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1
Chaban, Inna A., Alexander A. Gulevich, Neonila V. Kononenko, Marat R. Khaliluev e Ekaterina N. Baranova. "Morphological and Structural Details of Tomato Seed Coat Formation: A Different Functional Role of the Inner and Outer Epidermises in Unitegmic Ovule". Plants 11, n. 9 (19 aprile 2022): 1101. http://dx.doi.org/10.3390/plants11091101.
Testo completoAbstract (sommario):
In order to understand how and what structures of the tomato ovule with a single integument form the seed coat of a mature seed, a detailed study of the main development stages of the tomato ovule integument was carried out using the methods of light and electron microscopy. The integument itself it was shown to transform in the course of development into the coat (skin) of a mature seed, but the outer and inner epidermises of the integument and some layers of the integument parenchyma are mainly involved in this process. The outer epidermis cells are highly modified in later stages; their walls are thickened and lignified, creating a unique relatively hard outer coat. The fate of the inner epidermis of integument is completely different. It is separated from the other parenchyma cells of integument and is transformed into an independent new secretory tissue, an endothelium, which fences off the forming embryo and endosperm from the death zone. Due to the secretory activity of the endothelium, the dying inner parenchyma cells of the integument are lysed. Soon after the cuticle covers the endosperm, the lysis of dead integument cells stops and their flattened remnants form dense layers, which then enter the final composition of the coat of mature tomato seed. The endothelium itself returns to the location of the integument inner epidermis.
2
Baker, Daniel M., Harry C. Minor e Billy G. Cumbie. "Scanning electron microscopy examination of soybean testa development". Canadian Journal of Botany 65, n. 11 (1 novembre 1987): 2420–24. http://dx.doi.org/10.1139/b87-329.
Testo completoAbstract (sommario):
Seeds of soybean (Glycine max (L.) Merr.) were harvested from greenhouse-grown plants and fractures of the seed coat were examined with a scanning electron microscope. The seed coat was well differentiated from the outer integument when the seed had reached approximately 30% maximum seed size. At this time, the osteosclereids began to separate, becoming fully detached along their radial walls by 50% maximum seed size. Macrosclereid secondary wall development occurred during growth of the seed from 50 to 100% maximum seed size. Near R6 (100% maximum seed size) the endothelium began differentiation from the integumentary tapetum (inner integument) and was fully differentiated by physiological maturity (R7). From R7 to harvest maturity (R8) the seed lost moisture content and decreased in size. The parenchyma of the seed coat collapsed in response to this dehydration.
3
Zhou, Jing, Yanrong Wang e Jason Trethewey. "Semi-permeable layer formation during seed development in Elymus nutans and Elymus sibiricus". Acta Societatis Botanicorum Poloniae 82, n. 2 (2013): 165–73. http://dx.doi.org/10.5586/asbp.2013.012.
Testo completoAbstract (sommario):
<p>The semi-permeable layer is a layer in the seeds of certain plants that restricts or impedes the exchange of the solute while allowing the permeability of internal and external water and gas, which is valuable protection to sustain the health and secure the growth, development and germination. In this study, the formation time and location of the semi-permeable layer in seed coats of <em>Elymus nutants</em> (Griseb.) and <em>Elymus sibiricus</em> (L.) were investigated. The experimental seed materials were gathered in the field from the flowering to seed maturation. The light microscopy and transmission electron microscopy for lanthanum nitrate identification were used to examine the characteristics of pericarp, seed coat and nucellus. The results showed that the semi-permeable layer was identified as the position, which can inhibit the penetration of the lanthanum, and it was checked as an amorphous membrane located at the outermost layer of the seed coat that is firmly attached to the seed coat. With seed development, the cells had differentiated and some parts of the ovary and the outer integument had disappeared. The semi-permeable layer originated from the outer layer of the inner integument, which was the original form of the seed coat. It can be stained by the Sudan III and clearly distinguished from other parts of the seed. The formation time of the semi-permeable layer in both species was nearly at 10 to 12 days post-anthesis (dpa), whereas seed physiological maturity was 24 to 26 dpa.</p>
4
Hamilton, Kim N., Sarah E. Ashmore, Rod A. Drew e Hugh W. Pritchard. "Seed morphology and ultrastructure in Citrus garrawayi (Rutaceae) in relation to germinability". Australian Journal of Botany 55, n. 6 (2007): 618. http://dx.doi.org/10.1071/bt06188.
Testo completoAbstract (sommario):
Combinational traits of seed size and seed-coat hardness in Citrus garrawayi (F.M.Bailey) (syn. of Microcitrus garrowayi) were investigated as markers for estimation of seed morphological and physiological maturity. Seed size (length) and coat hardness correlated well with changes in seed coat and embryo morphological development, dry-weight accumulation, decreases in moisture content and a significant increase in germinability. Seed moisture content decreased from 82 ± 1% in immature seeds to 40 ± 1% at seed maturation. The outer integument of immature seeds consisted of thin-walled epidermal fibres from which outgrowths of emerging protrusions were observed. In comparison, mature seed coats were characterised by the thickening of the cell walls of the epidermal fibres from which arose numerous protrusions covered by an extensive mucilage layer. Immature seeds, with incomplete embryo and seed-coat histodiffereniation, had a low mean germination percentage of 4 ± 4%. Premature seeds, with a differentiated embryonic axis, were capable of much higher levels of germination (51 ± 10%) before the attainment of mass maturity. Mature seeds, with the most well differentiated embryonic axis and maximum mean dry weight, had the significantly highest level of germination (88 ± 3%).
5
Shinke, Ikumi, e Toru Tokuoka. "Embryology of Styracaceae and implications for the evolution of the integument number in Ericales". Botanical Journal of the Linnean Society 193, n. 1 (19 marzo 2020): 125–39. http://dx.doi.org/10.1093/botlinnean/boaa007.
Testo completoAbstract (sommario):
Abstract Phylogenetic relationships in Styracaceae are well understood, but embryological characters and the ontogeny of integument(s) are still uncertain in many species. The goals of this study are to evaluate the systematic implications of embryological characters in Styracaceae, clarify the character evolution of the number of integuments and suggest a mechanism for the transition between unitegmic and bitegmic ovules. We examined the embryological characters of four genera and five species of Styracaceae, most of which were shared across taxa. However, Styrax has specific embryological features including bitegmic ovules, a multiplicative and sclerotic outer mesotesta and vascular bundles in the testa, all possible autapomorphies. The other three genera of Styracaceae share a unitegmic ovule, a parenchymatous mesotesta and a seed coat without vascular bundles, possible plesiomorphies with Diapensiaceae and Symplocaceae. The transition from a unitegmic to a bitegmic condition can be interpreted to be caused by a downwards shift of the boundary between the inner and outer integument, due to reduced activity in the subdermal initials and increased activity in the dermal initials of the outer integument at its base.
6
Neumann, Ulla, e Angela Hay. "Seed coat development in explosively dispersed seeds of Cardamine hirsuta". Annals of Botany 126, n. 1 (4 dicembre 2019): 39–59. http://dx.doi.org/10.1093/aob/mcz190.
Testo completoAbstract (sommario):
Abstract Background and Aims Seeds are dispersed by explosive coiling of the fruit valves in Cardamine hirsuta. This rapid coiling launches the small seeds on ballistic trajectories to spread over a 2 m radius around the parent plant. The seed surface interacts with both the coiling fruit valve during launch and subsequently with the air during flight. We aim to identify features of the seed surface that may contribute to these interactions by characterizing seed coat differentiation. Methods Differentiation of the outermost seed coat layers from the outer integuments of the ovule involves dramatic cellular changes that we characterize in detail at the light and electron microscopical level including immunofluorescence and immunogold labelling. Key Results We found that the two outer integument (oi) layers of the seed coat contributed differently to the topography of the seed surface in the explosively dispersed seeds of C. hirsuta vs. the related species Arabidopsis thaliana where seed dispersal is non-explosive. The surface of A. thaliana seeds is shaped by the columella and the anticlinal cell walls of the epidermal oi2 layer. In contrast, the surface of C. hirsuta seeds is shaped by a network of prominent ridges formed by the anticlinal walls of asymmetrically thickened cells of the sub-epidermal oi1 layer, especially at the seed margin. Both the oi2 and oi1 cell layers in C. hirsuta seeds are characterized by specialized, pectin-rich cell walls that are deposited asymmetrically in the cell. Conclusions The two outermost seed coat layers in C. hirsuta have distinct properties: the sub-epidermal oi1 layer determines the topography of the seed surface, while the epidermal oi2 layer accumulates mucilage. These properties are influenced by polar deposition of distinct pectin polysaccharides in the cell wall. Although the ridged seed surface formed by oi1 cell walls is associated with ballistic dispersal in C. hirsuta, it is not restricted to explosively dispersed seeds in the Brassicaceae.
