Fehr Marcus, Wolf Antje, Stammler Gerd
BASF SE, Crop Protection, Limburgerhof, Germany.
BASF SE, Biological and Effect Systems Research, Ludwigshafen, Germany.
Pest Manag Sci. 2016 Mar;72(3):591-602. doi: 10.1002/ps.4031. Epub 2015 May 20.
Ametoctradin is an agricultural fungicide that inhibits the mitochondrial bc1 complex of oomycetes. The bc1 complex has two quinone binding sites that can be addressed by inhibitors. Depending on their binding sites and binding modes, the inhibitors show different degrees of cross-resistance that need to be considered when designing spray programmes for agricultural fungicides. The binding site of ametoctradin was unknown.
Cross-resistance analyses, the reduction of isolated Pythium sp. bc1 complex in the presence of different inhibitors and molecular modelling studies were used to analyse the binding site and binding mode of ametoctradin. All three approaches provide data supporting the argument that ametoctradin binds to the Pythium bc1 complex similarly to stigmatellin.
The binding mode of ametoctradin differs from other agricultural fungicides such as cyazofamid and the strobilurins. This explains the lack of cross-resistance with strobilurins and related inhibitors, where resistance is mainly caused by G143A amino acid exchange. Accordingly, mixtures or alternating applications of these fungicides and ametoctradin can help to minimise the risk of the emergence of new resistant isolates.
嘧菌酯是一种农业杀菌剂，可抑制卵菌纲的线粒体bc1复合体。bc1复合体有两个醌结合位点，可被抑制剂作用。根据其结合位点和结合模式，抑制剂表现出不同程度的交叉抗性，这在设计农业杀菌剂喷雾方案时需要考虑。嘧菌酯的结合位点尚不清楚。
通过交叉抗性分析、在不同抑制剂存在下对分离的腐霉菌bc1复合体的还原以及分子模拟研究，来分析嘧菌酯的结合位点和结合模式。所有这三种方法都提供了数据，支持嘧菌酯与抑菌灵类似地结合到腐霉菌bc1复合体的观点。
嘧菌酯的结合模式不同于其他农业杀菌剂，如氰霜唑和甲氧基丙烯酸酯类杀菌剂。这解释了其与甲氧基丙烯酸酯类杀菌剂及相关抑制剂不存在交叉抗性的原因，后者的抗性主要由G143A氨基酸交换引起。因此，这些杀菌剂与嘧菌酯的混合使用或交替使用有助于将新的抗性菌株出现的风险降至最低。
