Silica bodies and their systematic implications in Pteridaceae (Pteridophyta)

Wet ashing was used to study the occurrence of silica bodies in the fern family Pteridaceae. They were recovered in 48 of the 77 species examined. Silica bodies of Pteridaceae are elongate, ranging from 90–1320 × 5–40 µm, linear to elliptic, with blunt or acute apices and smooth to sinuate sides. All previous records of silica bodies and venuloid idioblasts among Pteridaceae that were examined were confirmed by the results of this study, corroborating our assumptions regarding the presence of silica bodies. In contrast, assumptions regarding the absence of silica bodies were incorrect; in many species of Adiantum, for example, silica bodies are present but cannot be seen with the naked eye. Farris optimization demonstrates that the distribution of epidermal silica bodies is homoplastic within Pteridaceae, but that they act as a potential synapomorphies for several different groups within the family. These include the adiantoid clade: Adiantum and the 11 vittaroid genera, and in some pteridoid fern clades such as the sister pair Onychium and Actiniopteris and the genus Pityrogramma. They are also present in Pterozonium brevifrons and some species of the polyphyletic genus Pteris. Among cheilanthoid ferns, they were found in Mildella intramarginalis and two species of Aspidotis. Morphology of silica bodies differs between major lineages, reflecting their independent origins. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 161 , 422–435.     

The number and distribution pattern of Golgi bodies in cells of Micrasterias (Conjugates, Chlorophyta) examined by fluorescence microscopy and electron microscopy

The number and the distribution pattern of Golgi bodies in cells of Micrasterias americana and Micrasterias crux-melitensis were examined both by fluorescence microscopy and by electron microscopy. Golgi bodies intensely absorbed the fluorescent dye DiOC6(3) and strongly radiated fluorescent light. The number of Golgi bodies nearly doubled before septum formation, and half of the Golgi bodies entered each sister cell. Many Golgi bodies migrated from the non-growing half-cell to the growing half-cell where new cell walls were actively being synthesized. Most Golgi bodies were not in contact with chloroplasts in the growing half-cell. Half of the Golgi bodies moved back to the non-growing half-cell 6–12 h after completion of the new half-cell. Golgi bodies were in contact with the surfaces of chloroplasts 12 h after full growth.     

Preliminary Investigation on Protein Bodies of Soybean Seeds

With the purpose of separation and isolation of protein bodies from soybean, soybean seeds were homogenized in oil and fractionated by successively adjusting densities of extracts with carbon tetrachloride. Isolated protein bodies consist of about 10% nitrogen, 0.8% phosphorus, 8.5% sugar, 7% ash and 0.5% RNA. Over 93% of protein in the bodies is found as particle-bound protein which is insoluble in 15% Carbowax 6000 solution but soluble in 10% sodium chloride solution. Protein bodies in intact cells, isolated bodies and those treated with Carbowax 6000 solution were respectively observed by electron-microscopy.     

A study of the ultrastructure of the shoot apex and leaf cells in two liverworts,with special reference to the oil bodies

Summary In this investigation attention has been paid to the general ultrastructure of the shoot apical and leaf cells in the liverwortsBazzania trilobata andLophozia ventricosa but especially to the different developmental stages of their oil bodies. These species have been chosen because their oil bodies differ from each other in size and shape.The appearance of the different organelles, nucleus, chloroplasts, mitochondria, ER, and Golgi bodies, are in their main features the same as those of higher plants described in the literature. The dark cytoplasm seen in the leaf cells ofLophozia in the vicinity of the oil bodies but without any surrounding membrane when fixed in double fixative 2, seems to be specific to this species. On the other hand, granular dense bodies were visible in the cells of the shoot apex ofBazzania, which shrank in size as the development of the oil bodies proceeded and were lacking in the mature leaf cells.In both species investigated, the oil bodies have the same component parts: (1) an outer membrane enveloping the whole body, (2) inside this, a granular stroma layer of varying thickness enveloping (3) specific globules of varying size and number, each of which is surrounded by (4) a thin inner membrane (Fig. 28).The oil bodies develop in at least two ways and usually in one way for each species. InBazzania they seem to develop from vacuole-like formations in the shoot apex or in the leaf primordia into which substances have segregated. InLophozia they seem to originate by aggregation and fusion of lipid bodies.     

