Types Of Buds Research Articles

Regional Specializations in the Oro-Pharyngeal Wall and Food Processing in the Carp (Cyprinus Carpio L.)

The structure of the oro-pharyngeal wall of the bottomfeeding common carp is investigated using light-and scanning electron microscopy. Densities of taste buds, mucus, club cells and the thickness of muscular layers are measured. Distribution patterns of these elements over the oro-pharyngeal surface are reconstructed from local counts. Six areas characterized by a specific combination of morphological features are distinguished and related to twelve feeding actions composing the process of food intake and handling in the carp. These areas are the lips (detection and oral manipulation of food), the orobuccal cavity (suction and resuspension chamber of ingested food and non-food particles), the most anterior pharynx (coarse selection of large food particles), the lateral pharynx (selection of small food particles), the posterior part of the anterior pharynx (formation of boluses, transport and loading of food into the chewing cavity) and the posterior pharynx (mastication and deglutition). The conical shape of the orobuccal cavity and the slit-shaped anterior pharynx reflect two different mechanisms for particle handling viz. by suction and by muscular bulging respectively. The opercular cavities serve large volume changes for suction feeding. Protruding types of taste buds and oligovillous epithelial cells may well serve mechanoreceptive functions required for steering the process. Otherwise, specialized mechanoreceptors have not been recognized. Mucous cells producing low-viscosity sialomucines occur in the anterior part of the oro-pharynx. They will serve maintaining a laminar flow during suction and lubrication of particle handling in the pharynx. Epithelial microridges may aid in holding the mucus. High-viscosity sulfomucines only appear in the posterior part of the pharynx and will aid in trapping small particles and aggregating them into boluses. The commonly accepted alarming function of club cells and their mechanism for release is questioned in view of their abundancy in the orobuccal cavity. The structure of the muscular palatal organ is discussed with respect to its role in selection between food and non-food particles. The available information on the afferent, efferent and central neural pathways of this system is briefly reviewed. Three levels of movement, related to the particle size to be handled, are proposed. Movement of the palatal organ as a whole, local outbulging of its surface into the pharyngeal slit and a possible very local movement of the muscular papillae in its anterior part. These hypotheses are based on the almost maximal taste bud densities (820/mm 2 ) in the palatal organ, the known complex laminated cyto-architecture of the enormous vagal lobes processing its input and suggestive of a palatotopic mapping, and on the complex muscle fiber systems in this organ. The movable gill rakers of the branchial sieve, each supplied with a muscular pad and numerous taste buds (325-625/mm 2 ), suggest their additional active role in selection. Muscle fiber systems in the posterior part of the palatal as well as in the closely appressed postlingual organ serve a peristalsis-like transport to the chewing cavity. Both are copiously supplied with sulfomucines from their deep crypts. Together these morphological and physiological features allow the carp a bottom feeding behaviour requiring the effective separation of food from soiled mixtures.

Sampling for Field Evaluation of Peach and Nectarine Flower Bud Survival

Abstract Sample sizes for detection of differences of flower bud survival in peach and nectarine [Prunus persica (L.) Batsch] were chosen on the basis of theoretical confidence intervals (Cl) and least detectable differences (LDD) for the binomial distribution. Theoretical Cl and LDD for 1000-bud samples were comparable to Cl and Duncan's multiple range test separation computed from an analysis of variance for 1000 buds, based upon 10 replicates of 100 buds. Variability in survival was a function of eultivar, height of bud in canopy, and bud type. Variability may be minimized by sampling a given bud type (single, double, distal) at >1.5 m above ground level.

Activités ATPasiques du nœud cotylédonaire et du bourgeon cotylédonaire du pois inhibé, réactivé ou soumis à la fusicoccine

The activity of enzymes which hydrolyse ATP at neutral pH was demonstrated cytochemically in the cotyledonary node and in three types of cotyledonary buds (inhibited, released from dominance, treated with fusicoccin). In the intact plant, the transfer cells of the cotyledonary node showed a very strong Mg2+-dependent, ouabaïne-insensitive ATPase activity, essentially located on the outer surface of the plasmalemma. A high concentration of K+ stimulated the ATPase activity of the plasmalemma of transfer cells and sieve elements. ATPase activity was even more specifically detected along mitochondrial cristae and the tonoplast of the phloem transfer cells and along the reticular membranes of the xylem transfer cells. All these activities which were not modified by decapitation increased after a fusicoccin treatment. In the inhibited bud the same pattern of ATPase activity occurred along the plasma membrane but with a lesser intensity. At the base of the first-bud internodes the phloem transfer cells were the only ones with a high ATPase activity. Decapitation induced, without cell specificity, an increase in the ATPase activity of the plasmalemma for the entire bud, while after fusicoccin treatment, the increase extended to the tonoplast. Proper controls eliminate the possibility of artifactual reactions or interactions with other enzymes.