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Windsor, J. Brian, V. Vaughan Symonds, John Mendenhall e Alan M. Lloyd. "Arabidopsis seed coat development: morphological differentiation of the outer integument". Plant Journal 22, n. 6 (giugno 2000): 483–93. http://dx.doi.org/10.1046/j.1365-313x.2000.00756.x.
Testo completo
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Wu, Limin, Aliaa El-Mezawy e Saleh Shah. "A seed coat outer integument-specific promoter for Brassica napus". Plant Cell Reports 30, n. 1 (4 novembre 2010): 75–80. http://dx.doi.org/10.1007/s00299-010-0945-2.
Testo completo
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Liu, Zhenhua, Yan Wang, Wenjiang Pu, Haifeng Zhu, Jinjun Liang, Jiang Wu, Liang Hong, Pingyin Guan e Jianfang Hu. "4-CPA (4-Chlorophenoxyacetic Acid) Induces the Formation and Development of Defective “Fenghou” (Vitis vinifera × V. labrusca) Grape Seeds". Biomolecules 11, n. 4 (30 marzo 2021): 515. http://dx.doi.org/10.3390/biom11040515.
Testo completoAbstract (sommario):
For some horticultural plants, auxins can not only induce normal fruit setting but also form fake seeds in the induced fruits. This phenomenon is relatively rare, and, so far, the underlying mechanism remains unclear. In this study, “Fenghou” (Vitis vinifera × V. labrusca) grapes were artificially emasculated before flowering and then sprayed with 4-CPA (4-chlorophenoxyacetic acid) to analyze its effect on seed formation. The results show that 4-CPA can induce normal fruit setting in “Fenghou” grapes. Although more seeds were detected in the fruits of the 4-CPA-treated grapevine, most seeds were immature. There was no significant difference in the seed shape; namely, both fruit seeds of the grapevines with and without 4-CPA treatment contained a hard seed coat. However, the immature seeds lacked embryo and endosperm tissue and could not germinate successfully; these were considered defective seeds. Tissue structure observation of defective seeds revealed that a lot of tissue redifferentiation occurred at the top of the ovule, which increased the number of cell layers of the outer integument; some even differentiated into new ovule primordia. The qRT-PCR results demonstrated that 4-CPA application regulated the expression of the genes VvARF2 and VvAP2, which are associated with integument development in “Fenghou” grape ovules. Together, this study evokes the regulatory role of 4-CPA in the division and continuous redifferentiation of integument cells, which eventually develop into defective seeds with thick seed coats in grapes.
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Carrillo-Ocampo, Aida, e E. Mark Engleman. "Anatomía de la semilla de Chenopodium berlandieri ssp. nuttalliae (Chenopodiaceae) "huauzontle"". Botanical Sciences, n. 54 (25 aprile 2017): 17. http://dx.doi.org/10.17129/botsci.1426.
Testo completoAbstract (sommario):
The seed of huauzontle (Chenopodium berlandieri ssp. nuttalliae) was studied by light microscopy and scanning electron microscopy. When the outer integument arises around the young ovule, instead of covering the inner integument and the nucellus, it grows backwards and partially surrounds the funiculus . When the pericarp is removed from the mature fruit, the seed is straw colored, because only the tegmen covers the seed. The chalaza of this seed has the form of a truncate cone, with the elliptical base towards the nucellus. In this zone of contact between the chalaza and the nucellus. a cuticle is deposited that surrounds some cells and makes a three dimensional network. This chalazal network is in contact with a smooth nucellar cuticle that fom1s part of the seed coat. The inversion of the inner integument could represent a selected mutation during the process of domestication.
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Zhang, Keliang, Yin Zhang, Yusong Ji, Jeffrey L. Walck e Jun Tao. "Seed Biology of Lepidium apetalum (Brassicaceae), with Particular Reference to Dormancy and Mucilage Development". Plants 9, n. 3 (5 marzo 2020): 333. http://dx.doi.org/10.3390/plants9030333.
Testo completoAbstract (sommario):
Lepidium apetalum (Brassicaceae) is an annual or biennial weed widely distributed in Asia and Europe. The outer surface of L. apetalum seeds produces a large amount of mucilage. The primary aim of this study was to explore the dormancy characteristics and to determine how mucilage develops. The role of mucilage in water absorption/dehydration, the effects of after-ripening, gibberellin acid (GA3), cold stratification and seed coat scarification on germination, the role of mucilage in germination and seedling growth during drought, and the progress of mucilage production during seed development were investigated. The results indicate that the best temperature regime for germination was 10/20 °C. After-ripening, GA3 and seed coat scarification helped to break dormancy. Light promoted germination. Seedling growth of mucilaged seeds were significantly higher than those of demucilaged seeds at −0.606 and −1.027 MPa. Anatomical changes during seed development showed that mucilage was derived from the outer layer of the outer integument cells. Our findings suggest that seeds of L. apetalum exhibited non-deep physiological dormancy. The dormancy characteristics along with mucilage production give seeds of L. apetalum a competitive advantage over other species, and thus contribute to its potential as a weed. Effective control of this weed can be achieved by deep tillage.
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García-Villanueva, Eduardo, e E. Mark Engleman. "Ontogenia de la semilla de Yucca periculosa (Agavaceae)". Botanical Sciences, n. 61 (20 maggio 2017): 5. http://dx.doi.org/10.17129/botsci.1534.
Testo completoAbstract (sommario):
Seeds of several Yucca species have been studied by Arnott and Horner. They mainly studied the nature condition and stated that the extra-embryonic food reserve tissue is a perisperm. This paper provides ontogenic evidence that this tissue is an endosperm with nuclear development type. The seed shape is nearly a triangular prism less than 1 cm long, black color and the raphe groove is conspicuous. The seed coat is derived exclusively from the outer integument. The exotesta external periclinal cell wall appears with irregular thickness. Both mesotesta and endotesta grow irregularly inward the seed confering to the endosperm a ruminate appearance. Toward seed maturity, the inner integument tissues disappear, thus fusion between intertegumentary and tegmen-nucellar cuticles occurs; valuable ontogenic information is showed by the cuticles, due to its persistence in spite of its generative tissue disappearance. The embryo development increases until 10 weeks after anthesis, it is cylindric, folds like "S" and two thirds of its chalazal lenght correspond to the cotyledon.
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Tobe, H., e PH Raven. "The embryology and relationships of Gyrostemonaceae*". Australian Systematic Botany 4, n. 2 (1991): 407. http://dx.doi.org/10.1071/sb9910407.
Testo completoAbstract (sommario):
On the basis of studies of Codonocalpus and Gyrostemon, this is the first report on the embryology of the Gyrostemonaceae, one of 15 glucosinolate-producing families. The embryology of Gyrostemonaceae was studied in an effort to clarify the phylogenetic relationships of those families that have been the subject of some dispute. Embryologically, Gyrostemonaceae possess distinctive features in integuments, seeds and seed coats. These include: the outer integument (or testa), non-multiplicative (i.e. two-cell-layered) and non-vascularised; seeds reniform and albuminous; the seed coat 'exotegmic', with exotegmic cells fibrous and all other tegmic cells crushed. Nearly all of these features are common to Capparaceae and Resedaceae (glucosinolate-producing families of Capparales), but are not found in Sapindaceae (a non-glucosinolateproducing family of Sapindales), both of which have recently been considered to be close allies of Gyrostemonaceae. Shared embryological features suggest strongly that Gyrostemonaceae are closely related to Capparaceae and Resedaceae and should be placed near them within Capparales. Available embryological evidence neither supports close relationships between Gyrostemonaceae and Bataceae nor one linking Gyrosternonaceae with Sapindaceae.* Dedicated to Professor G. B. Marini Bettolo, on the occasion of his 75th birthday in 1990, and his retirement from the Università Degli Studi di Roma.
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Feng, Qiuhong, Ming Cai, Honglin Li e Xin Zhang. "How Seeds Attract and Protect: Seed Coat Development of Magnolia". Plants 13, n. 5 (29 febbraio 2024): 688. http://dx.doi.org/10.3390/plants13050688.
Testo completoAbstract (sommario):
Seeds are one of the most important characteristics of plant evolution. Within a seed, the embryo, which will grow into a plant, can survive harsh environments. When the seeds are mature, the mother plant will disperse them from its body, allowing them to be taken away to grow in a new place. Otherwise, if the young generation grows alongside the mother plants in the same place, they will compete for sunlight and nutrition. The mother plants use different strategies to send away their seeds. One of these strategies is endozoochory, which means that the seeds disperse via ingestion by animals. There is a conflict between the seeds’ abilities to attract animals and protect the embryo within the digestion systems of animals. Magnolia seeds exhibit typical endozoochory. The seed coats of Magnolia feature sarcotestas and sclerotestas. The sarcotesta, which is fleshy, bright-colored, and edible, attracts animals. The sclerotesta is hard and woody, protecting the embryo from the digestive systems of animals. In this study, we used scanning electron and light microscopes to examine the development of the sarcotesta and sclerotesta of Magnolia stellata seed coats. The results showed that the sarcotesta and sclerotesta come from the outer integument. This result confirms the hypothesis of Asa Gray from 1848. The dependence of the seed dispersal strategy on structural development is discussed.
