Rice consumption per capta, in South Korea, has been decreased dramatically, owing to the changes of living patterns. Because of not only the major energy source of Korean people but also major income source of Korean farmers, diversifying end-use-quality of rice has been demanded. To the context, 'Suweon 472', a high yielding and early mature japonica line and released as 'Namilbyeo' to framers in 2002, was treated with a chemical mutagen, Sodium Azide to find endosperm mutant types. A total of nine endosperm mutat lines, including five waxy, one dull, two floury, and one white core type, were identified from the 3,542 mutatagen treated lines. Amylose contents, iodine reaction, disintegration in alkali solution, gelatinization in urea solution and amylogram properties of those nine endosperm mutant lines were evaluated to address the possibility as new genetic materials for diversifying rice quality of Korean japonica cultivars. All embryo mutants were clearly differentiated from their wild type, 'Suweon 472', in terms of physic-chemical properties evaluated. The endosperm mutant lines would be very useful in expanding untiliztation of rice through opening new rice markets of processed foods from Korean japonica rice.

Seed storage proteins of different solubility were extracted and denatured subunits of each protein were evaluated with malting barley quality parameters. Its been known that each subunit of seed storage protein encoded by each gene and subunit profiles were highly related to end-use quality in cereals. The purpose of this study is to provide selection criteria for high quality malting barleys with aid of bichemical-genetic information. Total 13 regional test lines and three locations (Naju, Jinju, and Jeju) were incorporated in this study. Albumin and hordein were extracted, denatured, and separated in 12% SDS-PAGE. Presence and absence of subunits of each protein were scored. Dendrogram (using XLSTAT program) was constructed to evaluated the relatedness of lines. The correlation between band profiles and quality test were assessed through Agglomerative Hierarchical Clustering (AHC) for statistics analysis. Hordein subunits can be classified into four groups, A, B, C, and D group. In general, hordein fractions contribute higher than albumine to determine malting quality. Specific molecular weight ranges (97.4-31.0, 66.2-31.0, and 45.0-31.0 kDa) of subunits were highly correlated with malting barley quality parameters. The subunit information would be directly incorporated in providing selection criteria for high quality malting barley in the malting barley breeding program.

Previously, the wheat non-specific lipid transfer proteins (TaLTP), members of a small multigene family, appear to show a complex pattern of expression regulation. For further assessment of expression diversity of the TaLTP genes, we have attempted to evaluate their expression profiles of responses to abiotic stresses via the semi-quantitative RT-PCR method. The expression profiles revealed that the TaLTP genes in group A evidenced highly similar (but not identical) responses against abiotic stresses, whereas much differential expression pattern among genes in each group. The four promoters of TaLTP1, TaLTP7, and TaLTP10 of group A and TaLTP3 of group B were fused to a GUS reporter gene and the recombinant genes were introduced into Arabidopsis. The promoters of TaLTP1, TaLTP7 and TaLTP10 of group A, drove strong but various GUS expression in cotyledons, hypocotyls, epidemic and sub-epidemic cells of young shoots and leaves, floral organs as well as siliques. By contrast, the promoter of TaLTP3 just directed trace expression in cotyledons, young emerged leaves and epidemic cells of flower ovaries. The promoter of TaLTP1 directed the expression in root system whereas the promoters of TaLTP1 and TaLTP10 showed some degree of expression during seed development. The expression diversity of TaLTP genes suggests their multiple physiological functions, evidencing subfunctionalization over evolutionary time.

