Phytopathology. 2004 Oct;94(10):1129-35. doi: 10.1094/PHYTO.2004.94.10.1129.
ABSTRACT DNA sequence polymorphisms in the putative two-component histidine protein kinase encoded by the Daf1 gene have been identified within a sample of 5 sensitive and 27 dicarboximide-resistant field strains of Botryotinia fuckeliana (anamorph Botrytis cinerea). The gene of 3948 bp is predicted to encode a 1315-amino acid protein comprising an N-terminal region, an amino acid repeat region, which has been hypothesized to be the binding site for dicarboximide fungicide, and a C-terminal region encompassing kinase and response regulator domains. Two amino acid variants were distinguished among the sensitive strains characterized by alanine (group 1), or threonine (group 2), at position 1259 in the C-terminal region. All resistant strains could be classified into either group 1 or group 2 but, in addition, all showed changes in the second amino acid repeat region. On the basis of the differences in this repeat region, four classes of resistant strains were recognized; class 1 characterized by an isoleucine to serine mutation, class 2 by an isoleucine to asparagine mutation, class 3 by an isoleucine to arginine mutation (all at position 365), and class 4 by an isoleucine to serine mutation (position 365) as well as a glutamine to proline mutation (position 369). All classes showed similar low levels of resistance to iprodione and to vinclozolin, except for class 3 and class 4 strains, which show low resistance to iprodione but moderate (class 3) or high (class 4) resistance to vinclozolin. The classes as a group did not differ from sensitive strains in osmotic sensitivity measured as mycelial growth response, but some class 1 strains showed an abnormal morphology on osmotically amended medium. The evolution of the amino acid differences is discussed in relation to field observations. It is proposed that class 1 and class 2 strains arose by single mutations within the sensitive population, whereas classes 3 and 4 arose by single mutations within a resistant population.
摘要 在 5 株敏感和 27 株二羧酰亚胺抗性的 Botryotinia fuckeliana（无性型 Botrytis cinerea）田间分离菌中，鉴定了 DAF1 基因编码的假定双组分组氨酸蛋白激酶的 DNA 序列多态性。该基因长 3948bp，预测编码 1315 个氨基酸的蛋白质，包括 N 端区域、假定与二羧酰亚胺杀菌剂结合的氨基酸重复区和包含激酶和反应调节区的 C 端区域。在敏感菌中，第 1259 位氨基酸存在丙氨酸（第 1 组）或苏氨酸（第 2 组）两种氨基酸变异。所有抗性菌可分为第 1 组或第 2 组，但此外，第 2 个氨基酸重复区也发生了变化。基于此重复区的差异，鉴定出 4 种抗性菌，第 1 类是异亮氨酸至丝氨酸突变，第 2 类是异亮氨酸至天冬酰胺突变，第 3 类是异亮氨酸至精氨酸突变（均在第 365 位），第 4 类是异亮氨酸至丝氨酸突变（第 365 位）和谷氨酰胺至脯氨酸突变（第 369 位）。除第 3 类和第 4 类菌株对 iprodione 表现出低水平抗性，而对 vinclozolin 表现出中度（第 3 类）或高度（第 4 类）抗性外，所有类均表现出对 iprodione 和 vinclozolin 的低水平抗性。与敏感菌相比，各组在渗透压敏感性方面（通过菌丝生长反应测量）没有差异，但一些第 1 类菌株在渗透压改良培养基上表现出异常形态。讨论了氨基酸差异的进化与田间观察的关系。提出第 1 类和第 2 类菌株是由敏感群体中的单个突变产生的，而第 3 类和第 4 类菌株是由抗性群体中的单个突变产生的。
