The outer integument and funicular outgrowth complex in the ovule of<Emphasis Type="Italic"> Magnolia grandiflora</Emphasis> (Magnoliaceae)

The development of the outer integument and funicular outgrowth in the ovule of Magnolia grandiflora was examined by microtomy and scanning electron microscopy to reveal the morphology and evolution of the outer integument, a novel angiosperm structure. Early in development the outer integument is semiannular, decurrent to the lateral sides of the funiculus, and extends downwards beyond the funicular outgrowth that forms in the gap of the outer integument, and is transverse to the funiculus. The outer integument then overgrows the funicular outgrowth perpendicularly to the funiculus to form a micropyle together. The hood-shaped outer integument and the funicular outgrowth compose an envelope complex, and the interpretation of a single cupular outer integument is not supported. This envelope complex may differ from the cupular outer integument of other angiosperms, e.g., Nymphaeaceae, suggesting independent origin of apparently cupular outer integuments and hood-shaped outer integuments. Anatropous curving is due mainly to differential growth of the chalaza. The bistomic micropyle of Magnoliaceae seems to represent a derived character state, compared to an endostomic micropyle. T. Yamada is a research fellow of the Japan Society for the Promotion of Science.     

长豇豆种皮和种脐的发育

长豇豆的胚珠具内外两层珠被,内珠被在种子发育早期退化消失,种皮仅由外珠被发育而成。外珠被的外表皮细胞径向伸长,外壁和经向壁增厚,形成约占成熟种皮厚度一半的栅栏层;亚表皮细胞发育为骨状石细胞层。第三层细胞类似于亚表皮层但细胞壁增厚不明显,其内方的多层薄壁细胞形成海绵组织。种脐具两层栅栏细胞,外栅栏层及其以外部分由珠柄组织发育而成管胞群。本文还对脐缝和管胞群的作用以及豆科种子的吸水机制进行了讨论。     

Expression-based discovery of candidate ovule development regulators through transcriptional profiling of ovule mutants

Background  

Arabidopsis ovules comprise four morphologically distinct parts: the nucellus, which contains the embryo sac, two integuments that become the seed coat, and the funiculus that anchors the ovule within the carpel. Analysis of developmental mutants has shown that ovule morphogenesis relies on tightly regulated genetic interactions that can serve as a model for developmental regulation. Redundancy, pleiotropic effects and subtle phenotypes may preclude identification of mutants affecting some processes in screens for phenotypic changes. Expression-based gene discovery can be used access such obscured genes.     

Relationships of musculus rhomboideus, ligamentum nuchae and vertebrae thoracis and lumbales in Bos indicus

The funicular part of the ligamentum nuchae of Bos indicus attaches to the dorsolateral edges of the bifid spines of the seventh thoracic through third lumbar vertebrate. Cranially, the funiculus nuchae runs freely medial to the deep thoracic fascia which separates it from the overlying rhomboideus thoracis. The zebu hump is composed primarily of rhomboideus cervicis which in the thoracic position is clearly separable from underlying structures.     

Formation of the vascular system of developing bean (<Emphasis Type="Italic">Phaseolus limensis</Emphasis> L.) seeds according to nuclear magnetic resonance microtomography

¹H magnetic resonance microtomography imaging was applied to study vascular systems in developing bean (Phaseolus limensis L.) seeds. Using the gradient echo method, we recorded 2D tomographic sections in the sagittal and axial planes of the fruits sampled from a vegetating plant on days 10, 17, 24, and 31 after fertilization. Any vascular connection between the tissues of maternal plant (bean pod and seed coat) and the embryo were undetectable. The embryo has an autonomous branched network of procambial strands in the cotyledons, converging to the embryonic axis. The bean pods are covered with a network of vascular bundles; large vascular strands run along the dorsal and ventral sutures. The seed coat vascular bundles are formed in the process of seed ripening and are represented by a developed vascular system multiply branching in the middle part of the ground parenchyma at the stage of physiological maturity. They are connected with the source of assimilates via the lateral pod veins and a large vascular bundle, entering the seed below the hilum via the placenta. Assimilates enter the external part of the seed coat, which contains no vascular bundles, via the funiculus vascular bundles and hilum tissue.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. II. PRUNOIDEAE: MADDENIA,PYGEUM; OSMARONIA

