THE BETA-TUBULIN GENE OF EPICHLOE-TYPHINA FROM PERENNIAL RYEGRASS (LOLIUM-PERENNE)
THE BETA-TUBULIN GENE OF EPICHLOE-TYPHINA FROM PERENNIAL RYEGRASS (LOLIUM-PERENNE)
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DOI：
10.1007/bf00318216
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发表时间：
1990-11-01
期刊：
影响因子：
2.5
通讯作者：
SIEGEL, MR
中科院分区：
文献类型：
--
作者：
BYRD, AD;SCHARDL, CL;SIEGEL, MR
香柱菌（Epichloe typhina）是一种活体营养型真菌病原体，可导致早熟禾亚科草类的香柱病。其无性态——香柱顶孢（Acremonium typhinum）与相关的、共生的、通过种子传播的内生菌一起被归为白毛组（section Albo - lanosa）。作为对香柱菌及相关内生菌基因结构和进化的初步研究，多年生黑麦草香柱病原体（EtPRG）的β - 微管蛋白基因tub2被克隆并测序。其编码序列和预测的β - 微管蛋白氨基酸序列与粗糙脉孢菌（Neurospora crassa）的同源序列以及构巢裸孢壳（Emericella nidulans）的两个β - 微管蛋白基因之一高度同源。然而，粗糙脉孢菌和构巢裸孢壳基因中特有的两个内含子在香柱菌基因中缺失。此外，剩余的一个内含子具有不常见的5′ - 剪接位点GC。与已发表的关于其他子囊菌的观察结果相反，一个因对多菌灵（甲基 - 2 - 苯并咪唑氨基甲酸酯）具有抗性而被筛选出的EtPRG突变体，其β - 微管蛋白编码序列没有改变。
Epichloe typhina is a biotrophic fungal pathogen which causes choke disease of pooid grasses. The anamorphic state, Acremonium typhinum is placed in the section Albo-lanosa along with related, mutualistic, seed-disseminated endophytes. As an initial study of gene structure and evolution in Epichloe and related endophytes, the .beta.-tubulin gene, tub2, of the perennial ryegrass choke pathogen (EtPRG) was cloned and sequenced. The coding sequence and the predicted .beta.-tubulin amino acid sequence were highly homologous tothe NEurospora crassa homologs, and to one of the two .beta.-tubulin genes of Emericella nidulans. However, two introns characteristic of the N. crassa and Em. nidulans genes were absent in the E. typhina gene. Furthermore, one of the remaining introns possessed the uncommon 5''-splice junction, GC. In contrast to published observations concerning other Ascomycetes, a mutant of EtPRG, selected for resistance to methyl-2-benzimidazole carbamate (benomyl), possessed no alteration of its .beta.-tubulin coding sequence.