• Title/Summary/Keyword: Biosynthesis of brassinosteroids

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Ability for Biosynthesis of C27 Brassinosteroids by an Enzyme Pool Prepared from Cultured Cells of Phaseolus vulgaris (강낭콩 현탁배양세포에서 추출된 Enzyme Pool의 C27 Brassinosteroids 합성 능력)

  • Kim Tae-Wuk;Joo Se-Hwan;Kim Seong-Ki
    • Journal of Plant Biotechnology
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    • v.32 no.1
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    • pp.63-71
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    • 2005

  • A cell-free enzyme solution prepared from suspension cultured cells of Phaseolus vulgaris successfully mediated conversions of cholesterol $\to$ cholestanol and 6-deoxo-28-norteasterone $\leftrightarrow$ 6-deoxo-28-nor-3-dehydroteasterone $\leftrightarrow$ 6-deoxo-28-nortyphasterol $\to$ 6-deoxo-28-norcastasterone $\to$ 28-norcastasterone. Al-though conversion of cholestanol to 6-deoxo-28-norteasterone intermediated by 6-deoxo-28-norcathasterone was not demonstrated, this strongly suggests that a complete set of biosynthetic enzymes catalyzing reactions from cholesterol to 28-norcastasterone via 6-deoxo-28-nor type brassinosteroids is endogenously present in the cells, which demonstrates that a $C_{27}$ brassinosteroids biosynthetic pathway, namely the late C-6 oxidation for $C_{27}$ brassinosteroids, is operative in the cells. Additionally, the enzyme solution mediated conversion of 28-norcastasterone to castasterone in the presence of S-adenosyl-methionine and NADPH, providing that the $C_{27}$ brassinosteroids biosynthesis is an important route to generate castasterone in the cells. Together with our previous finding that castasterone can be biosynthesized by the same biosynthetic pathway in tomato, this study demonstrates that the $C_{27}$ brassinosteroids biosynthesis is a common alternative process to maintain endo-genous level of castasterone, an active $C_{28}$ brassinosteroid, in plants.

  • https://doi.org/10.5010/JPB.2005.32.1.063 인용 PDF KSCI