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Puspitaningtyas, D. M., E. K. Agustin, I. F. Wanda, M. Zanzibar, Sahromi, D. Latifah e A. H. Widjaya. "The conservation of wild species banana (Musa velutina H.Wendl. & Drude) through seed germination technology". IOP Conference Series: Earth and Environmental Science 1271, n. 1 (1 dicembre 2023): 012012. http://dx.doi.org/10.1088/1755-1315/1271/1/012012.
Testo completoAbstract (sommario):
Abstract Musa velutina H. Wendl. & Drude is a member of the Musaceae family, which is known as the pink velvet banana. This species has problems with seed germination. The seed coat has a hard layer of the outer integument that inhibits the germination process. This study aimed to determine the effect of the soaking time at various soaking media of the seven treatments on the seed germination of M. velutina. The method used a completely randomized design with seven treatments and three replications. The seeds were collected from a fruit bunch of M. velutina in Bogor Botanic Gardens. The number of seeds was 10 for each treatment. The treatments in this study were scarification by seed wounds, soaking seeds in 1% H2O2 and 5% H2O2 for four days, soaking seeds in hot water at 60°C and 80°C for 1 hour, soaking seeds in water for 24 hours and 72 hours. Then, as a control, the fresh seeds were sowed directly without treatment. The results showed that soaking in water for 24 hours was the best method for the early emergence of sprouts, the percentage of germination rate, the coefficient of germination rate, and the coefficient of simultaneous germination.
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Trimanto, Trimanto, Elga Renjana, Dewi Ayu Lestari, Elok Rifqi Firdiana, Shofiyatul Mas’udah, Apriyono Rahadiantoro, Linda Wige Ningrum e Lia Hapsari. "Morphological Characterization and Seed Germination Study of Wild Banana <i>Musa acuminata</i> var. <i>flava</i> (Ridl.) Nasution". Journal of Tropical Biodiversity and Biotechnology 7, n. 1 (14 febbraio 2022): 66645. http://dx.doi.org/10.22146/jtbb.66645.
Testo completoAbstract (sommario):
Wild bananas provide important genetic materials for further banana improvement, therefore they need to be conserved and studied. This study aimed to describe morphological characteristics of plant and seed and also to study the seed germination of wild banana M. acuminata var. flava (Ridl.) Nasution. The morphological characteristics were observed descriptively by referring to the descriptor for banana. The internal and external morphology of the seeds were observed using a digital microscope. The germination testing was carried out by a completely randomized design, using fresh seeds extracted from a bunch of fruits with two ripeness levels i.e. fully-ripe (yellow peel) and under-ripe (green-yellow peel). The data resulted was then analyzed using an independent t-test. The results showed that M. acuminata var. flava is characterized as a perennial herb; pseudostem height ≥3 m; male bud like a top with prominent green-yellow bracts; fruit curved and tasted mild-sweet when ripe. The seed is angular with wrinkled surface, and dark brown-black color when ripe. The longitudinal section showed parts of the seeds comprising the seed coat, outer and inner integument, embryo, endosperm, chalazal mass, micropyle cap and channel. The seeds are classified as orthodox, with hypogeal type and gradual germination pattern. The seeds extracted from fully-ripe fruit germinated faster with higher germination percentage and growth variables (root number and plant height). Thus, it is suggested to use physiologically mature seeds (seeds from fully-ripe fruits) which should be separated from the seeds of under-ripe fruits to lower the heterogeneity.
17
Clarke, Kerri, e Nallamilli Prakash. "Floral morphology and embryology of two Australian species of Citrus (Rutaceae)". Australian Journal of Botany 49, n. 2 (2001): 199. http://dx.doi.org/10.1071/bt99054.
Testo completoAbstract (sommario):
The floral morphology and embryology of two species of Australian Citrus L. occurring in the most southerly range of the genus, C. australasica F.Muell. and C. australis (Mudie) Planchon, have been studied. Cytokinesis in the microsporocytes was simultaneous resulting in tetrahedral tetrads. Tapetal cells were bi- to multinucleate and unevenly one- or two-layered. Microspore development was frequently asynchronous. Anther wall consisted of a layer of endothecium, three to five middle layers and one or two layers of Secretory tapetum. The ovules were anatropous, bitegmic and crassinucellate. Although multiple sporogenous cells that grew into multiple megasporocytes were common, occurrence of twin or multiple gametophytes was rare. Development of the female gametophyte was of the Polygonum type, with antipodal cells frequently persisting until after fertilisation. Endosperm was of the Nuclear type while embryogeny was of the Onagrad type. Both integuments contributed to the seed coat. Cells of the outer layer of the testa developed fibrous thickenings and secreted mucilage. Seeds were monoembryonate and seed germination was hypogeal. The recent move incorporating Australian native citrus species in to the genus Citrus was supported on the grounds of close embryological similarities.
18
Castro, Elisa de Melo, Édila Vilela de Resende Von Pinho, Amador Eduardo de Lima, Cláudia Regina Gontijo Labory, Heloisa Oliveira dos Santos, Eduardo Alves e Alisson Francelino dos Reis Guerra. "Physiological quality, lignin and the ultrastructural characterization of soybean seeds". Acta Scientiarum. Agronomy 46, n. 1 (12 dicembre 2023): e63621. http://dx.doi.org/10.4025/actasciagron.v46i1.63621.
Testo completoAbstract (sommario):
In soybeans, the integument or seed coat is an important modulator between the external and internal environment. It plays a fundamental role in seed vitality, and its lignin content may influence the seed quality. The objective of this experiment was to evaluate the quality of soybean seeds from a partial diallel and their reciprocals and its relationship with lignin content, seed coat thickness, and deposition location. The seeds were also evaluated for physiological quality through germination and accelerated aging tests. The lignin content was quantified by absorbance, and the integument thickness was analyzed and measured using scanning electron microscopy. The most contrasting cultivars for lignin content were analyzed using fluorescence microscopy and histochemical techniques. Cultivars and their reciprocals differed in seed physiological quality. We found differences in the genotypes for integument thickness. Using histochemical techniques, autofluorescence was observed in the same regions identified as lignified. Positive staining for lignin was observed in the hilum region. Among the genotypes, we found variations in the physiological quality of seeds (germination and accelerated aging test), lignin content, and integument thickness.
19
Id, Vera Lygia El Id, e Nelson Augusto dos Santos Junior. "Adaptive advantage of Sesbania virgata (Cav.) Pers. in the phytochemical production: the influence on fungi occurring in seeds". Acta Scientiarum. Biological Sciences 45 (27 ottobre 2023): e65301. http://dx.doi.org/10.4025/actascibiolsci.v45i1.65301.
Testo completoAbstract (sommario):
Sesbania virgata is a native Brazilian plant species. It exhibits rapid growth, a high soil cover potential, and efficient soil seed bank formation and is used in environmental restoration projects. The soil seed bank is susceptible to fungal infection and other biotic factors. However, only a few studies have reported on the fungi on the surface of S. virgata seeds. Moreover, little is known about how substances present in the seed integument affect fungal communities and their role in adapting to and thriving in new environments. Herein, S. virgata seeds were collected from populations that produce or do not produce the flavonoid catechin in the seed coat. These seeds were subjected to laboratory tests to identify and quantify the fungal populations in the integument. We selected and subjected three genera to irrigation and inoculation tests with S. virgata extracts and seeds from both populations. We observed that the aqueous seed coat extracts inhibited Alternaria sp. micellar and augmented Phoma sp. growth. Phoma sp. also caused post-germinated seed lethality. Our data indicate that the seed coat of S. virgata contains antifungal substances that endow this species with an adaptive advantage.
20
Matilla, Angel J. "Seed coat formation: its evolution and regulation". Seed Science Research 29, n. 4 (dicembre 2019): 215–26. http://dx.doi.org/10.1017/s0960258519000254.
Testo completoAbstract (sommario):
AbstractIn higher plants, the seed precursor (ovule primordia) is composed of three parts: funiculus, nucellus and chalaza, generating the latter one (II) or two (OI and II) protective maternal integuments (seed coat, SC). The appearance of a viable seed requires the coordinate growth and development of the preceding three compartments. Integuments are essentials for seed life as they nourish, protect and facilitate seed dispersion. Endosperm and integument growth and development are tightly coupled. Gymnosperm and angiosperm ovules are commonly unitegmic and bitegmic, respectively. Unusually, ategmy and threetegmy (OI, II and aril) also exist. The expression of the INO, ATS and ETT genes, involved in integument development, seems to have demonstrated that the fusion of OI and II leads to the appearance of unitegmy in higher plants. Likewise, INO expression also manifests the conservation of OI during evolution. The molecular control of SC development is constituted by a signalling network with still a multitude of gaps. The fertilization-independent development of the ovule is repressed by the FERTILIZATION INDEPENDENT SEED (FIS), a Polycomb-Repressive-Complex-2 (PRC2). Both endosperm and SC development are tightly linked to PRC2 function. As in many other developmental processes, auxin plays an essential role during ovule and SC development. Auxin transport from the endosperm to the integuments is regulated by AGL62 (AGAMOUS-LIKE 62), the encoding gene of which is specifically expressed in the endosperm to suppress its cellularization. In the absence of AGL62 (i.e. agl62 mutants), auxin remains trapped in the endosperm and the SC fails to develop (i.e. seed abortion). This update shows that auxin biosynthesis, transport and signalling play a predominant role and seem to be absolutely required in the pathway(s) that lead to SC formation, most likely not as a unique hormonal component.
