Fungicide SYP-14288 Inducing Multidrug Resistance in Rhizoctonia solani

Abstract

Rhizoctonia solani is a widely distributed soilborne plant pathogen, and can cause significant economic losses to crop production. In chemical controls, SYP-14288 is highly effective against plant pathogens, including R. solani. To examine the sensitivity to SYP-14288, 112 R. solani isolates were collected from infected rice plants. An established baseline sensitivity showed that values of effective concentration for 50% growth inhibition (EC50) ranged from 0.0003 to 0.0138 μg/ml, with an average of 0.0055 ± 0.0030 μg/ml. The frequency distribution of the EC50 was unimodal and the range of variation factor (the ratio of maximal over minimal EC50) was 46.03, indicating that all wild-type strains were sensitive to SYP-14288. To examine the risk of fungicide resistance, 20 SYP-14288-resistant mutants were generated on agar plates amended with SYP-14288. Eighteen mutants remained resistant after 10 transfers, and their fitness was significantly different from the parental strain. All of the mutants grew more slowly but showed high virulence to rice plants, though lower than the parental strain. A cross-resistance assay demonstrated that there was a positive correlation between SYP-14288 and fungicides having or not having the same mode of action with SYP-14288, including fluazinam, fentin chloride, fludioxonil, difenoconazole, cyazofamid, chlorothalonil, and 2,4-dinitrophen. This result showed a multidrug resistance induced by SYP-14288, which could be a concern in increasing the spectrum of resistance in R. solani to commonly used fungicides.

Screening of Tomato Seed Bacterial Endophytes for Antifungal Activity Reveals Lipopeptide Producing Bacillus siamensis Strain NKIT9 as a Potential Bio-Control Agent

“…The use of chemical fungicides is the most common strategy to prevent fungal pathogens ( Windels and Brantner, 2005 ). The prolonged use of chemicals has led to the development of resistance in phytopathogens, such as Fluazinam, fentin chloride, fludioxonil, difenoconazole, 28 cyazofamid, chlorothalonil, and 2, 4-dinitrophen, which have all been reported to cause multi drug resistance in R. solani ( Cheng et al, 2020 ).…”

Temporal progress of web blight in three common bean genotypes on the central coast of Ecuador

“…The experiment established in this last year was in a different place than in the other years, having previously been occupied by a banana crop. This implies that carbendazim seed treatment did not show efficacy, despite the fact that this fungicide is used to control R. solani 29 .…”

Cytochrome P450 and Glutathione S-Transferase Confer Metabolic Resistance to SYP-14288 and Multi-Drug Resistance in Rhizoctonia solani

“…Rhizoctonia solani wild-type strain X19 was collected from rice plant, and SYP-14288-resistant mutant X19-7 with resistance factor being 56.7 was obtained through domestication of the parental strain X19 by exposing the culture to SYP-14288-amended media. X19-7 was not only resistant to SYP-14288 but also to fluazinam, fludioxonil, difenoconazole, chlorothalonil, and carbendazim ( Cheng et al, 2020 ). In addition, sequence analysis showed that there were no mutations on the common target site including β -tubulin , cytb , sdhB , and histidine kinase gene of X19-7 compared with X19.…”

“…An example is that fluazinam resistance has been reported in Botrytis cinerea ( Tamura, 2000 ) and Ustilago maydis ( Vitoratos, 2014 ). Moreover, a laboratory-generated mutant of R. solani resistant to SYP-14288 has cross-resistance with fungicides having not only the same but also different MoAs, indicating a multi-drug resistance (MDR) occurs ( Cheng et al, 2020 ).…”