국제적으로 유전자변형작물(Genetically Modified, GM)의 개발 및 재배는 지속적으로 증가하고 있으며, 국내에도 GM작물 개발에 대한 많은 연구가 진행되고 있다. 국내에서 GM작물은 상업적 재배 및 이용에 앞서 이들이 인체 및 환경에 미칠 수 있는 잠재적인 위해성을 과학적으로 검토하고 안전성을 입증하도록 법으로 규정하고 있으며, 특히 안전성평가항목에 대해서는 LMO법 통합고시 별표 10-1에 규정되어 있다. GM작물의 안전성평가는 사안별(case-by-case) 평가 원칙에 따라 도입 형질 및 작물별로 평가방법을 달리하여야 하지만 통합고시에서는 모든 유전자변형생물체를 대상으로 기술되어 있어 개발자가 특정 작물의 안전성평가를 수행하여 심사서를 작성하는데 여러 가지 어려움을 제기하고 있는 실정이다. 따라서 본 연구에서는 국내 주요 식량작물이자 가장 많은 유전자변형 연구가 진행되고 있는 벼에 대한 안전성평가 연구 가이드를 제시하여 국내외 개발자 및 안전성평가 연구자를 지원하고자 하였다. 본 발표에서는 안전성평가에 대한 통합고시 별표 10-1의 항목 중 분자생물학적 평가를 대상으로 하였다.

현재 작물에서 분자육종학의 기술은 1994년 미국 칼젠사 (Calgene)가 개발한 숙성과정 중 물러지지 않는 토마토, Flavr Savr라는 상품을 개발하여 일반인들에게도 많이 알려지며 관심을 갖는 분야가 되었다. 그 이후 미국 몬산토 (Monsanto)에서 개발한 Round up ready 라는 제초제저항성 콩을 상품으로 발표하면서 외래형질을 도입한 작물에 대한 위해성의 논란이 야기되어, 이를 잠재울 만한 기술 및 방법들이 연구되어 지고 있다. 형질전환 작물, 다시 말하여 유전자변형생물 (GMO, genetically modified organism) 의 위해성의 논란의 하나인 외래유전자가 도입된 형질전환체의 유전자가 야생으로 이동하여 의도치 않은 유전자의 이동에 관한 것이다. 본 연구는 선행 연구에서 제초제저항성을 보이는 잔디, JG21（Jeju Green 21）에 방사선 (감마선)을 처리하여 얻은 여러 형질 중 화분에 이상을 보이는 (웅성불임) 라인을 선발하여 JG21-MS (Male Sterility)라고 명명된 웅성불임 들잔디 화분을 조사하였다. 그 결과 외형적으로 Wild-type, JG21의 정상적인 둥근 공 모양의 형태를 보이는 것에 비해 JG21-MS의 화분은 찌그러진 형태가 관찰되었고, 화분의 활성을 확인할 수 있는 Alexander 염색법을 이용하여 관찰한 결과 JG21-MS의 화분은 대부분 염색되지 않았다. 또한 실제적으로 JG21-MS의 화분이 발아하여 화분관 신장의 가능성을 확인하기 위해 화분관 발아배지를 이용하여 화분관을 유도하였으나 Wild-type, JG21에서 비슷한 수준으로 화분관이 신장된 것에 비해 JG21-MS는 0%의 화분관 신장를 보였다. JG21-MS의 화분은 Wild-type의 화분에 비해 양이 상당히 적고 모양 또한 찌그러진 형태로 유전자 이동의 가능성이 있는 화분관 신장을 보이지 않아 GM 작물의 안정성의 문제를 해소할 수 있을 것이다. 하지만 들잔디의 생육 환경에 따라 화분의 활성에 영향을 미칠 수 있어 이를 명확히 할 필요가 있으며, 한 해의 결과로 속단하기 이르므로 본 연구의 결과를 바탕으로 다음 세대 및 다양한 조건에서의 추가 연구가 필요하다.

