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Search Results: 1 - 10 of 1220 matches for " ovule extracts "
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Nicotiana ovule extracts induce nuclear reconstitution of demembranated Xenopus sperm in cell-free system
Ping Lu,Min Ren,Zhonghe Zhai
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9072
Abstract: Nicotiana tabaccum ovule extracts induced nuclear reconstitution of demembranated Xenopus leavis sperm in a cell-free system. Demembranated Xenopus sperm began to swell after 15 min of incubation with Nicotiana ovule extracts. Accompanying the process of incubation, Xenopus sperm decondensed and their shapes changed gradually from long and ellipse to round. The completely decondensed chromatin was surrounded with membrane structure, which was a mixture envelope of a double membrane and a single membrane. Nucleosome assembly was verified by means of micrococcal nuclease digestion to reconstituted nuclei and DNA electrophoresis. Nicotiana ovule extracts supplied one more experimental model and system. The new system could promote powerfully the research on mechanisms of cell division and cell cycle regulation.
Nicotiana ovule extracts induce nuclear reconstitution of demembranated Xenopus sperm in cell-free system

Ping Lu,Min Ren,Zhonghe Zhai,

科学通报(英文版) , 2002,
Abstract: Nicotiana tabaccum ovule extracts induced nuclear reconstitution of demembranated Xenopus leavis sperm in a cell-free system. Demembranated Xenopus sperm began to swell after 15 min of incubation with Nicotiana ovule extracts. Accompanying the process of incubation, Xenopus sperm decondensed and their shapes changed gradually from long and ellipse to round. The completely decondensed chromatin was surrounded with membrane structure, which was a mixture envelope of a double membrane and a single membrane. Nucleosome assembly was verified by means of micrococcal nuclease digestion to reconstituted nuclei and DNA electrophoresis. Nicotiana ovule extracts supplied one more experimental model and system. The new system could promote powerfully the research on mechanisms of cell division and cell cycle regulation.
ABOUT ARRANGEMENT OF THE HAIRS ON THE EPIDERMIS OF COTTON SEED
V Krakhmalev,A Paiziev
Journal of Central European Agriculture , 2006,
Abstract: The character of an arrangement of the hairs on seeds of fi ve cotton cultivars has been investigated. Unknown feature has been found in the processes of the cells-hairs appearance from the epidermis of ovule-seed. It is shown that from the beginning of certain moment of cotton ovule development, two closely located adjoining epidermis cells, which just have come out of mitotic process, are more often simultaneously differentiated into the hairs. Arising cells-hairs form various geometrical fi gures on a surface of а ovule epidermis: lines, arches, circles. The process of differentiation into pairs is simultaneously characteristic not only for the epidermal cells, which initiate hair appearance, but also for the cells which form stomatа on the ovule epidermis.
Some features of Glaucium flavum Crantz (Papaveraceae) embryology
Svetlana V. Shevchenko
Modern Phytomorphology , 2013,
Abstract: The processes of the development of micro- and megasporangium Glacium flavumCrantz have been characterized. The features of the male and female generative structures are shown.
Distribution of Nuclei of Different Ploidy Levels during Ovule, Seed and Protocorm Development in Phalaenopsis aphrodite subsp. formosana (Orchidaceae)  [PDF]
Goamg-Tyng Jean, Yu-Lin Kao, Ching-Yan Tang, Wen-Huei Chen
American Journal of Plant Sciences (AJPS) , 2011, DOI: 10.4236/ajps.2011.23037
Abstract: Distribution of nuclei of different ploidy levels was studied at different developmental stages in the embryonic tissue of the ovule, seed and protocorm of Phalaenopsis aphrodite subsp. formosana (Miwa) E.A. Christ. by a combination of flow cytometry and fluorescence microscopy with Apo Tome Slider. Three stages of ploidy patterns were identified in the ovular tissue at different days after pollination (DAP). Firstly, between pollination and fertilization (0 to 50 DAP), 2C nuclei were dominant over 4C nuclei and resulted in low level of cycle value. Secondly, between fertilization and seed maturation (50 to 110 DAP), amount of 4C nuclei increased rapidly, maintained at a high level and then decreased gradually to a low level. Small amount of 8C nuclei was also detected at this stage. Thirdly, at seed maturation (110 to 130 DAP), 2C nuclei became dominant over 4C nuclei again and the cycle value remained at a low but significant level at this stage. After seed sowing, nuclei with ploidy levels of 2C, 4C and 8C were observed in the developing protocorms as early as at 4 DAS (days after sowing). Nuclei with high ploidy levels (8C and 16C) increased gradually until 40 DAS in this study. Significant level of cycle value at this stage of protocorm development indicated the presence of endopolyploidy. 4,6-diamido-2-phenylindol (DAPI) staining showed large and prominent nuclei in the basal portions of the mature seeds before sowing and in the developing protocorms at 20 DAS. These findings clearly demonstrate the occurrence of different distribution patterns of nuclei with different ploidy levels during ovule, seed and protocorm de-velopment in Phalaenopsis aphrodite. These observations will provide fundamental information for further studies in Phalaenopsis orchids.
