Molecular Profiling of Rice Straw Degradability Discrepancy in <i>Stropharia rugosoannulata</i> Core Germplasm

The rice-<i>S. rugosoannulata</i> pattern is a rapidly growing agricultural practice for straw disposal and mushroom production in China. However, different <i>S. rugosoannulata</i> strains show a large variation in rice straw degradability. Here, we constructed a core collection of <i>S. rugosoannulata</i> containing 14 strains with rich genetic diversity. The molecular profiling of the lignocellulose degradability discrepancy of <i>S. rugosoannulata</i> strains was then explored using enzyme activity assays and transcriptome analysis. The results indicated that mycelial growth rate, lignocellulolytic enzyme activities, and rice straw degradability differed widely among the <i>S. rugosoannulata</i> core strains. The genes encoding lignin modifying and degrading auxiliary enzymes, oxidases, glycoside hydrolases, and detoxification proteins were differentially expressed between two representative <i>S. rugosoannulata</i> strains, resulting in differences in their lignocellulolytic enzyme activities and further causing differences in lignocellulose degradability. This study is useful to improve the production efficiency of <i>S. rugosoannulata</i> and promote the recycling of rice straw.