NEW ULTRASTRUCTURAL ASPECTS OF PYRENOIDS OF THE LICHEN PHOTOBIONT TREBOUXZA (MICROTHAMNIALES,CHLOROPHYTA)1

The pyrenoid structure of Trebouxia, a photobiont of two lichen species, Umbilicaria cinereorufescens (Schaer.) Frey and Parmelia sulcata Taylor, was investigated. In both lichen species, the pyrenoid of the photobiont exhibited straight, unbranched, long or short tubules. In the first lichen species, multiple pyrenoids were observed occasionally, while in the second one, homogeneous masses, called protein bodies, appeared between the thylakoids. These protein bodies were previously observed in some other species of the family Umbilicariaceae. Serial sections from single pyrenoids showed that tubules of the Impressa-type pyrenoid were closely associated with pyrenoglobuli. The three-dimensional reconstruction of a complete chloroplast of a P. sulcata algal cell showed that the protein bodies were spatially separate structures. Immunolocalization techniques to detect the presence of ribulose-bisphosphate carboxylase (Rubisco) in the chloroplast showed that this enzyme was present primarily in the pyrenoid matrix. When protein bodies were present in the chloroplast, Rubisco appeared to be localized in these structures. The presence of pyrenoid satellites and protein bodies with reactivity to anti-Rubisco may be related to the nutritional conditions of the thalli.     

OCCURRENCE OF TRI-LAMELLAR BODIES IN ISOLATES OF NOSTOC (CYANOPHYCEAE)1

Tri-lamellar bodies were observed in eight of 29 isolates of Nostoc examined. They appeared identical to the previously described bodies in various species of Anabaena. The bodies consist of three discoid lamellae each ca. 0.3 μm diam and 8 nm thick. The outer lamella (closest to the plasma membrane) is separated from the middle lamella by a 12 nm space whereas the middle and inner lamellae are ca. 8 nm apart. Osmiophilic striations 3 nm wide were generally observed running between the lamellae. Osmiophilic β granules were usually associated with the inner lamella. The bodies were most always located close to the plasma membrane along the longitudinal wall near the junction of the cross and longitudinal walls. In three isolates the bodies located near the cross walls were associated with gas vesicles and possessed a slightly different morphology. These tri-lamellar bodies consisted of three discoid lamellae, each ca. 2 nm thick, ca. 25 nm apart with electron dense material between the inner and middle lamellae. Pores 20 nm diam and ca. 60 nm apart were observed in layer 2 of the cell wall adjacent to the tri-lamellar bodies. These wall pores were also observed in isolates lacking tri-lamellar bodies.     

Changes in the absolute configuration of the basal/flagellar apparatus and evidence of centrin during male gametogenesis in Chara contraria var. nitelloides (Charales, Charophyta)

The absolute configurations of the basal/flagellar apparatus during male gametogenesis of Chara contraria var. nitelloides (Charales, Charophyta) were carefully analysed. Emphasis was placed on the changes in the angles and lengths of the basal bodies, the microtubular root angles and the development of the distal as well the proximal connecting fibers. Six principal stages were recognized: a) parallel, non-axonemal, developing basal bodies connected by a non-striated, proximal fiber; b) non-parallel, non-axonemal, mature basal bodies connected by a developing, striated, distal fiber; c) non-parallel, axonemal basal bodies connected by a fully developed, striated, distal fiber; d) opposite, axonemal basal bodies not connected by fibers, e) axonemal basal bodies not connected by fibers and directed backwards and f) parallel, axonemal basal bodies not connected by fibers. A headpiece, a 3-membered root and a reduced multilayered structure developed during ontogeny. The initial parallel disposition of the basal bodies, the initial lack of MLS and the presence of only two microtubular roots from the very inception of the basal apparatus development, suggest a Mamiella-like ancestor for Charales. Ontogenetic evidence supports previous ideas in the sense that similarities of sperm morphology of charalean and bryophytan gametes are likely due to convergent evolution. In addition, the present study clearly reveals the presence of centrin in Charales.     

