• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.132-139
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• 2010

To manage the effluent nutrients amounts from rice paddy fields using free range ducks or rice bran, we evaluated the effects of a purifying paddy field which is no fertilizer, no pesticides, and dense rice seedling having a concept of constructed wetland. The experimental paddy field was located at downstream in the watershed of ducks using rice culture area in Milyang. The purifying paddy of land design were treated with seeding method, and vegetation type. As land design, direct seeding on plane, and direct seeding on high-ridge field in 2007. Planting rice only, and planting rice with water hyacinth were treated as vegetation type in purifying paddy in 2008. The purifying paddy fields were effective to reduce amount of T-N and T-P contents in effluent to 33.2~45.3%, and 53.1~55.4%, respectively. The direct seeding on high-ridge treatment, having long residence time of effluent water was more effective than plane plot as T-N 0.29 $g^{-1}m^{-2}d^{-1}$, and T-P 0.031 $g^{-1}m^{-2}d^{-1}$. The planting rice with water hyacinth treatment was effective than planting rice only as T-N 0.23 $g^{-1}m^{-2}d^{-1}$, and T-P 0.049 $g^{-1}m^{-2}d^{-1}$. The optimum area of purifying paddy field to treats all effluent were found out 3.2~4.7% of rice culture area using free range ducks, and rice bran at upper stream.

• Journal of Life Science
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• v.23 no.1
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• pp.1-7
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• 2013

Understanding salt tolerance mechanisms is important for the increase of crop yields, and so, several screening approaches were developed to identify plant genes which are involved in salt tolerance of plants. Here, we transformed the Arabidopsis cDNA library into a salt-sensitive calcineurin (CaN)-deficient ($cnb{\Delta}$) yeast mutant and isolated the colonies which can suppress salt-sensitive phenotype of $cnb{\Delta}$ mutant. Through this functional complementation screen, a total of 34 colonies functionally suppressed the salt-sensitive phenotype of $cnb{\Delta}$ yeast cells, and sequencing analysis revealed that these are 9 genes, including CaS, AtSUMO1 and AtHB-12. Among these genes, the ectopic expression of CaS gene increased salt tolerance in yeast, and CaS transcript was up-regulated under high salinity conditions. CaS-antisense transgenic plants showed reduced root elongation under 100 mM NaCl treatment compared to the wild type plant, which survived under 150 mM NaCl treatment, whereas CaS-antisense transgenic plant leaves turned yellow under 150 mM NaCl treatment. These results indicate that the expression of CaS gene is important for stress tolerance in yeast and plants.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.409-419
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• 2016

With increasing social concerns for healthy food, the studies on the cultivation of crops to increase accumulation of functional metabolites in crops have been investigated. Accumulation of the metabolites in crops is highly affected by various types of stress, such as nutrient deficiency, water deficit (WD), extreme temperature and UV-B radiation as well as their own life cycle. This review summarizes the previous studies on the effects of environmental stresses, especially WD and UV-B radiation, on accumulation of functional metabolites in crops. UV-B radiation and WD during specific period (mainly at maturation stage) activates the adaptation and/or defense system in crops, thereby increasing biosynthesis of the metabolites. Although WD and UV-B radiation tend to decrease in crop yield, the decrease can be compensated by the production of high value crops having high content of functional metabolites.

• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.291-307
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• 2023

Medicinal crops are the most representative input among agricultural products for biomaterials. The actual situation of how medicinal crops are used as inputs in the downstream industry is analyzed, and the input demand function of medicinal crops is quantitatively estimated. The proportions of intermediate demand and final demand in the total production of medicinal crops were 52.1% and 47.9% in 1995, but changed to 74% and 26% in 2019, with the proportion of intermediate demand accounting for approximately increased by 3 times. Estimation results of the demand function for medicinal crops in the medicine industry show, a 1% increase in the production of medicine is found to increase the demand for medicinal crops by 0.3369%. If the production of health functional foods increase by 1%, the demand for medicinal crops is expected to increase by 0.6221%. It is also found that a 1% increase in the amount of cosmetic production would increase in the demand for medicinal crops by 0.3932%. This indicates that market expansion in downstream industries can have a significant impact on agricultural products for biomaterials.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.151-161
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• 2014

