Choi G H, Nuss D L
Department of Molecular Oncology and Virology, Roche Institute of Molecular Biology, Nutley, NJ 07110.
Science. 1992 Aug 7;257(5071):800-3. doi: 10.1126/science.1496400.
Strains of the chestnut blight fungus Cryphonectria parasitica that contain viral double-stranded RNAs often exhibit reduced virulence. Such hypovirulent strains act as biocontrol agents by virtue of their ability to convert virulent strains to hypovirulence after anastomosis. Transformation of virulent C. parasitica strains with a full-length complementary DNA copy of a hypovirulence-associated viral RNA conferred the complete hypovirulence phenotype. Cytoplasmic double-stranded RNA was resurrected from the chromosomally integrated complementary DNA copy and was able to convert compatible virulent strains to hypovirulence. These results establish viral double-stranded RNA as the casual agent of hypovirulence and demonstrate the feasibility of engineering hypovirulent fungal strains.
含有病毒双链RNA的栗疫病菌（Cryphonectria parasitica）菌株通常表现出毒力降低。这类低毒力菌株通过在菌丝融合后将强毒力菌株转化为低毒力菌株的能力，作为生物防治剂发挥作用。用与低毒力相关的病毒RNA的全长互补DNA拷贝转化强毒力的寄生隐孢壳菌株，赋予了完全的低毒力表型。细胞质双链RNA从染色体整合的互补DNA拷贝中复活，并能够将相容的强毒力菌株转化为低毒力菌株。这些结果确立了病毒双链RNA作为低毒力的致病因子，并证明了构建低毒力真菌菌株的可行性。