Composition of nuclear dense bodies and nucleolus-associated bodies in interphase nuclei of the unicellular green alga Chlamydomonas reinhardtii

Summary— The interphase nucleus of the green alga, Chlamydomonas reinhardtii, displayed two types of bodies some of them, the dense bodies, lying apparently free in the nucleoplasm while the others were attached to the nucleolus and were, therefore, referred to as nucleolus-associated bodies (NABs). The presence of DNA, RNA and histones in dense bodies was investigated by means of post-embedding immunocytochemistry and cytochemistry using a monoclonal antibody to single and double stranded DNA, a polyclonal antibody to rye H3 histones and RNase A-gold complexes. The dense bodies were shown to contain significant amounts of RNA but neither DNA nor histones were detected; their composition was thus similar to that of the dense bodies described in higher plant cells. We propose that dense bodies might be implicated in the assembly of the 25 to 45 nm granules observed throughout the nucleoplasm of Chalamydomonas interphase nuclei. The composition of NABs was found to be distinct from that of the dense bodies since they were labeled by the antibody to DNA, specially in cryofixed and cryosubstituted specimens. The presence of DNA in NABs together with their intimate association to the nucleolus suggest that they may correspond to specific segments of chromosomes.     

Elevation of oil body integrity and emulsion stability by polyoleosins,multiple oleosin units joined in tandem head‐to‐tail fusions

We have successfully created polyoleosins by joining multiple oleosin units in tandem head‐to‐tail fusions. Constructs encoding recombinant proteins of 1, 3 and 6 oleosin repeats were purposely expressed both in planta and in Escherichia coli. Recombinant polyoleosins accumulated in the seed oil bodies of transgenic plants and in the inclusion bodies of E. coli. Although polyoleosin was estimated to only accumulate to <2% of the total oil body protein in planta, their presence increased the freezing tolerance of imbibed seeds as well as emulsion stability and structural integrity of purified oil bodies; these increases were greater with increasing oleosin repeat number. Interestingly, the hexameric form of polyoleosin also led to an observable delay in germination which could be overcome with the addition of external sucrose. Prokaryotically produced polyoleosin was purified and used to generate artificial oil bodies and the increase in structural integrity of artificial oil bodies‐containing polyoleosin was found to mimic those produced in planta. We describe here the construction of polyoleosins, their purification from E. coli, and properties imparted on seeds as well as native and artificial oil bodies. A putative mechanism to account for these properties is also proposed.     

CHARACTERIZATION OF VACUOLAR BODIES IN SPARTINA ALTERNIFLORA: I. FORMATION,DEVELOPMENT, MORPHOLOGY,AND ULTRASTRUCTURE

Spherical, golden bodies, 0.5 to 25 μm in diameter, were noted in outer bundle sheath and mesophyll of cells of fresh sections of Spartina alterniflora leaves. Attempts to further characterize these structures with light and electron microscope (EM) techniques after dehydration failed initially because these bodies were soluble in organic solvents such as alcohol. Subsequently, it was found that certain heavy metals would stabilize the structure so that dehydration techniques could be used. The resultant stabilized bodies as viewed with EM were found to reside in the cell vacuole. Two major structural components were recognized: (1) a granular matrix and (2) a non-electron dense internal vesicle. Internal vesicles were not always present. No membranes were visible with this technique. These vacuolar bodies also were found to occur in parenchyma cells of roots, peduncles, glumes, and rhizomes of S. alterniflora. The material which forms the vacuolar body matrix is probably produced in the cytoplasm and gradually accumulates in the vacuole, forming larger and more numerous vacuolar bodies during the growing season. The matrix material remains in the leaf cells following their senescence.     

Cytochemical and histochemical characterization of cotyledonary bodies fromPharbitis nil seedlings

