吴茱萸果实分泌囊发育和精油产生过程的超微结构研究

吴茱萸（Ｅｖｏｄｉａｒｕｔａｅｃａｒｐａ（Ｊｕｓｓ．）Ｂｅｎｔｈ．）果实分泌囊是通过其原始细胞群的中央细胞之间分离,以裂生方式形成。根据分泌囊发育过程中上皮细胞各细胞器的变化规律分析,质体变化最为明显,其体积和数量逐渐增加,基质中出现嗜锇滴和管状结构,周围有油滴分布,因而认为质体是精油的合成场所。精油合成后,通过质体膜转运到质体周围的光滑内质网或液泡中,然后由内质网膜或液泡膜所包被。最后这些含油的小泡直接与质膜融合,将精油释放至油腔中。     

肯氏相思根瘤亚显微结构观察

肯氏相思根瘤亚显微结构观察结果表明：刚受侵染的寄主细胞的细胞核和质体膨大,线粒体内嵴消失成为圆球状体,内质网膜松散;幼年类菌体细胞外型较小,呈圆形和椭圆形,细胞质浓密,染色深而均匀;成熟类菌体外型较大,形态多样,细胞内聚-β-羟基丁酸（PHB）累积增多;随着根瘤细胞逐渐发育成熟,在类菌体包被内可允1至数个类菌体;在根瘤衰老细胞中,类菌体包被周膜解离破裂,流出电子透明物质。本文还对周膜扩增的问题进行了讨论。     

拟菌体包囊膜的动态变化和宿主细胞与细菌的相互关系

本文初次报道紫云英根瘤的超微结构。用根瘤中段的中心组织作实验材料,以显示受根瘤菌侵染的宿主细胞的一般结构。细菌借助于侵入线进入宿主细胞,发育成拟菌体,为包囊膜所裹。一个包囊膜内一般只有一个拟菌体。包囊膜可以与细胞质内的囊泡和小液泡融合而扩增,导致膜对拟菌体的包裹由紧密到疏松的变化。包囊膜和拟菌体表面都有突起,两者的突起相对接触和融合。对拟菌体包囊膜的动态变化与衰老的关系以及宿主细胞和拟菌体之间物质交换的关系进行了讨论。作者指出包囊膜的扩增和电子透明区域的存在,是拟菌体发育成熟的一个阶段,包囊膜和拟菌体通过互相突起、融合沟通的结构,可能是宿主细胞和细菌之间物质交换功能的一种表现。     

孢堆黑粉菌属三个新组合及中国黑粉菌补遗Ⅷ

本文报道了３个新组合种和３个中国新记录种。新组合是：广州孢堆黑粉菌［Ｓｐｏｒｉｓｏｒｉｕｍ ｃａｎｔｏｎｅｎｓｅ（Ｚｕｎｄｅｌ）Ｌ．Ｇｕｏ］香茅粒孢堆黑粉菌［Ｓｐｏｒｉｓｏｒｉｕｍ ｃｙｍｂｏｐｏｇｏｎｉｓ－ｄｉｓｔａｎｔｉｓ（Ｌｉｎｇ）Ｌ．Ｇｕｏ］和海南孢堆黑粉菌［Ｓｐｏｒｉｓｏｒｉｕｍ ｂａｉｎａｎａｅ（Ｚｕｎｄｅｌ）Ｌ．Ｇｕｏ］。中国新记录种为：中间黑粉菌（Ｕｓｔｉｌａｇｏ ｔａｎａｋａｅ     

低温逆境中不同抗寒性植物细胞内Ca^2＋稳定平衡的区别

电镜细胞化学观察揭示,不抗寒的玉米（Ｚｅａ ｍａｙｓ Ｌ．ｅｖ． Ｂｌａｃｋ Ｍｅｘｉｃａｎ Ｓｗｅｅｌ）和抗寒的小偃麦（Ｔｒｉｔｉｃｕｒｎ ｓｅｅｔ．Ｔｒｉｔｉｔｒｉｇｉａ ｍａｃｋｅｙ）细胞在２６℃悬浮培养时,标志Ｃａ＾２＋定位的锑酸钙沉淀物主要分布在液泡内,细胞质和细胞核中很少见到Ｃａ＾２＋沉淀;标志Ｃａ＾２＋－ＡＴＰａｓｅ活性的反应的磷权沉淀物丰富地分布在质膜上,显示这两种植物物质膜Ｃａ＾     

