Resistance assessment for SYP‐14288 in Phytophthora capsici and changes in mitochondria electric potential‐associated respiration and ATP production confers resistance

Abstract

BACKGROUND: Phytophthora capsici is a destructive plant oomycete pathogen that could lead to devastating losses in food production. Fungicide application is the main way to control plant disease caused by P. capsici. SYP-14288, a novel fungicide with a unique mode of action, could be used to control a broad range of plant diseases. Here, the potential for SYP-14288 resistance in P. capsici and the resistance mechanism involved were evaluated.RESULTS: Baseline sensitivities of 133 isolates to SYP-14288 were determined and found to conform to a unimodal curve with a mean half-maximal effective concentration (EC 50 ) of 0.625 ∼g mL −1 . In total, 21 stable SYP-14288-resistant mutants were generated by fungicide adaptation in three sensitive isolates. The fitness of all the mutants was found to be lower than that of the parental isolates. Otherwise, downregulation of various ATPases may confer different resistance levels in P. capsici. Finally, multiple biochemical studies strongly suggest that both ATP content and electric potential were reduced in SYP-14288-resistant mutants, and as a compensatory mechanism, respiration was facilitated to make up for the energy defect in mutants.

Uncoupler SYP‐14288 inducing multidrug resistance of Phytophthora capsici through overexpression of cytochrome P450 monooxygenases and P‐glycoprotein

“…Wild‐type strain JA8 (median effective concentration [EC 50 ] of 0.21 μg mL −1 ) and resistant‐strain RJ‐2 (EC 50 of 23.23 μg mL −1 ) were used in this study, and information on the two strains was described in the resistance assessment for SYP‐14288 in P. capsici 7 . The EC 50 value of RJ‐2 was changed to 1.48 μg mL −1 , probably due to the long storage time, but the subculture showed that the fungicide resistance was stable.…”

“…Therefore, fungicides with new modes of action are attractive for oomycete pathogen control. SYP‐14288, a diarylamine compound created based on the structure of fluazinam, has been recently proven to have an oxidative phosphorylation uncoupling activity on P. capsici by breaking the proton gradient potential between the inside and outside of the mitochondrial membrane 6–8 . However, the resistance mechanism of fluazinam and SYP‐14288 has not been clarified.…”

“…SYP-14288, a diarylamine compound created based on the structure of fluazinam, has been recently proven to have an oxidative phosphorylation uncoupling activity on P. capsici by breaking the proton gradient potential between the inside and outside of the mitochondrial membrane. [6][7][8] However, the resistance mechanism of fluazinam and SYP-14288 has not been clarified. SYP-14288 is a low-risk fungicide and not likely to develop resistance due to a lack of specific target proteins.…”

Discovery of zeylenone from Uvaria grandiflora as a potential botanical fungicide

“…12,13 Phytophthora blight, caused by Phytophthora capsici, is a devastating soil-borne disease of many vegetable crops, which seriously threatens the production and quality of the crops. 14,15 In addition to pepper and sweet pepper, its wide range of hosts also contain tomato, eggplant and some melon crops. 16 At present, the prevention and control of phytophthora blight mainly depends on chemical pesticides (e.g.…”

Novel Fungicide 4-Chlorocinnamaldehyde Thiosemicarbazide (PMDD) Inhibits Laccase and Controls the Causal Agent of Take-All Disease in Wheat, Gaeumannomyces graminis var. tritici

“…Many fungicides with various modes of action have been reported, , and they have become an integral part of efficient food production. However, with emerging problems related to toxic residues, disease resurgence, and pathogen resistance, the use of some fungicides is restricted in many countries . Therefore, novel fungicides demonstrating low toxicity to non-target organisms, high activity against target plant pathogens, and with new modes of action are urgently needed.…”