• Journal of Plant Biotechnology
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• v.50
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• pp.142-154
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• 2023

Plant abscission is a natural process in which plant organs or tissues undergo detachment, a strategy selected by nature for the disposal of nonessential organs and widespread dissemination of seeds and fruits. However, from an agricultural perspective, the abscission of seeds or fruits represents a major factor that reduces crop productivity and product quality. Therefore, during the crop domestication process in traditional agriculture, mutants exhibiting suppressed abscission were selected and crossbred, thereby enabling the production of modern crop varieties such as rice, tomatoes, canola, and soybeans. These crops possess a unique trait of retaining ripe fruits or seeds in contrast to disposal via abscission. During the previous century, research on quantitative trait loci along with genetic and molecular biological studies on Arabidopsis thaliana have elucidated various cell biological mechanisms, signaling pathways, and transcription regulators involved in abscission. Additionally, it has been revealed that various hormone signals, which are involved in plant growth, play crucial roles in modulating abscission activity. Researchers have developed several chemical treatments that target these hormones and signal transduction pathways to enhance crop yields. This review aimed to introduce the previously identified signal transduction pathways and pivotal regulators implicated in abscission activity. Moreover, this review will discuss the future direction of research required to investigate crop abscission mechanisms for their potential application in smart farming and other areas of agriculture, as well as areas within model systems that require extensive research.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.394-403
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• 2023

In the pursuit of sustainable and environmentally-friendly agricultural practices, we conducted an extensive study on the rhizosphere bacteria inhabiting soils that have been devoid of chemical fertilizers for an extended period exceeding 40 years. Through this investigation, we isolated a total of 80 species of plant growth-promoting rhizosphere bacteria and assessed their potential to enhance plant growth. Among these isolates, Burkholderia cepacia CD2 displayed remarkable plant growth-promoting activity, making it an optimal candidate for further analysis. Burkholderia cepacia CD2 exhibited a range of beneficial characteristics conducive to plant growth, including phosphate solubilization, siderophore production, denitrification, nitrate utilization, and urease activity. These attributes are well-known to positively influence the growth and development of plants. To validate the taxonomic classification of the strain, 16S rRNA gene sequencing confirmed its placement within the Burkholderia genus, providing further insights into its phylogenetic relationship. To delve deeper into the potential mechanisms underlying its plant growth-promoting properties, we sought to confirm the presence of specific genes associated with plant growth promotion in CD2. To achieve this, whole genome sequencing (WGS) was performed by Plasmidsaurus Inc. (USA) utilizing Oxford Nanopore technology (Abingdon, UK). The WGS analysis of the genome of CD2 revealed the existence of a subsystem function, which is thought to be a pivotal factor contributing to improved plant growth. Based on these findings, it can be concluded that Burkholderia cepacia CD2 has the potential to serve as a microbial fertilizer, offering a sustainable alternative to chemical fertilizers.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.3
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• pp.210-222
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• 1983

The chemical factors of topsoil, which are associated with the prediction models of urea nitrogen (N kg/ha) need under the concept of multinutrient factor balance in soil to maintain optimum nutrient balance in rice plant grown in flooded condition, were the x/z and the Kas/Kai values. In the prediction model or equation $NRe=(58.5+0.647x/z){\cdot}F$, the F was difined as the productivity factor, which was considered to be dependent on the variety, climate and soil, and found to be better estimated as the function of Kas/Kai rather than x/z from the equation Fb=0.65+1.086kas/kai, where the x, z, Kas and Kai, respectively, were available $SiO_2$ ppm, % organic matter, K activity ratio or exchangeable $K^+/(\sqrt{Ca+Mg}+Na^+)$ in topsoil and the ideal K activity ratio determined by the equation Kai=0.03+0.00083x/z for standard variety Jinheung. The relative K activity ratio or Kas/kai in topsoil, which have to be equal to 1.0 in the prediction of K fertilizer need for standard Japonica Variety Jinheung, found to be 1.63 for the varieties of Indica ${\times}$ Japonica or Milyang No. 23 grown in Korean condition and 0.322 for the Indica varieties of IR 8, 20, 36 and 42 gown in the Philippines condition. The ideal K activity rations for different Varieties such as Indies ${\times}$ Japonica grown in Korea or $Kai_1$ and Indica grown in the Philippines or $Kai_2$ were computed to be estimated from the following equations respectively ; $\\Kai_1=0.0489+0.001353X/Z\\Kai_2=0.01+0.000267X/Z$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.416-423
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• 2013

