Blue Light Receptor WC-2 Regulates Ganoderic Acid Biosynthesis in Ganoderma lingzhi

Ganoderic acid (GA) is a key bioactive component with pharmacological properties that is found in <i>Ganoderma lingzhi</i>, a renowned medicinal mushroom. Currently, the regulatory mechanisms underlying GA biosynthesis in <i>G. lingzhi</i> remain to be further elucidated. In this study, blue light induction was found to significantly enhance the GA content in <i>G. lingzhi</i>. To explore the regulatory mechanism of GA biosynthesis in response to blue light, the blue light receptor WC-2 was identified, and its regulatory role was characterized. The deletion of <i>wc-2</i> resulted in a significant reduction in both GA content and the accumulation of intermediates compared to the wild-type control strain, largely due to the strong downregulation of key GA biosynthetic genes. Additionally, decreased asexual spore production and reduced expression of sporulation-specific genes were observed with the deletion of <i>wc-2</i>. The overexpression of <i>wc-2</i> led to greatly enhanced GA accumulation. Under blue light induction, the maximum contents of GA-Mk, GA-T, GA-S, and GA-Me were 2.27-, 2.51-, 2.49-, and 2.08-fold higher, respectively, compared to the control kept in darkness. These results demonstrate that the blue light receptor WC-2 functions as a positive regulator of GA biosynthesis in <i>G. lingzhi</i>, influencing the expression of genes involved in GA biosynthesis and asexual spore production, thereby advancing our understanding of the intricate regulatory network of GA biosynthesis.