Vertical Transmission of RNA Mycoviruses in Lentinula edodes

Eunjin Kim¹ Mi-Jeong Park¹ Min-Jun Kim¹ Yeun Sug Jeong¹ Yeongseon Jang^1,* Kang-Hyeon Ka¹

¹Forest Microbiology Division, Department of Forest Bio-Resources, National Institute of Forest Science, Suwon 16631, Korea

Abstract

Lentinula edodes is an important commercial mushroom and there have been several reports of viral infections in L. edodes. Two mycoviruses (LeV-HKB and LeNSRV1) were detected in Sanbaekhyang (NIFoS 2778) and Taehyanggo (NIFoS 4317), the sawdust-cultivated commercial strains. The vertical transmission rates of the viruses were investigated by detecting the viruses in 80 monokaryotic strains derived from basidiospores isolated from the fruiting bodies of each strain. Most of the monokaryotic strains were infected with the virus and the two viruses showed different levels of meiotic stability, with LeV-HKB showing higher meiotic stability than LeNSRV1. Therefore, it seems that the vertical transmission mechanism of mycoviruses is different depending on the virus species. We also examined the mycelial growth rate of the monokaryotic strains and compared the growth rate according to virus infection status. Although there was no statistically significant correlation between viral infection and mycelial growth rate, we found that the average growth rate was reduced by additional virus infection. We expect our data to contribute to a greater understanding of the mechanism of the vertical transmission of mycoviruses, and promoting breeding using virus-free monokaryotic strains.

Figures & Tables

Fig. 1. RT-PCR detection of viral infection from Sanbaekhyang (NIFoS 2778) and Taehyanggo (NIFoS 4317) using specific primer sets targeting each virus-specific RNA-dependent RNA polymerase (RdRp) genes. SM, 100 bp marker; LeSV, spherical virus; LePV1, partitivirus 1; LeNSRV2, negative-strand RNA virus 2; LeV-HKB, mycovirus-HKB; LeNSRV1, negative-strand RNA virus