Production of a biosensor detecting nitrate in water and development of techniques to reduce nitrate compounds in water.

为了方便地检测河流、湖泊和海水中的硝酸盐浓度，研制了一种检测水中硝酸盐的生物传感器。它通过硝酸还原酶将硝酸盐转化为亚硝酸盐，并通过与磺胺和N-1-萘基乙烯反应检测亚硝酸盐。它检测到水中硝酸盐的含量为5ppm。为了减少河流、湖泊和海水中的氮含量，我们创造了过表达谷氨酰胺合成酶的转基因芦苇。芦苇植株吸收硝酸盐的速度是对照植物的15到20倍，生长速度是对照植物的3倍。谷氨酰胺合成酶是植物根部吸收氨的关键酶。它在根中的质体中表达，在植物中的表达水平普遍较低。我们试图通过叶绿体转化的方法在叶绿体中过表达谷氨酰胺合成酶，并获得了谷氨酰胺合成酶含量高30-40倍的烟草植株。它将被有效地用于减少水中的氮。

A biosensor detecting nitrate in water was produced to investigate easily the nitrate concentration in river, lake or sea water. It converts nitrate to nitrite by nitrate reductase, and detects the nitrite by reacting with sulfanilamide and N-1-naphtyl ethylene. It detects 5ppm of nitrate in water. It will be used in various places to detect easily nitrate concentration.In order to reduce the nitrogen in river, lake and sea water, we created the transgenic reed plants with over-expressed glutamine synthetase. The reed plants absorbed nitrate 15-to 20-times faster, and grew 3 times higher than control plants. It will be used efficiently to reduce the nitrate content in water.Glutamine synthetase is a key enzyme to assimilate ammonia in roots of plants. It is expressed in plastids in roots and the level of expression is generally low in plants. We tried to over-express the glutamine synthetase in plastids by means of chloroplast transformation, and have got tobacco plants with 30-to 40-times higher content of glutamine synthetase. It will be used efficiently to reduce nitrogen in water.