The relation between first-season bud morphology and second-season shoot morphology of jack pine seedlings

Seedlings of 20 open-pollinated families of Pinusbanksiana Lamb. from the Lake States region were grown the first season in two controlled environment rooms differing only in temperature. After a period of dormancy induction followed by a period of dormancy at low temperatures, all seedlings were grown a second season in a uniform greenhouse environment. Three bud types were recognized based on first-season bud dissections and confirmed by second-season shoot analyses. Type 1 buds consisted of a proximal zone of stem units bearing primary needles and a distal zone of stem units bearing scales. Type 2 buds, with a basal whorl of long-shoot primordia, were typical of 2-year-old buds. Type 3 buds were polycyclic. They were essentially a type 2 bud superimposed on a type 1 bud. Short-shoot activity was more prevalent in type 2 and 3 buds than on type 1 buds the first season suggesting that bud morphology may be established early during seedling development. Type 1 buds were unaffected by temperature, but the frequency of type 2 buds decreased and that of type 3 buds increased in the high compared with the low temperature environment. The frequency of type 1 and 2 buds differed among provenances; type 2 buds increased slightly from north to south within the study range. Significant differences in bud types were also found among the families examined.

The morphology and growth cycle of Anemone patens

The morphology and development of Anemone patens L. has been studied. An examination of the ontogeny of buds revealed a number of interesting developmental phenomena, and brought to attention the need to study more native prairie plants in their natural habitat. Two types of buds are produced annually: one replaces the terminal bud, which is transformed to a flowering apex, and one becomes dormant. During its first season of growth the former bud produces foliage leaf primordia, which expand the following season, and several bud-scale primordia. During the second season it produces additional bud scales before itself transforming to a floral apex; the resulting flower bud remains enclosed by the bud scales until the spring of the third season. The second type of bud produced annually is generally smaller, and after producing protective bud scales enters what may be a prolonged dormancy. The initiation of these two types of bud follows a regular pattern; the bud which replaces the main apex is normally found in the axil of the uppermost bud scale enclosing the developing flower bud, while the bud which will become dormant is formed in the axil of the uppermost expanding foliage leaf. The growth pattern of A. patens appears to be well suited to the plant's habitat. The reserve of viable dormant buds is augmented annually, and enables the plant to regenerate new branches if terminal apices are damaged. The largest, most highly branched specimens are frequently found in locations that are grazed or burned, and such periodic disturbances may in fact help the plant to thrive.

Distribution and ultrastructure of taste buds in the oropharyngeal cavity of the rainbow trout, Salmo gairdneri Richardson

The distribution, external surface morphology and ultrastructure of taste buds in the oropharyngeal cavity of the rainbow trout, Salmo gairdneri Richardson, were studied using scanning and transmission electron microscopes (SEM and TEM). The SEM revealed three taste bud types, varying only in their degree of elevation from the general level of the epithelium. Types I and II were located on elevated papillae associated with teeth on the dentary, maxilla, palate, tongue and pharyngeal pads while the unelevated Type III were mainly found in the anterior (branchial) pharynx.Each taste bud was composed of four cell types: basal, dark, intermediate and light cells, the apical processes of the last three filling the taste pores. The intermediate and light cells appeared similar in ultrastructure, varying only in the amount and organization of smooth endoplasmic reticulum (SER) in their cytoplasm. In addition to its contacts with the processes of intragemmal nerves distally, the basal cells established independent contacts with processes of extragemmal nerves basally. It is suggested that the distribution of the taste buds and their close association with teeth are adaptations to the predatory feeding habit of the rainbow trout. Age differences may account for the existence of two types of gustatory cells and the manner of innervation of the taste bud suggests the existence of two pathways for the transmission of gustatory sensation to the central nervous system (CNS).