Summary Cytological and histochemical characterization of the structures from which an obscure substance is secreted via open stomata to the abaxial surface of Japanese morning glory (Pharbitis nil Choisy cv. Violet) cotyledons has been carried out. Observation of intact cotyledons using the light microscope revealed randomly distributed semi-transparent structures. These structures, which were shown to be the same as those previously described as giant oil cells are referred to here as cotyledonary bodies. These bodies can be easily isolated and purified after enzymatic digestion of the cotyledons. Using different staining procedures we have confirmed that each cotyledonary body originates from an individual mesophyJl cell during embryo development. Purified bodies consist of (i) a thick shell-like envelope; (ii) a transparent, hydrophilic zone; (iii) a hydrophobic core. Hydrophobic contents of the bodies were readily extracted with methanol and shown to contain fatty acids and phenolic compounds using the gas chromatography/mass spectrometry (GC/MS) technique. Methanolic extracts of cotyledonary bodies showed high fluorescence with two excitation and emission maxima. Using a fluorescence microscope we have shown that the bodies isolated from seedlings grown in continuous light, conditions non-inductive for flowering, and those grown under conditions inductive for flowering (a single 16 h, long dark period) have different fluorescence emission spectra. Different levels of free Ca²⁺ inside cotyledonary bodies isolated from light-grown and single dark-period treatedP. nil seedlings were found using the fluorescent calcium indicator dye Fluo-3 under a confocal scanning laser microscope. On the basis of these observations we speculate that cotyledonary bodies could be involved in floral induction.     

Purification of the Endospores and Sporangia of Rhinosporidium Seeberi on Percoll Columns

Human rhinosporidial tissue was used as the source of the various developmental stages of Rhinosporidium seeberi - endospores with electron dense bodies, juvenile, and immature sporangia. After homogenisation in phosphate buffered saline (PBS) and removal of tissue fragments by centrifugation, the rhinosporidial bodies were isolated on centrifuged Percoll columns with gradients of densities or on triple-layered columns of varying density. The separated bands, after repeated washing in PBS gave bodies free from human tissue as shown on Leishman and PAS staining and indirect immunofluorescence with rabbit and human patients' anti-rhinosporidial sera. Sonicates of these bodies were tested on agarose gel for precipitation with antisera, and on SDS-PAG electrophoresis and Coomassie Blue staining. Percoll columns were shown to be capable of isolating these stages of R. seeberi, free from human tissue and contaminating bacteria. This revised version was published online in June 2006 with corrections to the Cover Date.     

不同分离方法对子实体形成和粘细菌分离的影响

【目的】基于模拟原位环境策略、可培养粘细菌的营养策略及细菌互作网络,改良分离培养基,以提高分离粘细菌的多样性。【方法】通过添加土壤浸提液、使用不同种类的诱导菌和改变诱导菌的接种方式设置分离方法,同时以传统的分离方法作对照。【结果】改良的分离方法比对照组诱导出了更多粘细菌子实体种类,采自4个地区的9份样品共分离纯化出40株粘细菌,按形态学和分子生物学,将其归类于原囊菌属(Archangium)、珊瑚菌属(Corallococcus)、软骨霉状菌属(Chondromyces)、粘球菌属(Myxococcus)、侏囊菌属(Nannocystis)、多囊菌属(Polyangium)、匣状球菌属(Pyxidicoccus)。【结论】与传统分离方法相比,添加土壤浸提液,诱导菌点接法能大大提高诱导出的粘细菌子实体种类的数目,革兰氏阳性菌和革兰氏阴性菌作为诱导菌对子实体种类影响较小,但是也发现革兰氏阳性菌特异性诱导出的子实体。虽然本研究通过对分离培养基的改良大大增加了子实体种类,但是纯化出的粘细菌种类远少于观察到的子实体种类,说明除改良分离方法外,还需进一步研究粘细菌的纯化方法,提高分离所得粘细菌的多样性,获取更多粘细菌新资源。     

Autophagy contributes to degradation of Hirano bodies

Hirano bodies are actin-rich inclusions reported most frequently in the hippocampus in association with a variety of conditions including neurodegenerative diseases, and aging. We have developed a model system for formation of Hirano bodies in Dictyostelium and cultured mammalian cells to permit detailed studies of the dynamics of these structures in living cells. Model Hirano bodies are frequently observed in membrane-enclosed vesicles in mammalian cells consistent with a role of autophagy in the degradation of these structures. Clearance of Hirano bodies by an exocytotic process is supported by images from electron microscopy showing extracellular release of Hirano bodies, and observation of Hirano bodies in the culture medium of Dictyostelium and mammalian cells. An autophagosome marker protein Atg8-GFP, was co-localized with model Hirano bodies in wild type Dictyostelium cells, but not in atg5- or atg1-1 autophagy mutant strains. Induction of model Hirano bodies in Dictyostelium with a high level expression of 34 kDa ΔEF1 from the inducible discoidin promoter resulted in larger Hirano bodies and a cessation of cell doubling. The degradation of model Hirano bodies still occurred rapidly in autophagy mutant (atg5-) Dictyostelium, suggesting that other mechanisms such as the ubiquitin-mediated proteasome pathway could contribute to the degradation of Hirano bodies. Chemical inhibition of the proteasome pathway with lactacystin, significantly decreased the turnover of Hirano bodies in Dictyostelium providing direct evidence that autophagy and the proteasome can both contribute to degradation of Hirano bodies. Short term treatment of mammalian cells with either lactacystin or 3-methyl adenine results in higher levels of Hirano bodies and a lower level of viable cells in the cultures, supporting the conclusion that both autophagy and the proteasome contribute to degradation of Hirano bodies.     

