Ultrastructural Studies of Barley Mesophyll Cella lnfected with Barley Yellow Mosaic Viruses

lexuous filamentous, rod-shaped particles, and laminated, pinwheel inclusions were observed in the mesophyll cells of the barley plants naturally infected with barley yellow mosaic viruses. These virus particles had a length of 480–920 nm and a width of 10–20 nm. In addition, bundles of filamentous structures which consisted of many particles with more 2000 nm in length were found in the leaves of the infected barley plants. The ultrastructural alterations of the infected mesophyll cells were rather conspicuous. The cytoplasmic matrix was lost seriously, and the chloroplast membrane system was destroyed. The cristae and matrix of the mitochondrium were decreased and some of them became vacuoles. The endoplasmic reticulum (ER) expanded teristic membranous network structures occurred in the cytoplasm of infected cells. The virus particles were often associated at one end with ER and with the membranes of network structures. The nucleus, membrane and wall of ceils also had somewhat variation.     

大麦黄花叶病毒侵染的大麦叶肉细胞超微结构研究

在自然感染大麦黄花叶病毒的大麦叶肉细胞中可见线条状和杆状的病毒粒体以及风轮状内含体。这些病毒的长度一般为480—920nm,宽为lo—20nm。此外,还观察到一种由许多病毒组成的堆束状结构,这种病毒的直径为13nm 左右,长度可达2000nm 以上。感病叶肉细胞的超微结构变化是相当明显的。在病害严重的细胞中,细胞基质丧失严重;叶绿体膜系统破坏;线粒体的嵴和基质减少;内质网膨大或断裂,小泡大量出现,病毒粒体的一端往往与内质网联结在一起,特征性膜性网络结构在感染的细胞质中形成。细胞核和细胞膜也发生了变化。     

NaCl对小麦幼苗叶肉细胞超微结构的影响

在含NaCl的培养液中培养小麦幼苗,3天后取样观察叶肉细胞,其超微结构基本正常,细胞核和细胞壁没有明显变化。但线粒体结构普遍受到损害,表现在外膜、内膜和嵴膨胀,结构模糊。叶绿体被膜和片层结构仍保持完整,仅有部分叶绿体的片层排列方向发生改变,由原来平行排列扭转为近于垂直排列。     

Fine Structure of Hepatozoon mocassini (Apicomplexa,Eucoccidiorida) Gamonts and Modifications of the Infected Erythrocyte Plasmalemma1

Transmission electron microscopy and scanning electron microscopy were used to investigate the fine structure of Hepatozoon mocassini gamonts and modifications of the infected erythrocyte plasmalemma. Intraerythrocytic gamonts were contained within a parasitophorous vacuole. An electron-lucid space observed between the gamont pellicle and the membrane of the vacuole corresponded to the unstained space described in light microscopy studies. Gamonts possessed a conoid, polar ring, subpellicular microtubules, four pairs of rhoptries, micronemes, ovoid granules, mitochondria with tubular cristae, and a pellicle composed of three individual unit membranes. The conoid had an anterior diameter of 320 nm, a posterior diameter of 360 nm, and a length of 150 nm. In contrast to a report on Hepatozoon aegypti, no micropore or “canopy-like structure” was observed. The plasmalemma of infected erythrocytes exhibited two types of modifications: gross membrane deformations and knobs with an electron-dense central mass. These knobs are structurally distinct from previously described membrane excrescences.     

脱硫废弃物对碱胁迫下油葵幼叶细胞钙分布及Ca2+-ATPase活性的影响

利用脱硫废弃物改良盐碱地对于确保国家粮食安全和生态安全,发展循环经济具有重要意义。为了探索脱硫废弃物提高植物抗盐碱机理,采用盆栽试验法, 研究了施入不同量脱硫废弃物和CaSO₄对碱胁迫下油葵叶片细胞钙分布、总钙含量以及质膜和液泡膜Ca²⁺-ATPase活性的影响。结果表明:在碱胁迫下(CK),Ca²⁺与焦锑酸钾结合成黑色颗粒成团零星分布于叶绿体和液泡中,叶绿体超微结构受到不同程度的破坏。施入脱硫废弃物和CaSO₄,叶绿体结构完整,细胞间隙、细胞壁和液泡中的钙颗粒逐渐增多,同时,质膜和液泡膜Ca²⁺-ATPase活性随脱硫废弃物和纯品硫酸钙施量的增加而增加,其中液泡膜Ca²⁺-ATPase活性无论是对照(CK)还是处理的活性均高于质膜Ca²⁺-ATPase活性。叶片细胞内总钙含量也随脱硫废弃物和CaSO₄施用量的增加呈升高趋势。说明脱硫废弃物和CaSO₄通过增加Ca²⁺-ATPase活性,有利于钙通过质膜和液泡膜进入细胞内,维持膜结构的稳定性,缓解碱对油葵的胁迫。     