A survey of species of the prunoid genera, Maddenia and Pygeum, and of the genus Osmaronia has been made. The ovules of all are pendent, campylotropous, and epitropic. In the prunoids, the ovular supply is intimately connected with a central vascular plexus in the base of the carpel; that plexus is absent from Osmaronia. The prunoid carpels are marked by an extensive degree of fusion among the ovular and wing bundles, by fusion of the sutural margins, by fusion of the 2 integuments of the ovule to a single massive one, and by the presence of 3 or 5 well-developed bundles in the base. The carpel of Osmaronia also has a strongly fused bipartite ovular supply, separate bundles of which, however, become very much attenuated before reaching the funiculus; it has independent ovular and wing bundles, completely separate carpellary margins, 2 clearly separate integuments in the ovule, and 6 distinctive bundles in the carpel base. At the funiculus, the wing bundle of Osmaronia is connected with the adjoining weak ovular bundle by a well-developed vascular branch. Various particularities in the morphology of Osmaronia lend support to its segregation into a unique tribe, the Osmaronieae of Rydberg.     

Anatomical diversity of funicles in Leguminosae

To clarify the diversity in funicular internal structures in Leguminosae, 59 legume species (classified into 46 genera, 20 tribes, and 3 subfamilies) were examined by a paraffin-sectioning method. The vascular bundles of legume funicles were clarified as collateral, amphicribral, or amphivasal. In species in which the funicular vascular bundle was collateral throughout the funicle, the xylem is positioned at the pericarpial side in the basal part of the funicle, and the xylem was always positioned at the micropylar side of the phloem in the apical end of the funicles. Whenever the seed direction (from hilum to the micropyle) faces the stylar side, the funicular vascular bundle appears to twist between the basal and the apical part of the funicle. This twist would involve a rotation of the seeds (ovules) during seed (ovule) development. This also may mean that the direction (from hilum to the micropyle) of legume seeds originally faces the pericarp.     

Development of ovule,fruit and seed of Xyris (Xyridaceae,Poales) and taxonomic considerations

The development of the ovule, fruit and seed of Xyris spp. was studied to assess the embryological characteristics of potential taxonomic usefulness. All of the studied species have (1) orthotropous, bitegmic and tenuinucellate ovules, with a micropyle formed by both the endostoma and exostoma; (2) a cuticle in the ovules and seeds between the nucellus/endosperm and the inner integument and between the inner and outer integuments; (3) helobial, starchy endosperm; (4) a reduced, campanulate and undifferentiated embryo; (5) a seed coat formed by a tanniferous endotegmen, endotesta with thick‐walled cells and exotesta with thin‐walled cells; and (6) a micropylar operculum formed from inner and outer integuments. The pericarp is composed of a mesocarp with cells containing starch grains and an endocarp and exocarp formed by cells with U‐shaped thickened walls. The studied species differ in the embryo sac development, which can be of the Polygonum or Allium type, and in the pericarp, which can have larger cells in either endocarp or exocarp. The Allium‐type embryo sac development was observed only in Xyris spp. within Xyridaceae. Xyris also differs from the other genera of Xyridaceae by the presence of orthotropous ovules and a seed coat formed by endotegmen, endotesta and exotesta, in agreement with the division of the family into Xyridoideae and Abolbodoideae. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 619–628.     

Cuticular structures on the antennae of Hypoderma bovis De Geer (Diptera : Oestridae) females

The antennae of Hypoderma bovis (Diptera: Oestridae) females were examined using scanning electron microscopy. Each antenna is composed of 3 parts: the scape, the pedicel, and the funiculus, with a large, protruding arista. Mechanoreceptors are found on the proximal and lateral margins of the scape and pedicel, respectively. Microtrichia, which are presumably non-innervated, are located evenly over both the outer surface of the scape and the inner surface of the pedicel. A narrow band of microtrichia is present proximally on the outer surface of the pedicel. The entire funicular surface is densely covered with microtrichia. Small patches lacking these microtrichia appear as depressions or “pits” (8–20 μm in diameter) on the surface of the funiculus. Olfactory sensilla found on the funicular surface include basiconica type 1, basiconica type 2, and trichoid sensilla. The sensilla basiconica commonly occur in pits on the anterodorsal surface of the funiculus. Trichoid sensilla are abundant on the posteroventral surface of the funiculus and do not appear to occur in pits. In addition, clavate and peg sensilla, whose functions are unknown, are found in low numbers on the funicular surface. There may be as many as 300 olfactory pits on the anterodorsal surface of each funiculus. These are single-chambered and contain 6 or fewer sensilla basiconica. We propose that a relatively high number of pits may be characteristic of flies in Superfamily Oestroidea (as compared with those of Superfamily Muscoidea), but that pit morphology within the Calyptratae is not Superfamily-specific.     

