Genes involved in sclerotium formation of Phlebopus portentosus

Abstract:

[Background] Phlebopus portentosus is the first edible species of Boletales that can be cultivated artificially, and the number of sclerotia varies during the artificial cultivation of different strains. [Objective] To explore the different mechanisms of sclerotium production of different strains. [Methods] The mature sclerotia of the strain with multiple sclerotia (JH1) and the strain with oligo-sclerotia (JH2) and the mycelia of the strain with no sclerotium (JH3) cultivated for the same time period were collected. Transcriptome sequencing was performed to identify the differentially expressed genes (DEGs) in sclerotium formation, and the roles of these DEGs were analyzed. [Results] The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment showed that the DEGs between JH2 and JH1 were mainly enriched in the phenylalanine, tyrosine, and tryptophan biosynthesis, arginine, proline metabolism, cysteine and methionine metabolism. The DEGs between JH3 and JH1 were mainly involved in glyoxalate and dicarboxylate metabolism, and those between JH3 and JH2 in glutathione metabolism and glyoxylate and dicarboxylate metabolism. Among the sclerotium formation-associated DEGs between JH2 and JH1, between JH3 and JH1, and between JH3 and JH2, respectively, 69, 118, and 82 genes were associated with signal transduction, sensory stimulation, defense, and carbohydrate active enzymes, and those associated with carbohydrate active enzymes had the highest abundance. The expression of carbohydrate active enzyme genes shared by the three comparison groups in JH1 was higher than that in JH2 and JH3, indicating that JH1 could make full use of the substrate to form more sclerotia. [Conclusion] The differences in sclerotium production among different strains of P. portentosus were preliminarily analyzed at the transcriptome level, which provided a theoretical basis for the subsequent research on the correlations of sclerotia with fruiting and yield.