D-37 新規アラビドプシス矮性変異体dwf5, dwf7におけるブラシノステロイドの生合成変異部位

概要

論文の詳細を見る
Two novel Arabidopsis dwarf mutants, dwf5 and dwf7, were originally identified in a screen of 14000 T-DNA transformed lines of Arabidopsis. To determine the defective step in brassinosteroid biosynthetic pathway, we have analyzed endogenous sterols and BRs in these mutants. In addition, feeding studies with ^<13>C-MVA and compactin were performed. Quantitative analysis revealed that endogenous levels of 24-methylenecholesterol and its downstream compounds in biosynthetic pathway of brassinolide were greatly reduced in dwf5 and dwf7, suggesting that each of dwf5 and dwf7 is blocked in a step before 24-methylenecholesterol. Further biochemical characterization was performed with ^<13>C-labeled mevalonic acid (MVA) and compactin, a MVA biosynthetic inhibitor. ^<13>C_5-Episterol, ^<13>C_5-24-methylenecholesterol and ^<13>C_5-campesterol were detected as metabolites of ^<13>C-MVA in wild type. In dwf7, ^<13>C_5-24-methylenecholesterol and ^<13>C_5-campesterol was not detected, whereas ^<13>C_5-episterol accumulated 4-fold as compared to wild type. In addition, an uncommon sterol, ^<13>C_5-7-dehydrocampestanol, greatly accumulated. In addition to ^<13>C_5-episterol and ^<13>C_5-7-dehydrocampestanol, ^<13>C_5-7-dehydrocampesterol was detected in dwf5. These results indicate that dwf5 and dwf7 are brassinosteroid deficient mutants, and defective steps in dwf5 and dwf7 are Δ^7-sterol-C7-reduction and Δ^7-sterol-C5-desaturation, respectively.
植物化学調節学会の論文
1998-10-01

D-37 新規アラビドプシス矮性変異体dwf5, dwf7におけるブラシノステロイドの生合成変異部位

スポンサーリンク

概要

著者

関連論文

スポンサーリンク