Dimorphism in bud regeneration in flax (Linum usitatissimum)

The study of the expression of morphogenetic potential in stem segments of flax (Linum usitatissimum L.) was undertaken as a function of donor plant age and level (basal, median, or apical) on the stem axis and in the absence of growth regulatory substances. Neoformation of normal buds (resembling seedlings) gave rise to shoots with no visible axillary buds, and a few roots were obtained from explants taken from young, vegetative plants; these organs were more numerous on basal than on apical explants. If the donor plant was in a prefloral or floral state, thus older and at a different physiological stage, a "modified" bud was formed, characterized by its slow growth, short thick stem and leaves, and sometimes with visible axillary buds. This type of bud was more numerous in apical than in basal segments. Callus was also formed and was reduced in size and limited to the cut extremities of explants when the donor plant was young, but was large and covered almost all the explant when the plant was older.

Structural differences between big bud types onCorylus avellana(L.)

Click to increase image sizeClick to decrease image sizeRésuméDeux types de « gros bourgeons » décrits sur Corylus avellana par KRANTZ (sous presse) ont été comparés du point de vue morphologique et anatomique. Les différences structurales observées suggèrent que les deux types de « gros bourgeons » sont dus à deux cécidozoaires différents.

Presence of type C particles containing reverse transcriptase in L1210 leukemia.

A murine L1210 leukemia cell line was grown either in vitro or in vivo by ip injection of 106 cells/mouse in C57BL × DBA)F1 mice. It contained particles that resembled murine leukemia virus. Electron microscopic examination of the cells showed both intracytoplasmic and budding type C particles. Similar particles were also seen in the high-speed pellet (90,000 × g) obtained from both mouse ascitic fluid and the supernatant from cells grown in tissue culture. When the high-speed pellet was centrifuged in a sucrose density gradient, particles banding at densities 1.16–1.18 g/ml were detected. The virus appeared to be N-tropic. These type C particles contained an RNA-dependent DNA polymerase (reverse transcriptase) activity and performed endogenous DNA synthesis. The enzyme was purified from the cells and virus particles; these enzymes were indistinguishable in their properties. The molecular weight, as determined by velocity sedimentation and gel filtration, was approximately 70,000. Primer template preference studies indicated that the purified enzyme utilized synthetic ribo templates better than synthetic deoxyribo templates. It could also utilize (dG)≈15 (Cm)n, a primer template specific for reverse transcriptase. The enzyme could transcribe heteropolymeric regions of 70S RNA from Rauscher murine leukemia virus (R-MuLV) and had RNaseH activity as well. The enzyme activity was inhibited by antibody directed against the reverse transcriptase from R-MuLV. The biophysical, biochemical, and immunologic properties of the purified enzyme resembled those of the reverse transcriptase from R-MuLV.

Development of long-shoot terminal buds of western white pine (Pinus monticola)

Long-shoot terminal bud (LSTB) development in western white pine (Pinus monticola Dougl.) was studied throughout the annual growth cycle to determine the phenology of LSTB development and the time of cone-bud differentiation. Development of LSTB began in early April and cataphylls were initiated from mid-August until early November. Cataphyll initiation was slow during May and June when shoots were elongating and then rapid just after shoot elongation was completed. Proximal cataphylls were sterile, whereas more distal cataphylls began to initiate axillary buds by late June or early July. Axillary buds were initiated first in the proximal portions of the LSTB and then acropetally in rapid succession. The last cataphylls to be initiated in the fall remained as sterile bud scales enclosing the LSTB apex. Axillary buds initiated sterile cataphylls which functioned as bud scales. The number varied with the type of axillary bud. Proximal axillary buds initiated few cataphylls and began to differentiate into dwarf shoots or pollen cones in August. The more distal axillary buds differentiated into dwarf shoots during September and October, The most distal axillary buds initiated many cataphylls during September and October but did not differentiate into seed-cone buds or lateral branch buds until after winter dormancy. Consequently, attempts to induce or enhance seed-cone production in P. monticola would probably be most successful in the spring when seed-cone buds differentiate. LSTB bearing seed cones were larger, had broader apices, and produced more cataphylls during the growing season than did LSTB bearing pollen cones. The phenology of LSTB development in soft pines and hard pines is discussed in relation to reports available on the association of cone crops and climatic conditions in several species of Pinus.

