유전자변형(GM) 식물의 개발과 제초제저항성 GM 들잔디의 환경위해성평가

Abstract

The present study was carried out for the development of genetically modified plant and ecological risk assessment of genetically modified (GM) herbicide-tolerant Zoysia grass (Zoysia japonica Steud.) for a formal approval to release the commercial planters. For establishment of ecological risk assessment was understand the full procedure of transformation method, analysis and integrated gene. The first section showed the development of transgenic dandelion (Taraxacum platycarpum H. Dablstaed) by Agrobacterium-mediated transformation. The pre-culture period of days were very important factor for the highly efficient transformation to insert the enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (hmgr) gene by Agrobacterium-mediated protocol. Expression of the integrated gene was well stabilized in regenerated transgenic plants. Evidence of efficient transformation obtained by molecular analysis. The GM plant became the raw material for ecological risk assessment. And the second section was indicated the ecological risk assessment of GM herbicide-tolerant Zoysia grass, as have stable characteristic of integrated gene at the next generation. The aim of herbicide-tolerant Zoysia grass was to decrease the cost, problem of environmental risks and management of weeds, and have to various functional cultivar. The transformation of Zoysia grass with bar gene derived from streptomyces hygroscopicus using Agrobacteroium-mediated method and characterization of the transgenic plants inculding response to herbicide-tolerance. The ecological risk assessments of GM herbicide-tolerant Zoysia grass were performed to get governmental approval of GM herbicide-tolerant Zoysia grass. Experiments were done according to the guidelines (Notification # 2002-2) of the Ministry of Agriculture and Forestry (MAF). In these assessments, substantial equivalence, cross fertilization, gene flow, occurrence of allergy, remove and studies of non-target biota in confined and unconfined test fields for environmental safety were included between wild-type (WT) and GM herbicide-tolerant Zoysia grass. The result of southern blot and segregation of T1 progeny showed that the bar transgene was stably integrated into the genome of transgenic plants. T₃ and T₄ progeny of GM herbicide-tolerant Zoysia grass showed herbicide-tolerance at the unconfined field. The integrated gene was stably inserted in chromosome at the plant genome. For substantial equivalence, there was no difference between WT and GM Zoysia species. To assess cross-fertilization and gene flow, the bialaphos, a non-selective herbicide, was used. The results showed that cross-fertilization and gene flow from GM herbicide-tolerant Zoysia grass was not identified in weed plants but was occurred in WT Zoysia grass (on average, 6% near 0 cm, 1.2% at the distance of 50 cm and 0.12% at a radius of 3 m, and 0 % at the distances over 3m). The Zoysia grass is not a dominant plant and does not spread into the weeded area easily. In fact, the Zoysia grass field is completely dominated by the weeds within 2-3 years of cohabitation. The effects of dominant weeds on the GM herbicide-tolerant Zoysia grass, showing the dominance of the weeds over the turf grass. This result indicates that the GM herbicide-tolerant Zoysia grass does not have negative impact on microbial flora in the gut of locust, We then investigated whether the horizontal gene transfer (HGT) occurred from GM herbicide-tolerant Zoysia grass to microbes in soil, rhizosphere and faecal pellets from locusts by utilizing molecular tools such as Southern hybridization and polymerase chain reaction (PCR). The skin test for allergic reaction using grass pollen extracts are under going six subjects (4.7% of the 127 test subjects) developed a positive allergenic reaction to both WT and GM Zoysia pollens. However, no difference between the two types of pollens were observed. The bar and hpt genes showed no apparent risks to human and animal health risks in terms of cytogenetic toxicity and allergenic reaction. The non-selective herbicides without glufosiante were efficiently eliminated the herbicide-tolerant Zoysia grass for the risk management. The herbicide-tolerant Zoysia grass in environment, had difficulty with growth by the dominant weeds and grass pathogens. when glufosiante dose not applied there were no advantage for the herbicide-tolerant Zoysia grass to grew. There for the herbicide-tolerant Zoysia grass did not cause any environment risk. On the basis of these initial studies, we conclude that the GM herbicide-tolerant Zoysia grass generated in our laboratory and tested in the Nam Jeju County field does not appear to pose a significant risk in its cultivation outside of the test field.