88 ジベレリンはメチルエリスリトールリン酸経路で生合成されるか?

概要

論文の詳細を見る
Gibberellins (GAs) are a group of growth-promoting hormones in plants. In past four decades, mevalonate (MVA) pathway has been believed to be the only route for providing isoprenoid precursors in GA biosynthesis. Actually, the conversion of MVA to GAs and ent-kaurene (a GA precursor) had been demonstrated by cell-free systems from immature seeds of several plant species such as Cucurbita maxima. In plants, however, the newly-discovered methylerythritol phosphate (MEP) pathway shares the role of isoprenoid precursor biosynthesis with MVA pathway. The MVA and MEP pathways exist in cytoplasm and in plastids, respectively. Since the site of ent-kaurene biosynthesis has been indicated to be plastid, the MEP pathway may have an essential role in GA biosynthesis. To clarify the contribution of these pathways to GA biosynthesis, we carried out feeding experiments in Arabidopsis using ^<13>C-labeled precursors specific to respective pathways. Highly efficient labeling of metabolites was achieved by simultaneous feeding of the precursors to the Arabidopsis seedlings in which either pathway is genetically or chemically blocked. Gas chromatography-mass (GC-MS) spectrometry analysis demonstrated that GAs are predominantly synthesized from the MEP pathway in Arabidopsis seedlings, but also indicated a partial contribution of the MVA pathway to GA biosynthesis. Our GC-MS data also showed minor contribution of the MEP pathway to sterol biosynthesis in cytosol, where the MVA pathway plays a major role. We also carried out the feeding of ^<13>C-labeled precursors to C. maxima immature seeds and demonstrated that GAs can be synthesized through the MEP pathway in this tissue as well.
植物化学調節学会の論文
2002-10-31

88 ジベレリンはメチルエリスリトールリン酸経路で生合成されるか?

スポンサーリンク

概要

著者

関連論文

スポンサーリンク