[^3H]Cortisol及[^3H]Dexamethasone在大鼠肝细胞膜上的特异结合位点

本研究应用［３Ｈ］ｃｏｒｔｉｓｏｌ和［３Ｈ］ｄｅｘａｍｅｔｈａｓｏｎｅ（ＤＥＸ）两种配基,观察到大鼠肝细胞膜上存在一类糖皮质激素（ＧＣ）特异结合位点。这些位点与ＧＣ的结合具有饱和性、高亲和力及低容量。其平衡解离常数（Ｋｄ）分别为１２．８４±６．５８ｎｍｏｌ／Ｌ和４０．２７±２３．４４ｎｍｏｌ／Ｌ;最大结合容量（Ｂｍａｘ）分别为２．５７±１．８４ｐｍｏｌ／ｍｇ蛋白质与０．６４±０．１８ｐｍｏｌ／ｍｇ蛋白质（ｃｏｒｔｉｓｏｌ,ｎ＝４;ＤＥＸ,ｎ＝３;±ＳＥ）。动力学实验数据所得的Ｋｄ值与Ｓｃａｔｃｈａｒｄ分析所得的Ｋｄ值结果基本一致。［３Ｈ］ｃｏｒｔｉｓｏｌ和［３Ｈ］ＤＥＸ饱和结合实验数据用Ｓｃａｔｃｈａｒｄ作图分析,均显示为直线。Ｈｉｌｌ系数则分别为０．９８８０和０．９９９０．竞争抑制实验结果表明,ｃｏｒｔｉｓｏｌ对［３Ｈ］ｃｏｒｔｉｓｏｌ的结合位点有高度特异性竞争,比其它几种类固醇（强的松、黄体酮、ＲＵ４８６、ＤＥＸ）的竞争力至少强４０倍以上．用放射自显影技术进行研究,也提供了［３Ｈ］ｃｏｒｔｉｓｏｌ特异结合银粒位于大鼠肝细胞膜上的依据。     

旋扭山绿豆根瘤菌CB627结瘤因子的测定(简报)

Ｒｈｉｚｏｂｉｕｍ、Ｂｒａｄｙｒｈｉｚｏｂｉｕｍ和Ａｚｏｒｈｉｚｏｂｉｕｍ能侵染豆科植物并形成根瘤。在根瘤形成过程中,共生伙伴之间首先进行信号物质交换,植物分泌类黄酮（ｆｌａｖｏｎｏｉｄｓ）到根际,类黄酮与ＮｏｄＤ蛋白结合,进而在转录水平调节其它ｎｏｄ基因的表达,这些ｎｏｄ基因的产物（Ｎｏｄ蛋白）控制根瘤菌产生胞外信号物质（ｌｉｐｏｃｈｉｔｉｎｏｌｉｇｏｓａｃｃｈａｒｉｄｅ,简称ＬＣＯ）［１］。ＬＣＯ能引起宿主植物根毛变形、皮层细胞分裂、根瘤原基及根瘤的形成,因此ＬＣＯ定名为结瘤因子（ｎｏｄｆａ…     

侵染细胞质膜附近小泡的来源及其作用

箭舌豌豆根瘤幼龄侵染细胞的壁和质膜比较光滑,成熟侵染细胞与此不同,不仅细胞壁厚薄均,有较多的胞间连丝,而且质膜常常内陷形成各种突起,然后离质膜形成小泡。这些位于质膜附近的小泡体积较小,多呈圆形,既可单独存在,也可多个聚在一起。在向细胞中央移动中,有的小泡靠近细胞质膜,甚至与细菌周期融合,有的小泡不民附近的小液泡融合变为较大液泡,并常用降解程度不同的细菌位于其中,在衰老侵染细胞中,细胞壁附近有小泡,     

液泡膜转运蛋白与植物耐盐性研究进展

液泡膜转运蛋白与植物耐盐性研究进展王宝山１邹琦２赵可夫１１（山东师范大学逆境植物研究所,济南２５００１４）２（山东农业大学基础部植物生理教研室,泰安２７００１８）ＡｄｖａｎｃｅｓｉｎｔｈｅＶａｃｕｏｌａｒＴｒａｎｓｌｏｃａｔｉｎｇＰｒｏｔｅｉｎｓａ...     

