Characterization of the sterol 14α‐demethylases of Fusarium graminearum identifies a novel genus‐specific CYP51 function. Issue 3 (27th February 2013)

• Record Type: Journal Article
• Authors: Fan, Jieru; Urban, Martin; Parker, Josie E.; Brewer, Helen C.; Kelly, Steven L.; Hammond‐Kosack, Kim E.; Fraaije, Bart A.; Liu, Xili; Cools, Hans J.
• Is Part Of: New phytologist. Volume 198:Issue 3(2013)
• Page Start: 821
• Page End: 835
• Publication Date: 2013-02-27
• Subjects: Botany -- Periodicals; 580
• DOI: 10.1111/nph.12193
• Languages: English
• ISSNs: 0028-646X

Abstract

<abstract abstract-type="main" id="nph12193-abs-0001"> <title>Summary</title> <p> <list id="nph12193-list-0001" list-type="bullet"> <list-item> <p> <italic>CYP51</italic> encodes the cytochrome P450 sterol 14α‐demethylase, an enzyme essential for sterol biosynthesis and the target of azole fungicides. In <italic>Fusarium</italic> species, including pathogens of humans and plants, three <italic>CYP51</italic> paralogues have been identified with one unique to the genus. Currently, the functions of these three genes and the rationale for their conservation within the genus <italic>Fusarium</italic> are unknown.</p> </list-item> <list-item> <p>Three <italic>Fusarium graminearum CYP51</italic>s (<italic>FgCYP51</italic>s) were heterologously expressed in <italic>Saccharomyces cerevisiae</italic>. Single and double <italic>FgCYP51</italic> deletion mutants were generated and the functions of the <italic>FgCYP51</italic>s were characterized <italic>in vitro</italic> and <italic>in planta</italic>.</p> </list-item> <list-item> <p> <italic>FgCYP51A</italic> and <italic>FgCYP51B</italic> can complement yeast <italic>CYP51</italic> function, whereas <italic>FgCYP51C</italic> cannot. <italic>FgCYP51A</italic> deletion increases the sensitivity of <italic>F. graminearum</italic> to the tested azoles. In <italic>ΔFgCYP51B</italic> and <italic>ΔFgCYP51BC</italic> mutants, ascospore formation is blocked, and eburicol and two additional 14‐methylated sterols accumulate. <italic>FgCYP51C</italic> deletion reduces virulence on host wheat ears.</p> </list-item> <list-item> <p> <italic>FgCYP51B</italic> encodes the enzyme primarily responsible for sterol 14α‐demethylation, and plays an essential role in ascospore formation. <italic>FgCYP51A</italic> encodes an additional sterol 14α‐demethylase, induced on ergosterol depletion and responsible for the intrinsic variation in azole sensitivity. <italic>FgCYP51C</italic> does not encode a sterol 14α‐demethylase, but is required for full virulence on host wheat ears. This is the first example of the functional diversification of a fungal <italic>CYP51</italic>.</p> </list-item> </list> </p> </abstract>