본 리뷰의 목적은 벼 종자 저장단백질 구조분석 및 발현특성분석 결과 종합화를 통하여 종자형질 개선 등의 실용화연구를 위한 기반구축을 모색하는데 있다. 최근 벼 염색체염기서열완전해독 연구 결과를 이용한 유용형질 유전자 분리 및 실용화 연구가 많이 진행되고 있다. 특히 벼 종자 저장단백질은 인류에게는 주요 영양원으로 사용되어지며 종자 발아시에는 식물체 성장을 위한 질소원으로 사용되어진다. 벼 종자 저장단백질의 분류는 용매에서의 용해도에 따라 약산성 및 알카리 용해성의 glutelin, 알코올 용해성의 prolamin, 염 용해성의 globulin으로 나눈다. 벼 염색체 상에는 11개의 glutelin 유전자와 33개의 prolamin 유전자가 존재하며 prolamin 유전자의 경우 5번 염색체 15 Mb 부위에 15개의 유전자가 위치하였다. 이와 같이 종자저장단백질 유전자들이 동일 염색체 부위에 위치하고 있는 것은 진화학적으로 동일 염색체에서 유래하였거나 유사한 유전자발현 조절영역을 가지고 있음을 의미한다. Globulin 유전자는 5번 염색체에 단일 유전자로 존재하였다. 마이크로어레이를 이용한 종자저장 단백질 관련 유전자의 조직 특이 발현 양상을 분석한 결과 glutelin과 대다수의 prolamin 합성 유전자는 종자배유에서만 발현을 하였으며 소수의 prolamin과 globulin 합성 유전자는 종자배유와 발아종자에서도 발현을 나타내었다. 종자 저장단백질의 프로모터부위를 분리한 후 종자에서의 발현 양상을 분석한 결과 glutelin type C1 프로모터가 종자의 전체 부위에서 발현을 나타내었으며 glutelin type B5와 α-globulin 프로모터가 많은 양의 발현을 나타내었다. 본 리뷰를 통하여 벼 종자 저장단백질의 구조및 발현특성 연구 진행사항을 살펴보았다. 이러한 연구 동향분석은 종자형질 개선 및 물질생산 등의 실용화 연구를 수행하는 연구자들에게 최근의 연구 현황을 제공할 수 있을 것으로 생각된다.

In this study, we analyzed seed storage proteins in order to investigate the main factors related to the eating quality of japonica and tongil-type rice varieties. Sensory evaluation was performed by a trained panel to assess the appearance (color and glossiness), flavor, taste, stickiness, texture, and overall score of nine japonica and three tongil-type rice cultivars. Moreover, the pattern of variation in rice storage proteins was examined by electrophoresis of protein extracts. The electrophoretic pattern of rice proteins showed 16.4 kDa albumin, 26.4 kDa globulin, 34-39 kDa and 21-22 kDa glutelin, and 14.3 kDa prolamin. In terms of storage protein, the varietal differences between japonica and tongil-type rice were found in albumin, globulin, and the α-1, and α-2 sub-units of acidic glutelin. Furthermore, the overall sensory evaluation score was observed to be positively correlated with albumin (0.495 ** ) and globulin (0.567 ** ), and negatively correlated with α-1 glutelin (-0.612 ** ). Therefore, the results indicated that albumin, globulin, and α-1 glutelin can affect the eating quality of japonica and tongil-type rice varieties, with the latter having lower eating quality than the former.

Genetic variations of γ-/ω-gliadin and Spa (storage protein activator) in 40 Korean wheat cultivars were evaluated to provide genetic information for improving end-use quality in wheat breeding programs. Korean wheat cultivars were classified into 13 patterns at the Gli-1 locus based on the allelic variation using A-PAGE (acidic-polyacrylamide gel electrophoresis). Seven, five, and six alleles were identified at Gli-A1, Gli-B1, and Gli-D1 loci, respectively. Allele-specific PCR markers for γ-gliadin corresponded to specific allele at Gli-1 loci on A-PAGE, which Gli-A1f, Gli-A1h and Gli-A1l alleles corresponded to GliA1.2, Gli-B1h and Gli-B1f alleles corresponded to GliB1.2 and Gli-D1f, Gli-D1m and Gli-D1o alleles corresponded to GliD1.1. DNA markers for γ-45 and γ-42 also corresponded to the γ-gliadin patterns around 40kDa on A-PAGE, except in Sukang, Ol and Joongmo2003. However, allelic specific PCR markers for ω5-gliadin did not correspond to that of A-PAGE. Three alleles were identified at Spa-A1 locus, whereas there was no variation at Spa-B1 and Spa-D1 loci.