Floral Organogenesis and Ring Meristem in Phytolacca  [PDF]
Hongchun Zheng, Anming Lu, Zhenghai Hu
American Journal of Plant Sciences (AJPS) , 2015, DOI: 10.4236/ajps.2015.63050
Abstract: To further study the floral organogenesis and discussing the floral origin of Phytolacca, the procedures of floral organogenesis were observed in Phytolacca esculenta and Phytolacca zhejiangensis. The results showed that the floral organogenesis was consistent in Phytolacca. Their sepals were 2/5 helix, and with counter-clockwise and clockwise, usually the first sepal located at non-median of abaxial side. The first sepal of Phytolacca esculenta was initiated at non-median of adaxial side. There was no evident relationship between sepal and stamen initiating position, and the stamens initiated on ring meristem, they initiated approximately at the same time, and when the androecium member was numerous, they initiated centrifugally, the outer stamen initiated irregularly. Carpel initiated alternately with inner stamens. And the carpels connected by septum, if the septum grew more, the carpel was syncarpous at morphology, otherwise the carpel was apocarpous at morphology. So the syncarpous and the apocarpous have no successively relationship on evolution. Ovule initiated inside the carpel and opposite to carpel. Androecium, carpel and ovule initiated at ring meristem.
Effects of Acid Rain on the Developmental Stages of Ovules and Seed Proteins in Bean Plants (Phaseolus vulgaris L.)
Abdolkarim Chehregani,Farideh Kavianpour
American Journal of Plant Physiology , 2007,
Abstract: The aim of this research was to detect some microscopic effects of acid rain on ovule formation, development, structure and protein content in plants. Bean plants were grown in plots in different groups and treated by different acid solutions of HNO3, H2SO4 and both HNO3, H2SO4. The pH of each group regulated at 2, 3, 4, 4.5. Treatments were taken for 4 weeks, one in each day. Developmental stages of ovules were compared in acid treated and control plants. Results showed that developmental process of ovules show some abnormalities. Embryo sac was not completed its growth and was smaller in the treated plants than control ones. In treated plants, vesiculation of embryo sac and plasmolysis of nucellar tissue were seen. Accumulation of dark particles and disruption of nuclear envelope in embryonic cells are the results of acid treatments. Treatments by HNO3 with pH 2, was more effective than other acid solutions. SDS-PAGE showed that protein pattern was the same in experimental and control plants but quantity of protein bands was different.
Ovule development, a new model for lateral organ formation
Mara Cucinotta,Lucia Colombo,Irma Roig-Villanova
Frontiers in Plant Science , 2014, DOI: 10.3389/fpls.2014.00117
Abstract: In spermatophytes the ovules upon fertilization give rise to the seeds. It is essential to understand the mechanisms that control ovule number and development as they ultimately determine the final number of seeds and, thereby, the yield in crop plants. In Arabidopsis thaliana, ovules arise laterally from a meristematic tissue within the carpel referred to as placenta. For a correct determination of the number of ovules, a precise establishment of the positions where ovule primordia emerge is needed, and a tight definition of the boundaries between ovules is therefore also required. In the last decades, few factors have been identified to be involved in the determination of ovule number. Recently, plant hormones have also been revealed as fundamental players in the control of the initiation of ovule formation. In this review we summarize the current knowledge about both the molecular and hormonal mechanisms that control ovule formation in Arabidopsis thaliana.
Structure of the stigma and style in sunflower (Helianthus annuus L.)
Gotelli,M.M.; Galati,B.G.; Medan,D.;
Biocell , 2010,
Abstract: this is the first report of the ultrastructure of the stigma and style during and after anthesis in helianthus annuus l. using light and transmission electron microscopy. the stigma is bifid with unicellular papillae. there is no secretion of lipids, carbohydrates or proteins at anthesis. the style is semisolid in the upper portion, closer to the stigma, and becomes solid below. ultrastructural changes on cells of the stigma and the style are described. the transmitting tissue of the ovule is first evident 40 minutes after pollination and persists during the first stages of embryogenesis. only one pollen tube per micropyle was observed growing through this tissue.
Performance polínica em cacaueiros (Theobroma cacao L.) autocompatíveis e autoincompatíveis
Godoy, Paula Roberta Esteves de;Souza, Margarete Magalh?es;Roza, Francisvaldo Amaral;Lawinscky, Pabliane Ramos;Araújo, Ioná Santos;Ahnert, Dário;
Brazilian Journal of Botany , 2009, DOI: 10.1590/S0100-84042009000300019
Abstract: an adequate level of pollinization is necessary for abundance in fruit production. the economic importance of the cacao trees is mainly found in its fruit production from which the seeds are extracted and used as raw material in chocolate manufacturing. several factors can interfere with the production, but the reproductive characteristics of the cacao tree and their influence on the fructification have not been extensively studied. moreover, some genotypes are self-incompatible, but self-compatible clones are also found in the commercial populations. in order to compare the pollen performance and the reproduction process between the self-compatible clones ccn51, and the self-incompatible clones tsh1188 clones, were made studies of germination in vitro (using two tests) and the pollen grain-ovule ratio (p:o). test 1 (media without some essential elements but with a higher concentration of sacarose) gave better results for pollen germination, with averages higher than 77%, while in test 2 the highest was 39.95%. the percentage of pollen germinated in vitro was higher in self-incompatible plants. based on the p:o ratio, both clones were classified as obligate autogamous, which was considered a deviation from cruden classification.
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