Studies on the asexual reproduction in the polystyelid ascidian, Polyzoa vesiculiphora Tokioka

New blastozooids of Polyzoa vesiculiphora, the polysytelid ascidian are produced by pallial budding of three types depending on the method of "isolated bud" formation; stolonic, planktonic and intermediate types. Differences among each type of bud are attributed to behavior of test-vessels composing a part of the bud. Isolated buds produced by each type are essentially equal in terms of their internal structures and their subsequent fate, and develop independently of their parent zooids. New test-vessels originate directly from the epidermis of a "prefunctional zooid," while the test-vessels derived from the parent zooid finally disintegrate. The new test-vessels extended with branching under the ventral side of a "functional zooid," ascend to the lateral side of it and participate in bud formation. Budding regions exist in three dimensions on the lateral wall of the mantle of the functional zooid, especially the right posterior part. During the life cycle of one functional zooid, the stolonic type buds appear at early and/or aged stages. Appearances of the stolonic type buds in early stages tend to repress those of the planktonic types. The number of planktonic type buds formed on a functional zooid at the same time is many more than that of the stolonic type. Such budding features are discussed from the viewpoint of behavior of the test-vessel system.

Endogenous Abscisic Acid in Relation to Bud Growth in Alternate Bearing `Valencia' Orange

An investigation was conducted into the relation of ABA (cis-trans-abscisic acid) in the dormant buds of alternate bearing ;Valencia' orange (Citrus sinensis [L.] Osbeck) trees. ABA did not appear to be related to alternate bearing but t-ABA (2-transabscisic acid) did. There was 5- to 10-fold more t-ABA than ABA in the buds. There was more t-ABA in the buds of the "on" trees than in the buds of the "off" trees, and a drastic drop in t-ABA in both types of buds as spring growth approached. Bud dormancy and readiness for growth as related to t-ABA are discussed.

Growth pattern and seasonal behavior of buds of Colliguaya odorifera, a shrub from the Chilean mediterranean vegetation

Colliguaya odorifera Mol., an euphorbian shrub, grows among the sclerophyllous scrub of central Chile. The growth pattern and seasonal behavior of the floral and vegetative buds are analyzed, with special reference to the climatic conditions (cool humid winters and dry hot summers). Observations were conducted on marked twigs and in sections of embedded material.The branching system is of a Y-shaped sympodial type. The growth season of C. odorifera extends from early winter to the beginning of summer. When the dry season starts, the vegetative apical meristem is converted into a floral bud, and in the leaf axils partly predetermined, unprotected vegetative buds develop. Both types of buds remain dormant during the drought period. Soon after the first winter rains begin, activity is resumed: the preformed flowers and leaf buds unfold and grow, and a few more leaf pairs develop during the current year. Thus, buds are influenced partially by the climate of the previous and of the next year.

Les bourgeons adventifs de Gigartina acicularis (Wulf.) Lamour. (Rhodophyta, Gigartinales) en culture

Cultured segments of the frond of Gigartina acicularis produce adventitious buds at the cut ends. Two types of buds can be formed: (1) proliferations and (2) regenerations. Either one type or both may be found on cut surfaces. Suitable trophic conditions increase relative frequency of regenerations in comparison with proliferations. Moreover, segments of the distal part of the frond show a greater tendency to proliferate, while segments of the basal part show more regenerations. Intercalary segments are clearly polarized because distal buds appear before the proximal ones and attain a greater size. Growth rate of adventitious buds depends on the medium and light. The highest tested light intensities seem to promote development of distal buds and inhibit that of proximal buds. Low light intensities stimulate holdfast production by buds. Regenerative and proliferative behaviours in culture are compared with that of other Florideophycidae previously reported by the authors.

Obtaining Small Peach Plants Containing All Bud Types for “Rest” and Dormancy Studies1

Abstract A method for obtaining small (15-25 cm) plants of peach [Prunus persica (L.) Batsch] with all bud types present was developed by rooting peach cuttings following flower bud initiation. These small plants permit studies to be carried out in controlled-environmental chambers. The rest and dormancy periods of the rooted cuttings were similar to large field-grown trees of the same cultivar.

Type C RNA tumor virus isolated from cultured human acute myelogenous leukemia cells.

