Morphology and anatomy in Heliconia angusta Vell. and H. velloziana L. Emygd. (Zingiberales: Heliconiaceae) from the Atlantic forest of southeastern Brazil

Morphological and anatomical features of roots, stems, leaves, and scapes were studied in Heliconia angusta and H. velloziana from the Atlantic forest in the southeastern of Brazil. Morphologically H. angusta and H. velloziana show differences in their sizes, blade shapes, number and shape of inflorescence bracts. On the other hand, they have common anatomical characteristics such as: roots with air-canals in the cortex; rhizomes with isolated fiber bundles, collateral vascular bundles, and uniseriate endodermis and pericycle; leaves presenting air-canals and collateral vascular bundles forming arcs, and thin-walled epidermal cells; scapes with collateral vascular and fiber bundles in the cortex. The distribution of the fiber bundles in the leaves and in the scapes was different for each species, having a taxonomical value, H. velloziana presenting continuous fiber bundles. Air-canals in roots and leaves with narrow mesophyll might be related to the moist understorey of the Atlantic forest habitats.

Anatomy and ontogenesis of hymenopteran leaf galls of Struthanthus vulgaris Mart. (Loranthaceae)

Leaves of Struthanthus vulgaris Mart. (Loranthaceae) exhibit galls induced by a Hymenoptera. These galls pass through five developmental stages. In the first stage, a small brown swelling is observed on the surface of the leaf. Internally, the chlorenchyma cells around the eggs of the gall-makers are divided. In the second stage, the gall enlarges and its surface assumes a wavy appearance with a depressed region in its center. Within this depression, an incompletely divided gall chamber with embryos is observed. Neoformed parenchyma is present around the chamber and the secondary walls of fibers and sclereids are no longer observed. The vascular parenchyma shows hyperplasia. In the third stage, the gall grows larger and adopts an ellipsoidal shape. Fissures appear on the gall epidermis and the neoformed parenchyma is conspicuous, with a cortical and a medullar region. In the medullar region, each gall chamber, with one inducer in larval phase, is lined with 1-2 layers of nutritive tissue. The gall is larger still at the fourth stage of development and a periderm coats most of the gall. New vascular bundles, sclereids, and fibers are formed. The gall-makers are in advanced larval phase and no nutritive tissue cells are observed. In the fifth stage, the gall reaches its definitive size and the inducers are in the pupa phase. At this stage, the cortical region undergoes slight hypertrophy. The senescent gall shows the orifices of the exit channel made by the adult gallmakers. The anatomical studies of the hymenopteran gall enabled to compare this gall with a dipteran one, previously discribed in the same plant host. It is suggested that during the maturation of the gall, specific key processes are triggered, which bring about a specific cecidogenesis.

Vegetative organ anatomy of Ianthopappus corymbosus Roque & Hind (Asteraceae-Mutisieae)

A study on the vegetative organ anatomy of Ianthopappus corymbosus was conducted in order to provide a basis for comparison with the genus Richterago, since this species had been previously included in that genus. The anatomical characters of I. corymbosus that support its exclusion from the genus Richteragon are: epithelial cell organization of adventitious root secretory canals, non-glandular trichomes, and presence of cortical vascular bundles in the stem. In Ianthopappus corymbosus, the underground system consists of rhizophore from which adventitious roots branch off. The subapical meristem of the adventitious root revealed that the ground meristem forms the inner layer which in a meristematic phase, forms 2/3 of the cortex. This layer will differentiate in the endodermis, with Casparian strips, and is referred to as meristematic endodermis. Endodermic secretory canals, limited by four epithelial cells, appear in the region adjacent to the primary phloem.

Morphology and anatomy of the fruit and seed in development of Chorisia speciosa A. St.-Hil. - Bombacaceae

The structure of the fruit and seed in development of Chorisia speciosa are described with the main purpose of clarifying the origin and nature of the hairs that cover the seeds and aiding future taxonomical and ecological studies of the group. The fruit is an ellipsoid loculicide capsule and presents the exocarp formed by 7-10 cells layers, with very thick walls and evident simple pits. A great number of mucilage secretory cavities and ramified vascular bundles, accompanied by fibers, occur in the parenchymatic mesocarp. The endocarp derives from the ventral epidermis of the ovary wall, whose cells undergo a gradual elongation, become lignified, and constitute the trichomes which cover the mature seeds. The fruit aperture occurs by means of a suture evident in the ovarian wall in the middle region of the carpel leaf. Anatropous and bitegmic ovules, provided by a hypostase, give rise to campilotropous and bitegmic seeds. The testa is uniseriate, the exotegmen is completely formed by macrosclereids, and mucilage secretory cavities occur in the mesotegmen. The endotegmen, which is differentiated in the endothelium, is crushed in the mature seed. The plicate embryo, which occupies practically the entire seminal cavity, is found between endosperm layers, both being rich in lipids.