잔디는 비식용, 비사료용 작물이지만 스포츠공간용, 조경용, 지피용 등으로 전 세계적으로 가장 보편적으로 활용되는 작물이며, 경제성이 매우 높은 작물이다. 본 연구의 목적은 상업적 재배를 위해 개발된 제초제저항성 웅성불임 GM들잔디의 분자생물학적 특성을 평가하는 것이다. JG21-MS 웅성불임계통은 최초 선발된 해로부터 현재까지 6여 년 동안 제초제저항성 뿐만 아니라 웅성불임성을 잘 유지 하고 있다. BAR 유전자카세트와 T-DNA 삽입점에서 좌,우 1kb 정도의 주변 염기서열의 동등성 및 BAR유전자 발현의 동등성에서 모본과 차이를 보이지 않았다. T-DNA 삽입특성을 조사한 실험에서, T-DNA 오른쪽 경계(RB)의 삽입은 특이한 DNA단편의 첨가 또는 소실 없이 들잔디 DNA와 연결되어 있지만, hygromycin 저항성 유전자(HPH)가 위치한 왼쪽 경계(LB)의 삽입은 삽입과정에서 HPH 유전자의 4/5 정도가 소실되어 유전자의 기능을 상실하였다. 또한 왼쪽 끝 부분과 연결된 들잔디 DNA 쪽도 620bp가 소실되었다. T-DNA는 Ty1-copia retrotransposon-like 유전자 영역에 삽입 된 것으로 확인되었다. Ty1-copia retrotransposon은 식물 종에 조금 차이가 있지만 전체게놈의 10~50% 정도를 차지하는 것으로 알려져 있다. 또한 retrotransposon-like 유전자는 식물고유기능의 유전자가 아니므로 본 이벤트에서 T-DNA는 비유전자영역에 삽입된 것으로 간주할 수 있을 것으로 사료된다. 결국, JG21과 JG21-MS는 HPH 유전자가 소실되어 기능을 상실하였으므로 목표 유전자인 BAR 만 single copy로 존재하는 것으로 확인되었다. 차세대바이오그린21 GM작물실용화사업단에서 지원하는 GM작물 이벤트의 분자생물학적 특성의 최소기준은 단일복제수(single copy), 항생제마커 없이 목표유전자 도입(target gene only), 비유전자 내 삽입을 장려하고 있고, JG21와 JG21-MS 계통의 제초제저항성 들잔디는 이러한 기본조건을 만족시키고 있는 것으로 평가되었다.

In Korea, CMV (cucumber mosaic virus) is the most frequently occurring virus with a single infection rate of 45%. However, a total occurrence of CMV by co-infection, either couple or multiple, with BBWV (broad bean wilt virus), PepMoV (pepper mottle virus) and PMMoV (pepper mild mottle virus) covers over 90% in the field cultivation of pepper. The PepMoV is transmitted by several aphid species, and it has been considered the most frequently detected potyvirus when it co-infects with CMV or PMMoV. Since F1 hybrid that resistant to PepMoV has not been developed, we have developed transgenic peppers using Agrobacterium-mediated transformation with a Hc-Pro gene of the PepMoV. A large number of T1 peppers were tested for resistance to the PepMoV, and T1 peppers tolerant of PepMoV were selected. After consequent self-crossing up to T4 generation, highly tolerant peppers to PepMoV were selected. So far, BC3F1 lines have been selected by back-crossing with 4 elite lines through a breeding program. The horticultural differences of the GM line comparing to inbred lines were investigated and no statistical significance between GM and non-GM lines was found. Based on molecular analysis, One of GM lines, 10-2, contained the transgene in the non-coding region indicating that this line would be a GM event.

The cultivation of genetically modified (GM) crops has increased due to their economic and agronomic advantages. Before commercialization of GM crops, however, we must assess the potential risks of GM crops on human health and environment. The aim of this study was to investigate the possible impact of Bt rice on the soil microbial community. Microbial communities were isolated from the rhizosphere soil cultivated with Bt rice and Nakdong, parental cultivar and were subjected to be analyzed using both culture-dependent and molecular methods. The total counts of bacteria, fungi, and actinomycetes in the rhizosphere of transgenic and conventional rice were not significantly different. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA genes revealed that the bacterial community structures during cultural periods were very similar each other. Analysis of dominant isolates in the rhizosphere cultivated with Bt and Nakdong rice showed that the dominant isolates from the soil of Bt rice and Nakdong belonged to the Proteobacteria, Cloroflexi, Actinobacteria, Firmicutes, and Acidobacteria. These results indicate that the Bt rice has no significant impact on the soil microbial communities during cultivation period. Further study remains to be investigated whether the residue of Bt rice effect on the soil environment.

