Imaging of the nodule function in leguminous plants who utilize nitrogen gas in the air as nutrition

Fujimaki, Shu; Ishii, Satomi; Oyama, Takuji*

The nodule is a symbiotic organ developed on roots of leguminous plants which have been infected with rhizobia, a group of soil bacteria. The plants with nodules can obtain nitrogen nutrition as ammonia converted from nitrogen gas in the air by rhizobia in the nodules. This function, "symbiotic nitrogen fixation", plays a fundamental role in the food production in the world. Recently, we reported that we have successfully visualized the symbiotic nitrogen fixation in soybean plants non-invasively using a positron-emitting tracer imaging system (PETIS) and nitrogen-13-labelled nitrogen gas tracer. In this article, this study is described with the scientific and social backgrounds.