Assimilation and transport of nitrogen in rice I. ^<15>N-labelled ammonium nitrogen

概要

論文の詳細を見る
The assimilation and transport of ^<15>N-labelled ammonium nitrogen in rice plants (Oryza sativa L.) was studied. Plants assimilated large amounts of nitrogen from labelled ammonium into their amides and amino acids, particularly in the roots and stem, at the end of a 4-day ^<15>N feeding and 10 days later in the upper leaves, especially in the blades. Although the incorporation of ^<15>N into all the nitrogen fractions of the newly emerged panicle was evident, it was particularly pronounced in the amides and amino acids of the soluble fractions. The upper leaves had a greater ^<15>N incorporation in their organic N-fractions than did the lower ones. Amides and amino acids are considered to be the main forms of nitrogen transported to the shoot from the ammonium assimilated in the roots. The transport of the organic forms of nitrogen was possibly greater to the upper leaves than to the lower ones. The nitrite fraction had more ^<15>N than did the nitrate fraction in all parts of the plant, particularly in the upper leaf blades. It appeared that some of the ammonia might have been oxidized to nitrite, then to nitrate in some parts of the plant; probably in the upper leaves. The synthesis of protein and nucleic acid occurred rapidly in the upper leaves, especially in the blades, also in the roots as evidenced by the considerable incorporation of ^<15>N in the insoluble fractions of these parts. The variation in ^<15>N-distribution, during the 10 days, in the different plant parts suggests that the nitrogen incorporated during protein synthesis in the roots and tillers was remobilized and transported to the upper pars of the shoot. A concept for the transport of organic nitrogenous compounds from the roots to shoot through the phloem and xylem of the rice plant stem is discussed.
日本植物生理学会の論文

Assimilation and transport of nitrogen in rice I. ^<15>N-labelled ammonium nitrogen

スポンサーリンク

概要

著者

関連論文

スポンサーリンク