Photosynthetic Lamellae Research Articles

An electron microscope study of infection by the blue-green algal virus SM-1

The morphology of unicellular blue-green algae ( Synechococcus) infected with virus SM-1 has been studied in thin sections prepared at various times during the 48 hr required for one cycle of virus growth. No changes in the photosynthetic lamellae are seen prior to lysis, in contrast to the extensive invagination observed in other blue-green algal virus systems. SM-1 virions accumulate in the nucleoplasm; at last times the entire space interior to the photosynthetic lamellae is packed with virus particles. Forms that could be precursors of complete particles have been identified; these include apparently empty heads and condensed “cores.” One or both of these forms could be artifacts of preparation.

Crystal and molecular structure of methyl pheophorbide with applications to the chlorophyll arrangement in photosynthetic lamellae

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal and molecular structure of methyl pheophorbide with applications to the chlorophyll arrangement in photosynthetic lamellaeMark S. Fischer, David H. Templeton, Allan Zalkin, and Melvin CalvinCite this: J. Am. Chem. Soc. 1972, 94, 10, 3613–3619Publication Date (Print):May 1, 1972Publication History Published online1 May 2002Published inissue 1 May 1972https://doi.org/10.1021/ja00765a059RIGHTS & PERMISSIONSArticle Views204Altmetric-Citations69LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (751 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Further studies on the oxygen-reducing system of Anabaena variabilis

Photosynthetic lamellae from Anabaena variabilis accumulate a reductant when illuminated with an electron donor under anaerobic conditions. This reductant, the oxygen-reducing substance, is autooxidizable and both its formation and oxidation can be altered by substances which interact with Photosystem 1. Cyclic electron flow can be made to compete with oxygen for the reducing power generated by the photoact. The specificity of the lamellae toward electron donors can be altered by the detergent Tween 20. Using the procedure of Fujita and Meyers ( Plant Cell Physiol., 7 (1966) 599) for the isolation of the cytochrome-reducing substance, a substance can be reversibly removed from the lamellae which appears to be involved in oxygen reduction and in the oxidation of endogenous cytochromes by Photosystem 1. This material appears to be similar to the cytochrome-reducing substance, to the ferredoxin-reducing substance of Yocum and San Pietro ( Biochem. Biophys. Res. Commun., 36 (1969) 614) and the S L-eth factor of Regitz et al. ( Planta Berlin, 91 (1971) 8).

Fine structural identification of peroxisomes in the cells of the photosynthetic lamellae of the leaf ofPolytrichum communegametophytes

AbstractPeroxisomes are characterized, among plastids and mitochondria, in the photosynthetic lamellae of the leaf of Polytrichum commune gametophytes. The significance of such a functional association in the haploid phase of a Bryophyte is briefly discussed from an evolutionary standpoint.

The effect of rifamycins in the ultrastructure of Anacystis montana

The fine structure alterations produced in Anacystis montana by rifamycins were studied. The basic normal structure of this vegetative cell is a cytoplasmic matrix which extends throughout the cell. Photosynthetic lamellae and various granular inclusions are irregularly distributed throughout the cytoplasmic matrix. In these areas vesicles or vacuoles are mainly evident. When these cells are incubated in the presence of rifamycins, numerous dense bodies, which are acid phosphatase positive, appear in the cytoplasmic matrix. The origin of these dense bodies is clearly in the nucleoplasm. Also, similar dense bodies or amorphous electron dense acid phosphatase-positive substances, appear within the vacuoles. These results are discussed.

LPP-1 Infection of the Blue-Green Alga Plectonema boryanum

One-step growth and intracellular growth experiments were performed at high multiplicities of the virus LPP-1 during the infection of the blue-green alga Plectonema boryanum. The eclipse period lasts until 4 hr after infection, the latent period terminates at 6 hr, and the rise period continues until 14 to 16 hr after infection. The burst size was independent of multiplicity of infection over the ranges from 1 to 50. The burst size was 3,000 to 5,000 plaque-forming units (PFU) per infectious center or about 200 PFU per cell. Samples for electron microscopy were taken at characteristic times during the lytic cycle. The first sign of viral infection was the invagination of the photosynthetic lamellae at 3 hr after infection. Mature virions were visible at 4 hr. By 6 to 7 hr, many mature intracellular viral particles could be seen, with lysis beginning at 7 hr. By 10 hr after infection, all infected cells contained mature virions. No evidence for mass migration of performed viral precursors was obtained. The invagination of the lamellae could be prevented by the early addition of chloramphenicol, which implies that this process requires protein synthesis.