Leaf anatomy of Araucaria angustifolia (Bertol.) Kuntze (Araucariaceae)

Immature and mature leaves of juvenile and adult plants of Araucaria angustifolia (Araucariaceae) were observed with the objective of updating the morphoanatomical data of the leaves of this species, which were restricted to basic descriptions in previous studies. The observations, made in optical allowed to establish anatomical differences among mature leaves of juvenile and adult plants in relation to the number of palisade parenchimal layers, the number of compartmented cells and the transfusion tissue development. Epidermis, the albuminous cells, the phloem, and the transfusion tissue descriptions are in disagreement with the data obtained data by different authors. The epidermal tissue and the hypodermis differ entirely when the plant is still juvenile, being inferred that these tissues would soon perform the protection function against mechanical damages and water loss, the vital characteristics during the first development months of young offspring.

Leaf anatomy variation within and between three "restinga" populations of Erythroxylum ovalifolium Peyr: (Erythroxylaceae) in Southeast Brazil

Erythroxylum ovalifolium is a woody shrub widespread in the "restinga", i.e. the open scrub vegetation of the Brazilian coastal sandy plains. We examined leaf anatomy variation of this species both within populations and between populations of three "restingas" in the state of Rio de Janeiro. Sites were ca.100 km far from each other and differed in regard to rainfall and vegetation structure: a dry, open site; a wet, dense site and an intermediate one. Microhabitats within sites were: (i) exposed to full irradiance, outside vegetation islands; (ii) partially exposed to full irradiance, at the border of vegetation islands; (iii) shaded, inside vegetation islands. Leaf anatomy parameters were measured for five leaves collected in each of five plants per microhabitat, in each population; they were thickness of the leaf blade, of the palisade and spongy parenchyma, and of the adaxial and abaxial epidermis. Leaves from the dry, open site had narrower abaxial epidermis and a smaller contribution of spongy parenchyma to total leaf blade thickeness than the other two sites, which we attributed to water stress. Adaxial epidermis and leaf are thicker in more exposed microhabitats (i and ii, above), irrespective of site. We proposed that between-site anatomical variation in traits related to water stress, and within-site anatomical variation in traits related to light-use are indicative of ecological plasticity and might help explain the high abundance of E. ovalifolium in the studied populations and along the State of Rio de Janeiro coast.

Reprodução sexuada de Dyckia tuberosa (Vell.) Beer (Bromeliaceae, Pitcairnioideae) e interação planta-animal

Bromeliaceae é um componente importante em vários Biomas, sendo notável a variedade de contextos ecológicos em que pode ser encontrada. Ocorre no grupo a combinação entre dois modos de reprodução: sexuada e propagação clonal. Neste estudo descrevemos vários atributos relacionados à reprodução sexuada de Dyckia tuberosa, bem como interações planta-animal que se estabelecem em suas estruturas reprodutivas. Ao longo de 11 meses, 55 % dos indivíduos na população estudada floresceram e frutificaram. As flores se desenvolvem da base para o ápice e apresentam diferenças morfométricas quanto à posição na inflorescência que acarretam diferenças na produção de sementes. A concentração de açúcares no néctar foi de 20% e a produção total de néctar foi de c. de 24 µL flor-1 dia-1, sendo esta última maior no período da manhã entre 8h00 e 9h00. Dyckia tuberosa é auto-incompatível e o índice de auto-incompatibilidade (ISI) foi de 0,08. Somente beija-flores exploraram as flores de modo legítimo, contatando anteras e estigma, sendo 3,9 flores visitadas por hora. Chlorostilbon aureoventris, Colibri serrirostris e Phaethornis eurynome foram as espécies registradas. Em D. tuberosa a reprodução sexuada depende das visitas dos beijaflores. Houve patrulhamento das inflorescências de D. tuberosa pelas formigas Camponotus rufipes, Camponotus cf. mus e Cephalotes sp. Como há ausência de reprodução sexuada em muitos indivíduos, e esta espécie é dominante no afloramento rochoso estudado, consideramos que a propagação clonal seja uma estratégia importante para a disseminação de D. tuberosa na área. A presença de animais, polinizadores ou não, na inflorescência de D. tuberosa torna esta espécie adequada para avaliar como variações na disponibilidade de recursos florais alteram o resultado das interações planta-animal e o sucesso reprodutivo de D. tuberosa.

