• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.271-275
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• 2007

In the chloroplast transformation process, a chloroplast containing transformed chloroplast genome copies should be selected over wild-type chloroplasts on selection medium. It is more effective for a cell to become homoplasmic if the cell contains smaller number of chloroplasts. Therefore, to reduce the number of chloroplasts in mesophyll cells in tobacco, we overexpressed FtsZ to generate transgenic plants, of which mesophyll cell contained a few enlarged chloroplasts contrast to a wild-type mesophyll cell containing approximately 100 chloroplasts. It was demonstrated that transgenic leaf tissues comprising cells with a few enlarged chloroplasts gave rise to approximately 40% higher frequency of chloroplast-transformed adventitious shoots.

• Molecules and Cells
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• v.20 no.1
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• pp.112-118
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• 2005

It was previously shown that AtNAP1 is a plastidic SufB protein involved in Fe-S cluster assembly in Arabidopsis. In this study, we investigated the effects of depleting SufB protein from plant cells using virus-induced gene silencing (VIGS). VIGS of NbNAP1 encoding a Nicotiana benthamiana homolog of AtNAP1 resulted in a leaf yellowing phenotype. NbNAP1 was expressed ubiquitously in plant tissues with the highest level in roots. A GFP fusion protein of the N-terminal region (M1-V103) of NbNAP1 was targeted to chloroplasts. Depletion of NbNAP1 resulted in reduced numbers of chloroplasts of reduced size. Mitochondria also seemed to be affected. Despite the reduced number and size of the chloroplasts in the NbNAP1 VIGS lines, the expression of many nuclear genes encoding chloroplast-targeted proteins and chlorophyll biosynthesis genes remained unchanged.

• Journal of Plant Biology
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• v.37 no.3
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• pp.285-292
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• 1994

Ultrastructural changes in Panax ginseng C. A. Meyer mesophyll chloroplasts and variation of thylakoid membrane protein in responce to the light intensity were studied in leaves of two-y-old plants exposed to two different light intensities under field coditions. The leaves were allowed to function for three months after emergence under two contrasting light conditions. The ginseng chloroplasts of 5% light were filled with highly stacked grana of condensely arrayed thylakoids, so that the stroma space was hardly observed. In contrast, chloroplasts from leaves at 100% sunlight had fewer thylakoid membranes and smaller grana stacks. The number of osmiophilic globules increased. Total Chl content and Chl b content were lower at 100% sunlight than 5% sunlight. The thylakoid membrane proteins in the leaves grown at 100% sunlight showed lower CPIa, LHCII and CP29 than those with 5% sunlight. This effect was most obvious for LHCII. Polypeptides showed major bands at 90, 64, 29-30, 22 and 14 kD, and minor bands at 59, 58, 54, 52, 49, 46, 44, 35, 23, 21 and 18-19 kD. All these bands were lower in intensity in the leaves exposed to 100% sunlight. Moreover, the bands at 58-59, 46-47 and 23 kD disappeared.

• Applied Microscopy
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• v.24 no.4
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• pp.13-31
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• 1994

The fine structure of palisade chloroplasts has been studied in the mature leaves of 3 Dubautia species (D. scabra var. leiophylla, D. knudsenii and D. scabra var. leiophylla${\times}$D. knudsenii) to explore variation at the ultrastructural level, since the parental species exhibit quite different morphological and anatomical features. Types of thylakoidal membrane systems, occurrence and distribution of phytoferritin-like structures, lipid droplets, starch grains, mitochondria and microbodies were examined. Four different types of thylakoidal membranes were found in D. scabra var. leiophylla, 2 rather uniform types in D. knudsenii and 3 intermediate types in their hybrid. D. scabra var. leiophylla and the hybrid were marked by statistically significant differences in mean numbers of thylakoids per granum, while no significant difference was found between D. knudsenii and the hybrid. Phytoferritin-like structures which were about $100-120{\AA}$ in diameter as a whole particle each were found in all 3 species. The amount and distribution of particles varied by species. Lipid droplets, plastoglobuli, and starch grains occurred in all 3 species, but the frequency of starch grains also varied with the species. More frequent and larger starch grains were observed in D. knudsenii than in the other two species. Microbodies, or peroxisome, were observed throughout all species. They occurred, either with or without crystalline inclusions, around the chloroplasts.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.107-113
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• 2015

This study was conducted to find out the effective induction method of tetraploid plants to obtain potential data for cultivating superior varieties by colchicine treatment. The seed germination were decreased by the higher concentration of colchicine treatment and longer soaking time. A total of 907 individuals were germinated in 16 treated plots except control (untreated plot) and 28 tetraploids were induced which was about 3.1% of the number of seed germinated. The plant regeneration rate by colchicine treatment on explant of Prunella vulgaris for. albiflora Nakai under in vitro culture was decreased with the higher concentration of colchicine. While a total of 312 individuals were regenerated in all treatments, the explant was soaked in more than 0.05% for over 1 hour, tetraploid could be obtained. In particular, for the soaking treatment in 0.05% for 6 hours and 12 hours, 37 tetraploids were induced, which was about 57.8% of the number of plant regenerated. In accordance with the observation on doubling of DNA contents in leaf in order to identify polyploid, the peak DNA content of G1 phase was 101.3 for diploid and 197.2 for tetraploid. The result confirmed the doubling of DNA content. Furthermore, the number of chloroplasts per guard cell depending on polyploid was around 10 in diploid and 19.3 in tetraploid, which was around 1.9 times as much as diploid.