Germination is controlled by internal factors of seeds and external factors such as water, temperature and light. We investigated the relationship between germination characteristics of four waxy rice cultivars and patterns of water uptake, antioxidant enzymes and free soluble sugars during early imbibition. Seed viabilities by tetrazolium test of four different rice cultivars were higher than 95% and germination rates of the hulled rice seeds were on 95% average. However, germination rate of intact rice among four cultivars showed a big difference depending on temperature. Water uptake of hulled and intact rice seeds during imbibition reached a stationary phase at around 30% moisture content. Although rates of water uptake were faster in hulled rice and high temperature than intact rice and low temperature condition, difference of those among cultivars was greater under low temperature than high temperature. The time required for rice seeds to uptake 30% water was negatively correlated with percentage of germination, germination energy, germination speed and mean germination time. Guaiacol peroxidase activity at 24h of imbibition was correlated with germination energy and germination speed but not percentage of germination. Catalase activity, soluble protein and maltose concentration at 24h of imbibition were not correlated with characteristics of germination. These results suggest that a time required for rice seeds to uptake 30% of water significantly correlated with germination and guaiacol peroxidase activity during early imbibition plays an important role in initiation of germination.

• The Korean Journal of Food And Nutrition
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• v.27 no.6
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• pp.999-1005
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• 2014

This study was performed in order to compare the changes in Korean apples' qualities and antioxidant activity when stored at room temperature, $20^{\circ}C$, for fifteen days. The results showed that the weight, moisture content, soluble solid content, acidity, and hardness levels decreased as the storage period increased. However, pH and color value L increased as the storage period increased. Total phenol contents, total flavonoids contents, DPPH free radical scavenging activity, and vit. C contents of apples significantly decreased with increased storage period. Sensory parameters, such as appearance, sweetness, sourness, crunchiness, and overall acceptability of apples, also decreased as the storage period increased. Based on these results, if, the apple are being stored around $20^{\circ}C$, then, to have the highest quality, the apples should be sold within three days, We also suggested that it is desirable not to store the apples fore more than eight days.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.3
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• pp.200-205
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• 1991

To evaluate cold tolerance of rice cultivars on the basis of a relationship between cold tolerance in the field test and a biochemical character, transition-temperature of respiratory activity of mitochondria(TRM) which were isolated from different parts and at different growth stages and from etiolated rice seedling was investigated, and its relationship with degree of cold tolerance(DCT) in the field experiment was studied. The results obtained were summarized as follows. 1. The transition-temperature of respiratory activity of mitochodria (TRM) isolated from etiolated seedling ($25^{\circ}C$, two week-grown in the dark) of cold tolerant cultivars tended to be low, while that of cold susceptible cultivars to be high. 2. The correlation between TRM of etiolated seedling and the degree of cold tolerance(DCT) was $r=0.8935^{**}$ in 1988 and $r=0.8236^{**}$ in 1989. The correlation coefficient between TRM of 4-leaf seedling and DCT was $0.6239^{**}$ 3. TRM of young panicle was correlated with DCT except a few varieties. 4. TRM of seedling increased with growth as $12.5^{\circ}C$, $14.5^{\circ}C$, $15.5^{\circ}C$ and $16.5^{\circ}C$ at 1, 2, 3~4 and 5weeks respectively. 5. The transition temperature of mitochondrial respiratory activity was not significantly influenced by growth stages as $15.0{\sim}16.0^{\circ}C$ in Pungsanbyeo and $17.0{\sim}18.0^{\circ}C$ in Satbyelbyeo, while it was significantly different depending upon the degree of cold tolerance(tolerant, medium, susceptible).

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.571-576
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• 2006

In the present study, we investigated the compositions including protein, lipid, ash, carbohydrate, and minerals as well as antioxidant activity of Cirsium setidens Nakai in order to detect the biological activities and develop novel functional resources. Different organs commonly had the highest concentration of potassium among 7 minerals evaluated in this study. The leaf had K at the concentration of 5371.97 mg/100 g, while the flower, and stem, the root and the boiled leaf at the concentration of 1770.62 mg/100 g, 1983 mg/100 g, 6096.74 mg/100 g and 1604.2 mg/100 g, respectively. The monosaccharides were composed of the xylose, galactose and glucose. The xylose was only detected in the flower and stem and the galactose was only detected in the stem. DPPH scavenging activity was measured at the $88.22\;{\mu}g/mL$ and $111.19\;{\mu}g/mL$ in root and leaf at $IC_{50}$ value in ethanol extracts, while $53.27\;{\mu}g/mL$, $75.84\;{\mu}g/mL$ and $257.48\;{\mu}g/mL$ in flower, boiled leaf and stem at $IC_{50}$ value, respectively, in water extracts. These results suggest that extracts from Cirsium setidens Nakai can be potentially used as novel resources for antioxidant and biological active substances.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.403-411
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• 2009

