NITROGEN ASSIMILATION IN SOYBEAN NODULES : I. The Role of GS/GOGAT System in the Assimilation of Ammonia Produced by N_2-fixation

概要

論文の詳細を見る
In order to elucidate the pathways to assimilate the ammonia produced by N_2-fixation in soybean nodules, ^<15>N-labeled compounds were administered to intact nodules or nodule slices pretreated with various inhibitors of nitrogen assimilation. After exposure to ^<15>N_2,^<15>N-incorporation into various nitrogenous compounds was investigated in attached nodules injected with methionine sulfoximine (MSX) or azaserine (AS). MSX treatment increased the ^<15>N content of ammonia more than 6 times, however, depressed ^<15>N content of most of amides and amino acids. AS treatment enhanced ^<15>N content of amido-N of glutamine as well as ammonia, but decreased amino-N of glutamine and most of amino acids. Experiments with nodule slices pretreated with MSX or AS solution and then fed with ^<15>N-labeled ammonia or amido-^<15>N of glutamine showed the same trends. Aminooxyacetate inhibited nitrogen flow from glutamic acid to other amino acids. These results strongly indicate that the ammonia produced by N_2-fixation is assimilated by GS/GOGAT system to glutamic acid and then transaminated to various amino acids in situ. ^<15>N-incorporation patterns in nodule slices fed with ^<15>N-labeled ammonia, hydroxylamine, nitrite were similar, but nitrate seemed to be reduced in a definite compartment and assimilated similarly as in intact nodules fed with ^<15>N_2. Additional Index Words : nitrogen fixation, soybean nodule, ammonia assimilation, glutamine synthetase, glutamate synthase.
社団法人日本土壌肥料学会の論文

NITROGEN ASSIMILATION IN SOYBEAN NODULES : I. The Role of GS/GOGAT System in the Assimilation of Ammonia Produced by N_2-fixation

スポンサーリンク

概要

著者

関連論文

スポンサーリンク