Department of Bio-Environmental Chemistry, Wonkwang University, Iksan, Chonbuk 570-749, South Korea.
Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, Chonbuk 561-756, South Korea.
Virus Res. 2015 Feb 2;197:8-12. doi: 10.1016/j.virusres.2014.11.016. Epub 2014 Nov 20.
This study attempted to cure the edible mushroom Lentinula edodes strain FMRI0339 of the L. edodes mycovirus (LeV) in order to obtain an isogenic virus-free fungal strain as well as a virus-infected strain for comparison. Mycelial fragmentation, followed by being spread on a plate with serial dilutions resulted in a virus-free colony. Viral absence was confirmed with gel electrophoresis after dsRNA-specific virus purification, Northern blot analysis, and PCR using reverse transcriptase (RT-PCR). Once cured, all of fungal cultures remained virus-free over the next two years. Interestingly, the viral titer of LeV varied depending on the culture condition. The titer from the plate culture showed at least a 20-fold higher concentration than that grown in the liquid culture. However, the reduced virus titer in the liquid culture was recovered by transferring the mycelia to a plate containing the same medium. In addition, oxygen-depleted culture conditions resulted in a significant decrease of viral concentration, but not to the extent seen in the submerged liquid culture. Although no discernable phenotypic changes in colony morphology were observed, virus-cured strains showed significantly higher growth rates and mycelial mass than virus-infected strains. These results indicate that LeV infection has a deleterious effect on mycelial growth.
本研究试图治愈食用蘑菇香菇菌株 FMRI0339 的香菇病毒（LeV），以获得同基因无病毒真菌菌株和病毒感染菌株进行比较。通过菌丝体碎片化，然后在平板上进行系列稀释，产生了无病毒的菌落。通过 dsRNA 特异性病毒纯化、Northern blot 分析和使用逆转录酶（RT-PCR）的 PCR 证实了病毒的缺失。一旦治愈，所有真菌培养物在接下来的两年中都保持无病毒状态。有趣的是，LeV 的病毒滴度取决于培养条件。平板培养的滴度至少比液体培养的高 20 倍。然而，通过将菌丝体转移到含有相同培养基的平板上，可以恢复液体培养中较低的病毒滴度。此外，缺氧培养条件导致病毒浓度显著降低，但不如在浸没液体培养中观察到的那样显著。尽管在菌落形态上没有观察到明显的表型变化，但病毒治愈菌株的生长速度和菌丝体质量明显高于病毒感染菌株。这些结果表明，LeV 感染对菌丝体生长有有害影响。
