PROBLEM TO BE SOLVED: To provide a method for preparing a plant having improved ability of taking in nitrogen dioxide, which method makes at least one of followings possible; decreasing nitrogen compounds of reduced type nitrogen unrecoverable by Kjeldahl decomposition method and of non-inorganic nitrogen by the plant, providing a means for decreasing nitrogen oxide in air environment and/or soil environment, increasing yields, and the like. SOLUTION: The following items are provided: a method for preparing a plant expressing S-nitrosothiol reductase activity of the polypeptide and having improved ability of taking in nitrogen dioxide by introducing into a plant body a nucleic acid encoding polypeptide exhibiting S-nitrosothiol reductase activity; a transgenic plant having improved ability of taking in nitrogen dioxide; a method for decreasing nitrogen compounds of reduced type nitrogen unrecoverable by Kjeldahl decomposition method and of non-inorganic nitrogen by the plant; a method for promoting nitrogen dioxide metabolism by plant and for increasing S-nitrosothiol reductase activity in plant; and an environmental clean-up method decreasing NOxin air environment by using a transgenic plant. COPYRIGHT: (C)2006,JPO&NCIPI
