Study Of The Ecological Risk Of Transgenic Silver Birch (Betula Pendula Roth): Decomposition And Transgene Horizontal Transfer

In this study, the leaves of transgenic silver birch are used as the materials, what is used to analyze the effect of decomposition by changing the lignin component of transgenic plants, and the possibility of transgene horizontal transfer. The aim is to access the ecological risk of transgenic material's utilization and to provide useful information to both of the production and application of transgenic birch in the future.The transgenic birch clones in four years old with two genotypes 35S-PtCOMT and UbB1-PtCOMT are selected, the leaves are collected for decomposition in two soil types, one is forest soil from birch plantation, the other is farm field soil. The mass loss is calculated by measuring the weights of leaves before and after decomposition. The results show that the change of lignin component has affected on decomposition of the materials. One clone named No.23, whose S/G reduces by 69% to 72%, has higher mass loss by 7.2% and 1.8% in farm soil and forest soil respectivelyAlso, the horizontal transfer possibility of target gene from transgenic birch is discussed in this study. The ampicillin and kanamycin resistance of the soil microbes who touch and do not touch transgenic materials is tested, the results shows that both antibiotic resistance are increased, in which ampicillin resistance increases 1.42%, while kanamycin resistance increases 0.7% in the farm soil, and ampicillin resistance increases 5.64%, while kanamycin resistance increases 7.55% in the forest soil. In this case, it probably has some risks of transgene horizontal transfer to soil microbes. Generally speaking, the changes of antibiotic resistance in soil microbes are affected by many factors, so it is still difficult to prove whether or not the target gene of the materials is clearly transferred into soil microbes at present.According to this study, the transgenic silver birch that the lignin component has been changed does possibly affect the decomposition of the materials. Since the expression level of the target gene and its transfer are controlled by many factors, the further study on the ecological risk of transgenic COMT birch will be still needed.