The formation of perinucleolar bodies is important for normal leaf development and requires the zinc‐finger DNA‐binding motif in Arabidopsis ASYMMETRIC LEAVES2

In Arabidopsis, the ASYMMETRIC LEAVES2 (AS2) protein plays a key role in the formation of flat symmetric leaves via direct repression of the abaxial gene ETT/ARF3. AS2 encodes a plant‐specific nuclear protein that contains the AS2/LOB domain, which includes a z inc‐f inger (ZF) motif that is conserved in the AS2/LOB family. We have shown that AS2 binds to the coding DNA of ETT/ARF3, which requires the ZF motif. AS2 is co‐localized with AS1 in perinucleolar bodies (AS2 bodies). To identify the amino acid signals in AS2 required for formation of AS2 bodies and function(s) in leaf formation, we constructed recombinant DNAs that encoded mutant AS2 proteins fused to yellow fluorescent protein. We examined the subcellular localization of these proteins in cells of cotyledons and leaf primordia of transgenic plants and cultured cells. The amino acid signals essential for formation of AS2 bodies were located within and adjacent to the ZF motif. Mutant AS2 that failed to form AS2 bodies also failed to rescue the as2‐1 mutation. Our results suggest the importance of the formation of AS2 bodies and the nature of interactions of AS2 with its target DNA and nucleolar factors including NUCLEOLIN1. The partial overlap of AS2 bodies with perinucleolar chromocenters with condensed ribosomal RNA genes implies a correlation between AS2 bodies and the chromatin state. Patterns of AS2 bodies in cells during interphase and mitosis in leaf primordia were distinct from those in cultured cells, suggesting that the formation and distribution of AS2 bodies are developmentally modulated in plants.     

Stored cysteine proteinases start globulin mobilization in protein bodies of embryonic axes and cotyledons during vetch (Vicia sativa L.) seed germination

Inhibition of protein synthesis by cycloheximide during vetch seed germination, did not prevent globulin breakdown as indicated by a decrease in vicilin- and legumin-specific immunosignals on Western blots. Protein bodies isolated from embryo axes and cotyledons of dry vetch (Vicia sativa L.) seeds using a non-aqueous method were found to be free of cytoplasmic and organellar contaminations. Lysates of these purified protein bodies were capable of degrading globulins; this process was blocked by the cysteine proteinase (CPR) inhibitor iodoacetic acid. Protein bodies contained the papain-like CPR2 and CPR4, and the legumain-like CPR VsPB2. In vitro assays showed that albumin extracts from protein bodies degraded oligopeptide substrates in the PepTag-Assay and degraded the legumain substrate N-benzoyl-asparaginyl-p-nitroanilide. We conclude that, during germination, globulin mobilization is initiated by stored CPRs in protein bodies of embryonic axes as well as cotyledons, and that de-novo-formed proteolytic enzymes mainly mediate bulk degradation of stored globulin in cotyledons after germination. Received: 14 February 2000 / Accepted: 16 August 2000     

