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

Abstract

SYP-14288 is a fungicide as an uncoupler of oxidative phosphorylation, which is effective in controlling fungal pathogens like Rhizoctonia solani. To determine whether R. solani can develop SYP-14288 resistance and possibly multi-drug resistance (MDR), an SYP-14288-resistant mutant of R. solani X19-7 was generated from wild-type strain X19, and the mechanism of resistance was studied through metabolic and genetic assays. From metabolites of R. solani treated with SYP-14288, three compounds including M1, M2, and M3 were identified according to UPLC-MS/MS analysis, and M1 accumulated faster than M2 and M3 in X19-7. When X19-7 was treated by glutathione-S-transferase (GST) inhibitor diethyl maleate (DEM) and SYP-14288 together, or by DEM plus one of tested fungicides that have different modes of action, a synergistic activity of resistance occurred, implying that GSTs promoted metabolic resistance against SYP-14288 and therefore led to MDR. By comparing RNA sequences between X19-7 and X19, six cytochrome P450s (P450s) and two GST genes were selected as a target, which showed a higher expression in X19-7 than X19 both before and after the exposure to SYP-14288. Furthermore, heterologous expression of P450 and GST genes in yeast was conducted to confirm genes involved in metabolic resistance. In results, the P450 gene AG1IA_05136 and GST gene AG1IA_07383 were related to fungal resistance to multiple fungicides including SYP-14288, fluazinam, chlorothalonil, and difenoconazole. It was the first report that metabolic resistance of R. solani to uncouplers was associated with P450 and GST genes.

Carboxylesterase and Cytochrome P450 Confer Metabolic Resistance Simultaneously to Azoxystrobin and Some Other Fungicides in Botrytis cinerea

“…The mechanism of MDR in pathogenic fungi is primarily attributed to the overexpression of efflux transporters, 13−15 while metabolism-associated resistance or metabolic resistance have also been reported. 16,17 These types of resistance pose a significant threat to the successful management of Botrytis cinerea. 18 Metabolic resistance is often due to the increased metabolism of pesticides within an organism, transforming these chemicals from parent compounds into functionally inactive structures.…”

“…cinerea has developed resistance to QoIs, aniline pyrimidine, phenylpyrrole, benzimidazole, dicarboximide, and various fungicides with distinct modes of action (MOAs). − Moreover, some strains have developed resistance to fungicides with different (MOAs) simultaneously, indicating the emergence of multiple fungicide resistance (MFR) and multidrug resistance (MDR). ,− The MFR typically arises from multiple mutations in different target genes. The mechanism of MDR in pathogenic fungi is primarily attributed to the overexpression of efflux transporters, − while metabolism-associated resistance or metabolic resistance have also been reported. , These types of resistance pose a significant threat to the successful management of Botrytis cinerea …”

“…We have learned that the uncoupler chemical SYP-14288 induces metabolic resistance in Phytophthora capsici and Rhizoctonia solani, resulting in MDR to various fungicides with diverse MOAs. 16,17 It is unclear whether fungicide metabolism is involved in the B. cinerea MDR, necessitating further investigation. This study aimed to determine whether B. cinerea can develop resistance to azoxystrobin by enhancing their detoxification and metabolic capabilities, and whether this involves MDR mechanisms.…”

“…We have learned that the uncoupler chemical SYP-14288 induces metabolic resistance in Phytophthora capsici and Rhizoctonia solani, resulting in MDR to various fungicides with diverse MOAs. , It is unclear whether fungicide metabolism is involved in the B. cinerea MDR, necessitating further investigation.…”

ABC transporters linked to multiple herbicide resistance in blackgrass (Alopecurus myosuroides)

“…For EMR in weeds, the rates of herbicide detoxification are accelerated through the coordinated upregulation of enzymes involved in primary metabolic activation, notably cytochromes P450 monooxygenases (CYPs) and secondary bioconjugation catalysed by glutathione transferases (GSTs) or UDP-sugar-dependent glycosyltransferases (UGTs) (Edwards et al, 2005;Yu and Powles, 2014). As such, EMR in plants closely resembles a similar coordinated upregulation of detoxification enzymes underpinning multiple drug resistance (MDR) in animals and fungi (Housman et al, 2014;Cheng et al, 2022). In MDR, in addition to the upregulation of detoxification enzymes, energy-dependent membrane transporters are also enhanced, allowing for the accelerated cellular export of conjugated detoxification products, typically leading to extracellular extrusion (Choi and Yu, 2014).…”