Rice flour is used in many food products. However, dough made from rice lacks extensibility and elasticity, whereas that of wheat is suitable for many food products including breads. We have produced marker-free transgenic rice plants containing a wheat TaGlu-Ax1 gene encoding the HMG-GS from the Korean wheat cultivar ‘Jokyeong’ using the Agrobacteriummediated co-transformation method. The TaGlu-Bx7-own promoter was inserted into a binary vector for seed-specific expression of the TaGlu-Ax1 gene. Two expression cassettes comprised of separate DNA fragments containing only TaGlu-Ax1 and hygromycin phosphotransferase II (HPTII) resistance genes were introduced separately to the Agrobacterium tumefaciens EHA105 strain for co-infection. Each EHA105 strain harboring TaGlu-Ax1 or HPTII was infected to rice calli at a 3:1 ratio of TaGlu-Ax1 and HPTII, respectively. Then, among 210 hygromycin-resistant T0 plants, we obtained 20 transgenic lines with both TaGlu-Ax1 and HPTII genes inserted into the rice genome. We reconfirmed integration of the TaGlu-Ax1 gene into the rice genome by Southern blot analysis. Transcripts and proteins of the wheat TaGlu-Ax1 were stably expressed in the rice T1 seeds. Finally, the marker-free plants harboring only the TaGlu-Ax1 gene were successfully screened at the T1 generation.

Development of transgenic plant increasing crop yield or disease resistance is good way to solve the world food shortage. However, the persistence of marker genes in crops leads to serious public concerns about the safety of transgenic crops. In the present study, we developed marker-free transgenic rice inserted high molecular-weight glutenin subunit (HMW-GS) gene (Dx5) from the Korean wheat cultivar ‘Jokyeong’ using Agrobacterium-mediated co-transformation method. The Dx5’s own promoter was used for protein expression. Two expression cassettes comprised of separate DNA fragments containing only the Dx5 and hygromycin resistance (HPTII) genes were introduced separately into Agrobacterium tumefaciens EHA105 strain for co-infection. Each EHA105 strain harboring Dx5 or HPTII was infected into rice calli at a 3: 1 ratio of EHA105 with Dx5 gene and EHA105 with HPTII gene expressing cassette. Then, among 270 hygromycin-resistant transformants, we obtained 27 transgenic lines inserted with both the Dx5 and HPTII genes into the rice genome. We reconfirmed integration of the Dx5 gene into the rice genome by Southern blot analysis. Wheat Dx5 transcripts in T1 rice seeds were examined with semi-quantitative RT-PCR. Protein expression of the Dx5 was analyzed with Western blot using polyclonal antibody recognising x-type of glutenin subunits in T1 seeds. It was suggested that the protein-processing system was conserved between rice and wheat. Finally, the marker-free plants containing only the Dx5 gene were successfully screened at the T1 generation.

barley grain and malt is highly related to beer quality, especially hordein is known to be a more significant factor in malting process than albumin. In this study, we proposed selection criteria for high quality malting barley with aid of grain and malt quality parameter scores and storage protein subunit profile informations. Albumin and hordein were extracted and denatured protein subunits were evaluated with malt and grain quality parameters. Total 13 local adaptability test (LAT) lines were planted in four locations (Naju, Iksan, Jeju, and Jinju) and evaluated for malt and beer making qualities. Seventeen germplasms (world collections for high or low seed storage protein content) were also evaluated for biochemical genetic marker. Denatured seed storage protein subunits of albumin and hordein of all tested lines and germplasms were evaluated using 12% 1D SDS-PAGE. Scored data of protein subunit's presence or absence was applied to Agglomerative Hierarchical Clustering (AHC) for statistical analysis. Subunits fractionated within specific molecular weight ranges (97.4-31.0, 66.2-31.0, and 45.0-31.0 kDa) were highly correlated with agricultural characteristics. Several LAT lines showing good performance in agricultural characteristics were clustered in dendrogram constructed by biochemical-genetic assay using XLSTAT. Specific band pattern showed in good performance LAT lines were also observed in some germplasms of world collection having low protein contents which are known to have superior quality in malting. The results would provide selection criteria for high quality malting barley in the malting barley breeding program.

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.