Key Laboratory of Pesticide, College of Plant Protection, Nanjing Agricultural University, Nanjing, China.
Jiangsu Coastal Area Institute of Agricultural Science, Yancheng, China.
Pest Manag Sci. 2020 Dec;76(12):4093-4103. doi: 10.1002/ps.5964. Epub 2020 Jul 20.
Grape anthracnose caused by the ascomycete fungus Colletotrichum gloeosporioides has been widely controlled by demethylation inhibitors (DMIs) for decades in China. The resistance status and mechanism of C. gloeosporioides against DMIs is not well understood.
All difenoconazole-resistant (Dfn ) isolates from vineyards exhibited decreased fitness. Positive cross-resistance was detected between DMI triazoles. Sequence alignment results from the Dfn and Dfn isolates revealed that multiple mutations are distributed at CgCYP51A, concomitant with mutations at CgCYP51B. The half maximal effective concentration (EC ) values of single deleted and complemented mutants of CgCYP51A and CgCYP51B showed that ΔCgCYP51A became more sensitive to difenoconazole, but not ΔCgCYP51B. Furthermore, all single complemented mutants had a stronger biological fitness than the progenitor strain. All the defectives of ΔCgCYP51A and ΔCgCYP51B could be restored by complementation of the whole corresponding gene from the resistant strains. Relative gene expression of CgCYP51A and CgCYP51B in most of the mutants was greatly upregulated relative to the progenitor isolate when treated with difenoconazole at the same concentration. Moreover, the extension of five amino acids (GNETI) caused by mutation at the stop codon of CgCYP51A, concurrent with other seven amino acid substitutions and the synonymous mutation P10P (CCG → CCT), significantly enhanced DMI resistance.
The DMI resistance of C. gloeosporioides selected in vineyards is conferred by mutations at CgCYP51s, and validated by a genetics method. The roles of CgCYP51A and CgCYP51B overlap, and are counter-balanced, but cannot be replaced reciprocally. © 2020 Society of Chemical Industry.
在中国，灰葡萄孢菌（Colletotrichum gloeosporioides）引起的葡萄炭疽病已被脱甲基抑制剂（DMIs）广泛控制了数十年。然而，人们对灰葡萄孢菌对 DMIs 的抗性现状和机制仍了解甚少。
从葡萄园获得的所有对啶氧菌酯（Difenoconazole）具有抗性的（Dfn）分离株都表现出适应性降低。在 DMI 三唑类化合物之间检测到了正交叉抗性。从 Dfn 和 Dfn 分离株的序列比对结果表明，多个突变分布在 CgCYP51A 上，同时在 CgCYP51B 上也存在突变。CgCYP51A 和 CgCYP51B 的单一缺失和互补突变体的半最大有效浓度（EC）值表明，ΔCgCYP51A 对啶氧菌酯变得更加敏感，但 ΔCgCYP51B 则不然。此外，所有的单互补突变体的生物适应性都比原始菌株更强。通过从抗性菌株中互补整个相应基因，可恢复 ΔCgCYP51A 和 ΔCgCYP51B 的所有缺陷。与原始分离株相比，当用相同浓度的啶氧菌酯处理时，大多数突变体中 CgCYP51A 和 CgCYP51B 的相对基因表达都大大上调。此外，CgCYP51A 终止密码子突变导致的五个氨基酸（GNETI）的延伸，伴随着其他七个氨基酸取代和同义突变 P10P（CCG → CCT），显著增强了 DMI 抗性。
通过遗传学方法验证，从葡萄园选择的灰葡萄孢菌的 DMI 抗性是由 CgCYP51s 的突变引起的。CgCYP51A 和 CgCYP51B 的作用重叠且相互制衡，但不能相互替代。© 2020 化学工业协会。
