Characterization of mutations in the two-component histidine kinase gene AbNIK1 from Alternaria brassicicola that confer high dicarboximide and phenylpyrrole resistance
Characterization of mutations in the two-component histidine kinase gene AbNIK1 from Alternaria brassicicola that confer high dicarboximide and phenylpyrrole resistance
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DOI：
10.1007/s00294-005-0568-2
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发表时间：
2005-04-01
期刊：
影响因子：
2.5
通讯作者：
Bataillé-Simoneau, N
中科院分区：
文献类型：
--
作者：
Avenot, H;Simoneau, P;Bataillé-Simoneau, N
对异菌脲和咯菌腈具有高度抗性的田间和实验室分离株。芸苔属植物对渗透胁迫的敏感性和耐受性均为中等。AbNIK 1是一个双组分组氨酸激酶基因，从杀菌剂敏感菌株中分离得到。预测的蛋白质在N-末端具有6个串联氨基酸重复序列，这是丝状真菌中组氨酸传感器组氨酸激酶的标志。对杀真菌剂敏感和抗真菌剂分离株的AbNIK 1基因的核酸序列进行比较，发现分析的7种耐药菌株中有6种存在突变。这些突变体对渗透胁迫的敏感性都是中等的，表明它们与粗糙脉孢菌I型os-1突变体相似。只有一个突变，对应于一个单一的氨基酸的变化内的H盒的激酶结构域，被发现在耐药菌株。这些结果表明，AbNIK 1 p参与的调节和表达的全功能酶是必不可少的二甲酰亚胺和苯基吡咯抗真菌活性。
Highly iprodione- and fludioxonil-resistant field and laboratory isolates of A. brassicicola were found to be either moderately sensitive or tolerant to osmotic stress. AbNIK1, a two-component histidine kinase gene, was isolated from a fungicide-sensitive strain. The predicted protein possessed the six tandem amino acid repeats at the N-terminal end, which is a landmark of osmosensor histidine kinases from filamentous fungi. A comparison of the nucleic acid sequences of the AbNIK1 gene from fungicide-sensitive and fungicide-resistant isolates revealed the presence of mutations in six of the seven resistant strains analyzed. Null mutants were all found to be moderately sensitive to osmotic stress, indicating that they are similar to Neurospora crassa Type I os-1 mutants. Only one mutation, corresponding to a single amino acid change within the H-box of the kinase domain, was found in an osmotolerant strain. These results suggest that AbNIK1p participates in osmoregulation and that expression of the fully functional enzyme is essential for dicarboximide and phenylpyrrole antifungal activities.