Detection and characterisation of pr1 virulent gene deficiencies in the insect pathogenic fungus Metarhizium anisopliae
Detection and characterisation of pr1 virulent gene deficiencies in the insect pathogenic fungus Metarhizium anisopliae
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DOI：
10.1111/j.1574-6968.2002.tb11314.x
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发表时间：
2002-08-06
影响因子：
2.1
通讯作者：
Butt, TM
中科院分区：
文献类型：
--
作者：
Wang, CS;Typas, MA;Butt, TM
在最初尝试从金龟子绿僵菌野生型菌株V275中分离单孢子分离株时，检测到三种遗传上相同的自发pr 1A和pr 1B缺陷突变体。这些突变体通过Nested-PCR扩增鉴定，并通过Southern杂交验证。28 S rDNA结构域9-11的高度保守序列的测序和比较证实，突变体分离物是金龟子绿僵菌，但每个都与野生型亲本的形态和遗传差异。RAPD分析表明，野生型菌株与突变株之间的遗传相似性小于70%。酶活性测定表明，突变株的Pr 1和弹性蛋白酶活性显著降低。生物测定显示突变体对黄粉虫的致死活性降低（20%），但对大蜡螟幼虫的致死活性与野生型亲本相似。这篇论文首次表明，缺失最重要的pr 1基因的稳定突变株仍然能够感染其各自的宿主。我们的观察结果表明，金龟子绿僵菌在人工培养基上维持过程中，其毒力基因的丢失并不罕见。(C)2002年，欧洲微生物学会联合会。由Elsevier Science B. V.出版，版权所有。
In an initial attempt to characterise single-spore isolates from Metarhizium anisopliae wild-type strain V275, three genetically identical spontaneous pr1A- and pr1B-deficient mutants were detected. These mutants were identified by Nested-PCR amplification and verified by Southern hybridisation. Sequencing and comparison of the highly conserved sequences of 28S rDNA domains 9-11 confirmed that the mutant isolates were Metarhizium anisopliae, but each had both morphological and genetic differences from the wild-type parent. RAPD analyses indicated that the overall genetic similarity between wild-type strain and the mutant was less than 70%. Enzyme assays proved that the mutant isolates had significantly lower Pr1 and elastase activities. Bioassays showed reduced lethal activity of the mutants (20%) on Tenebrio molitor, but lethal activities were similar to those of the wild-type parent on the larvae of Galleria mellonella. This paper shows for the first time that a stable mutant strain lacking the most important pr1 genes is still able to infect its respective hosts. Our observations suggest that it is not uncommon for Metarhizium anisopliae to lose its virulence genes during maintenance on artificial medium. (C) 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.