title: Changes in the mycovirus (LeV) titer and viral effect on the vegetative growth of the edible mushroom Lentinula edodes.
abstract: 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.
authors.affiliation: Department of Bio-Environmental Chemistry, Wonkwang University, Iksan, Chonbuk 570-749, South Korea.
authors.forename: Jung-Mi
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Bio-Environmental Chemistry, Wonkwang University, Iksan, Chonbuk 570-749, South Korea.
authors.forename: Ha-Yeon
authors.initials: HY
authors.lastname: Song
authors.affiliation: Department of Bio-Environmental Chemistry, Wonkwang University, Iksan, Chonbuk 570-749, South Korea.
authors.forename: Hyo-Jin
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, Chonbuk 561-756, South Korea.
authors.forename: Suk-Hyun
authors.initials: SH
authors.lastname: Yun
authors.affiliation: Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, Chonbuk 561-756, South Korea.
authors.forename: Kum-Kang
authors.initials: KK
authors.lastname: So
authors.affiliation: Forest Mushroom Research Center, Yeoju, Gyeonggi 469-803, South Korea.
authors.forename: Han-Kyu
authors.initials: HK
authors.lastname: Ko
authors.affiliation: Institute for Molecular Biology and Genetics, Center for Fungal Pathogenesis, Chonbuk National University, Jeonju, Chonbuk 561-756, South Korea. Electronic address: dhkim@jbnu.ac.kr.
authors.forename: Dae-Hyuk
authors.initials: DH
authors.lastname: Kim
mesh_terms: D025282:Mycelium / Q000254:growth & development; D012328:RNA Viruses / Q000302:isolation & purification*; D020942:Shiitake Mushrooms / Q000254:growth & development* / Q000821:virology*; D019562:Viral Load
keywords: Isogenic strain; Lentinula edodes; Mycovirus; dsRNA