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Miart, Fabien, Jean-Xavier Fontaine, Gaëlle Mongelard, Christopher Wattier, Michelle Lequart, Sophie Bouton, Roland Molinié et al. "Integument-Specific Transcriptional Regulation in the Mid-Stage of Flax Seed Development Influences the Release of Mucilage and the Seed Oil Content". Cells 10, n. 10 (6 ottobre 2021): 2677. http://dx.doi.org/10.3390/cells10102677.
Testo completoAbstract (sommario):
Flax (Linum usitatissimum L.) seed oil, which accumulates in the embryo, and mucilage, which is synthesized in the seed coat, are of great economic importance for food, pharmaceutical as well as chemical industries. Theories on the link between oil and mucilage production in seeds consist in the spatio-temporal competition of both compounds for photosynthates during the very early stages of seed development. In this study, we demonstrate a positive relationship between seed oil production and seed coat mucilage extrusion in the agronomic model, flax. Three recombinant inbred lines were selected for low, medium and high mucilage and seed oil contents. Metabolite and transcript profiling (1H NMR and DNA oligo-microarrays) was performed on the seeds during seed development. These analyses showed main changes in the seed coat transcriptome during the mid-phase of seed development (25 Days Post-Anthesis), once the mucilage biosynthesis and modification processes are thought to be finished. These transcriptome changes comprised genes that are putatively involved in mucilage chemical modification and oil synthesis, as well as gibberellic acid (GA) metabolism. The results of this integrative biology approach suggest that transcriptional regulations of seed oil and fatty acid (FA) metabolism could occur in the seed coat during the mid-stage of seed development, once the seed coat carbon supplies have been used for mucilage biosynthesis and mechanochemical properties of the mucilage secretory cells.
22
Yu, Anmin, Zaiqing Wang, Yang Zhang, Fei Li e Aizhong Liu. "Global Gene Expression of Seed Coat Tissues Reveals a Potential Mechanism of Regulating Seed Size Formation in Castor Bean". International Journal of Molecular Sciences 20, n. 6 (14 marzo 2019): 1282. http://dx.doi.org/10.3390/ijms20061282.
Testo completoAbstract (sommario):
The physiological and molecular basis of seed size formation is complex, and the development of seed coat (derived from integument cells) might be a critical factor that determines seed size formation for many endospermic seeds. Castor bean (Ricinus communis L.), a model system of studying seed biology, has large and persistent endosperm with a hard seed coat at maturity. Here, we investigated the potential molecular mechanisms underlying seed size formation in castor bean by comparing the difference between global gene expression within developing seed coat tissues between the large-seed ZB107 and small-seed ZB306. First, we observed the cell size of seed coat and concluded that the large seed coat area of ZB107 resulted from more cell numbers (rather than cell size). Furthermore, we found that the lignin proportion of seed coat was higher in ZB306. An investigation into global gene expression of developing seed coat tissues revealed that 815 genes were up-regulated and 813 were down-regulated in ZB306 relative to ZB107. Interestingly, we found that many genes involved in regulating cell division were up-regulated in ZB107, whereas many genes involved in regulating lignin biosynthesis (including several NAC members, as well as MYB46/83 and MYB58/63) and in mediating programmed cell death (such as CysEP1 and βVPE) were up-regulated in ZB306. Furthermore, the expression patterns of the genes mentioned above indicated that the lignification of seed coat tissues was enhanced and occurred earlier in the developing seeds of ZB306. Taken together, we tentatively proposed a potential scenario for explaining the molecular mechanisms of seed coat governing seed size formation in castor bean by increasing the cell number and delaying the onset of lignification in seed coat tissues in large-seed ZB107. This study not only presents new information for possible modulation of seed coat related genes to improve castor seed yield, but also provides new insights into understanding the molecular basis of seed size formation in endospermic seeds with hard seed coat.
23
Baker, Daniel M., e Tadesse Mebrahtu. "Scanning electron microscopy examination of soybean hilum development". Canadian Journal of Botany 68, n. 3 (1 marzo 1990): 544–50. http://dx.doi.org/10.1139/b90-075.
Testo completoAbstract (sommario):
Seeds of the soybean (Glycine max (L.) Merr.) cultivar Tracy-M were harvested from field-grown plants, and fractures of the hilum were examined with a scanning electron microscope. Macrosclereid and hilar fissure differentiation were observed at approximately 1% maximum seed size. The tracheid bar, stellate cells, sclerenchyma, and rim aril began differentiation near 5% maximum seed size. Outer integument differentiation was nearly completed by 35% maximum seed size, when articulated parenchyma, aerenchyma, and pits in the developing tracheids were observed. Hilum development was completed when the aleurone differentiated from the inner integument prior to seed maturity. Partial seed abscission was observed during hilum development.
24
Oliveira, D. M. T., e E. A. S. Paiva. "Anatomy and ontogeny of Pterodon emarginatus (Fabaceae: Faboideae) seed". Brazilian Journal of Biology 65, n. 3 (agosto 2005): 483–94. http://dx.doi.org/10.1590/s1519-69842005000300014.
Testo completoAbstract (sommario):
The aim of this study was to describe the anatomy and ontogeny of Pterodon emarginatus seed using the usual techniques. The ovules are campilotropous, crassinucelate, and bitegmic. The following processes occur during integument development: anticlinal divisions and phenolic compound accumulations in the exotesta, whose cells become palisade; predominantly periclinal divisions and cell expansion in the mesotesta, where the rapheal bundle differentiates; differentiation of the hourglass-cell layer adjacent to the palisade; fusion of outer and inner integuments, which remain individualized structures only at the micropylar end; and intense pectin impregnation in the mesotesta thicker walls with lignification restricted to the xylem. At the hilar pole, the Faboideae seed characteristic structure develops, with double palisade layer, subhilar parenchyma, and tracheid bar. The younger nucellus shows thicker pectic cell walls and is consumed during seed formation. The endosperm is nuclear and, after cellularization, shows peripheral cells with dense lipid content; the seeds are albuminous. The axial embryo shows fleshy cotyledons, which accumulate lipid and protein reserves; starch is rare. Although the seed structure is characteristic of the Fabaceae, the inner integument coalesces into the outer integument without being reabsorbed.
25
Zhang, Mingxia, Rui Dong, Penghui Huang, Mingyang Lu, Xianzhong Feng, Yongfu Fu e Xiaomei Zhang. "Novel Seed Size: A Novel Seed-Developing Gene in Glycine max". International Journal of Molecular Sciences 24, n. 4 (20 febbraio 2023): 4189. http://dx.doi.org/10.3390/ijms24044189.
Testo completoAbstract (sommario):
Soybean-seed development is controlled in multiple ways, as in many known regulating genes. Here, we identify a novel gene, Novel Seed Size (NSS), involved in seed development, by analyzing a T-DNA mutant (S006). The S006 mutant is a random mutant of the GmFTL4pro:GUS transgenic line, with phenotypes with small and brown seed coats. An analysis of the metabolomics and transcriptome combined with RT-qPCR in the S006 seeds revealed that the brown coat may result from the increased expression of chalcone synthase 7/8 genes, while the down-regulated expression of NSS leads to small seed size. The seed phenotypes and a microscopic observation of the seed-coat integument cells in a CRISPR/Cas9-edited mutant nss1 confirmed that the NSS gene conferred small phenotypes of the S006 seeds. As mentioned in an annotation on the Phytozome website, NSS encodes a potential DNA helicase RuvA subunit, and no such genes were previously reported to be involved in seed development. Therefore, we identify a novel gene in a new pathway controlling seed development in soybeans.
26
Yamada, Toshihiro, Ryoko Imaichi, Nallamilli Prakash e Masahiro Kato. "Developmental morphology of ovules and seeds of Austrobaileyales". Australian Journal of Botany 51, n. 5 (2003): 555. http://dx.doi.org/10.1071/bt03056.
