Abstract:In order to analyze the function of CreA,a carbon metabolism regulator of Penicillium italicum,which is a postharvest pathogen of citrus fruits,the PicreA gene was successfully cloned.The gene has 1 236 bp cDNA length without intron,which encodes 411 amino acids and contains two typicalzinc finger domains of transcription factors.Phylogenetic tree analysis showed that the PiCreA protein had the highest homology with Penicillium expansum.Transcriptional analysis of PicreA revealed a complex express profile in response to different carbon sources.For monosaccharide,higher expression was induced in a short period of time.With the prolongation of time,in the case of repressing carbon source such as glucose,PicreA expression showed a gradual decline and then increased.It was presumed that selfinhibition of PicreA occurred.In term of the depressing carbon source like xylose,PicreA expression level lightly decreased and gradually remained fairly high.For nonmonosaccharide carbon source such as ethanol,high level of PicreA expression was maintained.The PicreA gene is stably expressed throughout the infection process of Penicillium italicum on citrus fruits.