Leaf anatomy of two Anemia Sw. species (Schizaeaceae-Pteridophyte) from a rocky outcrop in Niterói, Rio de Janeiro, Brazil

The ferns Anemia tomentosa (Sav.) Sw. var. anthriscifolia (Schrad.) Mickel and Anemia villosa Humb. & Bonpl. ex Willd. are widely associated with vegetation islands on rocky outcrops in Rio de Janeiro. Both species are desiccation tolerant. The leaf anatomy of these species was examined aiming to identify morphological characteristics that would allow the establishment of these species in water-scarce environments. The plants were harvested on "Pedra de Itacoatiara" and prepared according to the usual procedures. The petiole has a uniseriate epidermis with lignified cell walls, conical stegmata, and uniseriate multicelular and glandular trichomes. In A. villosa, the stomata protrude in a respiratory line. Under the epidermis the cells have thick, lignified walls. The parenchyma has phenolic compounds and starch grains. The petiole vascular bundles are surrounded by endodermis with Casparian strips and the xylem is V-shaped (A. villosa) or arc-shaped (A. tomentosa var. anthriscifolia). The leaf blades have a uniseriate epidermis with sinuous anticlinal and convex periclinal walls, conical stegmata and chloroplasts on both surfaces. The leaf margins of A. villosa have lignified cells. The guard cells of the stomata on the abaxial surface are on the same level or are raised above ordinary epidermal cells. Multicelular uniseriate trichomes and glandular hairs were observed. The dorsiventral mesophyll has loosely packed chlorenchyma with arm-shaped and H-shaped cells. The vascular bundles are surrounded by endodermis with Casparian strips and with parenchymatic extensions towards the epidermis. Anatomical results were analyzed considering the interaction of these plants with abiotic factors.

Anatomy of the floral scape of Bromeliaceae

This paper describes the anatomy of the floral scape for 12 species of Bromeliaceae, belonging to the subfamilies Bromelioideae, Tillandsioideae and Pitcairnioideae. Although all the scapes have a similar organization, there are variations in the structure of the epidermis, cortex and vascular cylinder. Such variations are described for the studied scapes and, when considered together they can help to identify the species. These aspects are described for each scape and discussed under a taxonomic point of view.

Anatomy, ultrastructure and secretion of Hibiscus pernambucensis Arruda (Malvaceae) extrafloral nectary

This paper reports on the extrafloral nectary (EFN) of Hibiscus pernambucensis, a native shrub species occurring in mangrove and restinga along Brazil's coastline. EFNs occur as furrows with a protuberant border on the abaxial surface veins of the leaf blade. Each nectary consists of numerous secretory multicellular trichomes, epidermal cells in palisade-like arrangements and non-vascularized parenchyma tissue. Nectar secretion is prolonged, since secretion starts in very young leaves and remains up to completely expanded leaves. Reduced sugars, lipids, and proteins were histochemically detected in all the nectary cells; phenolic substances were detected in the vacuoles of the epidermal palisade cells and in some secretory trichome cells. The secretory cells that constitute the body of trichomes have large nuclei, dense cytoplasm with numerous mitochondria, dictyosomes, scattered lipid droplets and plastids with different inclusions: protein, lipid droplets or starch grains; vacuoles with different sizes have membranous material, phenolic and lipophilic substances. The palisade cells show thick periclinal walls, reduced cytoplasm with voluminous lipid drops and developed vacuoles. The nectary parenchyma cells contain abundant plasmodesmata and cytoplasm with scattered lipid droplets, mitochondria, plastids with starch grains and endoplasmic reticulum. Mucilage idioblasts are common in the inner nectary parenchyma. Protoderm and ground meristem participate in the formation of EFN. Our data indicate that all nectary regions are involved in nectar production and secretion, constituting a functional unit. Longevity of the extrafloral nectaries is likely associated with the presence of mucilage idioblasts, which increases the capacity of the nectary parenchyma to store water.

