• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.2
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• pp.85-94
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• 2000

The effects of ozone on chloroplast development in barley seedlings during greening was investigated based on ultrastructural changes in the chloroplasts and band pattern changes in the chloroplast thylakoid membrane proteins. In this analysis of the chloroplast thylakoid membrane thylakoid protein band pattern by SDS-PAGE, none of the 24-hour greening bands included were clearer than the control. This means that the ozone treatment produced a dealy in chloroplast development and decreased the amount of thylakoid membrane proteins. LHC II chloroplast band of developing barley seedlings treated with 0.5 and 1.0 ppm ozone during the last 4 hours of the 24-hour greening period was weaker than the other bands. This result indicates that ozone affects the LHC II protein complex of the chloroplast thylakoid membrane. When investigating the ultastructural changes in ozone-treated chloroplast, the main site affected by 0.5 ppm ozone was the chloroplast grana, thereby explaining the delayed chloroplast development during the early phase of greening. In addition, there was also a structural change in the stromal grana of the ozone treated chloroplast during the middle phase of greening. The effects of ozone on the chloroplast of barley seedlings during the last phase of 48-hour greening were more functionally inhibiting than structural changes.

• Proceedings of the Botanical Society of Korea Conference
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• 1987.07a
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• pp.103-113
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• 1987

Along the developmental processes in higher plants, chloroplast follows a major route of development which is proplastid - etioplast - chloroplast. Development of chloroplast can be determined according to the expressions of the genes coded in the chloroplast DNA as well as in the chromosomal DNA. Most of the processes occuring in proplastid and etioplast seems to be coded in the chromosomal DNA, which the development of chloroplast from etioplast upon the exposure of plants to light is determined by harmonious expressions of the genes in the chloroplast and the chromosome.

• Journal of Plant Biology
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• v.19 no.3
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• pp.71-84
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• 1976

In order to observe the phosphate metabolism in chloroplast, the contents of inorganic phosphate and various compounds in chloroplast from spinach leaf tissues were investigated during the reaction in the light and dark in the reaction mixture and the turnover of phosphate in chloroplast was compared with that of whole cell system: 1. The phosphorus of DNA in chloroplast appears to be transferred from inorganic phosphate, while in whole cell system from phosphate pool. 2. $^{32}P-phosphate$ content of acid soluble fraction in chloroplast as well as in whole cell system was more increased in the light than dark during the reaction. It was noted to be caused by the stimulation of sugar phosphate synthesis in the light. 3. It was confirmed that polyphosphate exists in chloroplast as well as whole cell. Acid insoluble polyphosphate content in whole cell system was significantly decreased during the reaction and the similar tendency was also observed in chloroplst. It is, therefore, considered that acid insoluble polyphosphate also play an most important role as a phosphate pool respectively in chloroplast and in cytoplasm. 4. Protein and lipid phosphorus in chloroplast as well as whole cell system were transferred from acid insoluble polyphosphate.

• Journal of Plant Biology
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• v.33 no.1
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• pp.81-84
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• 1990

The chloroplast has been the prime light-energy harvesting organelle on earth. It also carries out several key metabolic processes, such as lipid synthesis and nitrogen metabolism. Even though the chloroplast has its own genome, its coding capacity can afford only dozens of proteins, and most of the proteins functioning in the chloroplast are imported from the cytosol where nuclear encoded chloroplast genes are synthesized on free cytosokic ribosomes. Precursor proteins synthesized on cytosolic ribosomes have transit peptides at the amino termini of the proteins, and the transit peptide is sufficient to transfer chloroplast proteins from the cytosol into the chloroplast. When comparing amino acid sequences duduced from the nucleotide sequences of the clones of the chloroplast proteins, high homologies can be found among the transit peptides of proteins with the same function. Overall amino acid compositions of the transit peptides show amphiphilic characters of the transit peptides, and the amphiphilicity indicates that three dimensional structure of the transit peptide is responsible for the translocation of the chloroplast proteins.

• The Plant Pathology Journal
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• v.39 no.1
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• pp.28-38
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• 2023

Plant viruses are responsible for worldwide production losses of numerous economically important crops. The most common plant RNA viruses are positivesense single-stranded RNA viruses [(+)ss RNA viruses]. These viruses have small genomes that encode a limited number of proteins. The viruses depend on their host's machinery for the replication of their RNA genome, assembly, movement, and attraction to the vectors for dispersal. Recently researchers have reported that chloroplast proteins are crucial for replicating (+)ss plant RNA viruses. Some chloroplast proteins, including translation initiation factor [eIF(iso)4E] and 75 DEAD-box RNA helicase RH8, help viruses fulfill their infection cycle in plants. In contrast, other chloroplast proteins such as PAP2.1, PSaC, and ATPsyn-α play active roles in plant defense against viruses. This is also consistent with the idea that reactive oxygen species, salicylic acid, jasmonic acid, and abscisic acid are produced in chloroplast. However, knowledge of molecular mechanisms and functions underlying these chloroplast host factors during the virus infection is still scarce and remains largely unknown. Our review briefly summarizes the latest knowledge regarding the possible role of chloroplast in plant virus replication, emphasizing chloroplast-related proteins. We have highlighted current advances regarding chloroplast-related proteins' role in replicating plant (+)ss RNA viruses.