Sesame lignan, including sesamin and sesamolin has been reported to have various content according to accessions and environmental factors. The objective of this study were to analyze the lignan variation of 143 sesame accessions from core collection in Korea and to test the effects of growing years and locations on lignan and lipid content of Korea sesame elite lines. The results showed that the core sesame germplasm in Korea has broad variation of lignan content from 2.33 to 12.17 mg/g with an average 8.18 mg/g. Among tested sesame accessions, the IT184615 had the highest lignan content of as 12.17 mg/g. So this accession will be a good genetic resource for developing a high lignan sesame variety. The sesamin and sesamolin content for sesame accessions across origin had significant difference. The average lignan content of accessions collected from Russia (10.0 mg/g) and Nepal (9.08 mg/g) were relatively higher than other countries. The sesamin and sesamolin content for sesame accessions across seed coat color had significant difference. The average lignan content of sesame with white, brown and black seed coat color was 8.61, 7.51, and 5.49 mg/g, respectively. The variation of lignan and lipid content was significantly different across elite lines, locations and growing years. Therefore, it is important to find sesame accessions having high lignan content with environmental stability.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.249-256
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• 2009

The amount of nutrients from the effluents of rice culture - free-range ducks (RCFD) paddy fields and the effects of natural wetlands located at downstream of RCFD on water quality and aquatic plants was evaluated. This was carried out in a 61.9 ha paddy fields in Ulsan, Gyeongnam, where downstream is a 5.9 ha natural wetland, 61% of which was covered with well-developed aquatic plants. The amounts of T-N and T-P in the effluent from paddy field with RCFD were 13.7 and $2.5kg\;ha^{-1}$, respectively, which is 1.2~2.5 times higher than those observed in conventional rice culture practice. The amount of runoff from the RCFD area, calculated using the revised TANK model, was $543mm\;ha^{-1}$ with 808 kg of T-N and 130 kg of T-P during rice cultivation period. The dominant aquatic plants in the wetland includes Phragmites communis, Zizania latifolia, Persicaria thunbergii. etc. The nutrient contents of the aquatic plants which amounted to 761 kg of T-N and 103 kg of T-P were almost equivalent to 94% and 79% of the T-N and T-P in RCFD and CRC effluent. Therefore, the use and maintenance of wetlands in RCFDs area could be a good solution to management the non-point pollution from duck feces in RCFD paddy fields.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1171-1178
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• 2010

This study was carried out to compare the physicochemical characteristics of vinegars fermented from cereal crops with Incalgyun. The crude protein, mineral and $P_2O_5$ contents of vinegars fermented from cereal crops with Incalgyun were higher than the circulated brown rice vinegar (CBRV). Brix degree, turbidity and pH of vinegar fermented from cereal crops with Incalgyun were higher, and total acidity was lower than the CBRV. The glucose content of the CBRV was 4.89 mg/mL, and vinegars fermented from glutinous foxtail millet without and with Incalgyun were 5.62 and 5.58 mg/mL. The major organic acids were acetic acid and succinic acid. The total organic acid content of the CBRV was 41.92 mg/mL, and vinegars fermented from cereal crops without and with Incalgyun were 12.14~42.31 and 13.07~41.80 mg/mL. Total amino acid content of the CBRV was $63.75\;{\mu}g/mL$, and vinegars fermented from cereal crops without and with Incalgyun were 1,125.24~1,976.37 and $1,045.36{\sim}2,057.34\;{\mu}g/mL$. The total polyphenol content of CBRV was 2.31 mg/100 mL, and vinegars fermented from cereal crops without and with Incalgyun were 28.59~41.26 and 26.57~39.62 mg/100 mL. The ABTS and DPPH radical scavenging activities of the CBRV were 1.45 and 2.85 mg TEAC/100 mL. The highest ABTS and DPPH radical scavenging activities were 37.10 and 20.26 mg TEAC/100 mL at the vinegars fermented from nonglutinous foxtail millet and glutinous foxtail millet with Incalgyun, respectively.

