• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.791-802
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• 2020

Theoredoxin (TRX) transgenic soybeans were developed using the human Theoredoxin gene under the control of the ��-conglycinin promoter with a selection marker, the phosphinothricin acetyltransferase (PAT) gene. This study was done to assess the acute toxicity of a genetically modified (GM) soybean using the fresh water planktonic crustacean Daphnia magna. The acute toxicity effect of the TRX soybean and non-GM soybean (Gwangan) on D. magna was investigated at different concentrations (0, 156, 313, 625, 1,250, 2,500, and 5,000 mg·L-1). The TRX soybean used for the test was confirmed to express the TRX/PAT genes by PCR and enzyme-linked immunosorbent assay (ELISA). D. magna feeding tests showed no significant differences in the cumulative immobility or an abnormal response with either the TRX soybean or non-GM soybean. The feeding study showed a similar abnormal response and cumulative immobility of the D. magna between the TRX soybean and Gwangan treatments. Additionally, the 48 h-EC50 values for the TRX and Gwangan soybeans were 755.6 and 778 mg·L-1, respectively. The soybean NOEC (no observed effect concentration) value for D. magna was suggested to be 156 mg·L-1. These results suggest that there is no significant difference in toxicity to Daphnia magna between the TRX soybean and its non-GM counterpart.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.369-374
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• 2004

Genetically modified (GM) soybean Roundup Ready carries Agrobacterium sp. CP4 gene, which expresses 5-enolpyruvylshikimate-3-phosphate synthase (CP4EPSPS). CP4EPSPS in GM soybeans and soybean curds was screened using CP4EPSPS-specific polyclonal and monoclonal antibodies (pab and mab, respectively) by immunoblotting. Isolated recombinant CP4EPSPS was detected at detection limits of $0.006\;and\;0.0006{\mu}g$, whereas those of CP4EPSPS expressed in GM soybean were $0.001\;and\;0.0001{\mu}g$g, using mab and pab, respectively. From nine screened soybean curds, two had positive results with pab Immunoblotting method with pab and mab developed in this study could be applied to screen glyphosate-tolerant GM soybeans in soybean products.

• Journal of Life Science
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• v.27 no.11
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• pp.1299-1307
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• 2017

The quality characteristics of three non-genetically modified (GM) LRS soybean cultivars free of LOX 1, 2 and 3, such as Jinyang, Hayoung and Daebok, were compared to the characteristics of Taekwang, a soybean with LOX 1, 2 and 3 and general contents of raffinose and stachyose. Taekwang was used as a control soybean. The weights of 100 for Taekwang and Hayoung soybeans were significantly higher than those of the other samples. The crude-protein contents of the Jinyang and Hayoung soybeans were significantly higher than the crude-protein content of the Taekwang soybeans. Similar tofu yields were observed in the Taekwang, Hayoung and Daebok soybeans. The highest tofu yield was observed in the Hayoung soybeans. The isoflavone contents of the soybeans and tofu were 1.4-1.6 times and 1.8-3.4 times higher than the contents of the control soybeans, respectively. The total phenol contents of the Hayoung and Daebok soybeans were significantly higher than the contents of the control soybeans. Additionally, the total phenol and flavonoid contents were significantly higher in the tofu made from the LRS cultivars than in the tofu made from the control cultivar. The antioxidant activities of the Taekwang soybeans were higher than the antioxidant activities of the LRS-cultivar soybeans. However, the antioxidant activities of tofu made from the LRS cultivars were significantly higher than the antioxidant activities of tofu made from the control cultivar. The results suggested that the soybeans of the LRS cultivars were suitable for tofu products. The Hayoung cultivar may be the most suitable due to its higher crude protein and isoflavone contents and its significant antioxidant activity.

• The Plant Pathology Journal
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• v.32 no.2
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• pp.112-122
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• 2016

