• Journal of Plant Biology
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• v.29 no.4
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• pp.295-315
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• 1986

Structure and differentiation mechanism of the seed coat of Panax ginseng are studied with light and electron microscopes to clarify the developmental processes of seed coat and the structural changes during the differentiation of the seed. The seed coat of ginseng is differentiated from the inner cell layers of ovary wall, which can be compared with the seed coat differentiated from integument(s) in other plants. The single integument is differentiated into endothelium, which is degenerated to one layer of 4${\mu}{\textrm}{m}$ in thickness, composed of remants of cell wall components in fully ripened seed. The ripened seed coat is composed of three layers; fringe layer, inner layer and palisade layer, and all of the them are crossed at right angles with one another. This may be the cause of protection of the kernel from other mechanical injuries. The thickness of fully ripened seed coat is about 300~600 ${\mu}{\textrm}{m}$, and arrangements of sclereids are irregular. However, the raphe region of seed coat is thin about 200 ${\mu}{\textrm}{m}$ in thickness and sclereids in that region are arranged regularly. This is the important cause for the cleavage of the seed coat during post-maturation process. The vascular bundles on the raphe are still remaining after sarcocarps are removed, and one of the branches of vascular bundles entered into the seed coat through the hilum and extended to chalazal region. During post-maturation process, the supply of water being necessary for growth of embryo may be accompolished by the vascular bundles entered into the seed coat through the opened hilum.

• Journal of Plant Biology
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• v.35 no.3
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• pp.191-195
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• 1992

Changes in activity of gibberellin C20-hydroxylase which converts $[^{14}C]GA_{12}\;to\;GA_{l5}$ were studied during seed maturation using the partially purified enzyme preparations of two cultivars, Kentucky Wonder (normal) and Masterpiece (dwarf) of Phaseolus vulgaris. The preparations obtained by methanol precipitation and hydrophobic interaction chromatography efficiently converted; $GA_{l2}\;to\;GA_{4},\;via\;GA_{15},\;GA_{24}\;and\;GA_{9};\;GA_{20}\;to\;GA_{1},\;GA_{5}\;and\;GA_{6}$. The activities of C20-hydroxylase which converts $GA_{l2}\;to\;GA_{l5}$ were almost the same in both cultivars. The C20-hydroxylase activity per protein reached a maximum at the very early immature seed stage, followed by a subsequent rapid decrease during seed maturation, whereas the enzyme specific activity per seed reached a maximum at 21 days after flowering, and showed a similar fiuctuation to that of the 313-hydroxylase which converts $GA_{20}\;to\;GA_{l}$ during seed maturation.ration.

• Journal of the Korean Applied Science and Technology
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• v.3 no.2
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• pp.17-22
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• 1986

Compositional and quantitative changes of 4-desmethylsterols in soybean (Glycine max. cv. Gangrim) seed and pod at six stages of development from flowering were investigated. The content of 4-desmethyl-, 4-monomethyl- and 4,4-dimethylsterols in developing soybean seed and pod was found to vary between 0.16-0.35, 0.04-0.12 and 0.04-0.06%, respectively. The predominating 4-desmethylsterols were sitosterol, campesterol and stigmasterol. The proportion of sitosterol in seed decreased to 57.0% with maturation, while in pod increased up to 88.7%. ${\triangle}^{7,22,25}$ Stigmastatrienol estimated 7.5% was detected in the fully mature seed.

• Journal of Plant Biology
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• v.36 no.4
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• pp.327-335
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• 1993

The active sites, intracellular transport, function of cellulase in association with the disintegration of the storage materials of the endosperm cells during seed maturation and after-ripening of Panax ginseng C.A. Meyer seeds were studied by electron microscopy. Cytochemical activities of the cellulase occurred in protein bodies and vesicles of endosperm cells in seed with red seed coat. In after-ripening seed, the activities were strongly found in the cell wall of endosperm near the umbiliform layer and on neighbouring vesicles, so it is assumed that these cells begin to be decomposed. Cellulase activities were initiated before the decomposition of storage materials. But, no activity was observed in the umbiliform layer, so it is suggested that cellulase lose its activity after the completion of lysis process.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.157-157
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• 2023

Pre-harvest sprouting (PHS) in rice (Oryza sativa L.) is one of the main problems associated with seed dormancy. PHS causes yield loss and reduction of grain quality under unpredictable humid conditions at the ripening stage, thus affecting the economic value of the rice crop. To resolve this issue, it is important to understand the molecular mechanism underlying seed dormancy in rice. Recent studies have shown that seed dormancy is affected by a large number of genes associated with plant hormones. However, the effect of heat stress on seed dormancy and plant hormones is not well understood. In this study, we compared the PHS rate as well as the transcriptome and small RNAome of the seed embryo and endosperm of two different accessions of rice, PHS-susceptible rice (low dormancy) and PHS-resistant rice (high dormancy) under three different maturation stages. We identified and verified the candidate genes associated with seed dormancy and heat stress-related responses in rice using quantitative real-time PCR. We newly discovered hormone-related genes, heat shock protein-related genes, and miRNAs potentially involved in PHS. These findings provide a foundation for understanding the dynamics of transcriptome and small RNAome of hormone- and heat stress-related genes, which affect PHS during seed maturation.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1158-1158
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• 2001