Electron Microscopic Studies of the Development of Kinetes in Theileria annulata Dschunkowsky & Luhs, 1904 (Sporozoa, Piroplasmea)

SYNOPSIS. Gamogony of Theileria annulata Dschunkowsky & Luhs occurs within the intestine of nymphs of the tick Hyalomma anatolicum excavatum Koch. After the 5th day post repletionem (p.r.) of the ticks spherical and ovoid parasites were found within the intestinal cells. These stages were thought to represent fertilized macrogametes. These underwent a transformation process leading ultimately to the differentiation of a motile stage, the kinete , which leaves the intestinal cells on the 14th-17th day p.r. and penetrates the alveoles of the salivary glands. The transformation of the stationary into a motile stage takes place by formation of a growing protrusion (= anlage) into an inner, enlarging vacuole. During this process the limiting membrane of the vacuole serves as the outer membrane of the developing motile stage, whereas the 2 inner membranes of its pellicle are newly formed. The steps of this differentiation in T. annulata are compared to the process of ookinete formation in haemosporina.     

Electron microscopic studies of the development of kinetes in Theileria annulata Dschunkowsky & Luhs, 1904 (Sporozoa, Piroplasmea).

Gamogony of Theileria annulata Dschunkowsky & Luhs occurs within the intestine of nymphs of the tick Hyalomma anatolicum excavatum Koch. After the 5th day post repletionem (p.r.) of the ticks spherical and ovoid parasites were found within the intestinal cells. These stages were thought to represent fertilized macrogametes. These underwent a transformation process leading ultimately to the differentiation of a motile stage, the kinete, which leaves the intestinal cells on the 14th-17th day p.r. and penetrates the alveoles of the salivary glands. The transformation of the stationary into a motile stage takes place by formation of a growing protrusion (= anlage) into an inner, enlarging vacuole. During this process the limiting membrane of the vacuole serves as the outer membrane of the developing motile stage, whereas the 2 inner membranes of its pellicle are newly formed. The steps of this differentiation in T. annulata are compared to the process of ookinete formation in haemosporina.     

Investigations into the fire structure of the asexual developmental stages of Frenkelia in the liver of the bank vole (author's transl)]

Bank voles (Clethrionomys glareolus) were infected by stomach tube with Frenkelia sporocysts from the faeces of buzzards (Buteo buteo). The voles were sacrificed at regular intervals and their livers examined electronmicroscopically. Seven days p.i. developmental stages of Frenkelia could be detected in liver parenchymal cells. The youngest schizonts detected are enveloped by a pellicle consisting of two membranes. This pellicle, which is in direct contact with the host cell mitochondria, shows marked invaginations which increase with the development of the schizont. A parasitophorous vacuole is not detectable. In developing schizonts numerous sections through nuclei with nucleic spindles and merozoite anlagen (dome-shaped) structures) are visible. It is not clear whether there are several nuclei or a section through one large and lobed nucleus. Within the merozoite anlagen the conoid and the subpellicular microtubules are formed first. By the prolongation of the dome-shaped structures towards the posterior pole, the nucleus and the other newly formed cell organelles are incorporated into the forming merozoite. The posterior pole of the merozoite still remains open at this stage of development. With increasing differentiation the merozoites become lancet-shaped, their apical poles bing always directed towards the periphery of the schizont. The outer membrane of the pellicle of the schizont forms the outer part of the pellicle of the merozoites by invaginating around them. At this stage of development the inner membrane of the pellicle of the schizont is no longer detectable. Thus the typical pellicle of the motile stages of sporozoaonsisting of three membranes is formed. In the centre of the merozoites which lie freely in the liver cell a residual body is present. The host cell reacts against the parasites by forming a thick border of mitochondria and distinct endoplasmic reticulum.     