Testo completoAbstract (sommario):
Development of ovules of Illicium anisatum (Illiciaceae), Trimenia moorei (Trimeniaceae), and Austrobaileya scandens (Austrobaileyaceae) (Austrobaileyales) was observed. In Austrobaileya scandens and Trimenia moorei the outer integument is hood-shaped, while it is cup-shaped in Illicium anisatum. On the basis of a phylogeny, the ovule with the hood-shaped outer integument is suggested to be primitive in Austrobaileyales. Seed development of Austrobaileyales was also examined. In Austrobaileya scandens the seed is mesotestal, ruminated, not pachychalazal, and has a micropyle–hilum complex. In Trimenia moorei the seed is exotestal, perispermous, not pachychalazal, and has a micropyle–hilum complex and a circular cap. The seed of Illicium anisatum is exotestal, not pachychalazal, and has a circular cap. Taking the character states of other basal angiosperms into account, primitive seeds of angiosperms are inferred to have such characters as the unilayered exotestal mechanical tissue, circular cap, micropyle–hilum complex and non-pachychalazy. The inferred primitive seed is very simple, suggesting that a great diversity of seeds is established through elaboration of organs/tissues of seeds, and not through reduction as hypothesised previously.
27
Alves-Junior, Clodomiro, Dinnara L. S. da Silva, Jussier O. Vitoriano, Anne P. C. B. Barbalho e Regina C. de Sousa. "The water path in plasma-treated Leucaena seeds". Seed Science Research 30, n. 1 (marzo 2020): 13–20. http://dx.doi.org/10.1017/s0960258520000045.
Testo completoAbstract (sommario):
AbstractThe effects of cold atmospheric plasma (CAP) of dielectric barrier discharges on the wettability, imbibition and germination of Leucaena leucocephala were investigated. It was established that CAP treatment markedly hydrophilized the seed coat, especially at longer treatment times. From the profile of the imbibition curve and visual observation, it was possible to verify that there are two resistance barriers to water penetration: integument surface and region of the macrosclereid cell wall (light line). Although the plasma interacts only in the integument, increasing the density of hydrophilic sites increases the capacity of water absorption, producing enough driving force to overcome the second resistance barrier. The existence of these two barriers changes the three-phase pattern generally observed during seed germination. Despite an increase in imbibition, the plasma treatment conditions used in this work, were not enough to overcome completely the dormancy barrier.
28
Boesewinkel, F. D. "Ovules and Seeds of Tremandraceae". Australian Journal of Botany 47, n. 5 (1999): 769. http://dx.doi.org/10.1071/bt98016.
Testo completoAbstract (sommario):
The Tremandraceae have bitegmic, anatropous and crassinucellate ovules with dermal integuments and a very thick inner integument. A chalazal appendage is present in Tetratheca and Tremandra. The hairy seeds have a seed coat with a crystalliferous endotesta and a fibrous exotegmen. The cream-coloured chalazal appendage functions as an elaiosome and the walls of the epidermal cells are rich in fatty substances. The seeds of Platytheca lack the elaiosome but are covered with inflated and thinner hairs. The ovule and seed characters of Tremandraceae suggest a relationship with the Linales alliance.
29
Pallavi, H. M., K. Vishwanath, Bapurayagouda Patil, N. Naveen e Manjunath Thattimani. "Seed anatomical studies on dormancy and germination in Chamaecrista absus". Journal of Applied and Natural Science 8, n. 2 (1 giugno 2016): 868–73. http://dx.doi.org/10.31018/jans.v8i2.888.
Testo completoAbstract (sommario):
Present study was conducted to analyze the anatomical structure of seed to study the dormancy behaviour in Chamaecrista absus. Seed germination behaviour was also studied after breaking the seed dormancy by artificial seed treatments. The anotamical studies revealed that seed has apical hilar region and seed coat has four layers consisting of outer cuticle, sub cuticle, palisade layer and inner tegma leading to physical dormancy. Outer cuticle and sub cuticle layers are very hard to break naturally and hence seeds possess hard seed coat dormancy. This physically hard seed coat should be made soft to enhance germination. Studies to break dormancy were conducted involving treatments like hot water, hormones and in combinations of both. The results revealed that seeds dipped in boiling water made inner layers permeable for water absorption in hilar region and thus germination enhanced. In specific seeds treated with boiling water for 5 minutes recorded higher germination (82 %) over untreated control (26 %). . Other artificial treatments with hormones gibberellic acid (33 % ) and ethrel (34 % ) did not enhanced the germination significantly over control. C. absus has hard coat dormancy and can be overcame by treating seeds with boiling water treatment.
30
Commey, Leslie, Theophilus K. Tengey, Christopher J. Cobos, Lavanya Dampanaboina, Kamalpreet K. Dhillon, Manish K. Pandey, Hari Kishan Sudini et al. "Peanut Seed Coat Acts as a Physical and Biochemical Barrier against Aspergillus flavus Infection". Journal of Fungi 7, n. 12 (23 novembre 2021): 1000. http://dx.doi.org/10.3390/jof7121000.
Testo completoAbstract (sommario):
Aflatoxin contamination is a global menace that adversely affects food crops and human health. Peanut seed coat is the outer layer protecting the cotyledon both at pre- and post-harvest stages from biotic and abiotic stresses. The aim of the present study is to investigate the role of seed coat against A. flavus infection. In-vitro seed colonization (IVSC) with and without seed coat showed that the seed coat acts as a physical barrier, and the developmental series of peanut seed coat showed the formation of a robust multilayered protective seed coat. Radial growth bioassay revealed that both insoluble and soluble seed coat extracts from 55-437 line (resistant) showed higher A. flavus inhibition compared to TMV-2 line (susceptible). Further analysis of seed coat biochemicals showed that hydroxycinnamic and hydroxybenzoic acid derivatives are the predominant phenolic compounds, and addition of these compounds to the media inhibited A. flavus growth. Gene expression analysis showed that genes involved in lignin monomer, proanthocyanidin, and flavonoid biosynthesis are highly abundant in 55-437 compared to TMV-2 seed coats. Overall, the present study showed that the seed coat acts as a physical and biochemical barrier against A. flavus infection and its potential use in mitigating the aflatoxin contamination.
31
Beardsell, DV, RB Knox e EG Williams. "Fruit and Seed Structure of Thryptomene calycina (Myrtaceae)". Australian Journal of Botany 41, n. 2 (1993): 183. http://dx.doi.org/10.1071/bt9930183.
Testo completoAbstract (sommario):
At anthesis the receptacle of flowers of T. calycina (Lindl.) Stapf is enclosed by a layer of small cells with a thick cuticle. The hypodermis consists mostly of large oil-containing cells interspersed with much smaller cells. The tissue surrounding the ovary consists mostly of spongy parenchyma. The micropyle of the ovule is formed only by the inner integument which is double-layered. The embryo sac at anthesis is typical of the Myrtaceae, and appears to follow the monosporic polygonum type, with considerable nucellar tissue surrounding it. In a mature fruit the parenchyma is compressed into a thin band surrounding the seed. The integuments form a two-layered seed coat within the fruit. The aborted ovule is displaced below and to one side of the developing seed. In fruit weathered for several years there is an accumulation of phenolic material giving the fruit a black appearance. The two layers of the seed coat within freshly shed fruit lie closely together and stain strongly with the lipid stain auramine O. In fruit weathered for at least 2 years the two layers of the seed coat become separated for at least part of their length and staining from auramine O is less intense. The breakdown in seed dormancy in weathered fruits is probably due to a less complete barrier to water uptake provided by the separation of the two layers. This would increase lateral and radial movement of water. The observed reduction in the hydrophobic lipid content of the testa layers probably also aids water entry into the seed in a weathered fruit.
32
Pelc, Stanisław. "Morphology and stucture of wild apple (Malus silvestris Mill.).common pear (Pyrus cofnmunis L.) and Chaenomeles japonica (Thunb) Lindl. seeds". Acta Societatis Botanicorum Poloniae 53, n. 2 (2014): 159–70. http://dx.doi.org/10.5586/asbp.1984.015.
Testo completoAbstract (sommario):
The outer and inner structure of wild apple (<em>Malus silvestris</em> Mill.), common pear (<em>Pyrus communis</em> L.) and <em>Chaenomeles japonica</em> (Thunb.) Lindl. seeds was investigated. It was found that the outer structure exhibits good diagnostic features expressed in the first place in the relief of the seed coat and further in the arrangement and appearance of the site of attachment of the free end of the funiculus and the shape of the seeds. In ripe seeds there is, under the thick seed coat, an endosperm layer completely surrounding the embryo which has large cotyledons and a thick rootlet.
33
Lisci, Marcello, e Ettore Pacini. "Fruit and seed structural characteristics and seed dispersal in Mercurialis annua L. (Euphorbiaceae)". Acta Societatis Botanicorum Poloniae 66, n. 3-4 (2014): 379–86. http://dx.doi.org/10.5586/asbp.1997.047.
