Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, Shandong Agricultural University, Tai'an, P.R. China.
College of Plant Protection, Shandong Agricultural University, Tai'an, P.R. China.
Pest Manag Sci. 2020 Aug;76(8):2799-2808. doi: 10.1002/ps.5827. Epub 2020 May 22.
A new generation of succinate dehydrogenase inhibitors (SDHIs) with high efficiency and broad-spectrum antifungal activity has been frequently used in crop production. Sclerotinia stem rot is a major disease of various plants and crops caused by Sclerotinia sclerotiorum. Although benzovindiflupyr and isopyrazam reportedly have high activity against S. sclerotiorum, little is known about the bioactivity of different SDHIs classes against S. sclerotiorum or the mechanism of their differential antifungal activity.
The in vitro tests revealed that the pyrazole-4-carboxamides of SDHIs (benzovindiflupyr, isopyrazam, fluxapyroxad, pydiflumetofen) had the highest activity against S. sclerotiorum followed by pyridine carboxamides (boscalid), pyridinyl-ethyl benzamides (fluopyram) and thiazole carboxamides (thifluzamide), and of these thifluzamide showed poor antifungal activity with EC values greater than 6.01 mg L . The pyrazole-4-carboxamides of SDHIs showed satisfactory protective and curative activity against Sclerotinia stem rot. After treatment with the pyrazole-4-carboxamides of SDHIs, mitochondrial function in S. sclerotiorum decreased significantly. The enzyme activity assays revealed a lower affinity between thifluzamide and the Sc-Sdh complex than was observed for the other six fungicides, with IC values ranging from 0.0036 to 1.2088 μmol L . Additionally, the docking positions of fungicides were similar, yet binding energies were different in the docking study with the Sdh complex. The correspondingly weaker hydrogen bonds may be responsible for the poor activity of thifluzamide against S. sclerotiorum.
Understanding different binding features of various SDHIs classes with the Sc-Sdh complex might be beneficial for the design and development of highly effective broad-spectrum fungicides to ensure high yield and quality in crops by reducing fungicide use. © 2020 Society of Chemical Industry.
新一代琥珀酸脱氢酶抑制剂（SDHI）具有高效广谱的抗真菌活性，在作物生产中被频繁使用。核盘菌茎腐病是由核盘菌引起的各种植物和作物的主要病害。虽然苯并维氟氯吡和异吡唑胺据称对 S. 核盘菌具有高活性，但对不同 SDHI 类别的生物活性及其对 S. 核盘菌的差异抗真菌活性机制知之甚少。
体外试验表明，SDHI 的吡唑-4-甲酰胺（苯并维氟氯吡、异吡唑胺、氟吡菌酰胺、吡噻菌胺）对 S. 核盘菌的活性最高，其次是吡啶甲酰胺（啶酰菌胺）、吡啶基乙基苯甲酰胺（氟吡菌酰胺）和噻唑甲酰胺（噻呋酰胺），其中噻呋酰胺的抗真菌活性较差，EC 值大于 6.01 mg/L。SDHI 的吡唑-4-甲酰胺对核盘菌茎腐病具有良好的保护和治疗活性。用 SDHI 的吡唑-4-甲酰胺处理后，S. 核盘菌的线粒体功能明显下降。酶活性测定表明，噻呋酰胺与 Sc-Sdh 复合物的亲和力低于其他六种杀菌剂，IC 值范围为 0.0036 至 1.2088 μmol/L。此外，在与 Sdh 复合物的对接研究中，杀菌剂的对接位置相似，但结合能不同。相应较弱的氢键可能是噻呋酰胺对 S. 核盘菌活性差的原因。
了解不同 SDHI 类别的不同结合特征与 Sc-Sdh 复合物可能有助于设计和开发高效广谱杀菌剂，通过减少杀菌剂的使用来确保作物的高产和高质量。© 2020 化学工业协会。
