Molecular characterization and functional expression of dihydroxypterocarpan 6a‐hydroxylase, an enzyme specific for pterocarpanoid phytoalexin biosynthesis in soybean (Glycine max L.)

FEBS Letters

Lottspeich, Friedrich³  Schopfer, Christel R²  Ebel, Jürgen²  Kochs, Georg¹ 

[1]Abteilung Virologie, Institut für Medizinische Mikrobiologie und Hygiene, Universität Freiburg, D-79008 Freiburg, Germany

[2]Botanisches Institut, Ludwig-Maximilians-Universität München, Menzinger Str. 67, D-80638 Munich, Germany

[3]Max-Planck-Institut für Biochemie, D-82152 Martinsried, Germany

关键词: Cytochrome P450;    Dihydroxypterocarpan 6a-hydroxylase;    Glyceollin biosynthesis;    Transcriptional control;    Heterologous expression in yeast;    Glycine max L. cell culture;    C4H;    cinnamate 4-hydroxylase;    CPR;    NADPH-cytochrome P450 reductase;    D6aH;    3;    9-dihydroxypterocarpan 6a-hydroxylase;    DHP;    3;    9-dihydroxypterocarpan;    DMSO;    dimethylsulfoxide;    HPLC;    high pressure liquid chromatography;    HPTLC;    high performance thin layer chromatography;    P450;    cytochrome P450;    THP;    3;    6a;    9-trihydroxypterocarpan;    TLC;    thin layer chromatography;   

DOI  :  10.1016/S0014-5793(98)00866-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Four cytochrome P450-dependent enzymes, among them dihydroxypterocarpan 6a-hydroxylase (D6aH), are specifically involved in the elicitor-inducible biosynthesis of glyceollins, the phytoalexins of soybean. Here we report that CYP93A1 cDNA, which we isolated previously from elicitor-induced soybean cells, codes for a protein with D6aH activity. Analysis of the catalytic properties of recombinant CYP93A1 expressed in yeast, its NADPH dependency, stereoselectivity and high substrate affinity confirmed that D6aH is the physiological function of CYP93A1. It thus represents the first isoflavonoid-specific CYP to be characterized at the molecular level. In elicitor-treated soybean cells producing phytoalexins, increases in D6aH activity were correlated with elevated transcript levels which indicates that expression of the enzyme is regulated at the level of transcription. Therefore, CYP93A1 cDNA can be used as a specific molecular marker for the inducible defense response against pathogen attack.

【 授权许可】

Unknown