Previously, type C RNA tumor virus-related components have been described in blood leukocytes from patients with acute myelogenous leukemia. These components, for example, reverse transcriptase, have been shown to be most closely related to those from two oncogenic subhuman primate type C viruses (woolly monkey sarcoma virus and gibbon ape leukemia virus). Now, we report the continuous production of budding type C viruses with the same characteristic reverse transcriptase by three separate culturings of leukocytes from a single bleeding from a patient with acute myelogenous leukemia. These isolations were made possible by the discovery of a source of conditioned media which sustains exponential growth of human myelogenous leukemia cells in liquid suspension culture.

PHYSIO-ECOLOGICAL STUDY ON THE BEECH (« FAGUS SYLYATICA » L.) OF THE CANSIGLIO PLATEAU (VENETIAN PRE-ALPS)

SUMMARY Bud water content changes in connection with microclimatic conditions have been studied on the beech trees of the «Fontana Boi» station in the Cansiglio Plateau, as a prosecution of previous physio-ecological researches (PAGANELLI and PAGANELLI CAPPELLETTI, 1971). The seasonal trends of the dry and fresh weights and of the moisture contents of buds from different levels in the crown and from beech trees of different exposures, have been studied in the whole buds and in the bud components. The microclimatic differences between the two slopes and the seasonal changes of bud weights and water contents have been compared in connection with bud ontogenetic cycle. Significant and positive correlations have been found between bud water contents and air temperatures. Significant differences between buds from different crown levels and between buds from beech trees at different exposures have been observed only for the indexes which express more directly the morphological differences among the bud types.

Ultrastructural alterations in rabbit taste buds induced by prolonged treatment with cycloheximide.

Prolonged administration of cycloheximide, an inhibitor of ribosomal protein synthesis, induces degeneration of rabbit taste bud cells: the degenerative changes resemble early changes in denervated taste buds. Our observations show that the pattern of degeneration is quite different in the three cell types of the taste buds. The earliest changes in type II and III cells are an increase in cytoplasmic filaments and extreme dilatation of rough endoplasmic cisternae. Profiles of dead type I and II cells vastly increase in number. Type I cells appear less affected by the drug and the only sign of degeneration was an increase in the number of autophagic vacuoles in their cytoplasm. There was no indication that degenerating type I cells undergo transformation to type II or III cells. These findings support our hypothesis that type I, II and III cells represent distinct cell types and do not undergo transformation to other types in the course of their life span.

The occurrence of the cell type containing a specific monoamine in the taste bud of the rabbit's foliate papila.

The fluorescence histochemical examination on biogenic amines of the rabbit's foliate papilla revealed that a specific monoamine exhibiting an yellow fluorescence was present in a certain cell type of taste buds. The fluorescence had the emission maximum at 520 mmu and faded rapidly under the influence of the UV-irradiation. The green fluorescence of adrenergic nerve had the emission maximum at 480 mmu and was fairly stable upon the UV-irradiation. The yellow fluorescence disappeared completely following reserpine treatment, while it was markedly enhanced by nialamide treatment. From the observations, it is suggested that certain taste bud cells of the foliate papilla contain a biogenic monoamine, probably 5-hydroxytryptamine (serotonin).

AXILLARY AND DICHOTOMOUS BRANCHING IN THE PALM CHAMAEDOREA

In both Chamaedorea seifrizii Burret and C. cataractarum Martius each adult foliage leaf subtends one axillary bud. The proximal buds in C. seifrizii are always vegetative, producing branches (= new shoots or suckers); and the distal buds on a shoot are always reproductive, producing inflorescences. The prophyll and first few scale leaves of a vegetative branch lack buds. Transitional leaves subtend vegetative buds and adult leaves subtend reproductive buds. Both types of buds are first initiated in the axil of the second or third leaf primordia from the apex, P2 or P3. Later development of both types of bud tends to be more on the adaxial surface of the subtending leaf base than on the shoot axis. Axillary buds of C. cataractarum are similarly initiated in the axil of P2 or P3 and also have an insertion that is more foliar than cauline. However, all buds develop as inflorescences. Vegetative branches arise irregularly by a division of the apex within an enclosing leaf (= P1). A typical inflorescence bud is initiated in the axil of the enclosing leaf when it is in the position of P2 and when each new branch has initiated its own P1. No scale leaves are produced by either branch and the morphological relationship among branches and the enclosing leaf varies. Often the branches are unequal and the enclosing leaf is fasciated. The vegetative branching in C. cataractarum is considered to be developmentally a true dichotomy and is compared with other examples of dichotomous (= terminal) branching in the Angiospermae.