Mechanism Underlying Light Intensity-Induced Melanin Synthesis of Auricularia heimuer Revealed by Transcriptome Analysis

Abstract

Auricularia heimuer is a traditional edible and medicinal mushroom, which is widely used in biochemical research and is regarded as a good dietary supplement. The color of the ear-like fruiting body is an important indicator of its commercial quality. However, the mechanism by which light intensity influences the melanin synthesis of A. heimuer remains unclear. Here, we show that fruiting body color is significantly affected by light intensity. Transcriptional profiles of the fruiting bodies of A. heimuer grown in different light intensities were further analyzed. More differentially expressed genes (DEGs) were identified with a greater light intensity difference. A total of 1388 DEGs were identified from six comparisons, including 503 up-regulated genes and 885 down-regulated genes. The up-regulated genes were mainly associated with light sensing via photoreceptors, signal transduction via the mitogen-activated protein kinase (MAPK) signaling pathway, and melanin synthesis via the tyrosine metabolic pathway. Therefore, the genes involved in these processes may participate in regulating melanin synthesis under high light intensity. This insight into the transcriptional regulation of A. heimuer to light intensity should help to further comprehensively elucidate the underlying mechanism of light-induced melanin synthesis.

Transcriptome Analysis Reveals Candidate Genes for Light Regulation of Elsinochrome Biosynthesis in Elsinoë arachidis

“…Marked disparities in gene expression have been observed across various fungi under the influence of light, underscoring the profound impact of photic stimuli on fungal biology [22]. Detailed transcriptome analysis of Auricularia heimuer under varying light intensities reveals that the augmentation of gene expression under high-intensity conditions primarily pertains to the photoreceptors responsible for light perception, the signal transduction mechanisms of the mitogen-activated protein kinase (MAPK) signaling pathway, and the melanin synthesis pathways within tyrosine metabolism [23]. This upregulation suggests these genes play pivotal roles in augmenting the production of secondary metabolites in A. heimuer under intense light exposure.…”