Hydroxylations of trichothecene rings in the biosynthesis of Fusarium trichothecenes: evolution of alternative pathways in the nivalenol chemotype.
Fusarium sporotrichioides genes FsTri11, FsTri13, and FsTri1 encode cytochrome P450 monooxygenases (CYPs) responsible for hydroxylations at C-15, C-4, and C-8 of the trichothecene skeleton, respectively. However, the corresponding genes of nivalenol (NIV)-chemotype Fusarium graminearum remain to be functionally elucidated. In this study, we characterized the roles of these CYPs in NIV biosynthesis. Analyses of the metabolites of the F. graminearum Fgtri11-mutant, a disruptant of FgTri11 encoding isotrichodermin (ITD) C-15 hydroxylase, revealed a small amount of NIV-type trichothecenes suggesting that an alternative C-15 hydroxylase partially complemented FgTRI11p. In contrast, the C-7/C-8 hydroxylations depended solely on FgTRI1p, as suggested by the metabolite profiles of the Fgtri11-Fgtri1-double gene disruptant. Disruption of FgTri1 in both the wild-type and Fgtri13-mutant backgrounds revealed that FgTRI13p exhibits marginal activity toward calonectrin (CAL) and that it was the only C-4 hydroxylase. In addition, feeding experiments demonstrated that the C-4 hydroxylation of a 7-hydroxytrichothecene lacking C-8 ketone was extremely limited. The marginal activity of FgTRI13p toward CAL was advantageous for the C-7/C-8 hydroxylation steps in NIV biosynthesis, as transformation of a C-4 oxygenated trichothecene lacking C-7/C-8 modifications into NIV-type trichothecenes was quite inefficient. The significance of hydroxylation steps in the evolution of Fusarium trichothecenes is discussed.
Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8601, Japan.
Kazuyuki
K
Maeda
Graduate School of Science and Engineering, Toyo University, Kujirai 2100, Kawagoe, Saitama, 350-0815, Japan.
Akira
A
Tanaka
Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8601, Japan.
Ryosuke
R
Sugiura
Molecular Structure Characterization Unit, RIKEN CSRS, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Hiroyuki
H
Koshino
Graduate School of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Gunma, 374-0193, Japan.|Plant and Microbial Metabolic Engineering Research Unit, RIKEN DRI, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Takeshi
T
Tokai
Graduate School of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Gunma, 374-0193, Japan.|Plant and Microbial Metabolic Engineering Research Unit, RIKEN DRI, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Masayuki
M
Sato
Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8601, Japan.
Yuichi
Y
Nakajima
Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8601, Japan.
Yoshikazu
Y
Tanahashi
Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8601, Japan.
Kyoko
K
Kanamaru
Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8601, Japan.
Tetsuo
T
Kobayashi
Division of Functional Genomics, Advanced Science Research Centre, 13-1 Takara-machi, Kanazawa University, Kanazawa, Ishikawa, 920-0934, Japan.
Takumi
T
Nishiuchi
Graduate School of Life Sciences, Toyo University, 1-1-1 Izumino, Itakura, Gunma, 374-0193, Japan.
Makoto
M
Fujimura
Graduate School of Science and Engineering, Toyo University, Kujirai 2100, Kawagoe, Saitama, 350-0815, Japan.|Plant and Microbial Metabolic Engineering Research Unit, RIKEN DRI, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Naoko
N
Takahashi-Ando
Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa, Nagoya, Aichi, 464-8601, Japan.|Plant and Microbial Metabolic Engineering Research Unit, RIKEN DRI, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
Makoto
M
Kimura
D005075:Biological Evolution; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005670:Fusarium / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D006900:Hydroxylation; D014255:Trichothecenes / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism
D005656:Fungal Proteins; D014255:Trichothecenes; C038405:nivalenol; D003577:Cytochrome P-450 Enzyme System