THE EFFECTS OF LIGHT INTENSITY ON THE ULTRASTRUCTURE OF CHLOROGLOEA FRITSCHII MITRA GROWN AT HIGH TEMPERATURE1,2,3,4

SUMMARYThe effects of high and low light intensities on the ultrastructure of the large, single cells (designated as Stage IV cell types in the life cycle) of Chlorogloea fritschii grown at 45 C are described. The most noticeable difference between cells grown at 20–60 ft‐c and at 700 ft‐c is in the number and arrangement of the photosynthetic lamellae. In the former, the lamellae are in groups of 4–6 units, the component membranes of which are compact and, closely appressed. While the thylakoids are long, continuous, and frequently invaginated into the central cytoplasm to form concentric whorls, there is no evidence of swelling or separation to form vacuole‐like structures. In contrast, in cells grown at 700 ft‐c, the photosynthetic lamellae are fewer and fragmented, with the segments peripherally arranged dint frequently swollen and vesiculate. There are also differences in the, nature of the sheath, in the amount of cyanophycean starch, and in the cytoplasmic inclusions. At 20–60 ft‐c, the sheath, is extensive and. fibrillar; cyanophycean starch is abundant; and cytoplasmic inclusions (e.g., αand β‐granules) arc sparse. At 700 ft‐c the sheath is less extensive and frequently composed of short segments of fibrils and of particulate material; cyanophycean starch is sparse; and cytoplasmic inclusions are abundant.

A light-dependent oxygen-reducing system from Anabaena variabilis

Photosynthetic lamellae from Anabaena variabilis catalyze a vigorous photoreduction of O 2 to H 2O 2. The electrons come to O 2 from an artificial donor, reduced 2,3′,6-trichlorophenolindophenol, and the reaction does not require an exogenous autoxidizable substance. Evidence is presented to show that reduced 2,3′,6-trichlorophenolindophenol can donate electrons at two distinct sites. Photoreduction of O 2 is inhibited by antibodies which block the function of the ferredoxin-reducing substance. The O 2-reducing system may result from the formation of a reduced photoproduct which is more accessible to autoxidation than is the analogous product formed in higher plant chloroplasts.

Biogenesis of chloroplast membranes. V. A radioautographic study of membrane growth in a mutant of Chlamydomonas reinhardi y-1.

The development of photosynthetic lamellae during greening of dark-grown Chlamydomonas y-1 cells was investigated by radioautography. Acetate-(3)H was used as a marker for membrane lipids. In short pulse-labeling experiments, about 50-60% of the radioactivity incorporated was found in the lipid fraction and about 25-50% in starch granules present in the chloroplast of these algae. The relative specificity of acetate-(3)H used as a marker for membranes was artificially increased through quantitative removal of the starch granules from fixed cells by amylase treatment. Analysis of turnover coefficients of different membrane constituents and of the contribution of turnover and net synthesis to the total label incorporated in pulse experiments indicated that the incorporation of acetate into specific lipids was mainly due to net synthesis. The distribution of radioactivity in the different lipid constituents at the end of a short pulse and after 30- and 60-min chases indicated that transacylation is minimal and may be disregarded as a possible cause of randomization of the label. Statistical analysis of radioautographic grain distribution and measurements of different structural parameters indicate that (a) the chloroplast volume and surface remain constant during the process, whereas the growth of the photosynthetic lamellae parallels the increase in chlorophyll; (b) the lamellae do not develop from the chloroplast envelope or from the tubular system of the pyrenoid; (c) all the lamellae grow by incorporation of new material within preexisting structures; (d) different types of lamellae grow at different rates. The pyrenoid tubular system develops faster than the thylakoids, and single thylakoids develop about twice as fast as those which are paired or fused to grana. It is concluded that growth of the membranes occurs by a mechanism of random intussusception of molecular complexes within different types of preexisting membranes.

The ultrastructure of chloroplast of a brown alga Sphacelaria sp. : II. Association between the chloroplast DNA and the photosynthetic lamellae

Further to the observation of the spatial relationship between the ring genophore and the internal membranes of Sphacelaria chloroplasts, the attachment of the DNA filaments and the photosynthetic lamellae can be demonstrated by both thin-sectioning and isolation techniques. DNA filaments released by osmotic shock are found attached to the membrane: The configurations of the filaments are either linear, single loop, double loop, or a combination of a loop and linear. The last two are interpreted as the replicated forms. It is concluded that chloroplast DNA in Sphacelaria exists as a number of replicons of either linear or loop forms intermingled within the genophore. It is logical to assume that the mechanism for the replication and segregation of these replicons is similar to that of bacterial DNA.

