Plant sterol 14 alpha-demethylase affinity for azole fungicides

David Christopher Lamb, Diane Elizabeth Kelly, Soren Bak, Andrew G. S. Warrilow, Steven Lewis Kelly, Michel Cannieux, Rachel A. Kahn, Nigel J. Manning

Research output: Contribution to journalArticlepeer-review

30 Citations (SciVal)


Azole fungicides were thought to have much greater affinity for the fungal cytochrome P450 enzyme, sterol 14α-demthylase (CYP51) than the plant orthologue. Using purified CYP51 from the plant Sorghum bicolor L Moenech, a direct comparison of the sensitivity to the fungicides triadimenol and tebuconazole has been carried out. S. bicolor CYP51 was purified to homogenity as determined by SDS–PAGE and specific heme content. Addition of the azole fungicides triadimenol and tebuconazole induced type II spectral changes, with saturation occurring at equimolar azole/P450 concentrations. Inhibition of reconstituted activities revealed only a threefold insensitivity of the plant CYP51 compared to a fungal CYP51, from the phytopathogen Ustilago maydis, as judged by IC50 values. The implications for fungicide mode of action and application are discussed.
Original languageEnglish
Pages (from-to)845-849
Number of pages5
JournalBiochemical and Biophysical Research Communications
Issue number3
Publication statusPublished - 15 Jun 2001


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