College of Plant Protection, Northwest A&F University, Yangling, China.
Shaanxi Biopesticide Engineering & Technology Research Center, Northwest A & F University, Yangling, China.
Pest Manag Sci. 2022 Dec;78(12):5281-5292. doi: 10.1002/ps.7150. Epub 2022 Sep 21.
Botrytis cinerea, the causal agent of gray mold, is one of the top 10 fungal pathogens in the world. Propamidine, an aromatic diamidine compound, exhibited both protective and therapeutic effects against B. cinerea. However, the resistance risk and mechanism of B. cinerea to propamidine are unclear.
Twelve high and stable resistant mutants were obtained from B. cinerea B05.10 by fungicide induction. Compared with the parental strain, the biological fitness of the mutants, including growth rate, spore germination, pathogenicity, and oxalic acid decreased significantly. There was no cross-resistance among propamidine and other commonly used fungicides, while the efficacy of propamidine against the resistance mutants declined. In addition, the cell membrane permeability, substance metabolism, and defense enzyme activities of the resistant mutants were significantly increased compared with the wild strain. Whole-genome sequencing of all resistant mutants found that there were 32 SNPs and nine InDels. Importantly, nine common single-point mutant genes in the exon region were found in all 12 resistant mutants, and these genes were related to multiple pathways in vivo, indicating that many factors contributed to the formation of propamidine resistance.
These data suggested the resistance risk of B. cinerea to propamidine was low to moderate and the mechanism of propamidine was different from that of the existing fungicides. These results will increase understanding of the resistance mechanism of propamidine and provide a critical basis for the rational design of pesticide molecules based on targets. © 2022 Society of Chemical Industry.
灰葡萄孢（Botrytis cinerea）是世界十大真菌病原体之一，其病原菌。丙脒是一种芳香二脒类化合物，对灰葡萄孢具有保护和治疗作用。然而，灰葡萄孢对丙脒的抗性风险和机制尚不清楚。
通过杀菌剂诱导，从 B. cinerea B05.10 中获得了 12 株高且稳定的抗性突变体。与亲本菌株相比，突变体的生物适应性，包括生长速度、孢子萌发、致病性和草酸显著降低。丙脒与其他常用杀菌剂之间没有交叉抗性，而丙脒对抗性突变体的疗效下降。此外，抗性突变体的细胞膜通透性、物质代谢和防御酶活性均显著高于野生型。对所有抗性突变体的全基因组测序发现有 32 个 SNP 和 9 个 InDels。重要的是，在所有 12 个抗性突变体中都发现了 9 个常见的exon 区域单点突变基因，这些基因与体内的多个途径有关，表明有许多因素导致了丙脒抗性的形成。
这些数据表明，灰葡萄孢对丙脒的抗性风险为中低水平，丙脒的作用机制与现有杀菌剂不同。这些结果将增加对丙脒抗性机制的认识，并为基于靶标的农药分子的合理设计提供重要依据。