Fast and dynamic biochemical, enzymatic and morphological changes occur during the so-called generative development and during the vegetative processes in seeds. The most characteristic biochemical and compositional changes of this period are the formation and decline of storage components or their precursors, the change of their degree in polymerization and an extensive change in water content. The aim of the present study was to detect the maturation processes in seed nondestructively and to verify the applicability of near infrared spectroscopic methods in the measurement of physiological, chemical and biochemical changes in wheat seed. The amount and variation of different water “species” has been changed intensively during maturation. Characteristic changes of three water absorption bands (1920, 1420 and 1150 nm) during maturation were analysed. It was concluded that the free/bound transition of water molecules could be followed sensitively in different region of NIR spectra. Kinetic changes of carbohydrate reserves were characteristic during maturation. An intensive formation and decline of carbohydrate reserves were observed during early stage of maturation (0 -13 days, high energy demand). An accelerated formation of storage carbohydrates (starch) was detected in the second phase of maturation. Five characteristic absorption bands were analysed which were sensitive indicators the changes of carbohydrates occurred during maturation. Precursors of protein synthesis and the synthesis of reserve proteins and their kinetic changes during maturation were followed from NIR spectra qualitative and qualitatively. Dynamic formation of amino acids and the changes of N forms were detected by spectroscopic, chromatographic and by capillary electrophoresis methods. Calibration equations were developed and validated in order to measure the optimal maturation time protein and moisture content of developing wheat seeds. The spectroscopic methods are offering chance and measurement potential in order to detect fine details of physiological processes. The spectra have many hidden details, which can help to understand the biochemical background of processes.

• ALGAE
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• v.35 no.2
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• pp.123-131
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• 2020

Sargassum macrocarpum is a rich source of anti-inflammatory compounds. Recently, one of the compounds, tuberatolide B, has been reported as a functional anti-inflammatory additive for foods and nutraceuticals. The artificial seeding, growth and maturation of S. macrocarpum were investigated from May 2018 to September 2019. Indoor culture experiments for induction of egg release were conducted at temperatures of 17, 20, 23, and 26℃ and irradiances of 0, 10, 20, 40, and 80 μmol photons m^-2 s^-1 under 14 : 10 h (L : D) photoperiod. Within a given treatment combination, higher temperatures and irradiance levels favoured the maturation of receptacles in S. macrocarpum. Using artificial temperature and irradiance control, thalli matured one month earlier than thalli in nature. Under natural condition, receptacle formation began in April, and the eggs were released in June and July. The release of eggs from the receptacles was promoted at 17-20℃ and 40-80 μmol photons m^-2 s^-1, and the fastest growth of germlings occuring at 15-17℃ and 40 μmol photons m^-2 s^-1. For mature thalli, 300 g wet-weight was sufficient to seed 100 m of seed string. Thalli grew to 10.5 ± 2.6 cm in length at a density of 6.7 ± 3.3 individuals m^-1 after 1 year of cultivation, from germination. This study demonstrates that it is possible to cultivate S. macrocarpum for the production of anti-inflammatory products.

• Korean Journal of Plant Resources
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• v.22 no.3
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• pp.227-235
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• 2009

Single seeds of common buckwheat cultivar Suwon No. 1 when subjected to SDS-PAGE revealed very high polymorphism. High variation existed for protein or protein subunits with molecular weight 54-47kDa, 45-25kDa and 16-11kDa. The electrophoregram showed variation for globulin as well as other protein fractions. About 300 proteins were separated by two-dimensional electrophoresis in common buckwheat (Fagopyrum esculentum Moench.) seed. Seed maturation is a dynamic and temporally regulated phase of seed development that determines the composition of storage proteins reserves in mature seeds. Buckwheat seeds from 5, 10, 15, 20, and 25 days after pollination and matured stage were used for the analysis. This led to the establishment of high-resolution proteome reference maps, expression profiles of 48 spots. It was identified 48 proteins from MALDI-TOF/MS analysis of wild buckwheat seed storage proteins. The 48 proteins were found identical or similar to those of proteins reported in buckwheat and other plants; it is belonging to 9 major functional categories including seed storage proteins, stress/defense response, protein synthesis, photosynthesis, allergy proteins, amino acid, enzyme, metabolism, and miscellaneous. It appears that the major allergenic storage protein separated played the important role in buckwheat breeding and biochemical characterization.

• Korean Journal of Organic Agriculture
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• v.9 no.1
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• pp.17-27
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• 2001

To clarify the proper and safe duration of maturation periods for sawdust-pig manure composts, leaf lettuces were applied with pig manure composts fermented for 15, 30, 45, 60, 75 days and 1 year (control) and cultivated in a plastic house with or without additional PE film tunnel. The changes in physiochemical properties of soil and leaf lettuce growth were measured. Shorter duration of maturation periods enhanced the generation of N $H_3$ gas from the composts and resulted in significant decrease in seed germination, growth and yield of leaf lettuce. Under with and without PE tunnel conditions the concentration of N $H_3$ from compost over 3.8 and 2.1 mg/100g composts, respectively induced growth reduction. In proportion to the increase of maturation duration saw-dust containing pig manure exhibited decrease in C/N ratio, N $H_4^{+}$-N, N $H_4^{+}$N $O_3^{-}$ ratio but increase in N $O_3^{-}$-N contents. In case of applying pig manure compost without PE film tunnel condition the minimum maturation period of pig manure composts for safe leaf growth was 60 days, while minimum 75 days of maturation was required when applied with PE film tunnel. tunnel.

• Preventive Nutrition and Food Science
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• v.2 no.3
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• pp.255-258
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• 1997

Isoflavones are associated with prevention of chronic diseases such as cancer, osteoporosis, and hypercholesterolemia. The isoflavone contents at different development stages of soybean were anayzed to examine the period of their formation and reaching maximum level. Soybean sedds have been collected from 13th to 21st week after sowing. Total daidzein and genistein contents increased from 115 and 37mg/kg at 13th week, to 795 and 699mg/kg at 21st week, respectively. Total glycitein content showed less remarkable change during seed development than other isoflavones. Thus mature soybean may have maximum preventive effect from chronic diseases since it contains the highest level of isoflavones.