This study was conducted to gather the basic data on the increase of utilization for the Japanese staunton vine (Stauntonia hexaphylla), native plants which were grown in the southern districts in Korea. We have also determined their partial physical and chemical compositions and their physiological activities. Vitamin C contents in fruit skin was 85.23 mg/100 g, and that in flesh was 61.67 mg/100 g. Total amino acids contents in fruit skin increased much more by 762.72 mg/100 g DW compared to that in flesh by 434.05 mg/100 g DW. Inorganic matter contents were more increased in the fruit skin (108.48 mg/$\ell$) and its main components were K (76.53 mg/$\ell$), Ca (20.20 mg/$\ell$) and Mg (6.22 mg/$\ell$). Total phenol compound and flavonoid contents in 1,000 mg/$\ell$ methanol extracts were 7.3-9.6 mg/$\ell$ and 5.1-6.7 mg/$\ell$. Nitrite radical scavenging activity in 4,000 mg/$\ell$ methanol extracts of fruit skin and flesh for Stauntonia hexaphylla were 79.5% and 77.8%, however, that in seeds was 17.1%. Overall mushroom tyrosinase inhibition activity (% of control) was less than 10.8%. Anti-microbial activities of methanol extracts from the fruit skin against the gram negative and positive microbial strains were not significant in the lower concentration of extracting solution, however, that from flesh and seeds in terms of the inhibition diameter were $8.91{\sim}12.25\;mm$.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.258-267
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• 2013

This study was conducted to determine the antioxidative and neuroprotective effect of pig skin extracts (PS) and pig skin gelatin hydrolysates (LPS) using a human neuroblastoma cell line (SH-SY5Y). The extraction yield of PS was 3 fold higher than that of LPS. The protein content of PS was about 10 fold higher than that of LPS (p<0.05). Also LPS increased antioxidative activity dose dependently, and the activity was significantly higher than PS at all concentration (p<0.05). DPPH radical scavenging activity of LPS at 50 mg/mL was 92.97%, which was similar to $1{\mu}M$ vitamin C as a positive control. ABTS radical scavenging activity of LPS (20 mg/mL) was 89.83% and oxygen radical absorbance capacity of LPS at 1 mg/mL was $141.39{\mu}M$ Trolox Equvalent/g. No significant change of human neuroblastoma cells was determined by MTT test. Cell death by oxidative stress induced by $H_2O_2$ and amyloid beta 1-42 ($A{\beta}_{1-42}$) was protected by LPS rather than PS. Acetylcholine esterase was significantly inhibited, by up to 33.62% by LPS at 10 mg/mL. Therefore, these results suggest that pig skin gelatin hydrolysates below 3 kDa have potential to be used as anti-oxidative and neuroprotective functional additives in the food industry, while further animal test should be determined in the future.

• Food Science and Preservation
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• v.23 no.7
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• pp.1033-1041
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• 2016

In this study, we evaluated antioxidant and antiproliferating effects of Setaria italica extract (SIE), Panicum miliaceum extract (PME) and Sorghum bicolor extract (SBE). Antioxidant effects of these extracts were determined by assessing DPPH radical scavenging activity, $ABTS^+$ radical scavenging activity, reducing power and superoxide dismutase (SOD)-like activity. From high concentrations ($1,000{\mu}g/mL$) of each extract at DPPH radical scavenging activities of SIE, PME and SBE were 10.5%, 5.5% and 86.8% respectively, $ABTS^+$ radical activities were 4.92%, 5.9% and 62.3% respectively, reducing powers (OD 700) were 0.15, 0.18 and 1.7 respectively, and SOD-like activities were 17.0%, 15.9% and 38.6% respectively. In addition, SBE significantly decreased the cell viability of androgen-sensitive lymph node metastasis type of prostate cancer (LNCaP) cells in a dose-dependent manner. Morphological study of SBE-treated LNCaP cells revealed distorted and shrunken cell masses. SBE-induced cell death was confirmed by observation of nuclear condensation and increased formation of apoptotic bodies. The antiproliferative effect of SBE seems to be associated with the antioxidant activity of its polyphenol content. The results of this study indicate that SBE can exert antioxidant and antiproliferative effects and may be as a useful food material.