Effect of redox and chelating agents on the properties of chloroplast ATPase

The effect of redox and chelating reagents on the ATPase and ATP-synthetase activity in chloroplast membranes as well as the ATPase activity of isolated CF1-coupling factor from chloroplasts has been studied. The Mg2+-ATPase in thylakoid membranes and isolated Ca2+-ATPase is stimulated by dithionite. In the presence of reduced glutathione the effect of dithionite is similar to those of prolonged illumination or heating. Dichlorophenolindophenol partially inhibits this activity as well as citrate, tenoyltrifluoroacetone and the excess fo ATP. Photophosphorylation in chloroplast lamellae is inhibited with dithionite. It is suggested that the membrane bound ATPase from chloroplasts may be in two structural states which differ in their enzymic activity and in the coupling to electron transfer in membrane. The transitions between these states can be induced by redox reagents.     

Study of amino acid composition and biosynthesis of protein components of the membrane system of corn plastids during biogenesis of chloroplasts]

The biosynthesis of membrane proteins in maize plastids at different stages of differentiation of the chloroplast lamellar system was studied. Prolamellar and lamellar system preparations were isolated from maize plastids, disintegrated by osmotic shock under hypotonic conditions. Changes in the amino acid composition of 14C membrane proteins were observed at all stages of chloroplast ultrastructure formation. The maximal level of the apolar amino acids was observed in the membrane fraction of chloroplasts. Washed membranes from maize proplastids and chloroplasts can be resolved into at least 14 protein bands on formic acid--urea polyacrylamide gel. It is pointed out that biogenesis process leads to the increase of lipophylic protein content in the chloroplast lamellae fraction.     

Cryofracture electron microscopy of the ookinete pellicle of Plasmodium gallinaceum reveals the existence of novel pores in the alveolar membranes

The malaria parasite invades the midgut tissue of its mosquito host as a motile form called the ookinete. We have examined the pellicle of the ookinete of Plasmodium gallinaceum by freeze-fracture and quick-freeze, deep-etch electron microscopy. The general organization is analogous to that of invasive stages of other members of Apicomplexa. The pellicle is composed of three membranes: the plasma membrane, and the two linked intermediate and inner membranes, which in the ookinete form one flattened vacuole that is located beneath the plasma membrane. The edges of this vacuole form a longitudinal suture. Beneath the vacuole is found an array of microtubules that are connected to the inner membrane by intramembranous particles. During freeze-fracture, the membranes can split along their hydrophobic planes, thus yielding six fracture faces, each of which displays a characteristic pattern of intramembranous particles. Additionally, we find that the ookinete pellicle differs from all other apicomplexan motile stages by the presence of large pores. These pores are of unknown function, but clearly might constitute a novel pathway for the transport of molecules to and from the cortex, which is independent of the well-described route through the apical micronemal/rhoptry complex. The pores may be the route by which motor proteins or other non micronemal surface proteins are trafficked, such as P25/P28 and SOAP, some of which are implicated in transmission blocking immunity.     

La Structure Fine de Chlorogonium elongatum. I. Etude Systematique au Microscope Electronique.

The flagellate Chlorogonium elongatum has been studied in the electron microscope by thin-sectioning techniques. The nucleus, limited by a porous membrane, contains a large nucleolus and some dense masses, probably of chromatin. When the medium is rich or the culture young, the chloroplast has few lamellae, and very few pyrenoids. Inversely, when the medium is poor or jthe culture old, the lamellae are abundant, appearing as piled discs or as a tortuous lamellar system. The pyrenoids are then numerous and are surrounded by starch grains. They are composed of an opaque, finely granular substance, and are never traversed by chloroplast lamellae. The stigma, within the chloroplast, is a circular or oval plate composed of a single tier of dense granulations. The cytoplasm contains mitochondria which are concentrated near the pellicle of the cell, an endoplasmic reticulum, an abundance of ribo-nucleoprotein particles or ribosomes, and a Golgi apparatus. These organelles resemble those observed in other protozoa. The two fiagella are encased in cylinders situated at the anterior end of the cell. At the base of the fiagella are the basal corpuscles or kinetosomes, which repose within a cupule. A dense granule which probably corresponds to the centrosome appears near this structure.     