Testo completoAbstract (sommario):
The fruit of <em>Mercurialis annua</em> L. is a two-seeded capsule with a caruncle, a small appendage which arises from the outer integument in the micropylar area. The inner integument has a thick layer of Malpighian-like cells, interrupted at the micropyle by a remnant of nucellus, the walls of which contain suberin. There is no cuticle covering the caruncle and its cells have lipids and protein bodies as reserves. Seed dispersal occurs by a combination of autochory followed by myrmecochory. The explosive ejection of seeds is caused by dehydration-induced torsion of the mechanical layer of the fruit walls. This phenomenon is due to the different orientation of the cells and a folding over of the mechanical layer in the chalazal area. The seeds were found to be thrown distances from 1 to 130 cm (mean 41.1 cm; modal peak 10-20 cm). Ballistic dispersal is influenced by the weight of the seed. The seeds were collected by ants in a mean time of 24.4 minutes the maximum and mean distances of dispersal being 14 and 3.4 m, respectively. Of the seeds removed, 95.2 % were recovered on excavation of the ant nest. The seeds in the nest were intact but without the caruncles. The mean distance of dispersal by diplochory was < 5 m. These features are discussed in relation to possible benefits to the plant species in terms of adaptive advantages of seeds.
34
Sampaio, Danielle Affonso, Alfredo José Dos Santos Junior, Natália Dias de Souza e Roberto Carlos Costa Lelis. "Diversity of Secondary Metabolites of Araucaria Seed (Araucaria angustifolia (Bert.) O. Ktze) Residues". Ensaios e Ciência C Biológicas Agrárias e da Saúde 26, n. 2 (23 giugno 2022): 289–92. http://dx.doi.org/10.17921/1415-6938.2022v26n2p289-292.
Testo completoAbstract (sommario):
A semente da Araucaria angustifolia (Bert.) O. Ktze é conhecida como pinhão e é considerada um alimento de alto valor nutricional. No consumo do pinhão, seu tegumento é descartado, gerando um resíduo que apresenta um processo lento de decomposição. Esse material é composto por três camadas de tecido: camada interna (endotesta), camada intermediária (mesotesta) e camada externa (exotesta). Estudos têm explorado o uso de extratos obtidos desse resíduo florestal, uma vez que a ocorrência de metabólitos pode levar à sua caracterização e isolamento proporcionando amplas aplicações. Considerando a importância de novos estudos na identificação das mais diversas classes de extrativos, este trabalho teve como objetivo realizar a prospecção fitoquímica das camadas do tegumento do pinhão. Sementes saudáveis e livre de injúrias foram descascadas, separando as três camadas do tegumento. Para a análise fitoquímica, foi utilizado o extrato hidrofílico (metanol) obtido de cada camada no ciclo de extração. Seções transversais e longitudinais das camadas externa e intermediária foram usadas para microscopia de luz e epifluorescência. Foi possível detectar a presença de diferentes classes de metabólitos nas três camadas do tegumento. Em todas as camadas foi possível encontrar taninos condensados, flavonóides e triterpenóides. Catequinas e resinas só foram encontradas na camada externa. Canais resiníferos foram observados na camada externa longitudinal. Este estudo permitiu registrar a diversidade de metabólitos secundários existentes nas camadas do tegumento, sugerindo possíveis usos para os mesmos. Palavras-chave: Pinhão. Casca de Semente. Antioxidantes. Fitoquímica. Microscopia de Fluorescência. Abstract The seed of Araucaria angustifolia (Bert.) O. Ktze is known as pinhão and is considered a high nutritional value food. In the pinhão consumption, its seed coat is discarded, generating a residue that presents a slow decomposition process. The pinhão seed coat is composed of three tissue layers: inner layer (endotesta), intermediate layer (mesotesta) and outer layer (exotesta). Studies have explored the use of extracts obtained from this forest residue, since the occurrence of metabolites can lead to characterization and isolation, providing wide applications. Considering the importance of new studies in the identification of the most diverse classes of extractives, this work aimed to carry out the phytochemical prospection of the layers of pinhão seed coat. Healthy and injury-free seeds were peeled, separating the three layers of seed coat. For the phytochemical analysis, the hydrophilic extract (methanol) obtained from each layer in the extraction cycle was used. Transverse and longitudinal sections of the outer and middle layers were used for light and epifluorescent microscopy. It was possible to detect the presence of different classes of metabolites in the three layers of the seed coat. In all the layers it was possible to find condensed tannins, flavonoids and triterpenoids. Catechins and Resins were only found in the outer layer. Resinous channels were observed in the outer longitudinal layer. This study allowed to register the diversity of secondary metabolites existing in the layers of the seed coat, suggesting possible uses for them. Keywords: Pinhão. Seed Coat. Antioxidants. Phytochemistry. Fluorescence Microscopy.
35
Edelstein, M., H. Nerson, F. Corbineau e J. Kigel. "838 PB 358 CONTROL OF LOW-TEMPERATURE GERMINATION OF MELON (CUCUMISMELO L.) SEEDS BY SEED-COAT STRUCTURE AND OXYGEN AVAILABILITY". HortScience 29, n. 5 (maggio 1994): 553c—553. http://dx.doi.org/10.21273/hortsci.29.5.553c.
Testo completoAbstract (sommario):
The involvement of the seed coat in low temperature germination of melon seeds was examined in two accessions differing in their ability to germinate at 14°C: `Noy Yizre'el' (NY) (a cold-sensitive cultivar) and `Persia 202' (P-202) (a cold-tolerant breeding line). Submerging the whole seed, or covering the hilum with lanolin, strongly depressed germination of NY, but not of P-202. Accessions differed in germination response to decreasing O2 concentration, with NY showing higher sensitivity to hypoxia. Intercellular spaces in the outer layer of the seed-coat were evident in the more tolerant P-202, while in the sensitive NY this layer is completely sealed. Sensitivity to hypoxia was greater at 15°C than at 25°C and was greater in NY than in P-202. It is proposed that the seed-coat imposed dormancy at low temperature in NY is the combined result of more restricted oxygen diffusion through the seed coat and a greater embryo sensitivity to hypoxia, rather than imbibition impairment or a physical constraint.
36
Miao, Z. H., J. A. Fortune e J. Gallagher. "Anatomical structure and nutritive value of lupin seed coats". Australian Journal of Agricultural Research 52, n. 10 (2001): 985. http://dx.doi.org/10.1071/ar00117.
Testo completoAbstract (sommario):
Selection and breeding for yield and adaptation to environmental conditions often changes a number of characteristics of crops, and may influence the value of seed for animals. A series of experiments was conducted to evaluate the effect of breeding and growing conditions on the structure and degradability of lupin seed coats. Breeding has had significant influences on both seed size and seed coat structure of lupins. For instance, cultivars of Lupinus angustifolius released in 1987 and 1988 tended to have smaller seeds with a thicker seed coat than those released in 1971 (P < 0.05). Selection for soft seeds has resulted in a reduction of seed coat thickness in L. angustifolius. Hardseeded and roughseeded lines of L. cosentinii had thicker coats (P < 0.05) than softseeded and smoothseeded, respectively. The main contributor to the thick seed coat of hardseeded lines was a layer of cells known as the hourglass layer, which is located between the outer palisade and inner parenchyma. Anatomical analysis revealed that the soft seed coat tended to have short and round cells, whereas the hard seed tended to have long cells in the palisade layer. Smooth seeds had round cells in the subpalisade, but rough seeds had long cells in this layer. Although the seed coats of lupins contained about 80% crude fibre, with L. cosentinii and L. pilosus having more fibre than L. angustifolius, the fibre in lupin seed coats was highly digestible by sheep.
37
WANG, LIU, YUN-YUN ZHAO e JIA-XI LIU. "Embryology of Myosoton and Stellaria and its taxonomic significance (Caryophyllaceae)". Phytotaxa 306, n. 2 (9 maggio 2017): 124. http://dx.doi.org/10.11646/phytotaxa.306.2.2.
Testo completoAbstract (sommario):
The systematic relationship between the genera Myosoton and Stellaria is a currently controversial. In this study, we compared their embryological characteristics of these two taxa using conventional paraffin section techniques and scanning electron microscopy. The results obtained showed that Myosoton and Stellaria share some common features. They all have tetrasporangiate anthers with dicotyledonous wall, secretory tapetum, microspore mother cells with simultaneous cytokinesis, tetrahedral tetrad, 3-celled mature pollen grains, linear megaspore tetrad, monosporic polygonum embryo sac, ovary with axial placenta at early development stage, secondary free central placenta at mature stage, bitegmic, crassinucellate amphitropous ovule, micropyle formed from inner integument, caryophyllad embryogenesis, nuclear endosperm, and seed with perisperm. In addition, their seed morphologies are also very similar. Both have rounded, polygonal seed coat cells with upward protrudings, V-shaped margin of testa cells and cross-intercellular contacts. The embryological characteristics support that genus Myosoton should be merged into genus Stellaria.
38
Chaban, Inna A., Alexander A. Gulevich e Ekaterina N. Baranova. "Formation of Unique Placental Seed Capsules in the Maturation Process of the Tomato Fruit". International Journal of Molecular Sciences 23, n. 19 (21 settembre 2022): 11101. http://dx.doi.org/10.3390/ijms231911101.
