물벼룩 급성 독성 평가를 위한 비타민A 강화벼의 분자생물학적 특성을 분석한 결과, Southern blot에서 베타-카로틴 생합성을 위한 Psy와 CrtI 유전자들이 one-copy로 도입됨을 확인하였으며, 선발마커인 Bar 유전자의 단백질 검출 immunostrip 분석에서도 비타민A 강화벼에서만 검출되었다. 비타민A 강화벼의 목적하는 최종 산물인 베타-카로틴 함량도 낙동벼에 비해 8.9배 증가됨을 확인하였다. 비타민A 강화벼와 낙동벼의 농업환경 생물지표종인 물벼룩(Daphniamagna)에 대한 급성독성시험을 실시한 결과, 비타민A 강화벼의 48시간-EC50은 3,311.40 mg/L(95% 신뢰한계 : 2,901.39 ~ 3,779.23 mg/L), 무영 향농도(NOEC)는 1,800 mg/L였고, 낙동벼는 48시간-EC50은 3,655.23 mg/L(95% 신뢰한계 : 3,156.71 ~ 4,232.86 mg/L), 무영향농도는 1,800 mg/L였다. 따라서 Psy와 CrtI 유전자가 형질전환된 비타민A 강화벼 및 낙동벼가 환경 지표생물종인 물벼룩에 미치는 영향 평가 결과 상대적 동등성을 보였으며, 이는 Psy와 CrtI 유전자의 단백질 노출이 물벼룩에 부정적인 영향을 미치지 않은 것으로 판단된다.
Two carotenoid biosynthetic genes, phytoene synthase (Psy) and carotene desaturase (CrtI) linked via synthetic 2A sequence under control of CaMV 35S promoter (two T0 plants 5 and 6) or β- conglycinin promoter (three T0 plants 7, 13 and 16) were transformed into soybean variety Kwangan. After agronomic and phenotypic selection at early generations, T5 progeny of PAC soybean were analyzed by Southern blot to confirm T-DNA copy numbers. A total of 27 homologous lines derived from one of three T0 plants (line 7 under the control of β- conglycinin promoter) with one copy T-DNA insertion, were separated and planted into greenhouse. Flanking sequence analysis was carried out on one of homologous line 6-2-3 and results indicated the T-DNA was intergenic inserted into chromosome 14 from 10,873,131 to 10,872,998 base of soybean chromosome. T-DNA insertion structure, flanking sequence and inserted gene expressions need to be analyzed in the further study.
Resveratrol rice Iksan526 was developed by overexpession of T-DNA (RB::P-Ubi::RS::T-NOS::P-35S::PAT::T-35S::LB) in rice variety Dongjin. To confirm one locus insertion of T-DNAs, Mendelian genetic analysis was carried out on selection marker bar gene and objective RS gene separately by using a F2 population derived from a cross of Dongjin/Iksan526 (T6). A total of 450 four-leaf-old plants from F2 population were treated by 0.3% basta, and a phenotypic separation ratio of 3:1 (321 survival: 129 dead, p>0.90) complied with Mendelian inheritance indicating one locus insertion of bar gene. Genotypic separation was analyzed by using PCR with specific primers for 300 plants, which were selected from 321 survival plants after phenotypic separation. Results revealed a ratio 1:2 of homologous to heterozygous (92:208, p>0.90), which further confirmed one locus insertion of RS gene. In addition, comparison on agronomic traits and resveratrol contents between transgenic rice and the donor variety were launched to evaluate the phenotypic performance over multi-generations (years).
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.
가뭄저항성벼의 복수세대에 대한 후대안정성을 서던 블롯과 PCR로 분석한 결과, 가뭄저항성벼의 CaMsrB2-8 T4 ~ T6 세대에서는 도입된 모든 유전자들이 안정적으로 도입되어 있으며, T-DNA 구성요소 이외의 backbone DNA는 가뭄저항성벼에 삽입되지 않았음을 확인하였다. 목적 유전자인 CaMsrB2와 제초제 저항성 선발 마커인 bar가 가뭄저항성벼의 CaMsrB2-8 T4 ~ T6 세대에서 안정적으로 발현됨을 검증하였다. 제초제 저항성 선발 마커로 도입된 PAT 단백질의 발현 분석 결과에서도 CaMsrB2-8 T4 ~ T6의 3세대에서 생육시기별, 부위별로 안정적으로 발현됨을 입증하였다. 도입유전자의 삽입 위치를 확인한 결과, 가뭄저항성벼 CaMsrB2-8의 도입유전자가 벼 1번 염색체 내에서 intergenic한 상태로 안정적으로 유지되고있음을 확인하였다. 이상의 분석 기법을 통해 복수세대에서 가뭄저항성벼의 도입 유전자들이 안정적으로 유지되고 목적 단백질들이 안정적으로 발현되고 있음을 확인하였다.
A Transgenic Kimch cabbage has been developed harboring T-DNAs expressing delta-endotoxin insecticidal protein, herbicide (basta) resistant protein, and antisense transcript of AsMADS2 gene. Three transgenic lines, #24, #45, and #51, originated from the same T0 plant were analyzed in terms of molecular characterization, phenotype, and agronomic traits. Flanking sequence analysis confirmed that T-DNA, with 7132 bp intact structure, was inserted onto the pseudochromosome A10 of B. rapa and all the genes in T-DNA were functionally active. Three of GM cabbage showed 69.2~75.3% of plant height and 81.8~89.7% of diameter to those of the isogenic variety ‘Nowon’, respectively. Curving upward leaf lamina attitude was observed on GM cabbage, while straight or slight concave on non-GM cabbage. In addition, an average range of 86~91.5% of head height and 87.4~94.8% of head diameter were observed on GM cabbage to those of the isogenic variety ‘Nowon’, respectively Moreover, curled inwards or slight overlap of head-forming leaf overlap at terminal region was observed on GM cabbage, but curled outwards or erect on non-GM cabbage. AsMADS2, a transcription factor reported to be involved in early flowering, was stably expressed to RNA in the GM cabbage, but it was not shown the significant influences to flowering time.
The rice water weevil (RWW), Lissorhoptrus oryzophilus are major pests of aquatic rice plant in Korea as well as throughout the country. Larvae of RWW sucking the nourishment on roots, causes a stunted root system and reduces grain yields. To prevent these damages, we constructed various plant expression vectors, which were harbored by insecticidal genes, cryBP1 and cryIIIa, and fused with the actin promoter and/or the modified RCg2 root-preferential promoters for expressing the insect-toxic genes in leaves and roots. A cryBP1 was cloned from Bacillus popilliae, producing crystal toxin against Japanese beetle, and CryIIIa was modified from the δ-endotoxin gene of Bacillus thuringiensis ssp. tenebrionis, encoding the coleoptera-specific toxin. The vectors containing the insecticidal genes were transferred into Oryza sativa japonica cultivar, Nakdong, by Agrobacterium -mediated transformation method. Several independent transgenic lines were selected by Southern blotting and Western blotting, confirming that cryBP1 and cryIIIa genes were stably integrated into the plant genomes and were expressed in transgenic plants. Upon insect bioassay using RWW, the mortality of insect larvae on cryBP1 and cryIIIa transgenic rice lines recorded up to 41% and 34%, respectively. These results suggested that the transgenic lines can be used to develop Coleoptera-resistant cultivars and could be valuable for later application in crop breeding for insect resistance.