Cloning of actin Promoter and Transformation of the Marine-Sourced Filamentous Fungus Phoma herbarum YS4108

ABSTRACTAIMTo establish a convenient and efficient transformation system of the marine-sourced filamentous fungus Phoma herbarum YS4108.METHODSThe endogenous actin promoter was cloned with degenerate primers and genome walking strategy, and utilized in the electroporation of P. herbarum YS4108. Using hygromycin B phosphotransferase gene as a selection marker and single cells prepared from mycelia as recipients, the effect of electroporation parameters on transformation efficiency was examined.RESULTSThe actin promoter was successfully cloned. The optimum parameters for electroporation were found to be 0.75 kV (0.2 cm cuvette) in voltage and 400 – in resistance with 9 μg of plasmid, under which more than 100 transformants per cuvette (106 recipients) could be obtained.CONCLUSIONBy using the endogenous actin promoter, the electric transformation system of P. herbarum YS4108 was established, which served as a practical approach for transgenic study on this fungus.