The ultrastructure of chloroplast of a brown alga Sphacelaria sp. : I. Plastid DNA configuration—the chloroplast genophore

The reconstruction of the ultrastructure of Sphacelaria chloroplast can be documented accurately because the orientation of the material for microtomy can be predetermined and serial sections of the chloroplasts in various planes can be obtained with comparative ease. This, together with evidence from fluorescence microscopy and freeze-etching methods, revealed the structure of the chloroplasts as organelles with orderly arranged lamellar systems. Chloroplast DNA is located in a distinct ring-like body, and the internal architecture of the chloroplast is such that direct contact between all the photosynthetic lamellae and the DNA-containing body occurs around the perimeter of the latter. The term “genophore” is suggested for the description of the DNA-containing configuration, denoting the fact that it is simply a gene-containing body and not nucleus-like. The contact between the genophore and the photosynthetic lamellae may be significant in the growth of the chloroplast membrane system.

Fine structure of the blue-green alga Nostoc sphaericum: the structured granule

Abstract The various granular inclusions of Nostoc sphaericum are described. The origin of structured granules may be traced to cytomembranes already present in the cell. Photosynthetic membranes become associated into irregular membranous bodies and by continued aggregation form the dense, osmiophilic structured granules. In a previous report it was shown that incubation with potassium tellurite and tetranitro-blue tetrazolium indicated respiratory reduction to be associated with the photosynthetic lamellae. In the present work, however, there is no evidence for such a reduction in the forming or matured structured granules. Differences in fixation images and stainability also suggest drastic changes in their internal membrane during the development. It is suggested that the structured granules are formed from photosynthetic membranes that have ceased to function and serve as reserve sites of membrane materials.

Possible respiratory sites in a blue-green alga Nostoc sphaericum as demonstrated by potassium tellurite and tetranitro-blue tetrazolium reduction

Colonies of Nostoc sphaericum were incubated in potassium tellurite and tetranitro-blue tetrazolium solutions with and without succinate substrate in the presence and absence of light. In all cases there is evidence that the reduction products are associated with the photosynthetic lamellae. Deposition of reduced tellurite with succinate substrate in the absence of light would rule out the reduction caused by photosynthesis (redox reaction). It seems, therefore, that the so-called photosynthetic lamellae in blue-green algal cells also function as mitochondrial equivalents. There is indication that reduced tellurite is continuously removed from the reduction site while TNBT-formazan is relatively immobile. There is no evidence for the reduction of tellurite on the plasma membrane or any of the cytoplasmic granules.

DEVELOPMENT OF CHLOROPLAST FINE STRUCTURE IN ASPEN TISSUE CULTURE

Chloroplast ontogeny has been examined in 42‐day etiolated triploid aspen callus (Populus tremuloides Michx.) subjected to two different light conditions. White and low‐intensity red illumination showed little differences in their stimulatory effects on plastid development, the red light‐irradiated plastids developing only slightly more slowly. Asynchronous plastid development was noted in both lighting systems. Etioplasts contained an interconnected tubular net, phytoferritin aggregates, electron‐transparent vesicles which seem to invaginate from the inner plastid membrane, membrane‐bound homogeneous spheroids and starch grains. Irradiation caused various morphological changes within the proplastids; the tubular complex became transformed into the more ordered prolamellar body‐like structure from which radiated membrane‐bound sacs filled with electron‐dense material. These sacs, characterized as thylakoid precursors, were transformed into a thylakoidal system typical of mature chloroplasts. This ontogenetic scheme represents an additional pathway for the development of photosynthetic lamellae. Other light‐induced changes in the developing plastid include disappearance of phytoferritin particles and homogeneous spheroids, decrease in starch content, and appearance of osmiophilic droplets.

Ultrastructure of blue-green algae.

Two freshwater blue-green algae, Tolypothrix tenuis and Fremyella diplosiphon, and an oscillatorialike marine alga, were found to possess structures on the photosynthetic lamellae which appear to correspond to the phycobilisomes of red algae. These homologous structures are important because they contain the phycobilins which are accessory pigments involved in photosynthesis. As in the red algae, the phycobilisomes were attached on the outer side of each lamellae, i.e., the side facing away from its own membrane pair. Although our study on Anacystis nidulans has not thus far revealed the presence of phycobilisomes, some observations were made on the structure of the polyhedral bodies. After negative staining, the polyhedral bodies were seen to be composed of regularly spaced subunits arranged in a crystalline array. Elongated segmented rods, which differed from the polyhedral bodies, were found in the nuclear region of apparently healthy Tolypothrix cells.

The ultrastructure of the marine blue green alga, Trichodesmium erythraeum, with special reference to the cell wall, gas vacuoles, and cylindrical bodies.