ONTOGENY,HISTOCHEMISTRY AND FINE STRUCTURE OF CELLULAR INCLUSIONS IN VEGETATIVE CELLS OF ANTITHAMNION DEFECTUM (CERAMIACEAE,RHODOPHYTA)1

The ultrastructure and histochemistry of developing and mature cell inclusions in vegetative cells of Antithamnion defectum Kylin were examined. Those studied were chloroplast inclusions, cytoplasmic crystals and spherical bodies within the vacuole. Chloroplasts of mature vegetative cells contain an interthylakoidal, apparently noncrystalline deposit of undetermined chemical identity. The bodies are parallel to the long axis of the plastid, are square (0.13 μm) in cross-section, and up to 3 μm long. Spherical vacuolar bodies (0.5–1.5 μum diam) are formed during early stages of vacuole formation by accumulation of protein deposits in swelling endoplasmic reticulum (ER) cisternae. Swelling of smooth ER contiguous to the ER containing the deposits results in the vacuole enclosing the spherical bodies. In mature cells, vesicles appear to be secreted into the preformed vacuole. Cytoplasmic proteinaceous crystalloids develop without a bounding membrane and may serve as protein reserves.     

Ultrastructural Localization of Adenosine Triphosphatase Activity in Cotyledon Cells of Tomato and Its Changes during Chilling Stress

The ultrastructural localization of adenosine tripkosphatase (ATPase) activity in cotyledon cells of tomato was carried out by use of the cytochemical method of lead phosphate precipitation, and the changes in ATPase activity during chilling stress of the tomato seedlings were studied. The following experimental results have been obtained: 1. The ATPase activity in the cotyledon cells of tomato seedlings germinated and grown at 28 ℃. was located at plasmolemma, plasmodesmata, nucleoli and nuclear chromatin chloroplast lamellae, many sites of cell wall, and the surface of cell wall bordering the intercellular spaces and their inclusions. 2. When the tomato seedlings were subjected to chilling treatment for 4 h. at 5 ℃., the ATPase activity in cotyledon cells was indifferent from that of non-chilling treated seedlings. After chilling treatment for 12 h. at 5 ℃., the reaction of ATPase activity at plasmolemma, and in cell wall and intercellular spaces was markedly reduced. though the high activity reaction of ATPase in nuclei and at chloroplast lamellae was still maintained. When the tomato seedlings were subjected to chilling stress for 24 h. at 5℃., the ATPase activity at plasmolemma and in cell wall was almost inactivated, while the ATPase activity in nuclei and at chloroplast lamellae was only slightly lowered. These results indicated that the chilling injury may influence firstly on the ATPase activity of cell surface (plasmolemma and cell wall). 3. The role of intercellular spaces used as the passage of materials and the process and mechanism of chilling injury are discussed.     

Cytochemical localization of ATPase in axon-myelin-Schwann cell complex type

ATPase activity was studied in the structures of axon-myelin-Schwann cell complex of sciatic nerves of rabbits of pre-and postnatal development. Positive reaction was observed on the plasma membrane, mitochondria and endoplasmic reticulum of Schwann cells, on the intraperiod lines of the compact myelin, in the split myelin lamellae in the paranodal regions and Schmidt-Lanterman clefts, in segment of outermost lamellae split off from the interparanodal myelin, in the mesaxons, in the loose myelin lamellae in the earlier stages of myelinization, on the axolemma (periaxonal space) and axoplasm. The ATPase activity on the Schwannian plasmalemma, axolemma and myelin sheath surface was found to be heterogeneously distributed. An accumulated of reaction deposits at the origin of the outer mesaxon, at the axoglial contacts as well as at the terminal part of the myelin sheath was respectively observed. Alterations of the enzyme activity distribution in axon-myelin-Schwann cell complex during rabbit's development were found to be associated with the growing myelin sheath and its node-paranode. Using controls with ouabain an attempt was made the possibilities of Wachstein and Meisel's method to be shown and the place of alpha+ form of Na+, K+-ATPase in the axon-myelin-Schwann cell Complex to be establish.     

