Molecular characterization and expression profiling of novel laccase isoenzyme genes from Fusarium solani X701, a wood-rotting ascomycete

Abstract Fusarium solani X701 is a wood-rotting ascomycete. Four laccase isoenzyme genes, lcc 1, lcc 2, lcc 3 and lcc 4, were cloned from this fungus, expression of these genes was profiled, and their relationship with other laccases was explored. Expression profiling of the isoenzymes in different media clearly shown that lcc 4 mRNA was significantly induced by lignin, suggesting that lcc 4 be the responsible gene for catabolizing lignin. Expression of lcc 1 was triggered by the switch from the presence to the absence of glucose, while lcc 2 was significantly induced in the glucose medium. Expression levels of lcc 3 were not affected by different carbon sources in the primary growth phase, but a short induction by lignin was observed in early secondary growth phase. Bioinformatical analyses revealed unique features in our isoenzymes in comparison with other laccase isoenzymes from ascomycete.