Virus-induced gene silencing (VIGS) is an effective tool for the study of soybean gene function. Successful VIGS depends on the interaction between virus spread and plant growth, which can be influenced by environmental conditions. Recently, we developed a new VIGS system derived from the Soybean yellow common mosaic virus (SYCMV). Here, we investigated several environmental and developmental factors to improve the efficiency of a SYCMV-based VIGS system to optimize the functional analysis of the soybean. Following SYCMV: Glycine max-phytoene desaturase (GmPDS) infiltration, we investigated the effect of photoperiod, inoculation time, concentration of Agrobacterium inoculm, and growth temperature on VIGS efficiency. In addition, the relative expression of GmPDS between non-silenced and silenced plants was measured by qRT-PCR. We found that gene silencing efficiency was highest at a photoperiod of 16/8 h (light/dark) at a growth temperature of approximately $27^{\circ}C$ following syringe infiltration to unrolled unifoliolate leaves in cotyledon stage with a final SYCMV:GmPDS optimal density $(OD)_{600}$ of 2.0. Using this optimized protocol, we achieved high efficiency of GmPDS-silencing in various soybean germplasms including cultivated and wild soybeans. We also confirmed that VIGS occurred in the entire plant, including the root, stem, leaves, and flowers, and could transmit GmPDS to other soybean germplasms via mechanical inoculation. This optimized protocol using a SYCMV-based VIGS system in the soybean should provide a fast and effective method to elucidate gene functions and for use in large-scale screening experiments.

• Korean Journal of Environmental Agriculture
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• v.39 no.3
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• pp.263-272
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• 2020

BACKGROUND: This paper describes the successful discrimination of GM crops from the respective wild type (WT) controls using spectroscopy and chemometric analysis. Despite the many benefits that GM crops, their development has raised concerns, particularly about their potential negative effects on food production and the environment. From this point of view, the introduction of GM crops into the market requires the development of rapid and accurate identification technologies to ensure consumer safety. METHODS AND RESULTS: The development of a GM crop discrimination model using spectroscopy involved the pre-processing of the collected spectral information, the selection of a discriminant model, and the verification of errors. Examples of GM versus WT discrimination using spectroscopy are available for soybeans, tomatoes, corn, sugarcane, soybean oil, canola oil, rice, and wheat. Here, we found that not only discrimination but also cultivar grouping was possible. CONCLUSION: Since for the determination of GM crop there is no pre-defined pre-processing method or calibration model, it is extremely important to select the appropriate ones to increase the accuracy in a case-by-case basis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1629-1637
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• 2013

The properties of non-GM soybeans with lipoxygenase (LOX) free genotypes, such as Gaechuck#1 (black, LOX2,3-free), Gaechuck#2 (yellow, LOX2,3-free) and Jinyangkong (yellow, LOX1,2,3-free), were compared to Taekwangkong (yellow, LOX1,2,3-present) as control. Length and weight of soybeans were significantly longer in Gaechuck#1, but LOX free genotypes of yellow beans was smaller than Taekwangkong, in terms the size and weight. After soaking for 12 hr, increased ratios of soybean weight were 217.07~226.55%, and they were significantly higher in Gaechuck#2. The total color difference (${\Delta}E$) to Taekwangkong was the highest in Gaechuck#1, but another yellow soybean were similar. Crude lipids content was significantly higher in Taekwangkong (17.30%), and these LOX free genotypes (13.71~14.66%) did not show significant difference. Crude protein contents were significantly higher in Gaechuck#1 (34.79%) compared to the other soybeans (32.93~33.47%). Contents of glutamic acid among the detected composition amino acid were highest, and its total contents were highest in Gaechuck#1 (32.42 g/100 g), and the total content of Gaechuck#2 was similar to Taekwangkong. Contents of total isoflavone were higher in LOX free genotypes than Taekwangkong, especially significantly higher in Gaechuck#1 (1672.54 ${\mu}g/g$). Contents of total phenol were highest in Gaechuck#1 (276.91 mg/100 g), and flavonoids content of Gaechuck#1 (26.93 mg/100 g) was 2.6~2.8 times higher than the other samples. DPPH, ABTS radical scavenging activities and reducing power were significantly higher in Gaechuck#1. The yield of soybean curd from tested samples was the highest in Gaechuck#2. Gaechuck#2 as LOX free genotypes was similar to Taekwangkong with regard to physicochemical properties and antioxidant activities. Therefore, we propose that Gaechuck#2 is a more suitable genotype for soybean curd products.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.694-699
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• 2009

A multiplex polymerase chain reaction (PCR) method was developed for the detection of 4 events of genetically modified (GM) soybean. The event-specific primers were designed from 4 events of GM soybean (RRS, A2704-12, DP356043-5, and MON89788). The lectin was used as an endogenous reference gene of soybean in the PCR detection. The primer pair YjLec-4-F/R producing 100 bp amplicon was used to amplify the lectin gene and no amplified product was observed in any of the 9 different plants used as templates. This multiplex PCR method allowed for the detection of event-specific targets in a genomic DNA mixture of up to 1% GM soybean mixture containing RRS, A2704-12, DP356043-5, and MON89788. In this study, 20 soybean products obtained from commercial food markets were analyzed by the multiplex PCR. As a result, 6 samples contained RRS. These results indicate that this multiplex PCR method could be a useful tool for monitoring GM soybean.