Le Basi Anatomiche Dei Rapporti Nutritivi Tra Pianta Madre,Seme Ed Embrione

Abstract

The anatomical basis of the nutritive relationships between mother plant, seed, and embryo. — The morphology and anatomy of the fruits and seeds of the Angiosperms show a great variety of structures and adaptments, even within the same family, and one must be cautious in drawing generalized conclusions.

If we first examine the ovary we see that the single carpel receives three vascular traces from which the three main bundles originate, a dorsal and two ventral ones, all more or less reduced. Except in the case of laminar placentation the ovule traces are connected to the ventral vascular system, but often the entire vascular system of the ovary is anastomosed and therefore reticular. However especially when the placentae are at the centre or at the basis of the ovary, it is possible to detect a tendency towards a separation between the vascular system of the ovarian wall and that of the placentae.

The ovular bundle runs through the funicle reaching the chalaza, where it can either end or continue towards the micropyle with a single bundle or with a few branches or even forming a complete reticular envelope surrounding the ovule. The ovular vascular bundles are normally found in the outer integument.

The ovule is made of an inner part (nucellus), and an outer one (integuments). The integuments play a very important role in the processes of seed maturation, dormancy, and germination. They are isolated from the interior of the seed by a cuticle which is a common production of the inner integumentary epidermis, and of the nucellus. The cuticle is not present in the chalaza and can be dissolved in the micropylar region: through these two apertures nutrients can penetrate into the seed or haustoria can grow out of it. During the course of maturation these openings become closed by various means, often through the formation of a new cuticle or of a suberised chalazal plate.

The nutrients which pass through the chalaza penetrate into the nucellus where in some cases one can find some structures which facilitate the communications between the chalaza and embryo sac. The endosperm feeds at the expense of the nucellus but often it can establish a direct contact with the chalaza or the integuments or even the placentae. This occurs often thanks to haustoria.

The embryo is normally surrounded at first by a more or less liquid endosperm: in a second stage the endosperm becomes cellular and the embryo grows at its expense through the digestive activity of the cotyledonar epidermis.

From an anatomo-physiological point of view the following points seem of particular interest:

(I) The endosperm and the embryo show a remarkable autonomy in respect of the mother plant: from an anatomical point of view this is shown by the isolation of the endosperm and embryo by means of a cuticular covering or substitutive structures and by the interposition of nutritive tissues between the vascular system of the mother plant and the endosperm.

(II) Given the importance of the inner cuticle its presence and its constitution should be ascertained in the various species having also in mind the properties of selective permeability shown by the testa.

(III) Two nutritive mechanisms exist: translocation of nutrients via the vascular system and the nutritive tissues, and digestion of surrounding cells. In the digestive phenomena it is important to explain the mechanisms by which only the right cells are digested and not the others.

(IV) The embryo very frequently is immersed at first in a more or less liquid endosperm and is later surrounded by a compact tissue; the nutritive mechanisms are probably different in the two cases.

(V) Two endospermic zones are often distinguishable: one having an haustorial or at least a digestive or elaborative function, and being typically non cellular; another zone, typically cellular, forms a tissue which is sooner or later absorbed by the embryo. The cellularization of this zone seems to coincide with the establishment of polarity and with the beginning of maximum growth of the embryo.

(VI) The relationships between the inner seed and the integuments is complex and there is a correlation between the histoanatomical and biochemical changes of these two parts during seed development. The modifications undergone by the integuments are important steps also towards the preparation of the seed to the processes of dispersal, dormancy, and germination.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE VI. POMOIDEAE: ERIOBOTRYA,HETEROMELES, PHOTINIA,POURTHIAEA, RAPHIOLEPIS,STRANVAESIA

The pomoid genera, Eriobotrya, Photinia, Pourthiaea, Raphiolepis, Stranvaesia, and Heteromeles, have compound inflorescences and biovulate carpels which become papery at maturity. The carpels of all of these except Heteromeles are fused with one another. There are open sutures in the carpels of Heteromeles, Photinia, Pourthiaea, and Raphiolepis, and in these four genera the extent of fusion of the ovular bundle with the wing bundle is related directly to the state of tegumentary fusion and to the extent of fusion of the carpel with the floral cup. In those species of Eriobotrya and Stranvaesia with closed sutures the integuments tend to be fused, as do the ovular and wing bundles, and the carpels are adnate with the floral cup for a considerable distance; in species with open sutures the integuments tend to be free, the ovular and wing bundles tend to be separate, and the extent of fusion of carpel with floral cup tends to be shorter. In genera with connate carpels the wing bundles of adjoining carpels may also be fused. The greatest extent of fusion occurs in Eriobotrya and Raphiolepis, in which there may also be attenuation and disappearance of the wing bundles above the region of ovular insertion and even reduction and disappearance of the carpellary margin.     

