• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.317-327
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• 2008

Phytocystatins, which are inhibitors of plant cysteine peptidases, are involved in the regulation of protein turnover and in the defense against insect pests and pathogens. Extensive searches in the Brassica rapa genome allowed the prediction of at least eight different phytocystatin genes on seven chromosomes in the B. rapa genome. Structure comparisons based on alignments of the all BrCYS ($\underline{B}$. $\underline{r}apa$ $phyto{\underline{cys}}tatin$) proteins using the CLUSTALW program revealed conservation of the three consensus motifs known to interact with the active site of cysteine peptidases. According to the phylogenetic analysis based on the deduced amino acid sequences, the eight BrCYS proteins were divided into several clusters related to the orthologous phytocystatin. The predicted three-dimensional structure models of the eight BrCYS proteins demonstrate that all of these proteins are similar to the reported crystal structure of oryzacystatin-I (OC-I). Digital northern and RT-PCR analyses indicated that the eight BrCYS genes exhibit different expression patterns in B. rapa tissues and respond differently to abiotic stimuli. The differences in gene structure and expression between the eight BrCYS genes suggest that these proteins may play diverse physiological roles in B. rapa and may interact with cysteine peptidases through different mechanisms.

• Journal of Microbiology and Biotechnology
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• v.15 no.5
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• pp.1087-1093
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• 2005

The population diversity and seasonal changes of bacterial communities in rice soils were monitored using both culture-dependent approaches and molecular methods. The rice field plot consisted of twelve subplots planted with two genetically-modified (GM) rice and two non-GM rice plants in three replicates. The DGGE analysis revealed that the bacterial community structures of the twelve subplot soils were quite similar to each other in a given month, indicating that there were no significant differences in the structure of the soil microbial populations between GM rice and non-GM rice during the experiment. However, the DGGE profiles of June soil after a sudden flooding were quite different from those of the other months. The June profiles exhibited a few intense DNA bands, compared with the others, indicating that flooding of rice field stimulated selective growth of some indigenous microorganisms. Phylogenetic analysis of l6S rDNA sequences from cultivated isolates showed that, while the isolates obtained from April soil before flooding were relatively evenly distributed among diverse genera such as Arthrobacter, Streptomyces, Terrabacter, and Bacillus/Paenibacillus, those from June soil after flooding mostly belonged to the Arthrobacter species. Phylogenetic analysis of 16S rDNA sequences obtained from the soil by cloning showed that April, August, and October had more diverse microorganisms than June. The results of this study indicated that flooding of rice fields gave a significant impact on the indigenous microbial community structure; however, the initial structure was gradually recovered over time after a sudden flooding.

• Animal Bioscience
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• v.34 no.12
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• pp.1940-1950
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• 2021

Objective: The objective of this study was to explore the effects of maize straw treated with calcium oxide (CaO) and various moisture, on the composition and molecular structure of the fiber, and gas production by fermentation in an in vitro rumen environment. Methods: The experiment used 4×3 Factorial treatment. Maize straws were treated with 4 concentrations of CaO (0%, 3%, 5%, and 7% of dry straw weight) and 3 moisture contents (40%, 50%, and 60%). Scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray fluorescence spectroscopy were employed to measure the surface texture, secondary molecular structure of carbohydrate, and calcium (Ca) content of the maize straw, respectively. The correlation of secondary molecular structures and fiber components of maize straw were analyzed by CORR procedure of SAS 9.2. In vitro rumen fermentation was performed for 6, 12, 24, 48, and 72 h to measure gas production. Results: Overall, the moisture factor had no obvious effect on the experimental results. Neutral detergent fiber (NDF), acid detergent fiber, acid detergent lignin, hemicellulose and cellulose contents decreased (p<0.05) with increasing concentrations of CaO treatment. Surface and secondary molecular structure of maize straw were affected by various CaO and moisture treatments. NDF had positive correlation (p<0.01) with Cell-H (H, height), Cell-A (A, area), CHO-2-H. Hemicellulose had positive correlation (p<0.01) with Lignin-H, Lignin-A, Cell-H, Cell-A. Ca content of maize straw increased as the concentration of CaO was increased (p<0.01). Gas production was highest in the group treated with 7% CaO. Conclusion: CaO can adhere to the surface of the maize straw, and then improve the digestibility of the maize straw in ruminants by modifying the structure of lignocellulose and facilitating the maize straw for microbial degradation.

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.221-221
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• 2018

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.222-222
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• 2018

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.223-223
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• 2018

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.E
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• pp.45-59
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• 1992

At downstream part of the hydraulic structures such as spiliway or drainage gate, jet flow can occur by gate opening. If stream bed is not hard or bed protection is not sufficient, scour hole will be formed due to high shear stress of the jet flow. We call this primary scour. Once the scour hole is formed, a vortex occurs in it and this vortex causes additional scour. We call this secondary scour. The primary scour proceeds to downstream together with flow direction but the secondary one proceeds to upstream direction opposite to it. If the secondary one continues and reaches to the hydraulic structure, it can undermine the bottom of hydraulic structure and this will lead to failure of structure itself. Thus, it is necessary to know the physical features of the vortex structure in a scour hole, which is the main mechanism of the secondary scour. This study deals with the characteristics of the vortex structure and its shear stress which causes the secondary scour.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.1
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• pp.1-7
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• 2018

Information on the patterns of genetic diversity and population structure is essential for the rational use and efficient management of germplasms; accurate information aids in monitoring germplasms, and can also be used to predict potential genetic gains. In this study, we assessed genetic diversity, focusing on Korean rice accessions for theand their sustainable conserved diversity. Using DNA profiling with 12 simple sequence repeat (SSR) markers, we detected a total of 333 alleles among 2,016 accessions. The number of alleles ranged from 21 to 53, with an average of 27.8. Average polymorphism information content was 0.797, with the lowest being 0.667 and the highest 0.940. CA cluster analysis and the model-based population structure revealed two main groups that could be subdivided into five subgroups. Analysis of the molecular variance study based on the SSR profile data showed 5% variance among the profiles, whereas we recorded 93% variance among individuals and 2% variance within individuals. Specifically, the utilized diversity for of the breeding program is restricted in that cultivars were located in limited clades. These results revealed that preserving the diversity of Korean landraces could be useful sources for breeding new rice cultivars, and cwould be the basis for the sustainable conservation and utilization of a Korean rice germplasm.

• Journal of Agricultural Extension & Community Development
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• v.12 no.1
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• pp.17-28
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• 2005

This study investigated structural changes of the Korea's agriculture and proposed the new direction of rural and agricultural policy in Korea after economic opening. The major results may be summarized as follows: Firstly, the study identified structural changes of the country's peasantry under the economic opening system. Korean agriculture has been deteriorated in population structure, arable land size, and income composition. Secondly, according to above analysis on these changes it suggested that the traditional rural communities were exposed to collapse and this unwanted disaster could result in serious adversities to the national economy. Thirdly, this study proposed preservation policies for small scale farming households and also administrative preparations of multi-dimensional approaches leading to successful rural and agricultural planning.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.102-107
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• 2005

All concrete structure in agricultural improvement project must satisfied durability, serviceability, safety. It is important for structure that satisfied these natures to good quality at design and construction step, and must continuous maintenance. Most of the concrete structures is construct at winter season, is contacted with water, has various type and sporadic in wide area. The objective of this study is to make the Concrete-Quality-Control diagram for agricultural infrastructure project using GIS. And, analyze the diagram with external factor(terrain, stream, economic etc.) to know the factor of concrete quality control.