Rice is an important model species and one of the most staple crops of the world. The use of rice appropriate promoters suitable for a specific target transgene is important for the control of spatial and temporal transgene expression. To isolate rice tissue-specific promoters, we exploited the potential of whole genome microarrays in 17 stages: callus, germinating seed, leaf, root, the size of the panicles before heading (1, 3, 5, 8, 10, 15, 20, and 22 cm), and the number of days after pollination (1, 3, 5, 11, 21 DAP) using a 300 K Rice Genome Microarray, covering 31,439 genes of the rice. Eight candidate genes for tissue-specific expression were selected in various organs and stage of reproductive development in rice: Histone H4 for constitutive expression, Dehydrin DHN1 for callus-specific expression, germinating seed-specific hypothetical protein, root-specific hypothetical protein, DNA topoisomerase and Retinoblastoma for expression at panicles before heading, heading-specific profiling, and invertase for expression at seed after pollination. Promoter regions of the selected genes were isolated and fused to the β-glucoronidase (GUS) reporter gene, and the constructs were introduced into rice plants. These promoters are highly active in the tissue-specific manner of rice and can be useful for the spatial and temporal enhancement of target gene(s).

고추(Capsicum annuum L.)는 가지과(Solanaceae)로 분류되는 일년초로서 온대에서 열대까지 널리 재배되고 있다. 또한 세계 50억 인구가 식생활에 활용하고 있고 재배면적이 7위인 세계적인 채소로서 식생 외에도 먹거리의 식품첨가제, 색소, 의약품재료, 화장품 등 산업적으로 많이 사용되고 있으며, 그 산업규모가 계속 증가하고 있다. 고추 관련 산업 매출은 300억불로서 상업적 가치가 매우 높은 채소작물이다. 따라서 고추는 채소류 중 동남아 등 해외로 수출가능성이 가장 높은 작물로써 수출전용 품종 개발이 시급하고, 국내 재배용으로는 바이러스 내병성이 강하고 고품질의 고추 품종 개발이 요구된다. 현대 생물공학은 고추의 병해충에 대한 유전적 개량을 통해 이익을 줄 수 있으며, 첫 번째 유전자 형질전환은 Agrobacterium tumefaciens로 neomycin phosphotransferase와 β-glucuronidase 유전자를 삽입한 것으로 (Liu et al., 1990) 그 후로 C. annuum에 대한 기술의 발달이 꾸준히 보고되었다. 최근 고추에서 개량하고자 하는 형질에는 CMV, TEV, TMV에 대한 바이러스 저항성(Cai et al., 2003), 담배나방(Heliothis assulta)에 대한 해충저항성(Kim et al., 2003), 과실성숙도 조절, 저장기간 연장 등으로 요약되고 있다(OECD 고추표준기술서, 2006). 본 연구에서는 국내에 존재하는 고추 품종과 계통을 모두 이병시키는 새로운 바이러스인 CMVP1에 대한 내성이 있는 GM고추 H15 event의 농업적 특성 포장시험을 실시하였다. 농업환경위해성 평가를 위한 농업적 특성 포장시험을 2012년 5월부터 9월까지 H15 event와 모본 P2377에 대하여 수행하였다. 조사내용은 식물체, 과실 및 꽃의 특성을 조사하였다. 식물체의 특성은 6월부터 9월까지 6항목을 조사하였으며, 8월 최성기는 18항목을 조사하였다. 조사결과는 6월부터 8월까지 식물체 특성은 통계적으로 유의한 차이가 없었으며, 9월에는 P2377 고추의 초폭이 H15 고추에 비해 유의하게 컸지만 초장, 주경장, 경경, 엽장 및 엽폭은 통계적으로 유의한 차이가 없었다. 과실의 특성은 미숙과 20항목과 숙과 19항목을 조사하였으며, 착과상태, 과장, 과경 등 조사대상 항목의 특성은 모두 통계적으로 유의한 차이가 없었다. 꽃의 특성은 화색 등 10가지 항목을 조사하였으며, 화색, 웅예수 등 통계적으로 유의한 차이가 없었다. 종자의 특성은 종자색등 4가지 항목을 조사하였으며, 종자색, 종자크기 등 통계적으로 유의한 차이가 없었다. 이와 같은 연구결과는 포장시험을 통한 농업적 특성의 위해성평가 기초자료로 제시할 수 있을 것이며, GMO식품안정성평가에 대한 가이드라인으로 제시 할 수 있을 것으로 기대된다.