黄瓜雌花发育过程中柱头的腺特征(英文)

利用透射电镜技术研究了黄瓜（Ｃｕｃｕｍｉｓ　ｓａｔｉｖｕｓ　Ｌ．）雌花柱头发育过程中传递组织、分泌组织和乳突细胞的超微结构。在整个发育过程中,乳突细胞和分泌组织细胞的细胞质内密布很多管状及槽库膨大的内质网,产生很多分泌囊泡;在成熟柱头的传递组织和分泌组织细胞间观察到大量的胞间连丝;乳突细胞和分泌细胞高度液泡化,质膜内折;在柱头发育过程中分泌组织细胞的核周腔扩大形成裂瓣状核,到柱头成熟阶段裂瓣状核更加明显。进一步的研究显示,在成熟柱头的不同组织细胞中,　ＡＴＰａｓｅ的活性呈现在质膜和液泡膜上,随着柱头的发育,ＰＭ－Ｈ＋－ＡＴＰａｓｅ的比活性明显增强。结果表明,黄瓜雌花柱头的腺特征随发育进程而趋于显著。     

Diversity of Origin and Expansion Mode of Peribacteroid Membrane in Legume Nodules

Bacteroids, in numbers of two, three or more, in the legume nodules of Sesbania cannabina (Retz.) Pers., Glycine max (L.) Merr. and Pisum sativum L. were enclosed in each peribacteroid membrane (PBM). In view that PBM was formed synchronously with the bacteroid reproduction, the origin as well as the expansion of PBM ought to be in large scale in order to meet the need of the physiologic process of symbiotic nature. It was observed that in the same nodule sample there were kinds of modes of the PBM expansion, such as chimeric fusion between, or among the PBMs in which a protrusion of one PBM fit into a depression of another PBM, fusions of the PBM with endoplasmic reticulum (ER) and its vesicles, with small vacuole membrane, etc. Cytochemical study indicated that PBM, plasma membrane, ER membrane, etc. possessed the same type of ATPase, and the PBM was structurally similar to the plasma membrane. Therefore, the PBM appears to be a mosaic membrane possessing features of the plasma membrane, ER membrane and vacuole membrane, etc. In final, the physiological significance of the diversity in the origin and expansion modes of the PBM was discussed.     

Iron Uptake by Symbiosomes from Soybean Root Nodules

To identify possible iron sources for bacteroids in planta, soybean (Glycine max L. Merr.) symbiosomes (consisting of the bacteroid-containing peribacteroid space enclosed by the peribacteroid membrane [PBM]) and bacteroids were assayed for the ability to transport iron supplied as various ferric [Fe(III)]-chelates. Iron presented as a number of Fe(III)-chelates was transported at much higher rates across the PBM than across the bacteroid membranes, suggesting the presence of an iron storage pool in the peribacteroid space. Pulse-chase experiments confirmed the presence of such an iron storage pool. Because the PBM is derived from the plant plasma membrane, we reasoned that it may possess a ferric-chelate reductase activity similar to that present in plant plasma membrane. We detected ferric-chelate reductase activity associated with the PBM and suggest that reduction of Fe(III) to ferrous [Fe(II)] plays a role in the movement of iron into soybean symbiosomes.     

Synthesis of an integral protein of the protein-body membrane in Phaseolus vulgaris cotyledons

Protein-body membranes (PBMs) were isolated from cotyledons of Phaseolus vulgaris L. by a procedure involving osmotic shock of purified protein bodies. The purified PBMs have a characteristic density of 1.16 g cm^-3. Treatment of the membranes with increasing concentrations of detergent (Triton X-100) or with a solution at pH 12.0 showed that the membranes contained a characteristic integral protein (IMP) with a relative molecular mass of 25,000. This IMP is not a glycoprotein. When developing cotyledons were labeled with ³H-amino acids for 2–3 h, a radioactive polypeptide with the same mobility on denaturing polyacrylamide gels as IMP was found to be associated with the rough endoplasmic reticulum (ER). During a 24-h chase, a considerable portion of the radioactivity slowly transferred into the IMP associated with more rapidly sedimenting organelles, which sedimented in the same region of the sucrose gradients as the PBMs. Antibodies prepared against purified IMP crossreacted with an ER-associated protein which had the same mobility on denaturing acrylamide gels as authentic IMP. Synthesis of IMP occurred at all stages of cotyledon development examined, but not during seed germination. The results show that a newly synthesized protein of the PBM is associated with the rough ER, just like the soluble matrix proteins, phaseolin (R. Bollini, W. Van der Wilden and M.J. Chrispeels, 1983, J. Cell Biol. 96,999–1007) and phytohemagglutinin (M.J. Chrispeels and R. Bollini, 1982, Plant Physiol. 70, 1425–1428), but that the chase-out from the ER is much slower for IMP than for the matrix proteins.Abbreviations EDTA ethylenediamino-tetraacetic acid - ER endoplasmic reticulum - IMP integral membrane protein - PB protein body - PBM protein-body membrane - PHA phytohemagglutinin - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis     

