Mushrooms Do Produce Flavonoids: Metabolite Profiling and Transcriptome Analysis of Flavonoid Synthesis in the Medicinal Mushroom Sanghuangporus baumii

Abstract

Mushrooms produce a large number of medicinal bioactive metabolites with antioxidant, anticancer, antiaging, and other biological activities. However, whether they produce flavonoids and, if so, how they synthesize them remains a matter of some debate. In the present study, we combined flavonoid-targeted metabolomics and transcriptome analysis to explore the flavonoid synthesis in the medicinal mushroom Sanghuangporus baumii. The S. baumii synthesized 81 flavonoids on a chemically defined medium. The multiple classes of flavonoids present were consistent with the biosynthetic routes in plants. However, paradoxically, most of the genes that encode enzymes involved in the flavonoid biosynthetic pathway are missing from S. baumii. Only four genes related to flavonoid synthesis were found in S. baumii, among which phenylalanine ammonia lyase gene (PAL) is a key gene regulating flavonoid synthesis, and overexpression of SbPAL increases the accumulation of flavonoids. These results suggest that the flavonoid synthesis pathway in S. baumii is different from that in known plants, and the missing genes may be replaced by genes from the same superfamilies but are only distantly related. Thus, this study provides a novel method to produce flavonoids by metabolic engineering using mushrooms.

The novel distribution of intracellular and extracellular flavonoids produced by Aspergillus sp. Gbtc 2, an endophytic fungus from Ginkgo biloba root

“…HPLC/LC–MS detection and metabolite database analysis showed that flavonoids in Gbtc 2 metabolites were diverse and abundant ( Bampali et al, 2021 ). As a prerequisite for the synthesis of flavonoids, the addition of phenylalanine in the medium can promote the production of flavonoids by Gbtc 2 ( Liu et al, 2022 ; Wang S. et al, 2022 ). A total of 71 flavonoids were identified, and the properties and structures of each flavonoid had certain uniqueness.…”

Genome‐wide analysis, metabolomics, and transcriptomics reveal the molecular basis of ZlRc overexpression in promoting phenolic compound accumulation in rice seeds

“…In this study, the expression level of PAL in OE rice was remarkably higher than that in WT rice (Figure 9), and the upregulation of PAL expression promoted the accumulation of phenolic compounds in OE rice seeds. Similarly, the overexpression of SbPAL in the medicinal mushroom Sanghuangporus baumii resulted in the increased accumulation of flavonoids (Wang et al., 2022). CHS catalyzes chalcone formation from 4‐coumaryl‐CoA and three molecules of malonyl‐CoA.…”

The Roles of Hormone Signals Involved in Rhizosphere Pressure Response Induce Corm Expansion in Sagittaria trifolia

“…The PAL genes, c85018.graph_c0 and c84792.graph_c2, in the upstream of SA biosynthesis were upregulated in hydroponics, which was contrary to the results of SA accumulation. A possible reason is that the synthesis of SA underwent multiple catalytic steps, and the intermediate products (such as trans-cinnamic acid and shikimic acid) produced during this process were also involved in the synthesis of other secondary metabolites; thus, the expression of upstream genes did not show a direct impact on the accumulation of SA [49,50]. Another interpretation could be that the hormones' biosynthesis also depended on the post-transcriptional control of genes and the regulation of protein levels [51].…”