Heterologous expression of the CYP51 gene of the obligate fungus Blumeria graminis in the necrotrophic fungus Botrytis cinerea.

As it is extremely difficult to make DNA transformation for the obligate fungus, Blumeria graminis f. sp. tritici (Bgt), we developed a heterologous expression system for characterization of a Bgt gene, CYP51, which encodes 14α-demethylase. The CYP51 gene from Bgt was transformed into the necrotrophic fungus, Botrytis cinerea. Reverse transcription polymerase chain reaction showed that the Bgt CYP51 was transcribed in B. cinerea. Green fluorescence was observed in the transformants of B. cinerea carrying the Bgt CYP51-GFP fusion cassette, suggesting that its translation was successful. Fungicide sensitivity tests revealed that B. cinerea transformed with Bgt CYP51 showed reduced sensitivity to a sterol demethylation inhibitor triadimefon, but not to a benzimidazole fungicide carbendazim. These results indicated that this heterologous expression system can be used for functional analysis of other Bgt genes.