Abstract
Ganoderic acid (GA) is a key bioactive component with pharmacological properties that is found in Ganoderma lingzhi, a renowned medicinal mushroom. Currently, the regulatory mechanisms underlying GA biosynthesis in G. lingzhi remain to be further elucidated. In this study, blue light induction was found to significantly enhance the GA content in G. lingzhi. 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 wc-2 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 wc-2. The overexpression of wc-2 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 G. lingzhi, 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.