Decreased sensitivity of cucumber powdery mildew (Sphaerotheca fuliginea) to ergosterol biosynthesis inhibitors.

1988 ◽  
Vol 54 (5) ◽  
pp. 629-632 ◽  
Author(s):  
Norio OHTSUKA ◽  
Kazuhiro SOU ◽  
Tetsuo AMANO ◽  
Masahiro OJIMA ◽  
Yasuhiko NAKAZAWA ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Ergosterol Biosynthesis ◽  
Sphaerotheca Fuliginea ◽  
Cucumber Powdery Mildew ◽  
Ergosterol Biosynthesis Inhibitors ◽  
Biosynthesis Inhibitors

Fungicide resistance in cucurbit powdery mildew (Sphaerotheca fuliginea) and its effect on field control

1988 ◽  
Vol 28 (3) ◽  
pp. 417 ◽  
Author(s):  
RG O'Brien ◽  
LL Vawdrey ◽  
RJ Glass
Keyword(s):  
Powdery Mildew ◽  
Disease Risk ◽  
Leaf Disc ◽  
Field Trials ◽  
Ergosterol Biosynthesis ◽  
Systemic Fungicide ◽  
Sphaerotheca Fuliginea ◽  
Ergosterol Biosynthesis Inhibitors ◽  
Resistant Strains ◽  
Low Sensitivity

Decreased fungicidal control of powdery mildew (Sphaerotheca fuliginea (Schlecht: Fr.) Poll.) in commercial cucurbit crops led to an investigation to determine whether fungicide resistant strains were present. In field trials, fungicides such as bupirimate (100 mg a.i. L-I), dimethirimol (250 mg a.i. L-1), fenarimol (36 mg a.i. L-1), penconazole (40 mg a.i. L-l) and triadimefon (125 mg a.i. L-1) were less effective (P=0.01) in controlling the disease than oxythioquinox (100 mg a.i. L-1). This disagreed with earlier trial results and suggested that fungicide resistant strains may have developed. The sensitiyities of 6 isolates of S. fuliginea to 12 fungicides were determined using a leaf disc technique. Two isolates collected in fields where fungicides had been used intensively showed reduced sensitivity to fungicides from several chemical groups including the ergosterol biosynthesis inhibitors, hydroxypyrimidines, organophosphates and benzimidazoles. Several spraying strategies were compared. The S. fuliginea populations receiving spray schedules which included the protectant fungicide oxythioquinox alone, or in alternation with a systemic (triadimefon) developed a lower proportion (66-73%) of resistant strains than those treated with systemic fungicide alone (89%). These findings suggest that S. fuliginea can develop strains with low sensitivity to several fungicides against powdery mildew. To prolong their efficacy, systemic fungicides should not be used continuously but should be reserved for use during the latter part of crop growth when disease risk is highest. Alternating or tank mixing with an effective protectant fungicide is also recommended.

Dehydrozingerone Inspired Discovery of Potential Broad-Spectrum Fungicidal Agents as Ergosterol Biosynthesis Inhibitors

2019 ◽  
Vol 67 (41) ◽  
pp. 11354-11363 ◽  
Author(s):  
Xiangmin Song ◽  
Xinyue Zhu ◽  
Ting Li ◽  
Cai Liang ◽  
Meng Zhang ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Ergosterol Biosynthesis ◽  
Ergosterol Biosynthesis Inhibitors ◽  
Biosynthesis Inhibitors

scholarly journals Ergosterol Biosynthesis Inhibitors Become Fungicidal when Combined with Calcineurin Inhibitors against Candida albicans, Candida glabrata, and Candida krusei

2003 ◽  
Vol 47 (3) ◽  
pp. 956-964 ◽  
Author(s):  
Chiatogu Onyewu ◽  
Jill R. Blankenship ◽  
Maurizio Del Poeta ◽  
Joseph Heitman
Keyword(s):  
Candida Albicans ◽  
Antifungal Agents ◽  
Calcineurin Inhibitors ◽  
Therapeutic Window ◽  
Ergosterol Biosynthesis ◽  
Drug Synergism ◽  
Wild Type ◽  
Ergosterol Biosynthesis Inhibitors ◽  
Biosynthesis Inhibitors ◽  
Mutant Strains

ABSTRACT Azoles target the ergosterol biosynthetic enzyme lanosterol 14α-demethylase and are a widely applied class of antifungal agents because of their broad therapeutic window, wide spectrum of activity, and low toxicity. Unfortunately, azoles are generally fungistatic and resistance to fluconazole is emerging in several fungal pathogens. We recently established that the protein phosphatase calcineurin allows survival of Candida albicans during the membrane stress exerted by azoles. The calcineurin inhibitors cyclosporine A (CsA) and tacrolimus (FK506) are dramatically synergistic with azoles, resulting in potent fungicidal activity, and mutant strains lacking calcineurin are markedly hypersensitive to azoles. Here we establish that drugs targeting other enzymes in the ergosterol biosynthetic pathway (terbinafine and fenpropimorph) also exhibit dramatic synergistic antifungal activity against wild-type C. albicans when used in conjunction with CsA and FK506. Similarly, C. albicans mutant strains lacking calcineurin B are markedly hypersensitive to terbinafine and fenpropimorph. The FK506 binding protein FKBP12 is required for FK506 synergism with ergosterol biosynthesis inhibitors, and a calcineurin mutation that confers FK506 resistance abolishes drug synergism. Additionally, we provide evidence of drug synergy between the nonimmunosuppressive FK506 analog L-685,818 and fenpropimorph or terbinafine against wild-type C. albicans. These drug combinations also exert synergistic effects against two other Candida species, C. glabrata and C. krusei, which are known for intrinsic or rapidly acquired resistance to azoles. These studies demonstrate that the activity of non-azole antifungal agents that target ergosterol biosynthesis can be enhanced by inhibition of the calcineurin signaling pathway, extending their spectrum of action and providing an alternative approach by which to overcome antifungal drug resistance.

Synthesis of 6(α,β)-aminocholestanols as ergosterol biosynthesis inhibitors

1998 ◽  
Vol 8 (24) ◽  
pp. 3627-3630 ◽  
Author(s):  
Pierre Beuchet ◽  
Laïla El kihel ◽  
Michel Dherbomez ◽  
Georges Charles ◽  
Yves Letourneux
Keyword(s):  
Ergosterol Biosynthesis ◽  
Ergosterol Biosynthesis Inhibitors ◽  
Biosynthesis Inhibitors
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