• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.284-288
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• 2001

Water deficit is a serious constraint to soybean [Glycine max L. (Merr.)] production in rainfed regions of Asia, Africa, and America. This study was conducted to develop a simple and effective screening method for drought tolerance in soybean. Fifteen soybean cultivars, eight identified to be drought-tolerant and seven drought-sensitive in previous studies, were used for the evaluation of drought tolerance under the new screening conditions. The seedling screening method was consisted of a treatment in a PEG solution and drought treatment in parafilm-layered pots. 5-day-old seedlings were treated in a 18% PEG solution for 4 days and their wilting and hypocotyl browning were recorded. Three seedlings grown in a parafilm-layered pot containing peat moss were drought-stressed by withholding water from the third day after seedling emergence, and root and seedling growth were examined. Degree of drought tolerance were rated based on seedling vigor in the PEG solution and drought-stressed parafilm-layered pots, and also on the penetration ability of roots through parafilm layer. Most of seedlings of the drought-tolerant cultivars showed higher vigour and root penetration than those of the drought-sensitive cultivars under the new screening conditions. Our results indicate that the new method can be used as a simple and effective screening procedure for drought tolerance in soybean breeding programs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.28-31
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• 1998

Nodule development was regulated partially by host plant factors originating in the shoots and roots. This study was performed to identify the origin of the factors regulating nodulation in supernodulating soybean (Glycine max [L.] Merr.) mutant 'SS2-2' which was isolated recently from ethyl methanesulfonate (EMS) mutagenesis of 'Sinpaldalkong 2'. Self- and reciprocal-grafts were made among three soybean genotypes which consisted of two supernodulating mutants, SS2-2 and 'nts 382', and a normal nodulating Sinpaldalkong 2. Self-grafted supernodulating mutants were characterized by greater nodule number, nodule dry weight, and $C_2$H$_2$ reduction activity than self-grafted wild types. They were also characterized by relatively higher nodule to root dry weight. Significant shoot genotypic effects were observed on nodule number, nodule dry weight, and $C_2\;H_2$ reduction activity per plant, whereas varying root genotypes had no effects. From this result, it is surmised that supernodulating characters are controlled by a graft-transmissible shoot factor, and mutant SS2-2 may have similar nodulation mechanism to the former supernodulating nts 382. In all grafts, both supernodulating mutants and Sinpaldalkong 2 maintained the similar balance between above ground and below ground parts regardless of significant differences in partitioning of dry matter into root and nodule between supernodulating mutants and Sinpaldalkong 2.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.61 no.1
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• pp.57-63
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• 2016

Soyasaponin I, II, III and V contents were investigated in seed, cotyledons and sprouts of soybean (Glycine max (L.) Merill) subjected to germination over five days. High-performance liquid chromatography coupled with tandem mass spectrometric (HPLC-MS/MS) method was used to evaluate the content of soyasaponins. Soyasaponins contents were different according to the varieties. Germination of soybeans dramatically increased soyasaponin contents in soybean sprouts in a time-dependent manner. Cotyledons had a higher contents of soyasaponins compared to dried seed (p<0.05). After five days of germination, Soyasaponin I and II increased 10 times higher after germination. Soyasaponin I and II are major metabolites in cotyledons and hypocotyls. Soyasaponin III and V were also detected in seed and increased depended on the germination stage. Soyasaponin V was at its highest levels in the hypocotyl, almost 7 times higher than the initial content in soybean seeds. Therefore, the germination of soybean sprouts significantly increased soyasaponin content.

• Journal of Crop Science and Biotechnology
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• v.10 no.4
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• pp.237-242
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• 2007

Genome duplication(i.e. polyploidy) is a common phenomenon in the evolution of plants. The objective of this study was to achieve a comprehensive understanding of genome duplication for SNP discovery by Thymine/Adenine(TA) cloning for confirmation. Primer pairs were designed from 793 EST contigs expressed in the roots of a supernodulating soybean mutant and screened between 'Pureunkong' and 'Jinpumkong 2' by direct sequencing. Almost 27% of the primer sets were failed to obtain sequence data due to multiple bands on agarose gel or poor quality sequence data from a single band. TA cloning was able to identify duplicate genes and the paralogous sequences were coincident with the nonspecific peaks in direct sequencing. Our study confirmed that heterogeneous products by the co-amplification of a gene family member were the main cause of obtaining multiple bands or poor quality sequence data in direct sequencing. Counts of amplified bands on agarose gel and peaks of sequencing trace suggested that almost 27% of nonrepetitive soybean sequences were present in as many as four copies with an average of 2.33 duplications per segment. Copy numbers would be underestimated because of the presence of long intron between primer binding sites or mutation on priming site. Also, the copy numbers were not accurately estimated due to deletion or tandem duplication in the entire soybean genome.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1173-1179
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• 2009

Trypsin inhibitors and lectins are defense proteins produced by many organisms. From Chinese 'Large Black Soybeans', a 60 kDa lectin and a 20 Da trypsin inhibitor (TI) were isolated using chromatography on Q-Sepharose, Mono Q, and Superdex 75. The TI inhibited trypsin and chymotrypsin with an $IC_{50}$ of 5.7 and $5{\mu}M$, respectively. Trypsin inhibitory activity of the TI was stable from pH 3 to 13 and from 0 to $65^{\circ}C$. Hemagglutinating activity of the lectin was stable from pH 2 to 13 and from 0 to $65^{\circ}C$. The TI was inhibited by dithiothreitol, signifying the importance of disulfide bond. The TI and the lectin inhibited HIV-1 reverse transcriptase ($IC_{50}$=44 and $26{\mu}M$), and proliferation of breast cancer cells ($IC_{50}$=42 and $13.5{\mu}M$) and hepatoma cells ($IC_{50}$=96 and $175{\mu}M$). The hemagglutinating activity of the lectin was inhibited most potently by L-arabinose. Neither the lectin nor the TI displayed antifungal activity.

