Phlebopus (Boletales, Boletinellaceae), a peculiar bolete genus with widely consumed edible species and potential for economic development in tropical countries

Genomic and Multi-Omics Analysis of Phlebopus portentosus: Effects of Cultivation on Secondary Metabolites

Phlebopus portentosus is an edible and medicinal ectomycorrhizal mushroom with delicious and high nutritional value. However, the mechanism of secondary metabolite biosynthesis in P. portentosus is still unclear. In this study, the genomics, metabolomics, and transcriptomics were integrated to reveal the biosynthesis mechanism of secondary metabolites in P. portentosus under different cultivation conditions. The 31.4 Mb genome of P. portentosus YAF023 with 15 scaffolds was assembled by Illumina and Nanopore sequencing and annotated, and 206 cytochrome P450s, 201 carbohydrate-active enzymes, 186 transcription factors, 18 terpene synthases (TPSs), and 5 polyketide synthases (PKSs) were identified. Multi-omics analysis showed that PpPKS1 is probably involved in the biosynthesis of Ethyl orsellinate; PpPKS2 and PpPKS5 are probably involved in the synthesis of 6-Methylsalicylic acid and Cytochalasin Z5, respectively; PpTRI5 was involved in the tetracyclic sesquiterpene β-type trichodiene compounds; and PpSTCs was involved in the synthesis of β-copaene analogs or derivatives. Co-expression network analysis and binding site prediction of the promoter regions suggested that PpHOX4 and PpHSF1 regulated the gene expression of PpPKS1, and Ppzf-C2H2 32 and PpHSF5 regulated the gene expression of PpSTCs 8, and PpSTCs 3, respectively. This study will provide an important foundation for further development and utilization of secondary metabolites of P. portentosus.

Pulvinic Acid Derivative Pigments in Lanmaoa asiatica and L. macrocarpa

Lanmaoa asiatica G. Wu & Zhu L. Yang and L. macrocarpa N. K. Zeng, H. Chai & S. Jiang are two important gourmet bolete in China, and locally named "Jian Shou Qing" meaning their fruiting bodies turn blue after bruising. The genus represents a distinct lineage in Boletaceae. The pigment(s) associated with the discoloration in Lanmaoa has not been identified. The aim of this study was to determine the pigment(s) underpinning the bluing reaction of L. asiatica and L. macrocarpa when bruised. Potential compounds were isolated by HPLC and identified by LC-HRMS and NMR. In total five to six pigments of hydroxylated pulvinic acid derivatives were detected with similar distribution patterns in both L. asiatica and L. macrocarpa, which by abundance were variegatic acid, variegatorubin, xerocomic acid (and/or isoxerocomic acid), xerocomorubin, and atromentic acid. Variegatic acid, the most abundant pigment, was isolated by HPLC, and the structure was further characterized by NMR. The amount of variegatic acid increased after regular cooking, which may suggest its enhanced health benefit as human diet. The types of pigments that cause bluing reactions often differ among families of Boletales. Our results showed that the pigments in Lanmaoa belong to the category of hydroxylated pulvinic acid derivatives, the major bluing compounds in Boletaceae.

Biochemical, nutritional, and toxicological properties of the edible species Phlebopus beniensis with ethnomycological notes from Paraguay

Abstract In recent decades, mushrooms have been recognized as an important resource and efforts to characterize their potential to aid nutrition and human health have increased. Phlebopus beniensis specimen from a semi-urban community in Paraguay were analyzed for its biochemical properties, nutritional value, and toxicity. The species was identified by morpho-anatomical and molecular tools. Analyses for antioxidants by Ultraviolet-visible (UV-VIS) and nutritional content revealed that P. beniensis is a favorable source of antioxidants, proteins, carbohydrates, dietary fiber, and fats. Spectrometry through Gas Chromatography-Mass Spectrometry (GC-MS) further showcased other mycochemicals such as the specific phenolic, antioxidant, and fatty acid compounds that serve important biological roles in human diets. Applying an ethnomycological framework across local Paraguayan populations, we also report accounts of histories, knowledge, and usage of P. beniensis in South America among settlers and Paraguayan people.