Fatty Acid Composition of the Peribacteroid Membrane and the ER in Nodules of Glycine max Varies after Infection by Different Strains of the Microsymbiont Bradyrhizobiumjaponicum

The fatty acid composition of ER, Golgi and peribacteroid membrane (PBM) from root nodules formed on Glycine max after infection with different strains of Bradyrhizobium japonicum has been analysed by gas chromatography. In each plant-microsymbiont combination the fatty acid composition (FAC) of the PBM is distinct from ER and Golgi. The similarity between ER and PBM fatty acid composition is significantly stronger than between Golgi and PBM. In addition the fatty acid composition of all membrane systems in nodules is affected by the microsymbiont strain. A comparison of four strains of Bradyrhizobium japonicum grown in agar surface culture and isolated as the symbiotic bacteroids reveals a decrease in oleic acid during bacteroid differentiation.     

Fractionation of suspension cultures of wild carrot and kinetics of membrane labeling

Summary Wild carrot (Daucus carota L.) cells, grown in suspension culture, were labeled with radioactive precursors and fractionated into constituent membranes to be analyzed for specific radioactivity. Results show rapid incorporation of [³H] leucine into endoplasmic reticulum (ER)-, Golgi apparatus-, and plasma membrane/tonoplast-enriched fractions. The time lag between incorporation into ER and its appearance in Golgi apparatus or plasma membrane/tonoplast were less than 5 minutes. With an average time of 3–4 minutes for cisternal formation estimated from studies with monensin, and an average of 5 cisternae per dictyosome (total transit time of 15–20 minutes), it was not possible to account for early incorporation of radioactivity into plasma membranes by passage of proteins from ER to plasma membrane via the Golgi apparatus. To account for the findings, it would appear that at least some proteins were delivered to the plasma membrane via the first membranes that exited (i.e., mature face vesicles) from the Golgi apparatus post-pulse and that some of these proteins had been translated and inserted into membranes at or near the mature face of the Golgi apparatus.     

Glycosylated polypeptides of soybean root endomembranes

Summary Endoplasmic reticulum, Golgi apparatus, plasma membrane and mitochondria vesicles were isolated from the roots of four-day-old dark-grown soybean [Glycine max (L.) Merr. cv. Wells II] seedlings and characterized by marker enzyme analyses. Glycoproteins of enriched membrane fractions were identified by concanavalin A (con A)-peroxidase staining of polypeptides separated by two-dimensional IEF-SDS-PAGE and transferred to nitrocellulose.Con A bound to many polypeptides in each endomembrane-enriched fraction with several glycopolypeptides common to all fractions. The mitochondria-enriched fraction possessed few glycopolypeptides and those appeared to be highly glycosylated contaminants of endomembrane origin. Comparison of the endomembrane con A-binding patterns revealed changes in relative stain intensity, molecular weight and isoelectric point of several membrane glycopolypeptides suggestive of processing reactions of the endomembrane complex.Abbreviations con A concanavalin A - PM plasma membrane - GA Golgi apparatus - ER endoplasmic reticulum     

Integrated stereological and biochemical studies on hepatocytic membranes. III. Relative surface of endoplasmic reticulum membranes in microsomal fractions estimated on freeze-fracture preparations

