34 times as that of dry seed, as plastid multiplied 4.6 times in the average during this period. Upon light illumination small pt nucleoids having basic genome size were separated from divided pt nucleoids, suggesting a relationship with the formation of thylakoid system. The significance of the procedure established in this study is discussed in analysing the dynamic changes of intracellular small genomes.On leave from Department of Biology, Faculty of Science, Nagoya University, Furocho, Chikusaku, Nagoya 464, Japan. 相似文献
995.
Summary Striated Ciliary Roots (SCRs), about 3 m long, are attached to the basal bodies of branchial crown ciliated epithelial cells ofOwenia. These SCRs appear to consist of 5–7-nm diameter filaments organized in a cross-striation pattern with an apparent variable periodicity of 50 to 80 nm. The most exciting observation emerging from this study is the constant and conspicuous close spatial relationship between SCRs and fairly well developed Golgi apparatus. By enhancing contrast and preservation of cell components, the OsFeCN postfixation-staining of material prefixed in glutaraldehyde in the presence of calcium has revealed some fine-structural details within the SCR-Golgi Association. By means of the calcium precipitation method, with antimonate or oxalate in conjunction with X-ray microanalysis, we have identified calcium within SCR dark bands and SCR-associated Golgi bodies. The ability to bind calcium makes the Golgi apparatus a likely candidate for Ca2+ regulation of putative contraction of the SCRs and/or ciliary motility. The slight period variability measured in the SCRs and cytochemical localization of Mg2+, Ca2+-dependent ATPase activities associated with cross striations support the view that theOwenia SCRs may be contractile organelles.The striking and specific close structural association between the Golgi apparatus and the SCR showing Ca2+-binding capabilities suggests that some sort of Ca2+-mediated functional relationship between these organelles may exist.Abbreviations SCR
striated ciliary root
- OsFeCN method
osmium tetroxide-ferricyanide method
- EDTA
ethylenediamine tetraacetic acid
- EGTA
ethyleneglycol-bis-(-aminoethyl ether) N,N-tetraacetic acid
- ATP
adenosine 5-triphosphoric acid
- ATPase
adenosine triphosphatase
- ASW
artificial sea-water 相似文献
996.
A. Steffen T. Eriksson O. Schieder 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1986,72(1):135-140
Summary Alternative methods for shoot regeneration in protoplast derived cultures were developed in Nicotiana paniculata and Physalis minima. In both species protoplast derived callus is not regeneratable to shoots by conventional methods, e.g. hormone treatment. Leaf discs and stem segments of N. paniculata and P. minima were incubated with Agrobacterium tumefaciens shooter strains harbouring pGV 2215 or pGV 2298 or wildtype strain B6S3. After 36 h of co-incubation protoplasts were prepared. (Leaf disc and stem segment cloning). Co-cultivation experiments were also undertaken with protoplasts of both species. Transformed clones, characterized by their hormone independent growth and octopine production, could be isolated after about two months. Transformation frequencies of leaf disc and stem segment cloning and co-cultivation experiments varied from 5×10–3 to 5×10–5. After about one year of cultivation on hormone-free culture medium, shoots could be recovered from colonies of N. paniculata, transformed by the strain harbouring pGV 2298. In protoplast derived colonies of P. minima, shoot induction was obtained only after transformation by bacteria carrying pGV 2215. This demonstrates the importance of the particular shooter mutant, as well as the response of the host plant. Transformed shoots of P. minima produced octopine, whereas octopine production in transformed shoots and callus of N. paniculata was undetectable after one year of cultivation, though T-DNA was still present in the plant genome. Transformed shoots of N. paniculata and P. minima do not produce any roots. Shoots of N. paniculata have an especially tumerous phenotype. Shoots of both species were successfully grafted to normal donor plants of N. tabacum.Abbreviations B5-h
Gamborg medium without hormones (Gamborg 1968)
- V47
protoplast medium (Binding 1974)
- D2a
protoplast medium (Li et al. 1980)
- MS-h
Murashige and Skoog medium without hormones (Murashige and Skoog 1962)
Dedicated to Professor Dr. G. Melchers in occasion of his 80th birthday 相似文献
997.