• Applied Biological Chemistry
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• v.45 no.4
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• pp.185-189
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• 2002

Along with the worldwide rapid increase of the cultivation area and commercial production of genetically modified (GM) crops, the amount of GM grains imported to Korea has also been increasing. Roundup-Ready soybean (RRS) was introduced with 5-enolpyruvyl shikimate-3-photphate synthase (EPSPS) gene derived from Agrobacterium CP4 to confer the resistance to herbicide, glyphosate. In this study, we tried to develop PCR-based analytical method to detection the presence of RRS among non-GM soybeans. In order to detect RRS specifically, oligonucleotide primers were specifically designed based on the nucleotide sequence of EPSPS transgene. Qualitative PCR method was established and its specificity and accuracy were confirmed by analysing the nucleotide sequence of PCR DNA fragments. Bioassay was also conducted by spraying glyphosate at seedling stage. Survived individuals showed obvious resistance to Roundup Ready, however all of non-GM seedlings died in two weeks after spray. Conclusively, the highly selective detection systems for RRS were successfully established by both PCR using specific primers to EPSPS transgene and bioassay using the herbicide resistance of RRS. In addition to, the imported soybean showed to be mixed to several varieties regarding to 100-seed weight and hilum color.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1310-1314
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• 2012

Gastrointestinal digestibility of new proteins inserted in the food supply is a significant parameter for assessing the safety of GM foods based on the assumption that digestive stability is undesirable. In this study, we performed in vitro digestion of CP4EPSPS, a new protein, expressed in genetically modified (GM) soybean in order to evaluate its digestibility in three different ratios of simulated gastric fluid with preheating. Ratios of GM soybean to simulated gastric fluid were 2:2, 2.5:1.5, and 1.5:2 and preheating was conducted at $100^{\circ}C$ for 5 min. Electrophoresis and Western blotting were used to confirm changes in soybean protein patterns and CP4EPSPS gene expression after in vitro digestion. At ratios in which the amount of gastric fluid was equal to (2:2) or relatively higher than that of soybean (1.5:2), no CP4EPSPS (47.4 kDa) protein was detected after 15 seconds of simulated gastric fluid incubation, the earliest time interval evaluated. However, when the ratio of GM soybean to gastric fluid was 2.5:1.5, CP4EPSPS was detected in 5 min and gradually decreased according to time. After preheating, no CP4EPSPS protein was detected after 15 seconds under all conditions. From these results, we concluded that the digestibility of CP4EPSPS in simulated gastric fluid increased upon preheating. Accordingly, we suggest that it is important to account for the ratio of gastric fluid to GM food in in vitro digestibility assessment models of GM food.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.875-890
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• 2021

In order to confirm the safety of a genetically modified organism (GMO), we assess its potential toxicity on non-target insects and spiders. In this study, the effects of GM soybean, a type of vitamin-A-enhanced transgenic soybean with tolerance to the herbicide glufosinate, were assessed under a field condition. The study compared this vitamin-A-enhanced transgenic soybean and a non-GM soybean (Gwangan) in a living modified organism (LMO) isolated field of Kyungpook National University (Gunwi) and the National Institute Agricultural Sciences (Jeonju) in the Republic of Korea in 2019 - 2020. In total, 207,760 individual insects and arachnids, representing 81 families and 13 orders, were collected during the study. From the two types of soybean fields, corresponding totals of 105,765 and 101,995 individuals from the vitamin-A-enhanced transgenic soybean and Gwangan samples areas were collected. An analysis of variance indicated no significant differences (p < 0.05). A multivariate analysis showed that the dominance and richness outcomes of plant-dwelling insects were similar. The data on insect species population densities were subjected to a principal component analysis (PCA) and an orthogonal partial least squares-discriminant analysis (OPLS-DA), which did not distinguish between the two varieties, i.e., the vitamin-A-enhanced transgenic soybean and the non-GM soybean in any cultivated field. However, the results of the PCA analysis could be divided overall into four groups based on the yearly survey areas. Therefore, there was no evidence for the different impact of vitamin A-enhanced transgenic soybean on the above-ground insects and spiders compared to non-GM soybean.