Morphology and anatomy of the developing fruit of Maclura tinctoria, Moraceae

(Morphology and anatomy of the developing fruit of Maclura tinctoria, Moraceae). Maclura tinctoria (L.) D. Don ex Steudel was selected for the present study due of its economic and medicinal importance. The purpose of this investigation is to present a detailed description of the fruit development, specially by: (a) defining the fruit type presented by the species, and (b) characterizing the seed type of the species based upon the presence or not of mechanical tissue on the seed-coat. The fruit originates from the subglobose female inflorescence which consists of small unipistillate flowers with superior ovary, unilocular and uniovular apical placentation. The mature fruit is multiple, constituted of small drupes. The ovule is ana-campylotropous, suspended, bitegmic and crassinucellate. The mature seed is flattened, slightly ovated, cream colored, with unspecialized membrane coat with thin-walled cells more or less crushed. The seed has parenchymatic endosperm with lipophilic content. The embryo is straight, with two cotyledons of the same size. Ontogenetic studies reveal that the fruits are infrutescences. The fleshy edible part is derived from the perigone and inflorescence axis. The drupes consist of a single pyrene of macrosclereids.

Production of recombinant antigens in plants for animal and human immunization - a review

Plants present a cost effective production system for high value proteins. There is an increasing world demand for cheap vaccines that can be readily administered to the population, especially in economically less developed regions. A promising concept is the production of vaccines in plants that could be grown locally. Expression of antigenic peptides in the palatable parts of plants can lead to the production of edible active vaccines. Two major strategies are: i) to express antigens in transgenic plants, and ii) to produce antigenic peptides on the surface of plant viruses that could be used to infect host plants. This review considers the experimental data and early results for both strategies, and discusses the potential and problems of this new technology

Animal models of anxiety: an ethological perspective

In the field of anxiety research, animal models are used as screening tools in the search for compounds with therapeutic potential and as simulations for research on mechanisms underlying emotional behaviour. However, a solely pharmacological approach to the validation of such tests has resulted in distinct problems with their applicability to systems other than those involving the benzodiazepine/GABAA receptor complex. In this context, recent developments in our understanding of mammalian defensive behaviour have not only prompted the development of new models but also attempts to refine existing ones. The present review focuses on the application of ethological techniques to one of the most widely used animal models of anxiety, the elevated plus-maze paradigm. This fresh approach to an established test has revealed a hitherto unrecognized multidimensionality to plus-maze behaviour and, as it yields comprehensive behavioural profiles, has many advantages over conventional methodology. This assertion is supported by reference to recent work on the effects of diverse manipulations including psychosocial stress, benzodiazepines, GABA receptor ligands, neurosteroids, 5-HT1A receptor ligands, and panicolytic/panicogenic agents. On the basis of this review, it is suggested that other models of anxiety may well benefit from greater attention to behavioural detail

The use of non-human primates as animal models for the study of hepatitis viruses

Hepatitis viruses belong to different families and have in common a striking hepatotropism and restrictions for propagation in cell culture. The transmissibility of hepatitis is in great part limited to non-human primates. Enterically transmitted hepatitis viruses (hepatitis A virus and hepatitis E virus) can induce hepatitis in a number of Old World and New World monkey species, while the host range of non-human primates susceptible to hepatitis viruses transmitted by the parenteral route (hepatitis B virus, hepatitis C virus and hepatitis delta virus) is restricted to few species of Old World monkeys, especially the chimpanzee. Experimental studies on non-human primates have provided an invaluable source of information regarding the biology and pathogenesis of these viruses, and represent a still indispensable tool for vaccine and drug testing.

Transgenic animal models for the functional analysis of vasoactive peptides

The interplay of vasoactive peptide systems is an essential determinant of blood pressure regulation in mammals. While the endothelin and the renin-angiotensin systems raise blood pressure by inducing vasoconstriction and sodium retention, the kallikrein-kinin and the natriuretic-peptide systems reduce arterial pressure by eliciting vasodilatation and natriuresis. Transgenic technology has proven to be very useful for the functional analysis of vasoactive peptide systems. As an outstanding example, transgenic rats overexpressing the mouse Ren-2 renin gene in several tissues become extremely hypertensive. Several other transgenic rat and mouse strains with genetic modifications of components of the renin-angiotensin system have been developed in the past decade. Moreover, in recent years gene-targeting technology was employed to produce mouse strains lacking these proteins. The established animal models as well as the main insights gained by their analysis are summarized in this review.