The marine blue green alga, Trichodesmium erythraeum, was studied with electron microscopy in an attempt to elucidate the structural basis for its rapid lysis when removed from its marine environment. In this connection, it was found that a thining of the electron-dense layer of the longitudinal wall at the site adjacent to transverse wall attachment was responsible for lysis. The underlying biochemical basis for this change has not been elucidated because of the extreme difficulties of maintaining and growing the alga in culture under defined conditions. Several other features of considerable interest also were found. Especially interesting is the very regular array of gas vacuoles in the form of a hollow cylinder which shields most of the photosynthetic system. It was suggested that the gas vacuoles might possibly function optically, having adaptive value in protecting the free-floating alga from excessive radiation. In addition, a detailed structure of the cylindrical bodies was presented, and its structure with the photosynthetic lamellae was compared. On the basis of sectoring to form fragments of double lamellar units from the cylindrical body which are identical in structure to the photosynthetic lamellae, it has been postulated that the cylindrical body may be the site of synthesis for the photosynthetic system in Trichodesmium erythraeum.

ULTRASTRUCTURE OF THE THERMOPHILIC BLUE-GREEN ALGA, SYNECHOCOCCUS LIVIDUS COPELAND(1).

The ultrastructure of Synechococcus lividus Copeland, a thermophilic blue-green alga, was studied in thin sections. The cell envelope reveals striking similarities with that of some gram-negative bacteria. In contrast to bacteria and to many other species of blue-green algae, ribosomes are predominantly found in the central nuclear region and appear to be associated with the DNA fibrils. Thylakoids (photo-synthetic lamellae) are arranged as concentric shells, around the nuclear equivalent, lying nearly parallel to one another and to the plasma membrane. Both plasma and thylakoidal membranes, as described by other authors for different Cyanophyceae, are of the unit membrane dimension and morphology. Various types of intracellular inclusions are found: (1) Lipid inclusions, located in the cytoplasm are similar to the osmiophilic globules of higher plant chloroplasts. (2) Polyphosphate inclusions (or volutin) resembling those of other species are generally found at the cell poles but within the nuclear region. (3) Polyhedral inclusions also located in the nuclear region are clearly recognized to be different from the polyphosphate bodies, but their function remains unknown.

Ultrastructure of the cell wall and cell division of unicellular blue-green algae.

The fine structure of the cell wall and the process of cell division were examined in thin sections of two unicellular blue-green algae grown under defined conditions. Unilateral invagination of the photosynthetic lamellae is the first sign of cell division in the rod-shaped organism, Anacystis nidulans. Symmetrical invagination of the cytoplasmic membrane and inner wall layers follows. One wall layer, which appears to be the mucopolymer layer, is then differentially synthesized to form the septum; the outer wall layers are not involved in septum formation. Centripetal splitting of the inner layer separates the two daughter cells. A second division, in a plane parallel to the first, usually occurs before the first daughter cells are separated. In the coccoid organism, Gleocapsa alpicola, the features of cell division are broadly similar; however, unilateral invagination of the lamellae is not observed and the second division takes place in a plane perpendicular to the plane of the previous division.

Reversible changes in the circular dichroism of phytochrome during photoisomerisation of the pigment

This chapter discusses the circular dichroism (CD) and optical rotatory dispersion (ORD) of photosynthetic organelles and their component pigments. The measurement of optical rotation, particularly CD, spectra can provide information relevant to a number of interesting molecular properties of chlorophylls. These include (1) determination of the absolute configurations at asymmetric carbon atoms of isolated chlorophylls; (2) characterization of the geometries of chlorophylls in dimers and higher aggregates; (3) evidence for the presence, number, and structures of associated chlorophylls in photosynthetic lamellae and information about changes in interaction on activation by light; and (4) evidence bearing on the interactions of asymmetric environments, such as the protein matrix of the naturally occurring chlorophyll complexes. The CD and magnetic circular dichroism (MCD) spectral changes associated with the conversion of protochlorophyll to chlorophyll following etiolation in higher plants are investigated in the chapter. There are important changes that occur as chloroplasts synthesize more chlorophyll during maturation. By using absorption, fluorescence, and structural measurements, the CD measurements provide a valuable tool in investigating the nature of pigment interactions in photosynthetic organelles.

The application of freeze-fracture replication in studying the fine structure of a blue-green alga

The ultrastructure of a blue-green alga studied by the freeze-fracture replication method verifies the results obtained from conventional preparatory methods for electron microscopy, and provides a method from which a three-dimensional view of the photosynthetic lamellae which pervade the peripheral cytoplasm can be ascertained. Numerous particles that are similar to ribosomes occur throughout the cytoplasm and between the membrane of the lamellar system, which correspond to the dense particles observed in fixed and sectioned preparations. The application of freeze-fracture replication to the fine structure of blue-green algae, provides an additional manipulation from which structural information concerning the three dimensional appearance of membranous components within these cells can be compared with the ultrastructural details seen in preparation by conventional methods.