Scanning Electronmicroscopic Observations on Development and Structure of Pericarp of Nelumbo nucifera Gaertn

Pericarp of Hindu lotus is developed from the ovary wall only. It is differentiated intothe exocarp, mesocarp and endocarp which can be clearly recognized. The vascular bundles,secretory apparatus and aerenchyma are present in the ground tissue. The aeration system is.associated with stomata (St), air passages (Ap)and chamber (Ch). St apparatus with a specific form are located deeply under epidermal cells. Ap is schizogenous. Chisschizolysigenous. The wall of Ch has perforations which lead to surrounding cells. Ap and Ch arein contact with St in both outer and inner epidermis (Ep), so the aeration system covers the wholepericarp. In Ep, there are several kinds of secretory apparatus with different slimes. Lacticifers are articulated, some of them are branched and some not. In xylem, annular and helicaltracheids and vessels, in phloem, sieve tubes, companion cells and their contents can be observed. On the opposite side of the funicular attachment near stigma develops a hump. Thepericarp hump (Ph) is a specific structure in lotus. After studies on its fine structure, developing process and the relation between fruit development and Ph, the author considered thatPb functions probably as a respiratory apparatus of the developing seed.     

澳洲杨(大戟科)胚珠及其种子附属结构的个体发育研究

以澳洲杨的胚珠及其种子为材料,运用光学显微镜和电镜扫描的方法对其从胚珠发生直到种子成熟的个体发育过程和结构进行观察,同时与鸭脚西番莲的种子附属结构的发育过程进行对比研究。结果表明:(1)澳洲杨的珠孔类型为外珠孔类型,种子附属结构起源于珠孔而非珠柄,其为种阜,而非假种皮。(2)鸭脚西番莲的珠孔类型为内珠孔类型,种子附属结构起源于珠柄,并且最终将珠孔包被,其为真正的假种皮结构。通过种阜与假种皮的不同个体发育过程,建立了大戟科种阜与假种皮的不同发育模式,并对种子附属结构的生物学功能及其暗示的不同植物进化路径进行了讨论。     

The soybean F3′H protein is localized to the tonoplast in the seed coat hilum

We previously isolated a soybean (Glycine max (L.) Merr.) flavonoid 3'-hydroxylase (F3'H) gene (sf3'h1) corresponding to the T locus, which controls pubescence and seed coat color, from two near-isogenic lines (NILs), To7B (TT) and To7G (tt). The T allele is also associated with chilling tolerance. Here, Western-blot analysis shows that the sf3'h1 protein was predominantly detected in the hilum and funiculus of the immature seed coat in To7B, whereas sf3'h1 was not detected in To7G. A truncated sf3'h1 protein isolated from To7G was detected only upon enrichment by immunoprecipitation. An analysis using diphenylboric acid 2-aminoethyl ester (DBPA) staining revealed that flavonoids accumulated in the hilum and the funiculus in both To7B and To7G. Further, the scavenging activity of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical in methanol extracts from the funiculus and hilum of To7B was higher than that of To7G. Moreover, the enzymatic activity of F3'H was detected using microsomal fractions from yeast transformed with sf3'h1 from To7B, but not from To7G. These results indicate that sf3'h1 is involved in flavonoid biosynthesis in the seed coat and affects the antioxidant properties of those tissues. As shown by immunofluorescence microscopy, the sf3'h1 protein was detected primarily around the vacuole in the parenchymatic cells of the hilum in To7B. Further immunoelectron microscopy detected sf3'h1 protein on the membranous structure of the vacuole. Based on these observations, we conclude that F3'H, which is a cytochrome P450 monooxygenase and has been found to be localized to the ER in other plant systems, is localized in the tonoplast in soybean.     

Structural Development and Respiratory Activity of the Funiculus During Bean Seed (Phaseolus vulgaris L.) Maturation

Changes in the structural organization of the funiculus of Phaseolusvulgaris were correlated with mitochondrial respiration rates,including both cytochrome and alternative pathway activitiesand seed weight during development of the seed. After fertilization,vascular elements are still differentiating within the funiculus.The central core of the funiculus consists mainly of procambialcells together with a few mature xylem and phloem elements.As the seed gradually matures, more vascular elements beginto appear. Procambial cells in the upper region of the funiculusadjacent to the pod differentiate and result in xylem and phloemappearing as a convoluted, intertwining network of strands.In the lower part of the funiculus adjacent to the seed, fewervascular elements are present and they organize into a smallbundle prior to entering the seed. The funiculus is fully developedat the cotyledon stage judging from the size of the funiculusand the organization of the vascular tissues. At the early maturationstage, the seed begins to enlarge in both size and weight. Correlatedwith development of the funiculus tissue is a gradual decreasein total rates of respiration. Inhibitor studies using potassiumcyanide and/or salicylhydroxamic acid show that the CN-insensitive,or alternative pathway is the predominant route of electrontransport in funiculus mitochondria during the early stagesof development. This pathway declines in activity with age whereuponcytochrome pathway activity accounts for all of the respirationby the time vascular tissues are mature and the seed is rapidlyexpanding.Copyright 1994, 1999 Academic Press Funiculus, vascular tissue, cytochrome, respiratory pathway, alternative respiratory pathway, Phaseolus vulgaris     

