Utilization of transgenic plants for phytoremediation of coplanar PCB

多氯联苯(RCB)的稳定性和疏水性使其成为一种持久的环境危害，因此，包括共面多氯联苯(Co-PCbs)在内的多氯联苯对环境的污染水平长期居高不下。因此，了解环境中多氯联苯的污染水平至关重要。为了准确地从环境样品中检测多氯联苯，人们很好地使用了配备高分辨率质谱仪的气相色谱仪，但这种仪器价格太高，不容易使用，而且需要很高的操作技能。本研究以拟南芥基因组中响应钴-多氯联苯胁迫的基因(S)为研究对象，探讨利用该基因作为生物标志物对多氯联苯污染进行环境风险评价的有效性。此外，还利用高分辨率GC-MS技术研究了海棠对Co-PCbs和TCDD的积累情况，为今后的植物修复研究奠定了基础。利用转基因拟南芥的增强子陷阱系，发现了两个在Co-PCbs暴露下表现出不同基因表达模式的系。利用RT-PCR差异显示方法，捕获了10个表达受Co-PCbs不同调控的基因。研究发现，Co-PCbs的累积水平取决于氯的含量或位置。(1)低氯化的Co-PCb同系物比高氯化的积累更多。(2)非邻位的Co-PCB同系物的积累比等氯化的邻位同系物少。(3)TCDD的积累比等氯化的Co-PCbs、四氯联苯少。从白腐菌中克隆了木质素过氧化物酶(Lip)基因的cDNA，并尝试将Lip基因导入拟南芥中。

The stability and hydrophobic nature of polychlorinated biphenyls (RCBs) make them a persistent environmental hazard ; thus, the environmental pollution level of PCBs including coplanar PCBs (Co-PCBs) has been kept high for a long time. So it is primary important to realize the pollution level of PCBs in the environment. To detect PCBs precisely from the environmental samples the gas chromatograph equipped with the high resolution mass spectrometry is well used ; however, such an instrument is too expensive to be used easily and the great skill is required to handle it. So the development of easy substitutive method for the instrumental analysis is expected for the monitoring PCBs.In this study, the gene(s) responding to the stress of Co-PCBs in the genome of plant, Arabidopsis thaliana (A. thaliana), was (were) sought to investigate the efficiency of monitoring gene expression as a biomarker in the environmental risk assessment of Co-PCBs contamination. The accumulation of Co-PCBs and TCDD by A. thaliana was also investigated for the future phytoremediation study using high-resolution GC-MS.1. Using the enhancer-trap lines of transgenic A. thaliana, two lines showing the different gene expression pattern by the exposure to Co-PCBs were found.2. Using the RT-PCR differential display method, 10 genes exhibiting the variously regulated expression by the exposure to Co-PCBs were trapped.3. It was found that the accumulation levels of Co-PCBs depended on the content or position of chlorine as below.(1) Lower chlorinated Co-PCB congeners were accumulated more than higher chlorinated ones.(2) Non-ortho Co-PCB congeners were less accumulated than equally chlorinated ortho congeners.(3) TCDD was less accumulated compared to equally chlorinated Co-PCBs, tetrachlorobiphenyls.4. The cloning of cDNA of lignin peroxidase (Lip) gene from white rot fungus, and then the transfection of Lip cDNA into A. thaliana was also tried.