注入碳离子对甜菊的生物学效应

对甜菊（Ｓｔｅｖｉａ ｒｅｂａｕｄｉａｎｕｍ Ｂｅｒｔｏｎｉ）种子注入能量为７５ｋｅＶ、剂量为１０＾１４／ｃｍ＾２的碳离子,研究其种子萌发期产生的一系列生物学效应。注入碳离子的种子萌发率略高于对照组,但种苗的成活率比对照组低（Ｐ〈０．０２）。运用假设检验法分析,结果表明注入离子的种子出苗株高显著高于对照组（Ｐ〈０．０１）。萌发４ｄ的处理组,叶片细胞壁增厚,胞间连丝扩大,内有高电子工的物质沉积,细胞     

水平回转对水稻幼苗叶细胞的影响

对在模拟微重力装置上回转１４ 天的水稻幼苗叶细胞进行了亚显微形态、电子探针和细胞酶化学研究。发现叶细胞质膜上Ｃａ２＋ －ＡＴＰ酶活性消失,膜内钙总量上升、膜外钙总量下降,细胞骨架变得疏松,细胞壁变薄并凹凸不平。叶绿体的基粒和线粒体的内嵴亦有部分变化。其变化机制,首先是细胞质膜上Ｃａ２＋ －ＡＴＰ酶活性消失,膜上钙泵停止工作,跨膜钙浓度差减小,膜内钙浓度上升,微管、微丝聚合受阻,细胞骨架疏松,分泌泡移动失去导向,从而导致细胞壁变薄等状态     

Immunohistological classification of ionocytes in the external gills of larval Japanese black salamander,Hynobius nigrescens Stejneger

In this cytological and immunohistological study, we clarified the localization of the membrane transporters Na⁺, K⁺‐ATPase (NKA), vacuolar‐type H⁺‐ATPase (VHA), and epithelial sodium channel (ENaC) and distinguished ionocyte subtypes in the gill of the Japanese salamander (Hynobius nigrescens). In larvae (IY stages 43–65), NKA immunoreactivity was observed on the basolateral plasma membrane in more than 60% cells and less than 20% cells in the primary filaments and secondary lamellae of the external gills, respectively. VHA immunoreactivity was observed on the apical membrane of some epithelial cells in the secondary lamellae of the external gills. High ENaCα immunoreactivity was widely observed on the apical cell membrane of a population of squamous cells, presumably pavement cells (PVCs), and mitochondria‐rich cells (MRCs), in the primary filaments and secondary lamellae of the external gills. Using double immunofluorescence microscopy, epithelial cell types involved in ionic regulation were characterized and divided into three ionocyte types: NKA‐, NKA‐ and ENaC‐, and VHA‐positive cells. VHA‐immunoreactive cells as well as NKA‐positive cells were observed during IY stages 43–65 of the salamander larvae. During late stages of metamorphosis, NKA, VHA, and ENaCα immunoreactivities in the external gills decreased and finally disappeared during the completion of metamorphosis (IY stage 68). PVCs and MRCs in the external gills are probably involved in acid–base balance regulation and osmoregulation in urodele amphibian larvae. The results are discussed in relation to the ionocytes previously reported in fish gills and the frog skin epithelium. J. Morphol., 2011. © 2011Wiley‐Liss, Inc.     

Biological Effects of Stevia rebaudianum Induced by Carbon Ion Implantation

The biological effects during seed germination were investigated after the dry seeds of Stevia rebaudianum Bertoni were implanted with carbon ion beam of 75 keV and 10 14 ions/cm 2. The results showed that the germination rate of carbon ion implanted seeds was slightly higher than that of the control, but the survival rate of the treated seedlings, on the contrary, was lower than that of the control (P <0.02), while the height of the treated seedlings was significantly higher than that of the control (P <0.01). On the 4th day after germination, the leaf cell wall in the treated group was thick, some high electron-dense substance deposited in the enlarged plasmodesma; Cell membrane reased with high electron-dense granules deposited on it. The plasma membrane protruded towards cell wall, and the granules shifted via plasmodesma or deposited onto cell wall. These phenomena may be related to the conveyance of implanted ions across cell wall, or be related to the accumulation of callose. In addition, the implantation of carbon ions could increase the lamellae of the chloroplast and cause high development of the chloroplast which sometimes contained two plastid centers in an individual chloroplast. Also, the highly developed cristae, abundant mitochondria and typical crystalloid structure in microbody could be found. All these results indicated that the anabolic and catabolic activities in the seedlings implanted with carbon ions before germination were obviously more active than those in the controls.