Use of oxathiapiprolin for controlling soybean root rot caused by Phytophthora sojae: efficacy and mechanism of action

Abstract

Background: Oxathiapiprolin is a new isoxazoline fungicide developed by DuPont to control oomycete diseases. Although oxathiapiprolin has shown strong inhibitory activity against oomycete pathogens, little is known about its ability to control Phytophthora sojae.Results: Oxathiapiprolin showed high inhibitory activity against Phytophthora sojae, with 50% effective concentration (EC 50 ) values ranging from 1.15 × 10 −4 to 4.43 × 10 −3 ∼g mL −1 . Oxathiapiprolin inhibited various stages of Phytophthora sojae development, including mycelial growth, sporangium formation, oospore production, and zoospore release. Electron microscopy studies revealed that oxathiapiprolin caused severe morphological and ultrastructural damage to Phytophthora sojae. Oxathiapiprolin affected the cell membrane and wall of Phytophthora sojae, making it more sensitive to osmotic and cell wall stress. Oxathiapiprolin exhibited translocation activity; it was absorbed by soybean roots and then translocated to the leaves. It was effective at reducing soybean Phytophthora root rot under glasshouse and field conditions. Both fungicide seed treatment and foliar spray significantly reduced disease incidence and yield losses compared with untreated controls in the field. Conclusion:Oxathiapiprolin exhibits high inhibitory activity against Phytophthora sojae, and has multiple mechanisms of action including severe mycelial damage and modulation of osmotic and cell wall stress. These results indicate that oxathiapiprolin can be used at low concentrations for highly effective management of soybean Phytophthora root rot caused by Phytophthora sojae.

Discovery of Novel Isoxazoline Derivatives Containing Diaryl Ether against Fall Armyworms

“…Melting points of all the compounds were measured by a WRX-4 micro melting point instrument and were not corrected (Shanghai Yice Test instrument & Equipage Co., Ltd.). The 1 H NMR and 13 C NMR of target compounds were recorded on a DPX 400 NMR spectrometer (Bruker, Germany) and an ECX 500 NMR spectrometer (JEOL, Tokyo, Japan) with dimethyl sulfoxide DMSO-d 6 as the solvent. Highresolution mass spectrometry (HRMS) data were tested by the Thermo Scientific Q Exactive (Thermo Scientific, USA).…”

“…The target compounds were synthesized according to this route with simple operation and stable process in all steps, and the final yields of the target compounds were 21.73−78.72%. The structures of L1−L37 were identified by 1 H NMR, 13 C NMR, 19 F NMR, and HRMS.…”

“…Characterization data; 1 H NMR, 13 C NMR, 19 F NMR, and HRMS spectra for title compounds, and determination of the absolute configuration and chromatogram and chemical structure of the L35 enantiomers (PDF)…”

“…Isoxazoline is a class of five-membered heterocyclic compounds containing N and O atoms, which exists in a number of bioactive substances and natural products and forms a crucial building block for the construction of medications and therapeutic candidates. , Moreover, the compounds with this fragment often display promising agricultural values of insecticidal, fungicidal, and herbicidal bioactivities. − In the field of insecticides, isoxazoline is a novel structure that has the ability to bind to insect gamma-aminobutyric acid (GABA) receptors and interfere with the normal function of the insect nervous system by noncompetitively blocking the influx of chloride ions in nerve cells, which prevents the normal function of neurotransmitter inhibition to achieve insecticidal purposes . More importantly, this substance type has a distinct targeting site from other known insecticides, and there is no cross-resistance, which is of great significance for alleviating the resistance problem.…”

Rationally Designed Novel Antimicrobial Peptides Targeting Chitin Synthase for Combating Soybean Phytophthora Blight

“…Notably, only a few drugs and one cyclic antifungal peptide from marine fungi have shown inhibitory effects against soybean phytophthora blight [ 21 , 22 , 23 , 24 ]. Interestingly, Fluoxapiprolin, Oxzthiapiprolin, and Ethaboxam, developed by Bayer and DuPont (Wilmington, DE, USA), have demonstrated the ability to inhibit the growth of P. sojae by targeting spores and mycelium ( Figure 1 ) [ 25 , 26 , 27 , 28 ]. However, it is worth noting that these compounds belong to the thiazole class, and mutations in the single dominant genes (Rps) and β-tubulin have been identified as potential causes of drug resistance [ 29 ].…”