Testo completoAbstract (sommario):
The morphological and anatomical study of the seed formation features in a juicy tomato fruit was carried out. The ovules, which form on the placenta, have been shown to be gradually enveloped by the protrusions of placental tissue that arises simultaneously with them. As a result of this process, each seed is enclosed in an individual capsule. These seed capsules have been shown in vivo to be airtight and air-filled. Tomato seeds, as has been shown in this study, develop inside these capsules until the full maturity of the fruit and do not come into contact with the detached and moldered cells of the placenta protrusions, which convert into a gel (pulp). Using scanning electron microscopy, it was possible to reveal the details of a ribbon-like “pubescence” formation of the tomato seed, as well as to understand the mechanism of cracking of the outer layer cells in the seed coat, associated with the detection of calcium oxalate crystals in these cells. The unique outer layer of the tomato seed coat seems to play the role of a scaffold that maintains a constant volume of the protective capsule.
39
Liu, Jianjian, Gaihua Qin, Chunyan Liu, Xiuli Liu, Jie Zhou, Jiyu Li, Bingxin Lu e Jianrong Zhao. "Genome-wide identification of candidate aquaporins involved in water accumulation of pomegranate outer seed coat". PeerJ 9 (15 luglio 2021): e11810. http://dx.doi.org/10.7717/peerj.11810.
Testo completoAbstract (sommario):
Aquaporins (AQPs) are a class of highly conserved integral membrane proteins that facilitate the uptake and transport of water and other small molecules across cell membranes. However, little is known about AQP genes in pomegranate (Punica granatum L.) and their potential role in water accumulation of the outer seed coat. We identified 38 PgrAQP genes in the pomegranate genome and divided them into five subfamilies based on a comparative analysis. Purifying selection played a role in the evolution of PgrAQP genes and a whole-genome duplication event in Myrtales may have contributed to the expansion of PgrTIP, PgrSIP, and PgrXIP genes. Transcriptome data analysis revealed that the PgrAQP genes exhibited different tissue-specific expression patterns. Among them, the transcript abundance of PgrPIPs were significantly higher than that of other subfamilies. The mRNA transcription levels of PgrPIP1.3, PgrPIP2.8, and PgrSIP1.2 showed a significant linear relationship with water accumulation in seed coats, indicating that PgrPIP1.3/PgrPIP2.8 located in the plasma membrane and PgrSIP1.2 proteins located on the tonoplast may be involved in water accumulation and contribute to the cell expansion of the outer seed coat, which then develops into juicy edible flesh. Overall, our results provided not only information on the characteristics and evolution of PgrAQPs, but also insights on the genetic improvement of outer seed coats.
40
Oh, Tae, you park, Chang Kim, Young cho e myoung jang. "Effect of Seed Disinfection on Bakanae disease in Ginkgo biloba Outer Seed Coat Extract". Emirates Journal of Food and Agriculture 28, n. 9 (2016): 671. http://dx.doi.org/10.9755/ejfa.2016-04-357.
Testo completo
41
Zhang, Hengyou, Wolfgang Goettel, Qijian Song, He Jiang, Zhenbin Hu, Ming Li Wang e Yong-qiang Charles An. "Selection of GmSWEET39 for oil and protein improvement in soybean". PLOS Genetics 16, n. 11 (11 novembre 2020): e1009114. http://dx.doi.org/10.1371/journal.pgen.1009114.
Testo completoAbstract (sommario):
Soybean [Glycine max (L.) Merr.] was domesticated from wild soybean (G. soja Sieb. and Zucc.) and has been further improved as a dual-use seed crop to provide highly valuable oil and protein for food, feed, and industrial applications. However, the underlying genetic and molecular basis remains less understood. Having combined high-confidence bi-parental linkage mapping with high-resolution association analysis based on 631 whole sequenced genomes, we mapped major soybean protein and oil QTLs on chromosome15 to a sugar transporter gene (GmSWEET39). A two-nucleotide CC deletion truncating C-terminus of GmSWEET39 was strongly associated with high seed oil and low seed protein, suggesting its pleiotropic effect on protein and oil content. GmSWEET39 was predominantly expressed in parenchyma and integument of the seed coat, and likely regulates oil and protein accumulation by affecting sugar delivery from maternal seed coat to the filial embryo. We demonstrated that GmSWEET39 has a dual function for both oil and protein improvement and undergoes two different paths of artificial selection. A CC deletion (CC-) haplotype H1 has been intensively selected during domestication and extensively used in soybean improvement worldwide. H1 is fixed in North American soybean cultivars. The protein-favored (CC+) haplotype H3 still undergoes ongoing selection, reflecting its sustainable role for soybean protein improvement. The comprehensive knowledge on the molecular basis underlying the major QTL and GmSWEET39 haplotypes associated with soybean improvement would be valuable to design new strategies for soybean seed quality improvement using molecular breeding and biotechnological approaches.
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Gonzalez, Antonio, John Mendenhall, Yujia Huo e Alan Lloyd. "TTG1 complex MYBs, MYB5 and TT2, control outer seed coat differentiation". Developmental Biology 325, n. 2 (gennaio 2009): 412–21. http://dx.doi.org/10.1016/j.ydbio.2008.10.005.
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Ribeiro, Rafaella C., Denise M. T. Oliveira e Fernando A. O. Silveira. "A new seed coat water-impermeability mechanism in Chaetostoma armatum (Melastomataceae): evolutionary and biogeographical implications of physiophysical dormancy". Seed Science Research 25, n. 2 (11 marzo 2015): 194–202. http://dx.doi.org/10.1017/s0960258515000070.
Testo completoAbstract (sommario):
AbstractDetermining the phylogenetic and biogeographic distribution of physical dormancy remains a major challenge in germination ecology. Here, our goal was to describe a novel water-impermeable seed coat mechanism causing physical dormancy (PY) in the seeds of Chaetostoma armatum (Melastomataceae). Although seed coat permeability tests indicated a significant increase in seed weight after soaking in distilled water, anatomical and dye-tracking analyses showed that both water and dyes penetrated the seed coat but not the embryo, which remained in a dry state. The water and dye penetrated the lumen of the exotestal cells, which have a thin outer periclinal face and thickened secondary walls with U-shaped phenolic compounds. Because of this structure, water and dye do not penetrate the inner periclinal face of the exotestal cells, indicating PY. Puncturing the seeds increased germination more than tenfold compared to that of the control, but GA3 did not increase germination further. A significant fraction of the seeds did not germinate after puncturing, indicating that embryos are also physiologically dormant (PD). This paper constitutes the first report of the water-impermeable seed coat in the Myrtales and the first report of physiophysical (PD+PY) dormancy in a shrub from a tropical montane area.
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Sharma, Dilip Kumar, e Kailash Agrawal. "Incidence and Histopathological Study of Xanthomonas axonopodis pv. vesicatoria (Doidge) Dye in Chilli (Capsicum spp.) Seeds in Western Rajasthan". Middle East Journal of Applied Science & Technology 05, n. 03 (2022): 01–12. http://dx.doi.org/10.46431/mejast.2022.5301.
Testo completoAbstract (sommario):
Bacterial leaf spot is a destructive disease in Rajasthan caused by Xanthomonas axonopodis pv. vesicatoria (Doidge) Dye. A field and market survey was conducted for the study of incidence and location. Dry seed examination of 103 seed samples of chilli (Capsicum spp.) belonging to 16 districts of Rajasthan that revealed a 10–100% incidence of Xanthomonas axonopodis pv. vesicatoria (XAV) on Tween-80 medium. Two naturally infected seed samples of chilli carrying a 100% incidence of XAV were selected and categorized into asymptomatic (06.25–94.25%), moderately discolored (01.75–42%), and heavily discolored (01.25–27.75%) seeds. The heavily discolored seeds showed shriveled, water-soaked symptoms on their surface, and on bisecting such types of infected seeds, the embryo and endosperm showed necrosis and browning. The pathogen was found confined to the outer seed coat layer, particularly at the ramnent of funiculus in a few asymptomatic seeds. In moderately discolored seeds, the pathogen was found in the seed coat and the space in between the seed coat and the endosperm. It colonized all the seed components, including embryo and endosperm, in heavily discolored seeds. The pathogen caused necrosis, the formation of lytic cavities, a reduction in cell contents, and aggregation of the bacterial cells. The pathogen was found to be extra-as well as intra-embryonic.
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Szkudlarz, Piotr, e Zbigniew Celka. "Morphological characters of the seed coat in selected species of the genus Hypericum L. and their taxonomic value". Biodiversity Research and Conservation 44, n. 1 (1 dicembre 2016): 1–9. http://dx.doi.org/10.1515/biorc-2016-0022.
