Kraft Lignin/Aromatic Compound-Induced Promoters In White Rot Fungi Gelatoporia subvermispora

White rot fungi are the only known group that can completely degrade lignin in plant cell walls. However, it is obscure whether lignin and its degradants regulate the lignin-modifying enzyme (LME) gene expression. In this study, the expression of LME genes in a selective lignin-degrading fungus, Gelatoporia subvermispora, on a medium supplemented with Kraft lignin and lignin-derived aromatic compounds was investigated. qRT-PCR results showed significant differences in the gene expression of LMEs between the cultivations supplemented with the different aromatic compounds and Kraft lignin. Especially, there is a strong correlation in the relative expression of LME genes in the presence of Kraft lignin and coniferyl alcohol/ferulic acid. Kraft lignin, coniferyl alcohol, and ferulic acid totally induced the expression of lcc1 and lcc4. To find out if the lcc1 and lcc4 promoters have (a) cis-element(s) responsible for Kraft lignin/coniferyl alcohol/ferulic acid induction, 3139-bp (lcc1) and 2000-bp (lcc4) promoters were fused with the luminous shrimp luciferase gene and knocked in at the G. subvermispora pyrG locus, respectively. The luciferase activities of the transformants were totally higher when supplemented with Kraft lignin/coniferyl alcohol/ferulic acid compared to the control. Coniferyl alcohol is a precursor of guaiacyl (G) in lignin structure, and ferulic acid is its derivative; they were reported to possibly originate from lignin degradation directly/indirectly. These results suggest a specific transcriptional regulatory response to lignin and its degradants in G. subvermispora. Furthermore, lcc1 and lcc4 promoters, Kraft lignin/aromatic compound-induced promoters, might be useful as components for genetic engineering in this fungus.