25 植物鉄輸送物質ムギネ酸類の生合成研究(口頭発表の部)

スポンサーリンク

概要

• 論文の詳細を見る

• Mugineic acids are a group of compounds having ferric chelating activity. They are secreted from the roots of some gramineous plants under iron deficiency. These compounds play an important role in the acquisition of insoluble iron from soils by the gramineous plants. In the present study, the biosynthetic pathways of five mugineic acids were investigated in different gramineous plants using feeding experiments with ^<13>-and/or ^2H-labeled compounds and by NMR techniques. The results revealed that L-Met serves as a precursor for all mugineic acids tested. All mugineic acids share the pathway from L-Met to 2'-deoxymugineic acid although subsequent steps differ and are dependent on the plant species and cultivars. In oats, avenic acid A is biosynthesized from 2'-deoxymugineic acid by cleavage of the azetidine ring. In barley, hydroxylation at the C-2' position in 2'-deoxymugineic acid yields mugineic acid. Further hydroxylation at the C-3 position in mugineic acid produces 3-epihydroxymugineic acid and hydroxymugineic acid in beer barley and rye, respectively. All mugineic acids were found to have similar effect on iron uptake, suggesting that 2'-deoxymugineic acid is a key phytosiderophore. The biosynthetic pathway between L-methionine and 2'-deoxymugineic acid was investigated by observing the incorporation of label from ^<13>C, ^2H, and ^<15>N-labeled methionine in wheat roots (Triticum aestivum L. cv Minori). As a result, only the deuterium atom from the C-2 position of L-methionine was lost, while other atoms were completely incorporated when three molecules of methionine were converted to 2'-deoxymugineic acid. These observations are consistent with the conversion of L-methionine to azetidine-2-carboxylic acid, suggesting that L-methionine is first converted to azetidine-2-carboxylic acid during biosynthesis leading to 2'-deoxymugineic acid. Based on these results, a hypothetical pathway from L-methionine to 2'-deoxymugineic acid was postulated.

• 天然有機化合物討論会の論文
• 1994-09-20

著者

• 野本 亨資

  東洋大生命科学

• 馬 建鋒

  財団法人サントリー生物有機科学研究所

• 野本 享資

  財団法人サントリー生物有機科学研究所

関連論文

• 新規ムギネ酸類2種の単離および同定(9. 植物の無機栄養, 2004年度大会講演要旨集)
• イネ科植物の鉄獲得戦略 ムギネ酸を軸とした巧みな機構が存在
• イネ科植物の根における鉄獲得物質ムギネ酸類の生合成経路
• 10-19 ムギネ酸類生合成とメチオニンリサイクル系との共役(10.植物の無機栄養・代謝)
• 植物における鉄輸送体 (生物無機化学の新展開) -- (生物無機化学をめぐる最近の話題)
• 25 植物鉄輸送物質ムギネ酸類の生合成研究(口頭発表の部)
• 5-3 L-メチオニンから2'-デオキシムギネ酸への生合成経路の検討(5.植物の無機栄養および養分吸収)
• 5-9 イネ科植物におけるムギネ酸類の生合成研究(5. 植物の無機栄養および養分吸収)
• BIOSYNTHESIS OF AVENIC ACID A, A FERRIC CHELATING SUBSTANCE SECRETED FROM AVENA SATIVA L.
• ムギネ酸類に関する生理生化学的研究

スポンサーリンク