Pectin, one of the main components of plant cell wall, is deesterified in muro by PME (Pectin methylesterase). PME activity is particularly regulated by inhibitor proteins known as the pectin methylesterase inhibitor (PMEI). The PMEI plays a key role in wounding, osmotic stress, senescence and seed development. However, the role of PMEI in plant species still remains to be demonstrated especially in wheat. To facilitate the studies on the expression of the TaPMEI gene, RT-PCR was performed using leaf, stem and root tissues in response to exogeneous application of phytohormones and abiotic stress treatments. Transcription of the TaPMEI gene was significantly induced in NaCl, H2O2 and SA treatments, and reduced when plants were treated with ABA. To elucidate the subcellular localization of the TaPMEI protein, TaPMEI:GFP fusion construct was transformed into onion epidermal cells by particle bombardment. The fluorescence signal was exclusively detected in cell wall of the cells. In order to obtain recombinant TaPMEI protein, the TaPMEI protein, expressed in E.coli as a MBP (~42.5 kDa) fusion protein recombinant. Purification and functinal analysis of TaPMEI as an inhibitor of PME activity are described.

Most vacuolar proteins are synthesized on the endoplasmic reticulum (ER) as a proprotein precursor and then transported to vacuoles. In vacuoles, they are converted into the respective mature form. TaVPE1 and TaVPE2 were isolated from the cDNA library that was prepared from the wheat kernels at 16 and 18 days after fertilization (DAF). Additionally, putative TaVPEs (TaVPE3, TaVPE4) were isolated by inverse PCR (IPCR) using GrainGenes database. Each open reading frame (ORF) encodes 495, 497, 495, 456 amino acids, respectively. TaVPEs were closely related in respect to peptide comparisons and their sequence homologies were ranged from 84% to 93%. The TaVPE genes showed various expression patterns in response to exogenous treatment of phytohormones. The transcript of TaVPE1 was detected slightly and steadily after exposure to all phytohormones and the accumulation of TaVPE2 transcript was increased from 24 hours in NaCl treatment. The transcript of TaVPE3 was increased from 48 hours in response to H2O2 and decreased after exogenous application of ABA and salicylic acid. In case of TaVPE4, the transcript of TaVPE4 were weakly detected all time points of each phytohormone treatment.

It was previously pointed out that mutation is the ultimate source of variation. Adequate variation is needed for plant breeding if there is a limitation in natural genetic resources. When the ionizing radiation has been known to cause chromosomal and genomic alternations, it is widely used for inducing mutagenesis. The electron beam as an ionizing radiation is the principal physical mutagens that induces mutation and effectively used in plant breeding. Since dose-response relationships of electron beam in plant species are rarely known, we investigated the seed germination rate and early seedling growth of irradiated seeds of creeping bentgrass (Agrostis palustris Huds., cv Penn-A1) with various electron beam irradiating conditions (1, 1.3, 2 MeV at both 0.03 mA and 0.06 mA with dose of 100 Gy (Gray) and 0.03, 1, 1.3, 2 MeV at 0.03 mA with dose of 200 Gy, respectively) using electron accelerator at Korea Atomic Energy Research Institute. The growth parameters in terms of shoot length, primary root length, and secondary root length showed similar response between 0.06 / 1 (mA / MeV) at 100 Gy and 0.03 / 0.3 (mA / MeV) at 200 Gy. Bentgrass seed germination was mainly affected by the intensity of irradiated dose (Gray). Germination rate was lowered as the irradiated dose increased. On the other hand, early seedling growth was mainly governed not by the dose of radiation but by voltage.

The genetic diversity was evaluated using RAPD and ISSR among natural populations and Korean wheat cultivars (Triticum aestivum). Understanding the genetic diversity of putative parental and wild stocks would be useful in wheat breeding programs. Ninety three populations were evaluated with fifty RAPD and three ISSR primers. A total of 185 RAPD and ISSR polymorphism were produced. These markers were considered to estimate the genetic distance among accessions. The genetic similarity ranged from 0.41 to 0.86. The dendrogram were constructed by using the UPGMA clustering algorithm based on genetic similarity. The genetic diversity within and among accession was assessed through Principal Component Analysis (PCA) for statistics analysis. In cluster analysis, four groups were clustered and 17 accessions were not clustered. The PCA was corresponded well to the result. This study provides basic information about the genetic relationships for breeding purposes.