Studies on interaction between carbon and nitrogen metabolism in C_3 and C_4 plants: 1. Effects of nitrogen nutrition on photosynthetic rates, and ribulose-1, 5-bisphosphate carboxylase and phosphoenolpyruvate carboxylase activities

DOI Web Site
  • OGATA Shoitsu
    Faculty of Applied Biological Science, Hiroshima University
  • KUBO Takashi
    Faculty of Applied Biological Science, Hiroshima University
  • FUJITA Konosuke
    Faculty of Applied Biological Science, Hiroshima University
  • KOUNO Kenji
    Faculty of Applied Biological Science, Hiroshima University

Bibliographic Information

Other Title
  • C_3・C_4植物の炭素・窒素代謝の相互関係に関する研究 : 1.光合成能,リブロース二リン酸カルボキシラーゼおよびホスホエノールピルビン酸カルボキシラーゼ活性におよぼす窒素栄養の影響
  • C3・C4植物の炭素・窒素代謝の相互関係に関する研究-1-光合成能,リブロース二リン酸カルボキシラーゼおよびオスホエノールピルビン酸カルボキシラーゼ活性におよぼす窒素栄養の影響
  • C3 C4 ショクブツ ノ タンソ チッソ タイシャ ノ ソウゴ カンケイ ニ

Search this article

Abstract

It is intended to elucidate the interaction between photosynthesis and nitrogen metabolism in C_3 and C_4 plants. In the present study, the effects of nitrogen nutrition on photosynthetic rates (P_0), RuBP- and PEP-carboxylase activities and photorespiration rates were examined. Using newly expanded leaves of C_3 and C_4 plants grown at graded nitrogen level or at certain nitrogen level with ammonium or nitrate in culture solutions, their rates of apparent photosynthesis (P_0), nitrogen contents, RuBP- and PEP-carboxylase activities, CO_2 compensation points and the rates of photorespiration and dark respiration were measured. The results obtained were as follows: 1. Total nitrogen contents were highly correlated to P_0 of forage leaves. Both P_0 and Po per unit nitrogen increment were significantly higher in C_4 plants than in C_3 plants. 2. Reasons why P_0 of C_4 plants was enhanced more than that of C_3 plants with an increase of nitrogen content in leaves were (a) C_4 plants had higher proportion of soluble protein fraction to the total nitrogen compounds, (b) Activities of enzymes related to C_4 cycle remarkably increased with an increase of nitrogen content in leaves. 3. No significant differences were observed in P_0 of C_3 and C_4 plants between forms of nitrogen source. In C_3 plants, the rate of photorespiration, as determined by the rate of CO_2 released in CO_2 free air, of plants supplied with nitrate was approximately 30 percent lower than that of those supplied with ammonium. However, the rate of true photosynthesis was also lower in plants supplied with nitrate than with ammonium.

Journal

Details 詳細情報について

Report a problem

Back to top