Abstract: This work is to investigate the effects of polycyclic aromatic hydrocarbons（PAHs）on laccase activity and transcriptional expression of different Ganoderma lucidum strains. Three G. lucidum（Meizhi,Rongbao No.1 and Chuanzhi）strains were used as experimental materials. After 5 days of static culture in the dark,a final concentration of 1.0 mg/L anthracene was added. Then the supernatant was collected for the determination of laccase activity after treatment for 1 h,3h,6 h,9 h,and 24 h. Further the mycelium samples were used for RNA extraction,and the effect of anthracene on laccase activity and transcriptional expression of laccase genes was analyzed. The results showed that the effects of anthracene on the laccase activity and transcriptional expression levels of 3 strains differed. Among the 3 strains of G. lucidum,Chuanzhi presented the highest laccase activity,followed by Meizhi,and he lowest activity for Rongbao No. 1. The laccase activity of Rongbao No.1 increased with the prolongation of treatment time,and was inhibited in the early stage of culture,while promoted in the later stage. The change trend of Meizhi’s laccase activity was similar to Rongbao No.1’s,and the change range was small. Enzyme activity of Chuanzhi was strongly inhibited by anthracene and differed insignificantly over time. Under the treatment of anthracene,little variations were observed in the transcript expression levels of Meizhi laccase gene,and most of the genes demonstrated peak transcriptional expression after 9 h treatment. The expression levels of Rongbao No. 1 laccase genes were similar to that of Meizhi. Under short-term treatment,the transcriptional expression level of Chuanzhi laccase genes were significantly up-regulated,and then down-regulated as the treatment time prolonged. In sum,the laccase activities and laccase genes expression levels of 3 strains of G. lucidum varied in response to anthracene;among them,Chuanzhi was the most sensitive,followed by Rongbao No. 1,and Meizhi had the smallest change and thus the strongest tolerance.

Key words: anthracene, Ganoderma lucidum, expression level, laccase activity