Abstract The chloroplast ultrastructure, especially the thylakoid organization, the polypeptide composition of the thylakoid membranes and photosynthetic O2 evolution rate, chlorophyll (Chl) content and Chi a/b ratio were studied in leaves of nine plants growing in contrasting biotopes in the wild in South Finland. All the measurements were made at the beginning of the period of main growth on leaves approaching full expansion, when the CO2-saturated O2 evolution rate (measured at 20°C and 1500 μmol photons m?2s?1) was at a maximum, ranging from 19.2 to 6.9 μmol O2 cm?2 h?1. Among the species, the Chi a/b ratio varied between 3.75 and 2.71. In the mesophyll chloroplasts, the ratio of the total length of appressed to non-appressed thylakoid membranes varied between 1.07 and 1.79, the number of partitions per granum varied between 2.8 and 12.0 and the grana area between 21 and 42% of the chloroplast area. There was a significant relationship between the rate of O2 evolution of the leaf discs and the thylakoid organization in the mesophyll chloroplasts. The higher the O2 evolution rate, the lower was the ratio of the total length of appressed to non-appressed thylakoid membranes and also the lower the grana area. Although the relationship of the photosynthetic rate with the Chi content and the Chi a/b ratio of the leaves was not as clear, a significant negative correlation existed between the Chi a/b ratio and the ratio of appressed to non-appressed thylakoid membranes, indicating lateral heterogeneity in the distribution of different Chl- protein complexes. 相似文献
998.
Many studies have established a correlation of differences in the activities of various muscle types with differences in the expression of myosin isoforms. In this paper we report the sequence determination of myosin light chain-2 from rabbit slow skeletal (LC2s) and ventricular (LC2v) nmscles. We sequenced tryptic peptides from LC2v which account for all except a few terminal amino acid residues. The major part (87 residues) of the rabbit LC2s sequence, obtained from tryptic and cyanogen bromide (CNBr) peptides, was found to be identical to rabbit LC2v. Our results provide the first sequence information on LC2s from any species, and lend strong support to the hypothesis that LC2s and LC2v are identical. Comparisons of rabbit LC2v and LC2s with rabbit LC2f (from fast skeletal muscle), and also with chicken LC2f and LC2v, show clearly that LC2s and LC2v from mammalian and avian species are more closely related to each other than they are to LC2f isoforms from the same species. 相似文献
999.
Soichi Kojima Wakako Soga Hiromi Hagiwara Motoyuki Shimonaka Yuji Saito Yuji Inada 《Bioscience reports》1986,6(12):1029-1033
We have succeeded in corroborating the enhancing effect of vitamin A, vitamin C, sitosterol and fucosterol on the fibrinolytic activity of endothelial cells. The assay system consisted of anin situ dissolution of a fibrin layer coated onto a culture dish, over which endothelial cells were grown in a culture medium containing 10 % serum. The dissolution was enhanced by the addition of these vitamins and phytosterols to the culture medium.To whom correspondence should be addressed. 相似文献
1000.
Selenocysteine lyase activity was detected in crude extracts from a cysteine-requiring mutant ofEscherichia coli K-12. The level of activity was the same whether cells had been grown aerobically or anaerobically, with or without selenocysteine.
Selenocysteine lyase catalyzes the conversion of selenocysteine to alanine and elemental Se, a reaction that is followed by
a nonenzymatic reduction of the Se to hydrogen selenide. Both of these end products were identified in this study. With cysteine
as the substrate, alanine and H2S were formed, but only at levels 50% less than the products formed from selenocysteine. Selenocysteine lyase has been identified
in a number of mammals and bacteria; its presence in a cysK mutant ofE. coli K-12 suggests a common route whereby hydrogen selenide, derived from selenocysteine, can then be assimilated into selenoproteins. 相似文献