The blue-light receptor CmWC-1 mediates fruit body development and secondary metabolism in Cordyceps militaris

Abstract

Light is an essential factor for pigment formation and fruit body development in Cordyceps militaris, a well-known edible and medicinal fungus. Cmwc-1, a homolog of the blue-light receptor gene white collar-1 (wc-1) in Neurospora crassa, was cloned from the C. militaris genome in our previous study. Here, Cmwc-1 gene inactivation results in thicker aerial hyphae, disordered fruit body development, a significant reduction in conidial formation, and carotenoid and cordycepin production. These characteristics were restored when the ΔCmwc-1 strains were hybridized with wild-type strains of the opposite mating type. A genome-wide expression analysis revealed that there were 1042 light-responsive genes in the wild-type strain and only 458 in the ΔCmwc-1 strain. Among five putative photoreceptors identified, Vivid, cryptochrome-1, and cyclobutane pyrimidine dimer photolyase are strongly induced by light in a Cmwc-1-dependent manner, while phytochrome and cryptochrome-2 were not induced. The transcription factors involved in the fungal light reaction were mainly of the Zn2Cys6 type. CmWC-1 regulates adenylosuccinate synthase, an important enzyme for adenosine de novo synthesis, which could explain the reduction in cordycepin production. Some G protein-coupled receptors that control fungal fruit body formation and the sexual cycle were regulated by CmWC-1, and the cAMP pathway involved in light signal transduction in N. crassa was not critical for the photoreaction in the fungus here. A transcriptional analysis indicated that steroid biosynthesis was more active in the ΔCmwc-1 strain, suggesting that CmWC-1 might switch the vegetative growth state to primordia differentiation by suppressing the expression of related genes.

Cmfhp Gene Mediates Fruiting Body Development and Carotenoid Production in Cordyceps militaris

“…Light is a necessary condition for the production of C. militaris fruiting bodies and pigments [18]. The Cmfhp gene of C. militaris was significantly upregulated after being treated with light.…”

“…Although three types of geranylgeranyl diphosphate synthase genes in C. militaris were cloned, their functions have yet to be identified [36]. It is noteworthy that the other two key enzymes (phytoene synthetase and phytoene dehydrogenase) were not found in the genome of C. militaris [13,18]. The induction of carotenoids was completely different between C. militaris and Neurospora crassa [13,18].…”

“…It is noteworthy that the other two key enzymes (phytoene synthetase and phytoene dehydrogenase) were not found in the genome of C. militaris [13,18]. The induction of carotenoids was completely different between C. militaris and Neurospora crassa [13,18]. Therefore, it is a great challenge to characterize the carotenoid biosynthetic pathway in C. militaris.…”

“…Mycelia were scraped from the PDA plates and resuspended in 10 mL of a Tween 80 solution (20%, w/v). After filtration, the conidial suspensions were counted using a hemocytometer under a microscope [18,30].…”

A WD40 Protein Encoding Gene Fvcpc2 Positively Regulates Mushroom Development and Yield in Flammulina velutipes

“…Although fruiting structures are distinct between Ascomycota and Basidiomycota, they are two closely related phyla separated only for about 500 million years ago (Berbee and Taylor, 2010;Oberwinkler, 2012). Two phyla share some common regulatory mechanisms in fruiting body development, including the blue light receptor WC-1 (Linden et al, 1997;Terashima et al, 2005;Ohm et al, 2013;Yang et al, 2016), the pheromone signaling (Debuchy et al, 2010;Raudaskoski and Kothe, 2010) and the heterotrimeric G-protein complex (Lengeler et al, 2000;Brown and Casselton, 2001;Li et al, 2007). Our study revealed that CPC-2 proteins also mediate fruiting body development in both phyla.…”