TILLING (Targeting Induced Local Lesions IN Genomes) is broadly regarded as an excellent methodology for reverse genetics applications. Approximately 15,000 M3 TILLING lines have been developed via the application of gamma-ray irradiation to rice seeds (cv. Donganbyeo), followed by subsequent selections. In an effort to evaluate the genetic diversity of the TILLING population, we have employed the AFLP multiple dominant marker technique. A total of 96 (0.64%) TILLING lines as well as Donganbyeo were selected randomly and their genetic diversity was assessed based on AFLP marker polymorphisms using 5 primer combinations. An average of 100.4 loci in a range of 97 to 106 was detected using these primer combinations, yielding a total of 158 (31.4%) polymorphic loci between Donganbyeo and each of the 96 lines. A broad range of similarity from 80% to 96% with an average of 89.4% between Donganbyeo and each of the 96 lines was also observed, reflecting the genetic diversity of the TILLING population. Approximately 28 polymorphic loci have been cloned and their sequences were BLAST-searched against rice whole genome sequences, resulting in 20 matches to each of the gene bodies including exon, intron, 1 kb upstream and 1 kb downstream regions. Six polymorphic loci evidenced changes in the coding regions of genes as compared to the rice pseudomolecules, 4 loci of which exhibited missense mutations and 2 loci of which exhibited silent mutations. Therefore, the results of our study show that the TILLING rice population should prove to be a useful genetic material pool for functional genomics as well as mutation breeding applications.

In order to select superior tree from Korea, five major phenolic compounds including (-)-epicatechin(EC), chlorogenic acid (ChA), hyperoside (HP), isoquercitrin (IQ), and procyanidin B2 (PC-B2) in hawthorn fruit were evaluated. We also compared these hawthorn fruits of five clones with Chinese hawthorn cultivars. HPLC with a diode-array detector was used to determine the contents of the individual compounds. Hawthorn fruits of five clones (selected from different area of Korea), and four Chinese hawthorn cultivars grown in the Korea Forest Research Institute (Suwon) were utilized. With their high functional components, Jungsun is the clone including the highest contents of EC (11.26 mg/g) and PC-B2 (24.46 mg/g). The clone of Chuncheon 15 had highest HP (0.53 mg/g) and IQ (0.41 mg/g). From the results, the clone of Jungsun and Chuncheon 15 can be evaluated to be selected breeding material for cultivar development.

TILLING (Targeting Induced local Lesions IN Genomes) is known to be an excellent methodology for reverse genetics approach. About 15,000 M3 TILLING lines have been developed after gamma-ray irradiation to the rice seeds of Donganbye. In order to assess genetic diversity of the TILLING population. we have employed a multiple dominant marker technique, such as AFLP. A total of 96 (0.64%) lines including Dongganbye were randomly selected and their genetic diversity was assessed on the basis of AFLP marker polymorphism by using 5 primer combinations. An average of 100.4 loci with a range of 97 to 106 were detected by using the primer combinations, resulting in 173 (34.6%) polymorphic loci among 96 lines. A broad range of similarities with 80% to 96% was evidenced between Donganbye and each of 96 TILLING lines, reflecting genetic diversity of the TILLING population. About 30 polymorphic loci have been cloned and their sequences have been blasted against rice whole genome sequences. The sequences evidenced highly significant matches to each of genes including exons and introns, upstream sequences and downstream of genes, and intergeneic sequences. Therefore, the TILLING rice population would be valuable genetic sources for rice functional genomics.

All aspects of plant life are controlled by the regulated synthesis of new proteins and the precise degradation of preexisting proteins, predicting up to 50% of total plants protein is replaced every week. The ubiquitin/26S proteosome pathway is known to be one of mechanisms to regulate signal pathways, developmental process and abiotic/biotic stress responses via protein degradations. In the previous study, we have identified a large number of the RING ubiquitin ligase proteins whose functions have been clarified in the protein degradation pathway. Curiously, one RING-H2 finger protein gene evidenced striking differences in expression patterns in response to salt and dehydration stress between leaf and culm-node tissues. Characterization of the gene evidenced its function as E3 ubiquitin ligase activity by using an in vitro ubiquitination assay. We have constructed a library with rice culm-node tissues under salt stress for Yeast two hybrid assay and performed primary yeast two-hybrid screening with the gene as a bait. A total of 13 candidate genes were isolated as positive interacting partners. Gene ontology of most candidate genes appears to be related with various abiotic stresses. Therefore, the RING-H2 finger protein genes might function to regulate plant abiotic stress responses via protein degradation pathways.

In this study, we estimated the equivalent roughness using an estimation model, which considered grain distribution on the bed and the protrusion height of the grains. We also reviewed the appropriateness of the estimated equivalent roughness at the Goksung and Gurey station in the Seomjin River. To review the appropriateness of this model, we presented the water level-discharge relation curve applying the equivalent roughness to the flow model and compared and reviewed it to observed data. Also, we compared and reviewed the observed data by estimating the Manning coefficient , the Chezy coefficient , and the Darcy-Weisbach friction coefficient by the equivalent roughness. The calculation results of the RMSE showed within 5% error range in comparison with observed value. Therefore the estimated equivalent roughness values by the model could be proved appropriate.

Flow resistance in a natural stream is caused by complex factors, such as the grains on the bed, vegetation, and bed-form, reach profile. Flow resistance in a generally stable gravel bed stream is due to protrudent grains from bed. Therefore, the flow resistance can be calculated by equivalent roughness in gravel bed stream, but estimation of equivalent roughness is difficult because nonuniform size and irregular arrangement of distributed grain on natural stream bed. In previous study, equivalent roughness is empirically estimated using characteristic grain size. However, application of empirical equation have uncertainty in stream that stream bed characteristic differs. In this study, we developed a model using an analytical method considering grain diameter distribution characteristics of grains on the bed and also taking into account flow resistance acting on each grain. Also, the model consider the protrusion height of grain.

The C3HC4 zinc RING finger proteins seem to be a family of protein-protein interactions. Little is information regarding the role of the C3HC4 zinc RING finger proteins in rice plant. We have attempted to assess their genome localization, phylogenetic relationship and expression patterns of members via in silico analysis as well as semi-quantitative RT-PCR. A total of 132 genes encoding C3HC4 zinc RING finger proteins appear to be distributed over 12 rice chromosomes, reflecting evolutionary dynamics of the rice genome, e.g. whole genome duplication and tandem duplications. A genome-wide dataset including 155 gene expression omnibus sample (GSM) plates evidenced a high degree of functional specialization of the rice C3HC4 zinc RING finger proteins, especially during developmental stages and against abiotic stresses. We have retrieved co-expression genes with each of the rice C3HC4 zinc RING finger proteins, probably providing some clues on specialized functions of individual genes. Expression patterns of 13 co-expression genes with one gene encoding C3HC4 zinc RING finger protein (Os04g51400) against salt and dehydration stresses were evaluated in crown tissues and leaf tissues, evidencing highly similar patterns among members. These findings might provide clues to shed further light on comprehensive functions of C3HC4 zinc RING finger proteins.