Testo completoAbstract (sommario):
Abstract Eight Hypericum species are native to Poland: H. elegans Stephan ex Willd., H. hirsutum L., H. humifusum L., H. maculatum Crantz, H. montanum L., H. perforatum L., H. pulchrum L., and H. tetrapterum Fr. Only seeds of H. elegans were investigated in detail in Poland before, so here we present results of qualitative and quantitative analyses of seed morphology of the other 7 species, based on characters like seed length, width, and shape, seed coat sculpture, shape of epidermal cells of the testa, and number of epidermal cells along the seed axis. The results show that seeds of the studied species are small, 0.56-1.15 mm long and 0.26-0.49 mm wide. In SEM images, seed coat sculpture is reticulate in 5 species, papillate in H. hirsutum, and cup-shaped in H. pulchrum. The differences are caused by the varied final development of the testa epidermis, which constitutes the outer layer of the seed coat. The mean number of epidermal cells along the seed axis ranges from 22 to 33. Results of cluster analysis, based on the agglomeration method and including also published data on seeds of H. elegans, show that the variation in the investigated characters of seeds is reflected in the taxonomic division of the genus into sections.
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Li, Guixiang, Jiyu Li, Gaihua Qin, Chunyan Liu, Xin Liu, Zhen Cao, Botao Jia e Huping Zhang. "Characterization and Expression Analysis of the UDP Glycosyltransferase Family in Pomegranate (Punica granatum L.)". Horticulturae 9, n. 1 (16 gennaio 2023): 119. http://dx.doi.org/10.3390/horticulturae9010119.
Testo completoAbstract (sommario):
UDP glycosyltransferases (UGTs) play an indispensable role in regulating signaling pathways and intracellular homeostasis in plants by catalyzing the glycosylation of metabolites. To date, the molecular characteristics and potential biological functions of the UGT gene family in pomegranate (Punica granatum L.) remain elusive. In this study, a total of 120 PgUGT genes were identified in the pomegranate genome. Phylogenetic analysis revealed that these PgUGTs were clustered into 15 groups: 13 conserved groups (A–J and L–N) and two newly discovered groups (P and R). Structural analysis showed that most members in the same evolutionary branch shared similar motifs and gene structures. Gene duplication analysis demonstrated that tandem duplication and fragment duplication were the primary driving force for the expansion of the PgUGT family. Expression analysis based on RNA-seq data indicated that PgUGTs exhibited various expression profiles in different pomegranate tissues. We further analyzed the expression patterns of the PgUGTs of groups E and L in the seed coat of the hard-seeded cultivar ‘Dabenzi’ and the soft-seeded cultivar ‘Tunisia’ at different developmental stages. There were eight PgUGTs with high expression levels in the seed coat of both cultivars: PgUGTE10 was highly expressed in inner and outer seed coats; PgUGTE20, PgUGTE21, PgUGTL6, PgUGTL11, and PgUGTL12 were mainly expressed in the inner seed coat; and PgUGTE12 and PgUGTL13 were mainly expressed in the outer seed coat. Interestingly, the relative expression levels of PgUGTE10 and PgUGTL11 in ‘Tunisia’ were higher than in ‘Dabenzi’. In the seedlings, quantitative real-time PCR analysis showed that the expression level of PgUGTE10 was induced by brassinolide treatment, while the expression of PgUGTL11 was up-regulated both by indole-3-acetic acid and the brassinolide treatment. In addition, the expressions of PgUGTE10 and PgUGTL11 were highly correlated with the expression of genes involved in hormone signaling and lignin biosynthesis pathways. These results suggested that PgUGTE10 and PgUGTL11 are potential candidate genes involved in seed hardness development by catalyzing the glycosylation of specific substrates.
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Espinosa-Osornio, Guadalupe, e E. Mark Engleman. "Anatomía del desarrollo de la semilla de Hippocratea celastroides". Botanical Sciences, n. 53 (24 aprile 2017): 43. http://dx.doi.org/10.17129/botsci.1415.
Testo completoAbstract (sommario):
Embryological studies of Hippocratea are restricted to few species, and they show similarity between Hippocratea and Celastraceae. Nevertheless, differences based on H. grahamii have originate controversy on the taxonomic position of the genus. We have examined the seed development of H. celastroides H.B.K, by ligth microscopy. This specie has anatropous and bitegmic ovules. At anthesis, the micropyle is formed only by the inner integument. In the endotegmen and exotesta there are tannin deposits beginning in early stages. After fertilization, the outer integument increases abundantly, it alone forms the wing. The endosperm development is of the nuclear type. After syngamy the zygote rests for 3 months before dividing. The mesoteste develops aerenquima, which differentiates gradually into tracheoidal cells. One layer of endosperm remains at madurity. The cotyledons are connate and rotate 90°. On the basis of these results, we consider that Hippocratea belongs the Celastraceae.
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Suhendra, D., Z. Ikhsan e S. Aisyah. "Seed structure and germination pattern of sugar palm [Arenga pinnata L.]". IOP Conference Series: Earth and Environmental Science 1160, n. 1 (1 aprile 2023): 012018. http://dx.doi.org/10.1088/1755-1315/1160/1/012018.
Testo completoAbstract (sommario):
Abstract Sugar palm is a type of palm plant, which can grow at various altitudes with different soil types. Sugar palm plants have high prospects because all parts of the plant can be used as traditional medicine, building materials, ingredients for making brown sugar, vinegar, starch, or flour, and as ingredients for various foods. In the cultivation of sugar palm plants, there are several problems found, one of which is the seeds that have a period of dormancy. The reason is the hard and impermeable seed coat that prevents water imbibition. This study aims to determine the structure and germination pattern of sugar palm seeds. This research was conducted at the Seed Technology Laboratory of the Faculty of Agriculture, Campus 3 Dharmasraya Universitas Andalas from April until September 2022. The observations obtained were the structure of the sugar palm seed consists of parts namely tip cap, testa, perisperm, endosperm, embryonic chamber, and embryo. The outer coat of the sugar palm seed is black and slippery. Each sugar palm seed has a small circle that spreads outside the seed coat where the small circle is the embryo. The duration of the sugar palm seeds’ germination from the beginning of germination until the leaves are fully open takes up to 120 days after planting.
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Barsberg, S. T., Y. I. Lee e H. N. Rasmussen. "Development of C-lignin with G/S-lignin and lipids in orchid seed coats – an unexpected diversity exposed by ATR-FT-IR spectroscopy". Seed Science Research 28, n. 1 (9 gennaio 2018): 41–51. http://dx.doi.org/10.1017/s0960258517000344.
Testo completoAbstract (sommario):
AbstractMembers of the orchid family occupy many germination niches, in terrestrial, epiphytic and epilithic environments. How orchid seeds attach to their substrate and survive after dispersal is largely unknown. C-lignin is a recently discovered specialized lignin, found in seed coats of some plants, including orchid species, but its functional and biological significance is obscure. We studied seed coat ontogenesis in three species (Neuwiedia veratrifolia, Cypripedium formosanum and Phalaenopsis aphrodite) that represent basal and advanced branches in orchid phylogeny and divergent life forms. From each species, controlled pollination yielded several stages of seed development, from which seed coats (testa) were isolated and analysed by ATR-FT-IR spectroscopy. The use of the ATR set-up ensured that the chemical information originated only from the integral outer seed surface layers. The FT-IR bands of C-lignin are presented here for the first time, and distinguished from bands of G/S-lignin. In the seed coats, C-lignin developed after G/S-lignin in N. veratrifolia and C. formosanum, while only G/S-lignin developed in P. aphrodite. We discuss C-lignin properties and possible function in relation to seed coat properties. The species differed with respect to sequence and amounts of deposition, not only of lignins but also lipids, resulting in differences in mature seed coat compositions. Thus we revealed an unexpected and marked diversity among orchids with respect to seed surface chemistry, with possible implications for seed and germination ecology.
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Nikolic, Natasa, Ljiljana Merkulov, Borivoj Krstic, Slobodanka Pajevic, Milan Borisev e Sasa Orlovic. "Variability of acorn anatomical characteristics in Quercus robur L. genotypes". Zbornik Matice srpske za prirodne nauke, n. 118 (2010): 47–58. http://dx.doi.org/10.2298/zmspn1018047n.
Testo completoAbstract (sommario):
The aim of this study was to examine variability of acorn anatomical characteristics in seventeen Quercus robur L. genotypes. Acorns were collected in clonal seed orchard Banov Brod (Srem, Vojvodina, Serbia). Microscopic measurements were done for pericarp (total thickness, thickness of exocarp and mesocarp), seed coat (total thickness, thickness of outer epidermis, parenchyma, and inner epidermis), and embryo axis (diameter, thickness of cortical region, and diameter of stellar zone). Obtained results revealed certain divergence between genotypes. The thickness of pericarp varied from 418 to 559 mm (genotypes 20 and 22, respectively). On average, the participation of exocarp in the total thickness of pericarp was 36.3%, of mesocarp 61.0%, while of endocarp 2.6%. The thickness of seed coat for individual genotypes ranged from 71 mm (genotype 28) to 157 mm (genotype 38). In addition, anatomic parameters of embryo axis varied among studied genotypes. The lowest cortical zone thickness and stellar zone diameter were measured in genotype 40, while the highest values in genotype 33.