Respiration Inhibitors: Complex II

115

This is the first report on the activity of benzovindiflupyr against Colletotrichum species. The broad-spectrum efficacy of benzovindiflupyr within the Colletotrichum genus might be exploited when designing disease management strategies against various pathogens on a wide range of crops. Other mechanism(s) than fungicide target-site modification may be responsible for differential sensitivity of Colletotrichum species to SDHI fungicides. © 2016 Society of Chemical Industry.

Section: Resultsmentioning

confidence: 79%

Efficacy of SDHI fungicides, including benzovindiflupyr, against Colletotrichum species

Ishii

Fan

et al. 2016

115

“…We classified F. graminearum as a medium risk pathogen in China because resistance evolved to the major fungicides carbendazim and tebuconazole used against F. graminearum in China after 10 to 30 years and no resistance has evolved to phenamacril to date . Many cases of SDHI field resistance has been reported in various pathogens and SDHIs have been classified as medium to high risk . In this study, pydiflumetofen‐resistant mutants of F. graminearum were easily generated in vitro through spontaneous selection, but some had seriously reduced fitness.…”

Section: Discussionmentioning

confidence: 92%

“…Molecular mechanisms of SDHI resistance in fungi have been investigated intensively. The common mechanisms of SDHIs resistance are mutations in the SdhB , SdhC , or SdhD gene of the SDH‐enzyme . In the current study, possible mechanisms leading to pydiflumetofen resistance in laboratory resistant mutants of F. graminearum were explored by sequencing and analyzing all four Sdh genes.…”

Section: Discussionmentioning

confidence: 99%

Resistance risk assessment for Fusarium graminearum to pydiflumetofen, a new succinate dehydrogenase inhibitor

Sun

Cui

Tian

et al. 2019

Background Pydiflumetofen is a new generation succinate dehydrogenase inhibitor currently undergoing the process of registration in China for the control of Fusarium head blight in wheat. A resistance risk assessment of Fusarium graminearum to pydiflumetofen was undertaken in this study. Results A total of 75 pydiflumetofen‐resistant mutants were generated through spontaneous selection and displayed high resistance with an average resistance factor (RF) value of 78. Four mutants were generated through UV mutagenesis and displayed very high resistance with an RF value >1000. The sequence analysis results for Sdh genes and fitness studies revealed the existence of four types of mutations. In particular, 32 spontaneous selection mutants (SP mutants) had an arginine (R) to histidine (H) transition at position 86 in FGSdhC, resulting in seriously reduced fitness. Seven SP mutants had an R to cysteine (C) transition at position 86 in FGSdhC, resulting in reduced fitness. Thirty‐six SP mutants had an alanine (A) to valine (V) transition at position 83 in FGSdhC and had no fitness penalties. The efficacy of pydiflumetofen towards a mutant carrying A83V in FGSdhC in vivo was significantly decreased at 42.7%. Four UV mutants had no mutations on all Sdh genes and no fitness penalties. Cross‐resistance among boscalid, fluopyram and pydiflumetofen was observed. Conclusion Sdhc mutations were found and other target site resistance may be present in laboratory PR mutants of F. graminearum. An overall moderate risk of resistance development in F. graminearum was recommended for pydiflumetofen. © 2019 Society of Chemical Industry

“…This histidine residue is included in the ubiquinone/SDHI binding pocket of complex II, leading to moderate resistance to most SDHIs. The other mutations concern histidine residues in SdhC and SdhD , which are iron ligands of haem b, with functions that remain unknown in complex II, and which are not part of the ubiquinone/SDHI binding site . The mutations of H139Y in RCSdhC and H116Y/D in RCSdhD detected in R. cerealis have never been observed in any other plant pathogens.…”

Section: Discussionmentioning

confidence: 99%

Homozygous and heterozygous point mutations in succinate dehydrogenase subunits b, c and d of Rhizoctonia cerealis conferring resistance to thifluzamide

Sun

et al. 2016