In this study, PAT protein of genetically modified maize was prepared from the recombinant E. coli strain BL21 (DE3), and mice were immunized with the recombinant PAT protein. After cell fusion and cloning, two hybridoma cells (PATmAb-7 and PATmAb-12) were chosen since the monoclonal antibodies (Mabs) produced by them were confirmed to be specific to PAT protein in the indirect enzyme-linked immunsorbent assay (ELISA) and western blot tests. There were no cross-reactions of either Mabs to other GM proteins or to the extracts of non-GM maize. The ELISA based on the PATmAb-7 can sensitively detect 0.3 ng/g PAT protein in corn. These results indicate that the developed Mabs can be used as bio-receptors in the development of immunosensors and biosensors for the rapid and simple detection of GM corn adulterated in foods.
Seashore Paspalum (Paspalum vaginatum Swartz) is a warm season grass and indigenous to tropical and subtropical regions of coastal areas worldwide. The species is used as feed for cattle and horses and has been very successful for golf courses worldwide. One of the most outstanding characteristics of seashore paspalum is its tolerance to saline soils compared to other warm season turfgrasses. The development of new seashore paspalum cultivars with improved traits could be facilitated through the application of biotechnological strategies. The purpose of this study was to product for herbicide resistant seashore paspalum using Arobacterium-mediated transformation and this study is the first report on transformation and herbicideresistant transgenic plants in seashore paspalum. Embryogenic calli were induced from the seeded variety of pseashore paspalum. Embryogenic calli were transformed with Agrobacterium tumefaciens strain EHA105 carrying the binary vector pCAMBIA3301 with two genes encoding gusA and bar. Transformed calli and plants were selected on medium containing 3 mg/l PPT. PCR detected the presence of the gusA and bar gene, indicating both genes are integrated into the genome of seashore paspalum. A chlorophenol red assay was used to confirm that the bar gene was expressed. By application of herbicide BASTA, the herbicide resistance in the transgenic seashore paspalum plants was confirmed.
Haploid system by anther culture allows the development of homozygous lines when doubled. The response of anther culture to Basta (glufosinate) resistance was investigated on transgenic plants (cv. Anjungbyeo) in order to identify inheritance of bar gene associated with Basta. Most of the regenerated transgenic plants were sterile, and only a few plants produced viable seeds (A1) in the greenhouse. The bar gene was analysis by PCR in basta resistant transgenic plant (TA0). The transgenic seeds (A1) were significantly germinated in Basta solution compared with non-transformed seeds. As a result of anther culture, in regenerated haploid plants, segregation ratio was 1:1 in five of eight cross combinations. In diploid plants, segregation ratio was 1:1 in seven of eight cross combinations. Although there was some differences in the cross combinations, most of the combinations had 1:1 segregation ratio which supports the theory. The difference may be a result of the small sample size or the difference of anther culture response caused by genotypic difference. Hence, when many cross combinations were anther-cultured the results would support the theory.
Agronomic characteristics of transgenic herbicide-resistant rice lines were evaluated under field condition. Differences in agronomic traits and rice quality were observed between transgenic plants and the corresponding untransformed controls. Transgenic Ilpumbyeo lines flowered earlier than untransformed controls, whereas transgenic Nagdongbyeo flowered at the same time as untransformed control. With regard to the yield and rice quality, most of the transgenic lines showed lower yield than control except some selected transgenic lines. Selected Nagdongbyeo transgenic line also showed good eating quality comparable to the control although most selected Ilpumbyeo transgenic lines showed slightly lower eating quality and increased white center/belly in the rice grain. In order to find the main factor leading to somaclonal variation among transgenic lines, Tos17, a rice retrotransposon activated by prolonged tissue culture period was investigated. Although the transgenic lines carried only one or two of transformed bar gene, the copy number of Tos17 increased in most transgenic lines compared with control. The activation of Tos17 was not detected in selected promising transgenic lines such as ND115-15-1-B and IP23-3-3, suggesting that the increased copy number of Tos17 may have negatively affected agronomic characteristics of transgenic rice.
This study was conducted to investigate the crossability, seed dormancy and overwintering ability of rice plant in GM (glufosinate ammonium-resistant lines. Iksan 483 and Milyang 204) and non-GM (their parents) or red rice (Andongaengmi). Seed-setting rate was not significantly different between GM and non-GM rice varieties. Iksan 483 and Milyang 204 showed the similar level of seed germination rate from 30 to 50 days after heading as compared to non-GM rice varieties. After overwintering in paddy field, seed germination rate of GM and non-GM rice varieties ranged from 14.3 % to 57.6 % in dry soil condition, but there was no germination in wet-soil except red rice. The result in wet-soil condition may help to set up a strategy for reducing the risk of gene flow of transgene via dispersal of seeds of GM plants. The crossability, seed dormancy and seed overwintering of Iksan 483 and Milyang 204, herbicide resistant GM rice varieties, were not significantly different compared to non-GM rice varieties. The results might be helpful to reduce the risk of transgene dispersal from GM crop via seeds and pollens.