• Weed & Turfgrass Science
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• v.3 no.4
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• pp.318-322
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• 2014

The effects of cover crops on weed suppression were evaluated in this study. Weed suppressing effects of hairy vetch cover crops were evaluated in summer grain fields. Cover crops were sown at the sowing rate of $60kg\;ha^{-1}$ on Oct. 2012 and Feb. 2013 without basal fertilization. Three weeks old sorghum seedlings were transplanted after minimum tillage on June 2013. Hairy vetch cover crop treatment significantly reduced weed biomass in the transplanted sorghum. By smothering, the cover crops reduced weed biomass to economic level in sorghum. Besides the weed suppression, hairy vetch cover crop resulted in green manure effect on crop growth. Hairy vetch treatment showed beneficial effects on sorghum growth. Reduction of weeds caused by use of strip-tillage machine and polyethylene film mulching was 71% and 88%, respectively. At harvest, yield of sorghum was greater in order of polyethylene film mulching > hairy vetch cover crop > control in transplanted fields.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1413-1421
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• 2013

The marine microalga Isochrysis sphaerica is rich in the very-long-chain polyunsaturated fatty acids, including eicosapentaenoic acid (EPA, $C20:5{\omega}-3$) and docosahexaenoic acid (DHA, $C22:6{\omega}-3$) that are important to human health. Here, we report a functional characterization of a ${\Delta}4$-fatty acid desaturase gene (FAD4) from I. sphaerica. IsFAD4 contains a 1,284 bp open reading frame encoding a 427 amino acid polypeptide. The deduced amino sequence comprises three conserved histidine motifs and a cytochrome b5 domain at its N-terminus. Phylogenetic analysis indicated that IsFad4 formed a unique Isochrysis clade distinct from the counterparts of other eukaryotes. Heterologous expression of IsFAD4 in Pichia pastoris showed that IsFad4 was able to desaturate docosapentaenoic acid (DPA) to form DHA, and the rate of converting DPA to DHA was 79.8%. These results throw light on the potential industrial production of specific polyunsaturated fatty acids through IsFAD4 transgenic yeast or oil crops.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.887-894
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• 2011

To evaluate the effects of abiotic factors of paddy fields on greenhouse gases (GHGs) emissions from rice paddy fields, $CH_4$ emission amounts were investigated from rice paddy fields by different soil organic matter contents, paddy types, and agricultural climatic zone in Yeongnam area during 3 years. $CH_4$ emission amounts according to soil organic matter contents in paddy field were conducted at having different contents of 5 soil organic matters fields (23.6, 28.7, 31.0, 34.5, and $38.0g\;kg^{-1}$), The highest $CH_4$ emission amount was recorded in the highest soil organic matters plot of $38.0g\;kg^{-1}$. High correlation coefficient (r=$0.963^{**}$) was obtained between $CH_4$ emissions from paddy fields and their soil organic matter contents. According to paddy field types, $CH_4$ emission amounts were investigated at 4 different paddy fields as wet paddy, sandy paddy, immature paddy, and mature paddy. The highest $CH_4$ emissions was recorded in wet paddy (100%) and followed as immature paddy 64.0%, mature paddy 46.8%, and sandy paddy 23.8%, respectively. For the effects of temperature on $CH_4$ emissions from paddy fields, 4 agricultural climatic zones were investigated, which were Yeongnam inland zone (YIZ), eastern coast of central zone (ECZ), plain area of Yeongnam inland mountainous zone (PMZ), and mountainous area of Yeongnam inland mountainous zone (MMZ). The order of $CH_4$ emission amounts from paddy fields by agricultural climatic zone were YIZ (100%) > ECZ (94.6%) > PMZ (91.6%) > MMZ (78.9%). The regression equation between $CH_4$ emission amounts from paddy fields and average air temperature of Jul. to Sep. of agricultural climatic zone was y = 389.7x-4,287 (x means average temperature of Jul. to Sep. of agricultural climatic zone, $R^2=0.906^*$)