This study investigated the nutrients and anti-nutrients of produced resveratrol GM rice (Iksan-515, Iksan-526, Dongjin) that were cultivated Iksan and Suwon regions. Among the rice samples, Iksan-515 and Iksan-526 are produced resveratrol GM rice. Reveratrol is health-beneficial compound with strong antioxidant and antitumor activities. Red wine is believed to the main source of resveratrol in the human diet. Recent studies have associated resveratrol with the cardio-protective effect observed among people with moderate resveratrol consumption. Moreover, resveratrol has been possess chemoprotective activity. In present study, we determined the substantial equivalence between GM rice and seedling sort. We investigated the nutrients and anti-nutrients of produced resveratrol GM rice and analyzed nutrients including moisture, crude fat, ash, crude protein, fatty acids, amino acids and minerals. The results of this analysis showed equivalence between GM rice and non-GM rice. We determined phenolic compounds including naringenin, vallin and investigated 4 tocopherols (α-, β-, γ-, δ-tocopherol) and 4 tocotrienols (α-, β-, γ-, δ-tocotrienol). Among the all rice cultivars, they showed substancial equivalence between resveratrol GM rices and non-GM rice.

Genetically modified (GM) plant claims to be the solution to global poverty, and potentially solving environmental change and food requirement by increased human population. In this study, we were evaluating agronomic characteristics and chemical properties of two GM drought-tolerant rice (CaMsrB2-8 and CaMsrB2-23) compared with donor cultivars (Ilmi). Statistical analysis agronomic characteristics GM and donor rice showed no significant difference between both of them. Yield and appearance of rice grain, GM rice was a similar to the donor rice. Chemical composition analysis showed that GM drought-tolerant rice has no different with donor rice. This result indicated that GM drought tolerant rice has no big significant difference agronomic character and chemical properties; it can be solve food shortages in spite of drought condition.

Rice (Oryza sativa) is the most important staple food of over half the world’s population. This study was conducted to evaluate the possible impact of transgenic rice cultivation on the soil microbial community. Microorganisms were isolated from the rhizosphere of GM and non-GM rice cultivation soils. Microbial community was identified based on the culture-dependent and molecular biology methods. The total numbers of bacteria, fungi, and actinomycete in the rhizosphere soils cultivated with GM and non-GM rice were similar to each other, and there was no significant difference between GM and non-GM rice. Dominant bacterial phyla in the rhizosphere soils cultivated with GM and non-GM rice were Actinobacteria, Firmicutes, and Proteobacteria. The microbial communities in GM and non-GM rice cultivated soils were characterized using the denaturing gradient gel electrophoresis (DGGE). The DGGE profiles showed similar patterns, but didn’t show significant difference to each other. DNAs were isolated from soils cultivating GM and non-GM rice and analyzed for persistence of inserted gene in the soil by using PCR. The PCR analysis revealed that there were no amplified protox gene in soil DNA. These data suggest that transgenic rice does not have a significant impact on soil microbial communities, although continued research may be necessary.