• Journal of Plant Biology
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• v.22 no.3
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• pp.55-57
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• 1979

These studies were undertaken to determine the $CO^2$fixation patterns following the chloroplast development in maize leaves. At the early stage of chloroplast development $^{14}C$ was incorporated into aspartate (41%) and malate (22%) respectively. Whereas the incorporation of $^{14}C$ into malate was higher than that of aspartate as chloroplast developed. Activity of NADPH-dependent malate dehydrogenase was increased throughout chloroplast development, but that of aspartate transaminase was not. Much incorporation of $^{14}C$ into aspartate at the early stage of chloroplast development and into malate at later stage of chloroplast development lead us to conclude that NADPH-dependent malate dehydrogenase activity is closely associated with chloroplast development, but activity of aspartate transaminase is not.

• Korean Journal of Plant Taxonomy
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• v.51 no.4
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• pp.353-362
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• 2021

The chloroplast genome of Glycyrrhiza uralensis Fisch was sequenced to investigate intraspecific variations on the chloroplast genome. Its length is 127,689 bp long (34.3% GC ratio) with atypical structure of chloroplast genome, which is congruent to those of Glycyrrhiza genus. It includes 110 genes (76 protein-coding genes, four rRNAs, and 30 tRNAs). Intronic region of ndhA presented the highest nucleotide diversity based on the six G. uralenesis chloroplast genomes. A total of 150 single nucleotide polymorphisms and 10 insertion and deletion (INDEL) regions were identified from the six G. uralensis chloroplast genomes. Phylogenetic trees show that the six chloroplast genomes of G. uralensis formed the two clades, requiring additional studies to understand it.

• Genomics & Informatics
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• v.20 no.4
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• pp.43.1-43.18
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• 2022

Atropa belladonna is a valuable medicinal plant and a commercial source of tropane alkaloids, which are frequently utilized in therapeutic practice. In this study, bioinformatic methodologies were used to examine the pattern of coding sequences and the factors that might influence codon usage bias in the chloroplast genome of Atropa belladonna and other nightshade genomes. The chloroplast engineering being a promising field in modern biotechnology, the characterization of chloroplast genome is very important. The results revealed that the chloroplast genomes of Nicotiana tabacum, Solanum lycopersicum, Capsicum frutescens, Datura stramonium, Lyciumbarbarum, Solanum melongena, and Solanum tuberosum exhibited comparable codon usage patterns. In these chloroplast genomes, we observed a weak codon usage bias. According to the correspondence analysis, the genesis of the codon use bias in these chloroplast genes might be explained by natural selection, directed mutational pressure, and other factors. GC12 and GC3S were shown to have no meaningful relationship. Further research revealed that natural selection primarily shaped the codon usage in A. belladonna and other nightshade genomes for translational efficiency. The sequencing properties of these chloroplast genomes were also investigated by investing the occurrences of palindromes and inverted repeats, which would be useful for future research on medicinal plants.

• Journal of Ginseng Research
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• v.17 no.1
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• pp.39-44
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• 1993

In Korean ginseng, Panax ginseng C.A Meyer, it was difficult to isolate chloroplast DNA with classical methods, because of the high polysaccharide content of ginseng chloroplast The simple and efficient method of chloroplast DNA isolation from ginseng leaves has been developed by motificalion of recently advanced methods. Also, it can be successfully applied to ctDNA isolation of Chinese cabbage, radish, petunia tobacco as well as ginseng. Isolated chloroplast DNA from ginseng was digested with various restriction endonucleases. It was estimated that the molecular weight of Korean ginseng chloroplast DNA was about 142 kb. There was no difference in restriction endonuclease digestion patterns between two variants of Korean ginseng, which are Jakyung-Jong (violet-stem variant) and Hwang- sook-Jong (yellow-berry variant).

• Journal of Ginseng Research
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• v.17 no.3
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• pp.236-239
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• 1993

We studied the chloroplast rearrangement, short-term regulation depending on the light conditions in plants, and the characteristic of photosynthic rate as affected by in Panax ginseng C.A. Meyer. The chloroplast rearrangement of ginseng mesophyll cell was induced with the irradiation of blue light (400~500 nm) and through this process the rate of leaf transmittance increased 5~7.5%. The time to reach the maximum value of photosynthesis was shorter above 20 minutes with the blue light irradiation than that of the red light.