人工疏蕾对杏鲍菇产量及品质的影响

【背景】工厂化栽培中,杏鲍菇是不定点出菇,通常采用人工疏蕾的方法来实现对子实体数目的控制,但目前关于人工疏蕾保留子实体的数目无具体的研究。【目的】通过人工疏蕾的方式,研究保留不同子实体数目对杏鲍菇产量及品质的影响。【方法】对各处理组进行基质利用情况测定,对采收后各组子实体进行产量、形态指标及质构特性的测定。【结果】保留3—4个子实体的基质利用率较高,在生产实际中对成本的浪费较少;保留不同子实体数目对子实体形态指标、单菇重量及单包产量都有显著影响,保留1个子实体时,单菇重量最大但单包产量最低,保留4个子实体时,单包产量较高且子实体形态一致;从质构特性来看,保留子实体数目为4个时,杏鲍菇子实体品质最好、口感最佳。【结论】在杏鲍菇工厂化生产的人工疏蕾环节,保留子实体数目为3—4个时可以减少对成本的浪费,获得产量较高、品质较好的产品。     

Ultrastructure and phylogenetic relationships of the unicellular green algae Ignatius tetrasporus and Pseudocharacium americanum (Chlorophyta)

The phylogenetic relationships of two unicellular green algae, Ignatius tetrasporus Bold et MacEntee and Pseudocharacium americanum Lee et Bold were investigated by ultrastructural and molecular methods. The zoospores from both species were covered neither by scales nor cell walls. The flagellar apparatus of the zoospores commonly included these features: the upper basal bodies were displaced counterclockwise in half to two‐thirds of the basal body diameter and did not overlap with each other; the lower basal bodies were directly opposed or slightly displaced clockwise; the distal fiber had gently sigmoid central striations; terminal caps were absent from the ends of the basal bodies; a V‐shaped proximal sheath extended from the upper basal bodies; a posterior fiber lay between the opposite lower basal bodies; and the coarsely striated band linked the sinister rootlet to the lower basal body. The suite of these features was not identical to that of any other quadriflagellate swimming cells, but some features including the lower basal body orientation, the striated distal fiber, and the coarsely striated fiber resemble those of the several organisms of the Siphonocladales sensu Floyd and O’Kelly. Phylogenetic analysis using 18S rDNA sequence data revealed that I. tetrasporus and P. americanum formed a monophyletic clade within the clade of Ulvophyceae sensu López‐Bautista and Chapman, but was not nested within any of the orders of the class that were examined.     

PEARL BODIES OF A NEOTROPICAL TREE,OCHROMA PYRAMIDALE: ECOLOGICAL IMPLICATIONS

Multicellular, spherical or club-shaped pearl bodies characterized by large intracellular lipid vesicles are produced on leaves and stems of juvenile Ochroma pyramidale, a tree of second growth vegetation in lowland wet forest of the neotropics. Several lines of evidence suggest that pearl bodies are linked to maintenance of foraging ants on the plant: (1) their production is closely associated with foliar nectar secretion; (2) they are abundant on saplings grown in the glasshouse (averaging 402 bodies leaf^–1) but were not observed in the field where ants are predictably associated with Ochroma samplings; (3) pearl bodies are energy- and lipid-rich averaging 27.80 kJ/g dry wt^–1 and 74.4% lipid; (4) they are constricted at the base and easily detach from the leaf; (5) four ant species collect pearl bodies from artificial depots and return them to their nests. Chelaner sp. detaches pearl bodies from the leaf and returns them to the nest. Production of pearl bodies represents about 25% of the energy allocated to foliar nectar by saplings. Characteristics of the pearl bodies of Ochroma are consistent with those of a widespread group of trichomes and leaf emergences suggesting a common ecological role as ant food for these structures.     

Influence of Regulatory Genes of Type 1 Human Immunodeficiency Virus on Proliferation and Differentiation of Murine Embryonic Stem Cells

Spontaneous formation of embryoid bodies and subsequent differentiation of some cells into cardiomyocytes were demonstrated on murine embryonic stem cells of R1 line. The lines of embryonic stem cells were obtained that had been transfected with genetic constructs carrying expressing regulatory genes of the human immunodeficiency virus tat and nef and green protein gene (GFP). The transfection of embryonic stem cells with the gene tat stimulated their proliferative activity, while this activity decreased in the cells transfected with the gene nef. The time necessary for the formation of embryoid bodies by all lines of transfected cells was similar to that in the control cells. In the cultures of cells transfected with nef and tat, the number of embryoid bodies and the percentage of embryoid bodies with contracting cardiomyocytes were higher and lower than in the control, respectively. Thus, an inverse correlation was observed between the effects of regulatory genes of the human immunodeficiency virus on proliferation and differentiation embryonic stem cells.