The level of CmFRQ is associated with the degeneration and rejuvenation of Cordyceps militaris fruiting body

Cordyceps militaris is a large fungus whose fruiting body is prone to degeneration. In the study of C. militaris FREQUENCY (CmFRQ), the negative regulator of C. militaris circadian clock, it was found that after the high concentration of mannitol was applied to the regeneration culture of conidial protoplast of degenerated C. militaris strain F3411D, the rejuvenated strain CmFRQ-454 with the increased content of CmFRQ was obtained, and its growth vitality of fruiting body was recovered. After six successive asexual subcultures of the rejuvenated C. militaris strain CmFRQ-454, the accumulation of CmFRQ in mycelia gradually decreased, and the fruiting bodies of C. militaris also tended to degenerate from generation to generation. After treatment with proteasome inhibitor MG132 or high concentration of sorbitol, the degenerated asexual reproduction strain CmFRQ-454 to the 7th or 11th generation regained its growth vitality, and the accumulation of CmFRQ in mycelium was increased. Our results demonstrate that after hypertonic solution or MG132 treatment, the key circadian regulator CmFRQ was accumulate in mycelium, which brought the rejuvenation to the degenerated C. militaris .