• Journal of Life Science
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• v.28 no.5
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• pp.605-614
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• 2018

Bee pollen has an outer wall which is resistant to both acidic and basic solutions and even the digestive enzymes in the gastrointestinal tract. Therefore, the oral bioavailability of bee pollen is only 10-15%. A previous study reported on wet-grinding technology which increased the extraction of active ingredients from bee pollen by 11 times. This study was designed to investigate the safety of wet-ground bee pollen. First, a single dose of wet-ground bee pollen was tested in both rats and beagle dogs at dosages of 5, 10, and 20 g/kg and 1.5, 3, and 6 g/kg, respectively. In rats, compound-colored stools were found in those administered 10 g/kg or more of wet-ground bee pollen. In beagle dogs, 6 g/kg of wet-ground bee pollen induced diarrhea in one male for four hours. However, no obvious clinical signs were found through the end of the experiment in rats and beagle dogs. In addition, no histological abnormality was found in all animals. The data indicates that a single dose of up to 20 g/kg of wet-ground bee pollen is safe. Next, the genetic toxicity of nano-sized bee pollen was tested. This study employed a bacterial reverse mutation test, a micronucleus assay, and a chromosomal aberration assay. In the micronucleus assay, there was no genetic toxicity up to the dosage of 2 g/kg. There was also no genetic toxicity in the bacterial reverse mutation test and chromosomal aberration assay. This data provides important information in developing nano-sized bee pollen into more advanced functional foods and herbal medicines.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.256-261
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• 2015

This study was conducted to assess the influence of hazard pattern in the surface structure of pollen grains of Campsis grandiflora, and cytotoxicity of different part extracts and nectar on RAW264.7 macrophages. The pollen grains were medium sized ($21.8{\mu}m$) with tricolpate aperture type. In equatorial view, the pollens were prolate (P/E=1.8) and the exine pattern was smooth and reticulate. This result contradict with the rumor of having a hook-shaped protuberance that can damage the cornea because we couldn't observed any protuberance on the surface of the outer wall. Furthermore, we investigated the 70% MeOH extracts (flower, leaf, stem) and nectar of C. grandiflora for their cell viability in temporal basis via MTT analysis on RAW264.7 macrophage cells. There was no significant difference in the cytotoxicity among the MeOH extracts and nectar of C. grandiflora after 24 h. However, nectar showed the dosedependent cytotoxicity on RAW264.7 macrophage cells after 48 h.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.271-291
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• 2022

Pectin methylesterase (PME) plays an important role in vegetative and reproductive development and biotic/abiotic stress responses by regulating the degree of methyl-esterification of pectic polysaccharides in the plant cell wall. PMEs are encoded by a large multigene family in higher land plant genomes. In general, the expression of plant PME genes shows tissue- or cell-specific patterns and is induced by endogenous and exogenous stimuli. In this study, we identified PME multigene family members (CsPMEs) from the sweet orange genome and report detailed molecular characterization and expression profiling in different citrus tissues and two fruit developmental stages. We also discussed the possible functional roles of some CsPME genes by comparing them with the known functions of PMEs from other plant species. We identified 48 CsPME genes from the citrus genome. A phylogenetic tree analysis revealed that the identified CsPMEs were divided into two groups/types. Some CsPMEs showed very close phylogenetic relationships with the PMEs whose functions were formerly addressed in Arabidopsis, tomato, and maize. Expression profiling showed that some CsPME genes are highly or specifically expressed in the leaf, root, flower, or fruit. Based on the phylogenetic relationships and gene expression profiling results, we suggest that some CsPMEs could play functional roles in pollen development, pollen tube growth, cross incompatibility, root development, embryo/seed development, stomata movement, and biotic/abiotic stress responses. Our results shed light on the biological roles of individual CsPME isoforms and contribute to the search for genetic variations in citrus genetic resources.

• Journal of Plant Biology
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• v.38 no.1
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• pp.95-105
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• 1995