• Korean Journal of Medicinal Crop Science
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• v.26 no.5
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• pp.362-369
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• 2018

Background: For stable induction of tetraploidy in Fallopia multiflora Haraldson, colchicine was treated to establish the condition of induction and investigated the morphological and cytogenetic traits of the tetraploid plants obtained compared to those of diploid ones. Methods and Results: For the induction of tetraploidy, F. multiflora plants were soaked in aqueous solutions of colchicine at various concentration (0.1, 0.5, and 1.0%). After this, 2% dimethyl sulfoxide (DMSO) was added at room temperature on a shaker set at 150 rpm for periods of 12, 24, and 48 h. The induction rate of tetraploids appeared to be the highest in plants treated with 0.5% colchicine for 24 h. As the colchicine concentration and soaking time increased above these levels, the growing tip of the roots did not develop and they began to rot. When compared to diploid plants, tetraploids differed greatly in various characteristics, including the sizes and shapes of the leaves, fruits, flowers and roots. The induced tetraploid F. multiflora had larger guard cells, and chloroplasts, increased number of chloroplast in the guard cells and decreased stomatal densities. Conclusions: When colchicine induced plants for tetraploid, it can be distinguished from diploids, in various characteristics such as morphological changes as stomatal size, number of chloroplasts per guard cell, number of chromosomes and flow cytometry. Therefore, it proved that these methods are suitable, quick and easy methods for the identification of the ploidy level of F. multiflora.

• Journal of environmental and Sanitary engineering
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• v.5 no.1
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• pp.1.2-6
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• 1990

The purpose of this experiment was to investigate boron deficient symptom of sugar beet. Sugar beet affected by boron deficiency was anatomized and observed by microscope and electron microscope. The sugar beet plants affected onboron deficiencyu with water culture and those of the experimental farm alike contained a small amount of boron. The symptom of boron deficiency began to show dark-brown lines at the ventral suface of the basal part of petiole and then, in the ridge of young leaf, growing point became darkened due to necrosis. The leaf blade was wrinked severely and finally the growth was stunted. The boron deficiency began with necrosis of the epidermis of the ventral surface of the basal part of petiole, and parenchyma under it. Necrosis and disintegration of the ridge of young leaf began to take place and were expanded gradually. Electron microscopic examination of boron deficient sugar beet plants revealed that chloroplasts degenerated, and appeared to contain larger amounts of starch, also observed larger number of osmophilic granules. And they peculiarly were found polyhedral crystals in the certain deficient chloroplasts.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.284-288
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• 2013

This study aimed to get the basic data on the breeding of good varieties in Hypericum patulum Thunberg. The optimum materials, concentration and soaking time were examined to identify the effective approach to induce tetraploid plant by colchicine treatment to cultivate the varieties. For the seed germination rate of seed by colchicine treatment, the higher colchicine concentration was and the longer soaking time was, the more the germination rate decreased. While individuals were germinated in 16 test groups except control group (no treatment group), all the plants were diploid and no tetraploid was induced. For the plant regeneration rate by colchicine treatment on the explant of Hypericum patulum Thunberg that was under in vitro culture, the higher the colchicine concentration increased, the ress the regeneration rate. While total 147 individuals were regenerated in all treatment, when the explant was soaking treatment in more than 0.05% for over 6 hours, tetraploid could be obtained. In the soaking treatment of 0.05% for over 6 hours, tetraploid could be obtained. In particular, for the soaking treatment in 0.05% for 12 hours, 8 tetraploids were induced, which was about 47.1% of the number of plant regenerated. In accordance with the observation on doubling of DNA contents in leaf in order to identify polyploidy, the peak DNA content of G1 phase was 94.5 for diploid and 192.5 for tetraploid. It confirmed doubling of DNA content. Furthermore, the number of chloroplasts per guard cell depending on polyploid was around 10 in diploid and 17 to 19 in tetraploid, which were around 1.7 to 1.9 times as much as diploid.

• Proceedings of the Botanical Society of Korea Conference
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• 1998.07a
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• pp.83-96
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• 1998

The plant pigment proteins phytochromes are a molecular light sensor or switch for photomorphogenesis involving a variety of growth and developmental responses of plants to red and far-red wavelength light. Underscoring the photomorphogenesis mediated by phytochromes is the light signal transduction at molecular and cellular levels. For example, a number of genes activated by the phytochrome-mediated signal transduction cascade have been identified and characterized, especially in Arabidopsis thaliana. The light sensor/switch function of phytochromes are based on photochromism of the covalently linked tetrapyrrole chromophore between the two photoreversible forms, Pr and Pfr. The photochromism of phytochromes involves photoisomerization of the tetrapyrrole chromophore. The "photosensor" Pr-form ("switch off" conformation) of phytochromes strongly absorbs 660 nm red light, whereas the "switch on" Pfr-conformation preferentially absorbs 730 nm far-red light. The latter is generally considered to be responsible for eliciting transduction cascades of the red light signal for various responses of plants to red light including positive or negative expression of light-responsive genes in plant nuclei and chloroplasts. In this paper, we discuss the structure-function of phytochromes in plant growth and development, with a few examples of biotechnological implications.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.611-618
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• 2015

Spirogyra is a zygnematalean green algal genus that is ubiquitous in a broad range of freshwater habitats throughout the world. Samples collected throughout Korea from October 2004 to July 2015 were examined using light microscopy. Morphological characteristics (e.g., size of vegetative cells, number of chloroplasts in each cell, type of end walls of adjacent cells, details of conjugation, shape of female gametangia, dimensions and shape of zygospores, color and ornamentation of median spore walls) were used as diagnostic characteristics for species identification. In this study, five species of Spirogyra (i.e., S. emilianensis Bonhomme, S. jaoensis Randhawa, S. pascheriana Czurda, S. weberi var. farlowii (Transeau) Petlovany, and S. weberi var. grevilleana (Hassall) Kirchner) were described as newly recorded in Korea.