The required for Mla12 resistance (RAR1) protein is essential for the plant immune response. In rice, a model monocot species, the function of Oryza sativa RAR1 (OsRAR1) has been little explored. In our current study, we characterized the response of a rice osrar1 T-DNA insertion mutant to infection by Magnaporthe oryzae, the causal agent of rice blast disease. osrar1 mutants displayed reduced resistance compared with wild type rice when inoculated with the normally virulent M. oryzae isolate PO6-6, indicating that OsRAR1 is required for an immune response to this pathogen. We also investigated the function of OsRAR1 in the resistance mechanism mediated by the immune receptor genes Pib and Pi5 that encode nucleotide binding-leucine rich repeat (NB-LRR) proteins. We inoculated progeny from Pib/osrar1 and Pi5/osrar1 heterozygous plants with the avirulent M. oryzae isolates, race 007 and PO6-6, respectively. We found that only Pib-mediated resistance was compromised by the osrar1 mutation and that the introduction of the OsRAR1 cDNA into Pib/osrar1 rescued Pib-mediated resistance. These results indicate that OsRAR1 is required for Pib-mediated resistance but not Pi5-mediated resistance to M. oryzae.

Bacillus thuringiensis(Bt) crystal protein (Cry1Ac) genes encode insecticidal δ-endotoxins that are widely used for the development of insect-resistant crops. Common soybean is a crop of economic and nutritious importance in many parts of the world. Korea soybean variety Kwangan was transformed with Bacillus thuringiensis(Bt) crystal protein genes. We transformed three difference Cry1Ac (Cry1Ac and two modified Cry1Ac) genes into Kwangan using highly efficient soybean transformation system. Transgenic plants with Bt crystal protein genes were confirmed for gene introduction and their expression using PCR, real-time PCR, and RT-PCR. We generated 30 independent lines of transgenic soybean plants. Analysis of the flanking sequences isolated by Inverse PCR revealed complex T-DNA insertion patterns and preferential integration of T-DNA into the intergenic spacer region of the soybean genome. We found 5 different intergenic transgenic soybean lines of soybean genome. Currently, the confirmation of stable gene introduction with Bt genes is also performing by southern blot analysis, physiology test, and agronomic characters are investigating.

CMVP1 (cucumber mosaic virus pathotype 1) has been frequently occurring virus causing damage in pepper farms, and it is hard to control the outbreak due to lack of the genetic source resistant to this specific pathotype. Therefore, we have developed transgenic peppers tolerant of CMVP1 using a CP gene of CMVP0 pathogen. In order to fulfill the requirement of the biosafety assessment criteria, we have studied the horizontal gene flow from GM pepper to non-GM pepper by monitoring the transgene movement. If the pepper farms are located closely each other and the pollen moves from GM pepper to non-GM pepper, it would cause unintended fertilization. Therefore, a buffer zone to separate the cultivation regions is required to avoid the contamination of transgene. Previously, several data regarding the movement distance of pepper pollen were reported by judging the phenotypic change. However, no tool as a trace marker was available. The objective of this study was to assess the frequencies of gene flow from GM peppers to non-GM peppers in neighboring farms using the transgene of CP as a trace marker. The GM and non-GM peppers were cultivated in the isolated farm of Nongwoo Bio Co. (NW GM pepper field) and pepper fruits were collected from the NW GM pepper field as well as the neighboring pepper farms. The pepper seeds collected from the farms were planted and the massive PCR analysis was performed to answer the question how far the pollen of GM pepper migrates. The conclusive data based on the consecutive experiments for 6 years is that the gene flow by pollen movement did not occur in peppers that were separated each other over 30 m.

Two-component regulatory system (TCS) is the dominant mechanism that controls almost physiological processes of bacteria, such as nutrition assimilation, cell motility, chemotaxis, biofilm formation, quorum sensing and virulence. The intracellular informing process by a typical TCS accompany transfer of a phosphoryl group from His of a histidine kinase (HK) to Asp of a response regulator (RR). In Xanthomonas oryzae pv. oryzae (Xoo) genome, the TCS genes comprise approximately 3% of the nucleotide sequences with 58 response regulators (RRs), 32 orthodox histidine kinase (HKs) and 13 hybrid histidine kinase (HyHKs). However, there is not much understanding of RRs in Xoo except the reported RRs in Xanthomonas spp. including RpfC-RpfG, RavS-RavR, HrpG, VgrS-VgrR (also named ColS-ColR), VemR, RaxH-RaxR, and PhoQ-PhoP. Although a genome-scale mutagenesis and phenotypic characterization of TCSs were studied in Xanthomonas campestris pv. campestris ATCC 33913, there is not any genome-scale research of TCSs in Xanthomonas oryzae pv. oryzae. We have mutagenized 52 predicted RR genes in Xoo PXO99A by marker-exchange mutagenesis method and characterized the phenotype of mutants to identify RR genes involving in pathogenicity of Xoo and understand how Xoo TCSs work in given conditions. Ours investigation with the RR knock-out mutant strains have identified four novel RR genesthat are likely involved in virulence of Xoo. We have studied with these genes in molecular level to elucidate the mechanism for Xoo pathogenicity.