Calcium Oxalate Crystals in Developing Seeds of Soybean

Young developing soybean seeds contain relatively large amountsof calcium oxalate (CaOx) monohydrate crystals. A test for Caand CaOx indicated that Ca deposits and crystals initially occurredin the funiculus, where a single vascular bundle enters theseed. Crystals formed in the integuments until the embryo enlargedenough to crush the inner portion of the inner integument. Crystalsthen appeared in the developing cotyledon tissues and embryoaxis. All crystals formed in cell vacuoles. Dense bodies andmembrane complexes were evident in the funiculus. In the innerintegument, cell vacuoles assumed the shape of the future crystals.This presumed predetermined crystal mould is reported here forthe first time for soybean seeds. As crystals in each tissuenear maturity, a wall forms around each crystal. This intracellularcrystal wall becomes contiguous with the cell wall. Integumentcrystals remain visible until the enlarging embryo crushes theinteguments; the crystals then disappear. A related study revealedthat the highest percent of oxalate by dry mass was reachedin the developing +16 d (post-fertilization) seeds, and thendecreased during late seed maturation. At +60 d, CaOx formationand disappearance are an integral part of developing soybeanseeds. Our results suggest that Ca deposits and crystals functionallyserve as Ca storage for the rapidly enlarging embryos. The oxalate,derived from one or more possible metabolic pathways, couldbe involved in seed storage protein synthesis. Copyright 2001Annals of Botany Company Calcium, crystals, development, Glycine max, ovule, oxalate, seed, soybean     

Embryogenesis and seed development in Sinomanglietia glauca (Magnoliaceae)

The development of the floral bud, especially the ovule and seed coat, of Sinomanglietia glauca was observed. Floral buds were covered by eight to nine hypsophyll pieces. The hypsophyll nearest the tepal was closed completely and characterized by two arrays of densely stained cells with dense cytoplasm, which split longitudinally at flowering. The perianth consisted of 16 tepals arranged in three whorls. The gynoecium was composed of numerous apocarpous carpels; the ovule was anatropous with two integuments. Embryogenesis was of the Polygonum type, and the endosperm was nuclear. The inner integument degenerated during seed development. The seed of S. glauca had an endotestal seed coat comprised of a sclerotic layer derived from the inner adaxial epidermis of the outer integument and a sarcotesta derived mainly from the middle cells between the inner and outer epidermis of the outer integument. The embryo developed normally, so embryogenesis is not the cause of difficult regeneration.     

Systematic implications of seed coat diversity in Gaultherieae (Ericaceae)

The seed morphology of 90 samples from 83 species of tribe Gaultherieae (Chamaedaphne, Diplycosia, Eubotryoides, Eubotrys, Gaultheria and Leucothoe) and relatives in tribes Andromedeae (Andromeda and Zenobia) and Vaccinieae (Satyria) was investigated with stereoscopic and scanning electron microscopy. Seeds exhibit variation in shape, colour, size, wing, hilum region, primary ornamentation and epidermal cells. Non‐metric multidimensional scaling (NMDS) analysis based on selected seed characters supports the affinities of some groups within Gaultherieae at various taxonomic levels. Seed characters corroborate the delimitation of Andromeda, Chamaedaphne, Leucothoe, Satyria and Zenobia and Gaultheria series Trichophyllae, series Hispidulae, section Amblyandra and section Brossaeopsis. Parsimony optimization of seed characters onto a previously published phylogenetic estimate of Gaultherieae reveals that small seeds have evolved from larger seeds and an areolate seed coat has evolved from a reticulate seed coat. Optimization also suggests that several seed character states are synapomorphies or potential synapomorphies for some major clades of Gaultherieae. Seeds of Gaultherieae from East Asia, temperate North America and the Pacific are more diverse than those from tropical America. Samples from the eastern Himalaya possess the highest variation in seed morphology. The wing and bulging edge cells observed in seeds of Leucothoe suggest dispersal by wind. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 162 , 477–495.