節位を異にする水稲根への窒素と炭素の転流 : 葉に供与した^<15>Nと^<13>Cの追跡

概要

論文の詳細を見る
The translocation of nitrogen and carbon from leaves to roots of the rice plant at vegetative stage was investigated using ^<15>N and ^<13>C as a tracer, emphasis being placed on the node position of the roots. The whole shoot of the plant at the stage of developing the 12th leaf (12L) and the 9th nodal roots (9nR) was fed with ^<13>C-labeled CO_2 gas for 60 min after being sprayed with ^<15>N-labeled urea solution, and the fate of ^<15>N and ^<13>C in the plant was followed over 12 days. A rapid transfer of ^<15>N and ^<13>C from the expanded leaves (3-11L) took place with-in 3 days and 1 day respectively, then a gradual transfer followed during the chase period. ^<15>N and ^<13>C were translocated to all parts of the plant, preferentially to the expanding leaf (12L) and the root system. Among the roots the upper roots (9nR) were the largest sink of ^<15>N and ^<13>C expected by the expanded laves. The lower roots (≦5nR, 6nR and 7nR) received substantial amount of ^<15>N as well as ^<13>C from the leaves, although they did not increase their N and C contents. Within 1 day when both translocated ^<15>N and ^<13>C in each nodal root increased, the ratio of ^<13>C gain to ^<15>N gain was the highest in the upper roots (9nR). The ratio decreased as the node position of the roots lowered. Whereas the ratio of ^<13>C loss to ^<15>N loss in the expanded leaves within 1 day was higher in the upper leaves (9-11L) than in the lower leaves (3-8L). The results indicate that not only the young upper roots but also the old lower roots are the sinks of the nitrogenous compounds translocated with the photosynthetic assimilates from the expanded leaves. The difference in the ^<13>C/^<15>N ratio among the nodal roots suggests that the C/N ratio of the foliar products imported by the roots varies with their node positions; lower roots receive the products containing more rich in N relative to C as compared with upper roots. Each leaf of different nodes seems to play a specific role to supply the root system with the products of varietical C/N ratio; upper leaves supply the products of higher C/N ratio mainly to upper roots, while lower leaves feed the products of lower C/N ratio to lower roots.
日本作物学会の論文
1983-06-05

節位を異にする水稲根への窒素と炭素の転流 : 葉に供与した^<15>Nと^<13>Cの追跡

スポンサーリンク

概要

著者

関連論文

スポンサーリンク