New methods are required for identifying membranes in subcellular fractions with respect to their origin, if such preparations are to be evaluated morphometrically. One method is freeze-fracturing which reveals intramembrane particles whose size, pattern, and numerical density differ for various membrane types. The question is examined whether the differences in numerical particle density per square micrometer of membrane (alpha) can be used to differentiate membrane vesicles found in microsomal fractions from liver cells with respect to their origin in the hepatocytes. It is found that the range of alpha for the protoplasmic face (PF) of endoplasmic reticulum (ER) membrane (1,900 less than alpha less than 3,250) is intermediate between those for plasma and mitochondrial membranes. Since PF(ER) should appear in the outer leaflet of microsomal vesicles, alpha was estimated on concave profiles of freeze-fracture preparations; the numerical frequency distribution of vesicles with respect to alpha was trimodal, with a major peak around 2,900/micrometer2 and 66% of the vesicles in the range determined for PF(ER). Using a new stereological method, it was calculated that 63% of the membrane surface in these microsomal fractions was of ER origin by this criterion. On the same preparations, an attempt was made to label the ER-derived membranes cytochemically for glucose-6-phosphatase. A line intersection count revealed 62% of the membrane surface to be of ER origin on the basis of marker enzyme labeling. These findings indicate a smaller part of ER membranes in microsomal fractions than would be predicted from biochemical data (77%). The possible reasons for such discrepancies are discussed; shifts in particle densities due to the preparation procedure could lead to an underestimate by freeze-fracturing, whereas the prediction from biochemical data could be overestimates if marker enzymes were not homogeneously distributed.     

Characterisation by proteomics of peribacteroid space and peribacteroid membrane preparations from pea (Pisum sativum) symbiosomes

The legume Rhizobium symbiosis leads to the formation of a new compartment in the plant cell, the symbiosome. This compartment harbours the bacteroids surrounded by a peribacteroid membrane (PBM) originating from the plant plasma membrane. The PBM and the space between the PBM and the bacteroid membrane, called peribacteroid space (PS), mediate the exchange of metabolites between the symbionts. Proteome analysis was used as an approach to characterise the proteins in the PBM and the PS. A standard differential centrifugation procedure including a Percoll gradient was used for symbiosome isolation from pea root nodules. Proteins in the PBM and PS fractions obtained from the symbiosomes were separated by two-dimensional gel electrophoresis, and 89 spots were analysed by tandem mass spectrometry. The proteins of 46 spots could be identified by database search. The results showed that PS and even PBM preparations from pea symbiosomes always contain abundant amounts of bacteroid proteins as a contaminate. Interestingly, in addition to a few PS/PBM proteins a number of endomembrane proteins (less likely representing a contaminate), including V-ATPase, BIP, and an integral membrane protein known from COPI-coated vesicles, were found in the PBM fraction, supporting the role of the endomembrane system in PBM biogenesis.     

Stereospecificity of NADH-ferricyanide reductase is a convenient marker for the endoplasmic reticulum of plant cells

The stereospecificity of NADH-ferricyanide reductase and NADH-cytochrome c reductase in the endoplasmic reticulum (ER) for the α-hydrogen on the nicotinamide ring is presented as a very sensitive and convenient assay to detect ER contamination in preparations of membranes lacking α-specific NADH-acceptor reductase, such as the plasma membrane and the tonoplast. The experimental details of the assay are given and the limitations explored (time-course, amount of protein, possible side reactions, speed, reproducibility, etc.). The NADH-ferricyanide reductase activity of plasma membranes from spinach and sugarbeet leaf was completely β-specific and always showed a latency (increase upon addition of Triton X-100), whereas the α-specificity in the ER was non-latent. This is consistent with the presence of mainly right-side-out vesicles in preparations of plasma membranes with the binding site for NADH and ferricyanide on the inner, cytoplasmic surface. In contrast, right-side-out ER vesicles have the binding site on the outer, cytoplasmic surface. The addition of as little as 1% of the α-specific ER (on an NADH-ferricyanide activity basis) to the spinach leaf plasma membrane could be detected with the stereospecificity assay. Wheat root plasma membrane showed some α-specificity (in addition to β-specificity) which was probably due to ER contamination since the activity was non-latent. The stereospecificity assay is also shown to be useful in monitoring the separation of tonoplast vesicles from ER vesicles by countercurrent distribution of a light microsomal fraction. It follows that the NADH-acceptor reductase activities in preparations of plasma membrane and tonoplast are due to distinct enzymes characteristic for those membranes.