Overexpression of LaeA enhances mevastatin production and reduces sporulation of Penicillium citrinum

Abstract:

Abstract:［Objective］ To study the regulation of laeA overexpression on mevastatin production and sporulation in Penicillium citrinum． ［Methods］We cloned the laeA gene from Penicillium citrinum and constructed the vector pGiHTGilaeA．The plasmid pGiHTGi-laeA was transformed in Penicillium citrinum by agrobacterium tumefaciens-mediated transformation．Positive transformants were detected by cloning the hygromycin gene．The mevastatin production of the wild type and OE::laeA was compared by HPLC．The conidia number was counted by blood counting chamber．The biosynthetic gene cluster expression quantity of mevastatin in the wild type and OE::laeA were analyzed by qRT-PCR.［Results］We constructed the plasmid pGiHTGi-laeA，and screened the positive transformants that overexpress the laeA in Penicillium citrinum．With the overexpression of laeA，the mevastatin production was increased from (0.69±0.12)mg/g to (4.02±0.50) mg/g dry cell weight．Compared to the wild type strain，the laeA expression quantity in the OE::laeA strain increased 29%，and the mlcB expression increased 72%，the mlcＲ expression increased 153%． Moreover，the overexpression of laeA would decrease the conidia number．［Conclusion］Overexpression of LaeA enhances mevastatin production and reduces sporulation of Penicillium citrinum，with increases expression of pathway-regulator mlcR，and biosynthetic gene MlcR．These results could guide global regulatory mechanism of mevastatin biosynthesis and the exploitation of high-production strain.