A rho-type GTPase activating protein affects the growth and development of Cordyceps cicadae.

Abstract

Cordyceps cicadae is recognized for its medicinal properties, attributed to bioactive constituents like polysaccharides and adenosine, which have been shown to improve kidney and liver functions and possess anti-tumor properties. Rho GTPase activating proteins (Rho GAPs) serve as inhibitory regulators of Rho GTPases in eukaryotic cells by accelerating the GTP hydrolysis of Rho GTPases, leading to their inactivation. In this study, we explored the function of the CcRga8 gene in C. cicadae, which encodes a Rho-type GTPase activating protein. Our study found that the knockout of CcRga8 resulted in a decrease in polysaccharide levels and an increase in adenosine concentration. Furthermore, the mutants exhibited altered spore yield and morphology, fruiting body development, decreased infectivity, reduced resistance to hyperosmotic stress, oxidative conditions, and cell wall inhibitors. These findings suggest that CcRga8 plays a crucial role in the development, stress response, and bioactive compound production of C. cicadae.