We investigated Arctic plants to determine if they have a specific mechanism enabling them to adapt to extreme environments because they are subject to such conditions throughout their life cycles. Among the cell defense systems of the Arctic mouse-ear chickweed Cerastium arcticum, we identified a stress-responsive dehydrin gene CaDHN that belongs to the SK5 subclass and contains conserved regions with 1 S-segment at the N-terminus and 5 K-segments from the N-terminus to the C-terminus. To investigate the molecular properties of CaDHN, yeast were transformed with CaDHN. CaDHN-expressing transgenic yeast (TG) cells recovered more rapidly from challenge with exogenous stimuli, including oxidants (hydrogen peroxide, menadione, and tert-butyl hydroperoxide), high salinity, freezing and thawing, and metal (Zn2+), than wild-type (WT) cells. TG cells were sensitive to copper, cobalt, and sodium dodecyl sulfate. In addition, the cell survival of TG cells was higher than that of WT cells when cells at the mid-log and stationary stages were exposed to increased ethanol concentrations. There was a significant difference in cultures that have an ethanol content >16%. During glucose-based batch fermentation at generally used (30℃) and low (18℃) temperatures, TG cells produced a higher alcohol concentration through improved cell survival. Specifically, the final alcohol concentrations were 13.3% and 13.2% in TG cells during fermentation at 30℃ and 18℃, respectively, whereas they were 10.2% and 9.4%, respectively, in WT cells under the same fermentation conditions. An in vitro assay revealed that purified CaDHN acted as a reactive oxygen species (ROS)-scavenger by neutralizing H2O2 and a chaperone by preventing high temperature-mediated catalase inactivation. Taken together, our results show that CaDHN expression in transgenic yeast confers tolerance to various abiotic stresses by improving redox homeostasis and enhances fermentation capacity, especially at low temperatures (18℃).

Soybean mosaic virus (SMV), a member of Potyviridae family, is one of the most typical viral diseases and results in yield and quality loss of cultivated soybean. Due to the depletion of genetic resources for resistance breeding, a trial of genetic transformation to improve disease resistance has been performed by introducing SMV-CP and HC-Pro gene by RNA interference (RNAi) method via Agrobacterium-mediated transformation. Transgenic plants were infected with SMV strain G5 and investigated the viral response. As a result, two lines (3 and 4) of SMV-CP(RNAi) transgenic plants and three lines (2, 5 and 6) of HC-Pro(RNAi) transgenic plants showed viral resistance. In genomic Southern blot analysis, most of lines contained at least one T-DNA insertion in both SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants. Subsequent investigation confirmed that no viral CP and HC-Pro gene expression was detected in two SMV-resistant lines of SMV-CP(RNAi) and three lines of HC-Pro(RNAi) transgenic plants, respectively. On the other hand, non-transgenic plants and other lines showed viral RNA expression. Viral symptoms affected seed morphology, and clean seeds were harvested from SMV-resistant line of SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants. In addition, strong viral gene expression was detected from seeds of SMV-susceptible non-transgenic plants and SMV-susceptible transgenic lines. When compared the viral resistance between SMV-CP(RNAi) and HC-Pro(RNAi) transgenic plants, soybean transgenic plants with the HC-Pro gene using RNAi strategy showed much stronger and higher frequency of viral resistance.

