From White to Reddish-Brown:\nThe Anthocyanin Journey\nin <i>Stropharia rugosoannulata</i> Driven by Auxin and\nGenetic Regulators

Stropharia rugosoannulata, or wine-cap\nStropharia, is a well-known edible mushroom cultivated globally. The\npileipellis color is a crucial quality attribute of S. rugosoannulata, exhibiting significant variation\nthroughout its developmental stages. However, the pigment types and\nregulatory mechanisms behind color variation remain unclear. The metabolome\nanalysis found that the anthocyanin biosynthesis pathway was significantly\nenriched and anthocyanins accumulated steadily in fruiting bodies\nduring three developmental stages. The pileipellis pigment was extracted,\nand HPLC-MS confirmed the presence of anthocyanins. Notably, significant\ndifferences in anthocyanin content were observed among the various\ncolored varieties. Thus, anthocyanins contribute to the pileipellis\ncolor of S. rugosoannulata. Through\nfurther investigation, this study elucidated, for the first time,\nthe relationship between the “SrNFYA-<i>SrDRF2</i>” regulatory module and anthocyanin accumulation. Combined\nmultiomics assays and HPLC analysis revealed that auxin functions\nas a signaling molecule that regulates the accumulation of anthocyanins\nin the pileipellis. Subsequently, the hub gene of anthranilate synthase\nfor auxin synthesis was identified as <i>SrTRP1,</i> and\nthe transcription factor SrMYB1 was verified as a regulator of <i>SrTRP1</i>, influencing auxin accumulation. These findings provide\na valuable resource for the targeted enhancement of the quality of S. rugosoannulata.