A HYPOVIRULENT ISOLATE OF CRYPHONECTRIA-PARASITICA WITH MULTIPLE, GENETICALLY UNIQUE DSRNA SEGMENTS
A HYPOVIRULENT ISOLATE OF CRYPHONECTRIA-PARASITICA WITH MULTIPLE, GENETICALLY UNIQUE DSRNA SEGMENTS
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DOI：
10.1094/mpmi-7-0590
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发表时间：
1994-09-01
影响因子：
3.5
通讯作者：
MACDONALD, WL
中科院分区：
文献类型：
--
作者：
ENEBAK, SA;HILLMAN, BI;MACDONALD, WL
在阿巴拉契亚山脉中部进行的调查中，已经鉴定出栗疫病菌（栗疫病菌）寄生的许多不同的含有dsRNA的分离株。分离物C-18，1989年从西弗吉尼亚州南部的一种有毒溃疡病中收集，发现含有11个大小为1至5 kb的dsRNA片段。毒力实验，使用金冠苹果，切除休眠的美国板栗茎，和美国板栗芽，确定了与隔离C-18的dsRNA显着降低毒力和改变文化形态时，比较含同基因dsRNA和dsRNA的无性后代。这11个dsRNA片段被传递到其他的C.寄生菌通过菌丝融合并以全或无的方式进入分生孢子。来自代表C-18 dsRNA的文库的互补DNA克隆不与与弱毒力分离株D2（宾夕法尼亚）、Ep-713（欧洲）、NB 58 -88（新泽西）相关的其他dsRNA、来自西弗吉尼亚的另一种多节段dsRNA（9 B-2-1）或伤口肿瘤病毒杂交。通过北方印迹分析，没有测试的cDNA克隆与多于一个dsRNA片段杂交。11个dsRNA片段中的8个被证明是遗传独特的。使用磷酸盐缓冲液提取方案，从分离物C-18的菌丝体组织中纯化直径约60 nm的二十面体颗粒。因此，与分离株C-18的低毒力相关的dsRNA病毒与迄今为止表征的其他低毒力相关病毒根本不同。
Many different dsRNA-containing isolates of Cryphonectria (Endothia) parasitica, the chestnut blight fungus, have been identified in surveys conducted in the central Appalachians. Isolate C-18, collected in 1989 from a virulent canker in southern West Virginia, was found to contain 11 segments of dsRNA ranging from 1 to 5 kb in size. Virulence experiments, using Golden Delicious apples, excised dormant American chestnut stems, and American chestnut sprouts, determined that the dsRNA associated with isolate C-18 significantly reduced virulence and altered cultural morphology when isogenic dsRNA-containing and dsRNA-free asexual progeny were compared. The 11 dsRNA segments were transmitted into other isolates of C. parasitica via hyphal anastomosis and into conidia in an all-or-none fashion. Complementary DNA clones from a library representing C-18 dsRNA did not hybridize to other dsRNAs associated with hypovirulent isolates D2 (Pennsylvania), Ep-713 (Europe), NB58-88 (New Jersey), to another multisegmented dsRNA from West Virginia (9B-2-1), or to wound tumor virus. None of the cDNA clones tested hybridized to more than one dsRNA segment by Northern blot analysis. Eight of the 11 dsRNA segments were demonstrated to be genetically unique. Using a phosphate buffer extraction protocol, icosahedral particles approximately 60 nm in diameter were purified from the mycelial tissue of isolate C-18. The dsRNA virus associated with hypovirulence of isolate C-18 is therefore fundamentally different from other hypovirulence-associated viruses characterized to date.