UGT72E3/2 gene encodes UDP-glycosyltransferase shown to glucosylate several phenylpropanoids such as syringin and coniferin. Syringin has effect of anti-stress and anti-fatigue. Korean soybean variety Kwangan was transformed with UGT72E3/2 gene. This gene was transformed into Kwangan using highly efficient soybean transformation system. This study used two promoters, beta-conglycinin promoter for seed-specific expression and 35s promoter for total expression. Transgenic plants were confirmed for gene introduction and their expression using PCR and RT-PCR. The analysis of syringin in transgenic plants was performed using HPLC. Currently, the confirmation of stable gene introduction with UGT72E3/2 gene is also performing by Southern blot analysis.

Glutamine synthetase (GS) is an enzyme that plays an essential role in the metabolism of nitrogen by catalyzing the condensation of glutamate and ammonia to form glutamine. Exposure of plants to cadmium (Cd) has been reported to decrease GS activity in maize, pea, bean, and rice. To better understand the function of the GS gene under Cd stress in rice, we constructed a recombinant pART vector carrying the GS gene under the control of the CaMV 35S promoter and OCS terminator and transformed using Agrobacterium tumefaciens. We then investigated GS overexpressing rice lines at the physiological and molecular levels under Cd toxicity. The GS activity along with mRNA expression were found higher in transgenic than in wild type plants. And this is validated by the low malondialdehyde contents observed 10 days after treatment. GS overexpression in rice resulted in the modulation of expression of enzymes responsible for membrane peroxidation, which may result in the sudden death of plants. Our results thus describe the features of a transgenic rice plants with enhanced tolerance to Cd toxicity.

Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by various agricultural biotechnological companies. Commercialization of GM crops will be required the assessment of risk associated with the release of GM crops. In this study, we carried out to provide the molecular characterization of introduced T-DNA in transgenic rice T4 ~ T6 generation lines harboring a pepper MsrB2 gene under the control of stress inducible Rab21 promoter, as a part of biosafety evaluation for drought-tolerant transgenic rice (CaMsrB2). We identified the structure and sequence of transformation vector of T-DNA and analyzed insertion sites, flanking sequences, and generational stability of inserted T-DNA in transgenic rice lines. The transformation vector was consisted of right border, a drought-tolerant CaMsrB2 gene unit, a selectable marker herbicide resistance unit, and left border in a sequential order. Based on the adaptor-ligation PCR and whole genome sequence database, we confirmed that T-DNA was introduced at the position of 41,737,284 bp of chromosome No. 1. From the generational stability study, T-DNAs were stably inherited through the T4 to T6 generations, and also stable expression of bar gene from T-DNA was confirmed. These results will be filed to biosafety assessment document of CaMsrB2 rice.

Arabidopsis STABILIZED1 (STA1) encodes a protein that is homologous to human U5 snRNP-associated 102-kDa protein (PRPF6), and the yeast pre-mRNA splicing factors, PRP1p (fission yeast) and Prp6p (budding yeast), and is important in pre-mRNA splicing and mRNA stability. The pleiotropic defects of development, chilling sensitivity and hypersensitivity to ABA are observed in sta1-1, a weak allele of sta1. sta1-1, showing enhanced luminescence under cold stress, was originally isolated from a mutant pool generated with the bioluminescent plant harboring the stress-inducible RD29A promoter-driven luciferase gene (RD29A-LUC). Some developmental defects found in sta1-1 resembled those found in miRNA biogenesis mutants such as hyponastic leaves1-1 (hyl1-1) and serrate-1 (se-1). Similar to these miRNA biogenesis mutants, sta1-1 accumulated significantly lower levels of mature miRNAs and concurrently higher levels of pri-miRNAs than wild type. The dramatic reductions of mature miRNAs were associated with the accumulation of their target gene transcripts and the corresponding developmental defects. The reduction of miRNA accumulation in sta1-1 appeared to be because of the sta1-1 decfects in splicing of intron containing pri-miRNAs. In addition, sta1-1 decreased transcript levels of DICER-LIKE1 (DCL1) gene. These results suggest that STA1 is involved in miRNA biogenesis directly by functioning in pri-miRNA splicing and indirectly by modulating the DCL1 transcript level. Our efforts and recent findings to establish STA1-mediated RNA metabolism will be presented and discussed.