Environmental risk assessment of genetically modified Herbicide-Tolerant zoysiagrass (Event: Jeju Green21)

Abstract

Transgenic zoysiagrass (Zoysia japonica Steud.) expressing the bar gene inserted in the plant genome has been generated previously through Agrobacterium tumefaciensmediated transformation. The GM zoysiagrass (event: JG21) permits efficient management of weed control of widely cultivated zoysiagrass fields, reducing the frequency and cost of using various herbicides for weed control. Now we have carried out the environmental risk assessment of JG21 prior to applying to the governmental regulatory agency for the commercial release of the GM turf grass outside of test plots. The morphological phenotypes, molecular analysis, weediness and gene flow from each test plot of JG21 and wild-type zoysiagrasses have been evaluated by selectively analyzing environmental effects. There were no marked differences in morphological phenotypes between JG21 and wild-type grasses. The JG21 retained its stable integration in the host plant in T 1 generation, exhibiting a 3:1 segregation ratio according to the Mendelian genetics. We confirmed the copy number (1) of JG21 by using Southern blot analysis, as the transgenic plants were tolerant to ammonium glufosinate throughout the culture period. From cross-fertilization and gene flow studies, we found a 9% cross-pollination rate at the center of JG21 field and 0% at distances over 3 m from the field. The JG21 and wild-type zoysiagrass plants are not considered "weed" because zoysiagrasses generally are not dominant and do not spread into weedy areas easily. We assessed the horizontal gene transfer (HGT) of the transgene DNA to soil microorganisms from JG21 and wild-type plants. The bar gene was not detected from the total genomic DNA extracted from each rhizosphere soil of GM and non-GM Zoysia grass fields. Through the monitoring of JG21 transgene's unintentional release into the environment, we found no evidence for either pollen mediated gene flow of zoysiagrass or seed dispersal from the test field within a 3 km radius of the natural habitat.

Environmental Monitoring of Herbicide Tolerant Genetically Modified Zoysiagrass (Zoysia japonica) around Confined Field Trials

“…이에 따라 다양한 형 질의 품종 육성이 요구되어 최근에는 기존의 전통육종 기 술에서 벗어나 생명공학 기술을 이용한 신품종 개발이 시 도되고 있으며, 유전자변형 기술을 이용한 제초제저항성 및 해충저항성 잔디의 개발이 보고되었다 (Toyama et al, 2003;Ge et al, 2006;Li et al, 2006;Zhang et al, 2007). (Bae et al, 2007(Bae et al, , 2008(Bae et al, , 2011. (Fig.…”

Development of distinction methods for male-sterile and dwarfism herbicide tolerant Zoysia japonica Steud

“…에 의 해 처음 소개되었으며, 이후 Lim 등(2004) (Ge et al, 2006;Li et al, 2006;Lei et al, 2004;Toyama et al, 2003;Choi et al, 2000). Toyama 등(2003) (Bae et al, 2011;Bae et al, 2010;Bae et al, 2008;Bae et al, 2007…”