Complete microsporogenesis of Hibiscus syriacus L. were carried out employing LM, TEM, and SEM to investigate the pollen ontogeny that undergoes considerable structural differentiation. The process first began with several cell diYisions in the anther primordium that produces 3 different tissues of epidennal, archesporial, and connective tissues. Only archesporial tissue involved further differentiation into the tapetum and formation of reproductive cells, pollen mother cells (PMC). The tapetum and PMC were closely associated with each other structurally and metabolically by exhibiting numerous plasmodesmata, mitochondria, and many small vacuoles in their dense cytoplasm. A callosic wall began to surround the PMC while meiosis took place in the PMC to produce 4 microspores. When thick callose encircled each microspore as a frame, the sporodenn development initiated from the plasma membrane of a pollen grain in a tetrad. The first fonned sporoderm layer was bacules and tectum of sexine that originated from the plasma membrane. After the dissolution of a callose, further development Qf sporoderm continued in the order of nexine 1, nexine 2, and intine layer. The nexine layer was thicker (ca. $2-3.5\;\mu\textrm{m}$) than the intine layer whose thickness was about $0.9-1.5\;\mu\textrm{m}$. Upon completion of the sporoderm development, that is after intine formation, spines and apertures of pollen surface ornamentation initiated from the tectum. Spines were dimorphic, about $4-9\;\mu\textrm{m}\;an;15-20\;\mu\textrm{m}$ in length, and no basal cushion was detected. The mature pollen grains ranged $100-200\;\mu\textrm{m}$ in diameter, but their average was about $170\;\mu\textrm{m}$. About 120 spines were observed over the spheroidal pollen surface. Apertures were simple punctures of $2-3\;\mu\textrm{m}$ in diameter and about 50 apertures were arranged somewhat helically over the surface. Comparing such features of form and size of the pollen, sporodenn sculpture and structure, and aperture and spine conditions with known evolutionary trends in the genus Hibiscus, Hibiscus syriacus seemed to possess many advanced features in the sporodenn differentiation.iation.

• Journal of Life Science
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• v.19 no.8
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• pp.1016-1022
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• 2009

Tapetum is the tissue in which nutrients are supplied to the developing microspore in angiosperm anther. At tetrad stage of microspore, the tapetal cells show maximum development, but they began to be degenerated by apoptotic programmed cell death (PCD) after sporopollenin accumulation in the pollen wall. The initial step of PCD was observed as vacuolar fusion. After that, cytoplasmic condensation and nuclear fragmentation followed. Lipid droplets are degenerated at a relatively late stage of PCD, and orbicular bodies are the last remains in tapetal cells. The cell wall was relatively resistant against vacuolar enzymes in tapetal cells; it was considered the last structure remaining during programmed cell death of tapetum in ginseng anther.

• Journal of Korean Society of Forest Science
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• v.13 no.1
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• pp.25-39
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• 1971

Recently successful induction of haploid plant by means of anther culture method has become a big topic among geneticists and plant breeders. The haploid plant can be used as a precious material for such basic researches as mutation or genetics. Once the haploid is obtained, production of homozygous plant is not a difficult problem. The method of producing homozygous plant can, also, be applied to the practical breeding works. When applied to the hybridization of self-fertilizing breeding period would be greatly shortened and in cross-fertilizing vegetables production of uniform hybrid seed would be very easily obtained. Last few years many scientists attempted anther cultures using various plant species, but it was successful only in several species. Unlike the other tissue cultures which use somatic organs or tissues as explants, anther culture seems to be very difficult because the plants or calli have to be induced from the haploid microspores or pollen grains. In the present experiment anther culture of fruit trees and ornamental shrubs of four genera and seven species was attemped. Anthers of Various stages ranging from tetrad and late microspore were cultured on the modified Murashige and Skoog's medium supplemented with various concentrations of auxins and kinetin as growth regulators. Handling of materials, sterilization, and other operations of culture were done by routine methods. The results were summarized as follows: 1. Calli were induced in the anthers of Forsythia Koreana Nak., Rhododendron mucronuratum Turcz., R. yedoense Max. var. Poukhanense Nak., and Prunus armeniaca L. var. ansu Max. No signs of callus were observed in Prunus persica Sieb. et Zucc. var. vurgaris Max., Pyrus ussuriensis var. macrostipes (Nak.), and Prunus salcina Lindley. 2. Calli were easily formed in any of the media with differing concentrations of auxins and kinetin. 3. In F. Koreana calli developed from anther surface and connective. Callus emerging out of anther locule was not observed. 4. Somatic calli arose from filament, connective, and inside of anther wall in R. mucronulatum. Many of the microspores accumulated starch grains. 5. The anther lobes located opposite the filament of R. yedoense turned easily to calli. This phenomenon was not observed in R. mucronulatum. Microspore embedded for a period in the medium became starch pollen. No callus was observed arising from microspore. 6. In P. armeniaca calli were not induced from somatic anther tissues. Instead, callus emerged out of anther locule rupturing the anther slit. Starch was not formed in the microspore. 7. In P. persica, Pyrus ussuriensis, and P. salcina, calli were not observed in the anthers examined more than 60 days after culture. Microspores of these species, however, were free of starch grains even after long period of subculture. 8. It was learned that somatic calli of the species examined arose usually from endothelium of anther wall, septum of two neighboring anther locules, parenchyma tissues of connectives, or anther lobes. 9. In the anther locule of P. armeniaca cultured long in medium, swollen microspores, polynucleate microspores, multicellular pollen grains, or callus mass were frequently observed, this indicating that the callus of this species was microspore-origin. 10. It was clarified that in P. armeniaca production of haploid plant by anther culture might be possible.