• Korean Journal of Plant Resources
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• v.20 no.6
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• pp.504-510
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• 2007

GE interaction is the expression of differential genotypic adaptation across environments. GE interactions through different stability parameters and performance of the traits of genotypes were studied. The traits were days to maturity, pod length, number of pods/ plant, 100-seed weight and seed yield/plant in ten soybean genotypes across five environments. Significant differences were observed for genotypes, environments and GE interactions. Stability analysis after Eberhart and Russell's model suggested that the genotypes used in this study were all more or less responsive to environmental changes. Most of the genotypes perform better in Env.3. Based on phenotypic indices(Pi), regression ($S^2di$) genotype Garurab was found fairly stable for days to maturity. BS-23 and G-2120 may be considered as stable genotype for pod length. All the genotypes except G-2120 showed that the genotypes were relatively unstable under environmental fluctuation for the number of pod/plant. Genotype BS-23 was found most stable among all the genotypes for 100-seed weight. BS-3 and Gaurab was the most stable and desirable genotypes for seed yield in soybean.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.441-445
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• 1987

The subcellular distribution of lipoxygenase in germinating soybean seeds (Glycine max[L.] AmSoy) was investigated by using differential centrifugation and sucrose density gradient fractionation. Most of lipoxygenase -1 and -2/3 activities was present in the supernatant fraction after differential centrifugation of homogenates prepared from three-day-old seedlings; only 1.5% of lipoxygenase activity remained in particulate fractions. The results of a sucrose density gradient fractionation (three-day-old) showed that the lipoxygenase activity coincided with acid phosphatase at the densities of 1.19, 1.23, $1.25g/cm^3$, even though most of lipoxygenase and acid phosphatase activities appeared in supernatant fractions. There was no indication that mitochondria contained any lipoxygenase activity, and it does not appear that glyoxysomes and ER contained any lipoxygenase activity either.

• The Plant Pathology Journal
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• v.21 no.4
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• pp.395-401
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• 2005

The dlm (disease lesion mimic) mutant of soybean (Glycine max L. Merr) shows the similar lesion of a soybean disease caused by a fungus, Corynespora cassilcola. The lesion was examined at cellular and molecular level. Trypan blue staining result indicated that cell death was detectable in the entire region of leaves excluding veins when the lesions had already been developed. We found that the mesophyll cells of palisade layer in the dim mutant appeared to be wider apart from each other. The chloroplasts of the dim mutant cells contained bigger starch granules than those in normal plants. We also found that the lesion development of dlm plant was light-dependent and the starch degradation during the dark period of diurnal cycle was impaired in the mutant. Three soybean pathogenesis-related genes, PR-1a, PR-4, and PR-10, were examined for their expression patterns during the development of disease lesion mimic. The expression of all three genes was up-regulated to some extent upon the appearance of the disease lesion mimic. Although the exact function of DLM protein remains elusive, our data would provide some insight into mechanism underling the cell death associated with the dim mutation.

• Journal of Life Science
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• v.7 no.4
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• pp.358-360
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• 1997

Soybean [Glycine max (L.) Merr.] seed size is a important yield component and is a primary consideration in the development of cultivars for specialty markets. Our objective was to examine the consistency of QTLs for seed size across generations. A 68-plant F$_{2} segregation population derived from a mating between Marcury (small seed) and PI 467.468 (large seed) was evaluated with RAPD markers. In the F$_{2} plant generation (i.e. F$_{3} seed), three markers, OPL09a, OPM)7a, and OPAC12 were significantly (P<0.01) associated with seed size QTLs. In the F$_{2} ; F$_{3} generation (i.e., F$_{4} seed), four markers, OPA092, OPG19, OPL09b, and OPP11 were significantly (P<0.01) associated with seed size QTLs. Just two markers, OPL09a, and OPL09b were significantly (P<0.05) associated with seed size QTLs in both generations. The consistency of QTLs across generations indicates that marker-assisted selection for seed size is possible in a soybean breeding program.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.27-27
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• 2022

(-)-Epicatechin (EC), a primary form of flavan-3ol and a building block of proanthocyanidins, has health benefits as it is a potent antioxidant. So far, no quantitative trait loci (QTLs) associated with EC have yet been identified in soybean. In this study, QTLs for EC and hilum color were identified in recombinant inbred lines (RILs) derived from the varieties Jinpung and IT109098 using high-resolution single nucleotide polymorphism linkage mapping. This revealed two major QTLs for EC content, qEC06 and qEC08. qEC06 spanned the T Locus encoding flavonoid 3'-hydroxylase. qEC08, located near the I locus on Chr08, was also a major QTL for hilum color; however, allelic stacking of qEC08 and I revealed no relationship between I and EC content. RILs with IT 109098 alleles at both qEC06 and qEC08 had higher EC content than other lines. These results will enable the production of soybean varieties with high EC content via marker-assisted selection.