The novel fungicide SYP-14288 acts as an uncoupler against Phytophthora capsici

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

“…There was no change in the electric potential of SYP‐14288‐resistant mutants upon stimulation with CCCP compared with their parental isolates, which indicates that SYP‐14288 acts as an uncoupler with a different mode of action from CCCP. While the SYP‐14288‐resistant mutants showed a similar insensitive pattern under fluazinam treatment, this implies that SYP‐14288 could act as with fluazinam, which may induce the disturbed membrane permeability and subsequently diminished all the energy‐intensive vital activities in the target organism …”

“…Real‐time PCR was performed using the ABI7500 sequence detection system (Applied Biosystems) and SYBR Premix Dimer Eraser Kit (TaKaRa), with the primers listed in Table S3 and following the manufacturers’ protocols. The relative quantities of PCR products were calculated using the 2 ‐△△Ct method; the geometric mean of WS21 and UBC genes was set as a reference to normalize the quantification of target genes expression . Three biological replicates were included and the entire experiment was conducted three times.…”

“…SYP‐14288 has excellent control effects on various plant pathogenic fungi and oomycetes, both in vitro and in the field . It has been shown to effectively accelerate respiration and inhibit ATP biosynthesis in P. capsici . Proteomics analysis suggests that SYP‐14288 could efficiently cause a shift in energy metabolism, resulting in the activation of compensatory mechanisms affecting carbohydrate and lipid metabolism .…”

“…Although it has been used for over 30 years, only a few field populations with fluazinam resistance have been reported . With higher bioactivity and lower cost, as well as being more environmentally friendly [with a median lethal dose (LD 50 ) of > 5000 mg kg −1 for acute oral toxicity and > 2000 mg kg −1 for acute percutaneous toxicity in rats, respectively (Liu, unpublished)], SYP‐14288 could be a better alternative than fluazinam to control plant diseases …”

Insights from the proteome profile of Phytophthora capsici in response to the novel fungicide SYP-14288

“…Like other diarylamine fungicides, SYP-14288 exhibits broad-spectrum fungicidal activity that provides excellent control of many plant diseases including Colletotrichum orbiculare and cucumber downy mildew Pseudoperonospora cubensis , as well as outstanding control of the pepper blight caused by Phytophthora capsici . Although SYP-14288 works as an uncoupler to control various plant pathogens, its exact target site(s) remains unclear (Wang et al, 2018). Given the great potential of SYP-14288 within the fungicide market, it is important to characterize its mode of action in greater detail.…”