Difenoconazole Resistance Shift in Botrytis cinerea From Tomato in China Associated With Inducible Expression of CYP51

作者：Can Zhang, Muhammad Imran, Lu Xiao, Zhìhóng Hú, Guixiang Li, Fan Zhang, Xili Liu · 发表于：Plant Disease · 年份：2020 · DOI：10.1094/pdis-03-20-0508-re · 被引用次数：39 · 研究领域：Fungal Plant Pathogen Control、Plant Disease Resistance and Genetics、Nematode management and characterization studies

Gray mold caused by Botrytis cinerea is one of the most important diseases in tomato. It can be controlled effectively by demethylation inhibitor (DMI) fungicides, but their resistance status after long-term use in the field is unclear. The baseline sensitivity to difenoconazole of 142 B. cinerea isolates from China with no history of DMI usage was characterized, with a mean effective concentration for 50% mycelial growth inhibition (EC 50 ) of 0.97 ± 0.50 μg/ml. EC 50 values for difenoconazole sensitivity of another 248 isolates collected in 2011 and 2016 ranged from 0.04 to 11.99 μg/ml, and the frequency of difenoconazole sensitivity formed a nonnormal distribution curve. Detached fruit studies revealed that isolates with EC 50 values of approximately 6.00 μg/ml were not controlled effectively. The mean EC 50 of the resistant isolates changed from 6.74 to 8.65 μg/ml between 2011 and 2016. Positive cross-resistance was only observed between difenoconazole and two DMIs. One dual resistant isolate and one triple resistant isolate were found among the difenoconazole-resistant isolates collected in 2016, associated with point mutations in corresponding target proteins of the fungicides azoxystrobin and fludioxonil. This indicated that B. cinerea not only showed higher difenoconazole resistance levels but gradually changed from single to multiple fungicide resistance over time. No amino acid variation was found in the CYP51 protein. In the absence of difenoconazole, the relative ...