Park S Y, Jung O J, Chung Y R, Lee C W
Department of Microbiology, College of Natural Sciences, Gyeongsang National University, Chinju, Korea.
Mol Cells. 1997 Feb 28;7(1):104-9.
As an initial step to develop a DNA-mediated transformation system using benomyl resistance as a dominant selectable marker in the phytopathogenic fungus Botryotinia fuckeliana (anamorph, Botrytis cinerea), we have constructed a phage lambda genomic DNA library of a benomyl-resistant strain 91T-1, and a beta-tubulin-encoding gene benA was isolated, cloned and sequenced. Southern blot analysis suggested that a single copy of benA is present in the genome of B. fuckeliana. The benA gene is composed of seven exons which are separated by six introns of 52 to 135 bp. The intron consensus sequences are similar to those of other fungal genes. The deduced amino acid sequence (447 amino acid residues) is highly homologous to those of other fungal beta-tubulin-encoding genes. Comparison of the sequences around codons 198 and 200 in benomyl-resistant and sensitive strains revealed that the benAHR allele from the benomyl-resistant strain 91T-1 contained a mutation at codon 198 from GAG (Glu) to GCG (Ala), which has been correlated with high resistance to benzimidazole fungicides including benomyl in various filamentous fungi.
作为利用苯菌灵抗性作为植物病原真菌灰葡萄孢（无性型，灰霉病菌）显性选择标记来开发DNA介导转化系统的第一步，我们构建了苯菌灵抗性菌株91T - 1的噬菌体λ基因组DNA文库，并分离、克隆和测序了编码β-微管蛋白的基因benA。Southern杂交分析表明，灰葡萄孢基因组中存在单拷贝的benA。benA基因由7个外显子组成，被6个长度为52至135 bp的内含子隔开。内含子共有序列与其他真菌基因的相似。推导的氨基酸序列（447个氨基酸残基）与其他真菌β-微管蛋白编码基因的高度同源。对苯菌灵抗性和敏感菌株中密码子198和200周围序列的比较显示，来自苯菌灵抗性菌株91T - 1的benAHR等位基因在密码子198处存在一个从GAG（Glu）到GCG（Ala）的突变，这与各种丝状真菌对包括苯菌灵在内的苯并咪唑类杀菌剂的高抗性相关。
