Systematic Analysis of the Pleurotus ostreatus Laccase Gene (PoLac) Family and Functional Characterization of PoLac2 Involved in the Degradation of Cotton-Straw Lignin.

Fungal laccases play important roles in the degradation of lignocellulose. Although some s have been reported in several studies, still no comprehensive bioinformatics study of the family in has been reported. In this study, we identified 12 laccase genes in the whole genome sequence of and their physical characteristics, gene distribution, phylogenic relationships, gene structure, conserved motifs, and cis-elements were also analyzed. The expression patterns of 12 genes at different developmental stages and under different culture substrates were also analyzed. The results revealed that and may be involved in the degradation of lignin and the formation of the fruiting body, respectively. Subsequently, we overexpressed in by the -mediated transformation (ATMT) method. The transformants' laccase activity increased in varying degrees, and the gene expression level of in transformants was 2-8 times higher than that of the wild-type strain. Furthermore, the lignin degradation rate by transgenic fungus over 30 days was 2.36-6.3% higher than that of wild-type. Our data show that overexpression of significantly enhanced the lignin degradation of cotton-straw. To our knowledge, this study is the first report to demonstrate the functions of in .