• Korean Journal of Plant Taxonomy
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• v.42 no.4
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• pp.260-266
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• 2012

Because the embryological features of Jeffersonia dubia are poorly understood, we conducted the first embryological study comparing it to other related genera of Berberidaceae. Important embryological features of J. dubia are as follows: the anther is tetrasporangiate, anther wall formation confirms basic type, glandular tapetum cells are two nucleate, the epidermis persistent, and the endothecium develops fibrous thickenings, anther dehiscence by two valves, meiosis in a microspore mother cell is accompanied by simultaneous cytokinesis, microspore tetrads are usually tetrahedral, pollen grains two cells at the time of anthesis. The ovule is bitegmic, anatropous and crassinucellate, archesporium single celled, development of the embryo sac Polygonum type, a mature embryo sac is ellipsoidal in shape. Endosperm formation is of Nuclear type and embryogeny Onagrad type. Seeds are arillate and seed coat exotestal type. Embryological comparisons showed that Jeffersonia resemble to Epimedium and Vancouveria rather than Berberis and Mahonia in some features, like as number of tapetal cells, cytokinesis in meiosis, and thickness of exotesta. It also resembles to Gymnospermium in mode of anther wall formation, number of tapetal cells, formation of nucellar cap, and nature of antipodal cells. Nevertheless, Jeffersonia and Gymnospermium differ from several other embryological features and molecular data too. Therefore, embryological evidences support that Jeffersonia is closely related with Epimedium and Vancouveria.

• Proceedings of the Ginseng society Conference
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• 1974.09a
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• pp.9-22
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• 1974

Unlike the tissue culture in animals and human being, in higher plants various parts of the plant are cultured for varied purposes, and they are named variously depending on which parts are used as explants or what purposes they are cultured for. Followings are some of the names of culture used frequently: organ culture, tissue culture, callus culture, single cell culture, meristem culture, mericlone culture, ovary culture, ovule culture, embryo culture, endosperm culture, anther culture, pollen culture, protoplast culture, etc.. As the names of the culture indicate, in some kinds of culture the explants used for culture are actually not tissues, but organs, single cells, or protoplasts. It seems, however, convenient to call all of the above-mentioned cultures grossly as tissue culture. Several kinds of tissue culture were attempted using Panax ginseng as material and some of the results were summarized below. 1. Callus culture After dormancy of the sed was broken, whole embryo or parts (hypocotyl, cotyledon and epicotyl) of partly grown embryo were cultured in the media supplemented with growth regulators. Rapid swelling occurred in a few weeks, but most of the swelling was observed only in the basal part of epicotyl, changes in the other parts of embryo appearing in much later stages. The swelling or increase in size, however, was resulted not from the divisions of cells, but from the mere expansion of cell. Real calli were formed about two months after inoculation of explants. Callus tissues developed from cortex, pith, and vascular bundle in the cases of hypo- and epicotyl, from mesophyl tissue in the case of cotyledon. Shoots developed more easily from cotyledons regardless of whether they are detached from or attached to the embryo proper. 2. Culture in the Knudson C medium When cotyledons, detached from or attached to the embryo proper, were cultured in the growth regulator-free Knudson C medium comprision only several kinds of mineral compounds and sucrose, shoot primordium or callus developed profusely and finally plantlets were produced directly from shoot primordium or indirectly through callus. In this medium epidermal cells as well as mesophyl cells of the cotyledon became meristematic and divided, changing into multinucleate cells or multicellular bodies, developing eventually into either shoot primordia or calli. 3. Anther culture Anthers were cultured in the media supplemented with various growth regulators applied singly or in combinations. Callus was formed mostly in the connective tissue of anther. Cells of anther wall layers changed in appearance, but no division occurred. Microspores of all stages in development were not changed, ruling out the possibility that microspore-originated callus might be formed. 4. Isolation of protoplast Protoplasts were isolated from young root, leaf, and epicotyl, using 0.7M D-mannitols as osmoticum and using macerozyme and cellulase respectively for maceration and digestion of the cell wall. Production in large number of naked intact protoplast was rather difficult as compared with other plant species. Fusion of protoplasts occurred infrequently mainly due to the fewer number of naked protoplasts in the solution.

