Kurumata Mami, Takahashi Misa, Sakamotoa Atsushi, Ramos Juan L, Nepovim Ales, Vanek Tomas, Hirata Toshifumi, Morikawa Hiromichi
Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Japan.
Z Naturforsch C J Biosci. 2005 Mar-Apr;60(3-4):272-8. doi: 10.1515/znc-2005-3-412.
Arabidopsis thaliana was transformed with a gene encoding a nitroreductase (NTR, E.C.1.6.99.7) with activity against a wide range of nitroaromatic compounds. The gene was transferred from Escherichia coli by an Agrobacterium-mediated in planta method. The obtained seeds were sowed to produce T1 plants, and they were assayed for the integration of the transgene in the plant genome. Transgenic plants that were positive with the PCR analysis were self-pollinated to produce T2 generation plants. Seven lines obtained were assayed for the NTR activity. While the non-transformed wild-type plants showed no detectable NTR activity, the enzyme activity of the transgenic plant lines was approx. 20 times higher. Using the line with the highest NTR activity, the phytoremediation characteristics of plants against 2,4,6-trinitrotoluene (TNT) was investigated. While the wild-type plants did not grow in the presence of 0.1 mM TNT, the transgenic plants grew almost normally in this condition. The uptake of TNT by seedlings of transgenic plants increased by 7 to 8 times when theywere floated on TNT solution. HPLC analysis showed that the peak due to TNT taken upinto plant body was much smaller in the transgenic plants as compared with that of the wild type, and that a number of peaks attributable to the degradation products of TNT, including 4-amino-2,6-dinitrotoluene, were detected in the extract from the transgenic plants. This indicates that the expression of bacterial NTR improved the capability of plants to degrade TNT.
用编码对多种硝基芳香化合物具有活性的硝基还原酶（NTR，E.C.1.6.99.7）的基因转化拟南芥。该基因通过农杆菌介导的植物体内方法从大肠杆菌转移而来。将获得的种子播种以产生T1代植株，并对它们进行转基因在植物基因组中的整合检测。PCR分析呈阳性的转基因植株进行自花授粉以产生T2代植株。对获得的7个株系进行NTR活性检测。未转化的野生型植株未检测到NTR活性，而转基因株系的酶活性约高20倍。使用NTR活性最高的株系，研究了植物对2,4,6-三硝基甲苯（TNT）的植物修复特性。野生型植株在0.1 mM TNT存在下不能生长，而转基因植株在这种条件下几乎能正常生长。当转基因植株幼苗漂浮在TNT溶液上时，其对TNT的吸收增加了7至8倍。HPLC分析表明，与野生型相比，转基因植株体内TNT吸收峰要小得多，并且在转基因植株提取物中检测到许多归因于TNT降解产物的峰，包括4-氨基-2,6-二硝基甲苯。这表明细菌NTR的表达提高了植物降解TNT的能力。
