Biosynthesis of brassinosteroids in cultured cells of Catharanthus roseus.
Precursor administration experiments with 2H-labeled 6-oxocampestanol, 6-deoxocastasterone and 6alpha-hydroxycastasterone in cultured cells of Catharanthus roseus were performed and the metabolites were analyzed by GC-MS. [2H6]Cathasterone was identified as a metabolite of [2H6]6-oxocampestanol, whereas [2H6]6alpha-hydroxycastasterone and [2H6]castasterone were identified as metabolites of [2H6]6-deoxocastasterone, and [2H6]castasterone was identified as a metabolite of [2H6]6alpha-hydroxycastasterone, indicating that 6-deoxocastasterone is converted to castasterone via 6alpha-hydroxycastasterone. In addition, 6-deoxocathasterone, a putative biosynthetic intermediate in the late C6-oxidation pathway, was identified as an endogenous brassinosteroid. These studies provide further evidence supporting our proposed biosynthetic pathways for brassinolide.
Fujioka
S
S
The Institute of Physical and Chemical Research (RIKEN), Saitama, Japan. sfujioka@postman.riken.go.jp
Noguchi
T
T
Watanabe
T
T
Takatsuto
S
S
Yoshida
S
S
D002478:Cells, Cultured; D002777:Cholestanols / Q000737:chemistry / Q000378:metabolism; D010840:Phytosterols / Q000378:metabolism; D010944:Plants / Q000737:chemistry / Q000378:metabolism*; D013256:Steroids / Q000096:biosynthesis*
C411124:6-deoxacastasterone; C411123:6-oxocampestanol; D002777:Cholestanols; D010840:Phytosterols; D013256:Steroids; C083545:castasterone