• Journal of Korean Society of Forest Science
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• v.23 no.1
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• pp.9-16
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• 1974

The anthers of late uninucleate microspore or early binucleate microspore stage of Paeonia suffruticosa Andr. (economic tree) were cultured on the modified Murashige and Skoog's medium suppliment with Keinetin, 2,4-D, and NAA for inducing haploid plants. The results are as follows; 1. Callus were induced from both anther locule and anther wall, where that from anther locule was identified as haploid. 2. Among 2,000 anthers cultured, fourteen haploid callus were developed. These haploid callus were clearly identified to be originated from the microspore in anther locule. 3. Diploid callus were induced only 0.5 percent from the callus of endothelium of anther wall, septium of two neighboring anther locule, parenchyma tissues of connectives and or anther locules. 4. In the anther locule of Paeonia suffruticosa Andr. cultured in medium, swollen microspores, polynucleate microspores, multicellurar pollen grains, or callus mass was frequently observed. And the haploids were seemed to be caused by the callus originated from the reduced microspore.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.5 no.1
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• pp.69-86
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• 1969

On the growing of the interspecific hybrid ginseng plant, the phenomena of hybrid vigoures are observed in the root, stem, and leaf, but it can not produce seeds favorably since the ovary is abortive in most cases in interspecific hybrid plants. The present investigation was undertaken in an attempt to elucidate the embryological dses of the seed failure in the interspecific hybrid of ginseng (Panax Ginseng ${\times}$ P. Quinque folium). And the results obtained may be summarized as follows. 1). The vegetative growth of the interspecific hybrid ginseng plant is normal or rather vigorous, but the generative growth is extremely obstructed. 2). Even though the generative growth is interrupted the normal development of ovary tissue of flower can be shown until the stage prior to meiosis. 3). The division of the male gameto-genetic cell and the female gameto-genetic cell are exceedingly irregular and some of them are constricted prior to meiosis. 4). At meiosis in the microspore mother cell of the interspecific hybrid, abnormal division is observed in that the univalent chromosome and chromosome bridge occure. And in most cases, metaphasic configuration is principally presented as 23 II+2I, though rarely 22II+4I is also found. 5). Through the process of microspore and pollen formation of F1, the various developmental phases occur even in an anther loclus. 6). Macro, micro and empty pollen grains occur and the functional pollen is very rare. 7). After the megaspore mother cell stage, the rate of ovule development is, on the whole, delayed but the ovary wall enlargement is nearly normal. 8). Degenerating phenomena of ovules occur from the megaspore mother cell stage to 8-nucleate embryo sac stage, and their beginning time of constricting shape is variously different. 9). The megaspore arrangement in the parent is principally of the linear type, though rarely the intermediate type is also observed, whereas various types, viz, linear, intermediate, Tshape, and I shape can be observed in hybrid. 10). After meiosis, three or five megaspore are some times counted. 11). Charazal end megaspore is generally functional in the parents, whereas, in F1, very rarely one of the center megaspores (the second of the third megaspore) grows as an embryo sac mother cell. 12). In accordance with the extent of irregularity or abnormality in meiosis, division of embryo sac nuclei and embryo sac formation cause more nucellus tissue to remain within th, embryo sac. 13). Even if one reached the stage of embryo sac formation, the embryo sac nuclei are always precarious and they can not be disposed to theil proper, respective position. 14). Within the embryo sac, which is lacking the endospermcell, the 4-celled proembryo, linear arrangement, is observed. 15). Through the above respects, the cause of sterile or seed failure of interspecific hybrid would be presumably as follows, By interspecific crossing gene reassortments takes place and the gene system influences the metabolism by the interference of certain enzyme as media. In the F1 plant, the quantity and quality of chemicals produced by the enzyme system and reaction system are entirely different from the case of the parents. Generally, in order to grow, form, and develop naw parts it is necessary to change the materials and energy with reasonable balance, whereas in the F1 plant the metabolic process becomes abnormal or irregular because of the breakdown of the balancing. Thus the changing of the gene-reaction system causes the alteration of the environmental condition of the gameto-genetic cells in the anther and ovule; the produced chemicals cause changes of oxidatio-reduction potential, PH value, protein denaturation and the polarity, etc. Then, the abnormal tissue growing in the ovule and emdryo sac, inhibition of normal development and storage of some chemicals, especially inhibitor, finally lead to sterility or seed failure. Inconclusion, we may presume that the first cause of sterile or seed abortion in interspecific hybrids is the gene reassortment, and the second is the irregularity of the metabolic system, storage of chemicals, especially inhibitor, the growth of abnormal tissue and the change of the polarity etc, and they finally lead to sexual defect, sterility and seed failure.