Insights into the molecular mechanism of tolerance to carboxylic acid amide (CAA) fungicides in Pythium aphanidermatum

2012 ◽  
Vol 68 (8) ◽  
pp. 1171-1183 ◽  
Author(s):  
Mathias Blum ◽  
Ulrich Gisi
Keyword(s):  
Carboxylic Acid ◽  
Molecular Mechanism ◽  
Acid Amide ◽  
Pythium Aphanidermatum ◽  
Carboxylic Acid Amide ◽  
Caa Fungicides

scholarly journals Inheritance of resistance to carboxylic acid amide (CAA) fungicides in Plasmopara viticola

2007 ◽  
Vol 56 (2) ◽  
pp. 199-208 ◽  
Author(s):  
U. Gisi ◽  
M. Waldner ◽  
N. Kraus ◽  
P. H. Dubuis ◽  
H. Sierotzki
Keyword(s):  
Carboxylic Acid ◽  
Acid Amide ◽  
Plasmopara Viticola ◽  
Inheritance Of Resistance ◽  
Carboxylic Acid Amide ◽  
Caa Fungicides

scholarly journals First Report of Carboxylic Acid Amide Fungicide Resistance in Plasmopara viticola (Grapevine Downy Mildew) in North America

2018 ◽  
Vol 19 (2) ◽  
pp. 139-139 ◽  
Author(s):  
Xuewen Feng ◽  
Anton Baudoin
Keyword(s):  
North Carolina ◽  
Carboxylic Acid ◽  
North America ◽  
Downy Mildew ◽  
Acid Amide ◽  
Plasmopara Viticola ◽  
Carboxylic Acid Amide ◽  
Grapevine Downy Mildew ◽  
Grape Downy Mildew ◽  
Caa Fungicides

This report documents the first known occurrence in North America of resistance in grape downy mildew (Plasmopara viticola) to the carboxylic acid amide (CAA) fungicides mandipropamid and dimethomorph. These fungicides (FRAC group 40) have been an important component of downy mildew management programs for the past decade. Resistant isolates were obtained at three locations in Virginia and one in North Carolina, at considerable distances from each other. Resistance was documented by bioassay and the presence of the G1105S mutation, which has been associated with CAA resistance of P. viticola in other areas. Further survey is needed to determine the geographic extent of this resistance.

scholarly journals Detection and Characterization of Carboxylic Acid Amide-Resistant Plasmopara viticola in China Using a TaqMan-MGB Real-Time PCR

Plant Disease ◽  
2020 ◽  
Vol 104 (9) ◽  
pp. 2338-2345
Author(s):  
Xiaoqing Huang ◽  
Xina Wang ◽  
Fanfang Kong ◽  
Theo van der Lee ◽  
Zhongyue Wang ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Real Time ◽  
Downy Mildew ◽  
Real Time Pcr ◽  
Fungicide Resistance ◽  
Management Strategies ◽  
Acid Amide ◽  
Plasmopara Viticola ◽  
Carboxylic Acid Amide ◽  
Caa Fungicides

Grape production is increasing globally and so are problems with downy mildew, one of the main constraints in grape production. Downy mildew on grape is caused by Plasmopara viticola, an obligate biotrophic pathogen belonging to the oomycetes. Control of the disease is usually performed by fungicide applications, of which carboxylic acid amide (CAA) fungicides represent one of the most widely used groups of fungicides. Our previous research showed that the extensive application of CAA fungicides can result in fungicide resistance and in China, CAA-resistant isolates of P. viticola were collected from the field in 2014. To monitor the distribution and spread of CAA fungicide resistance, we developed a TaqMan-minor groove binder (MGB) real-time PCR-based method designed on a functional mutation in the PvCesA3 gene that allows efficient identification of CAA fungicide resistant and sensitive genotypes. The assay was validated on 50 isolates using Sanger sequencing and fungicide bioassays and exploited in a comprehensive survey comprising 2,227 single-sporangiophore isolates from eight major grapevine regions in China. We demonstrate that CAA fungicide resistance in P. viticola is widespread in China. On average, 53.3% of the isolates were found to be resistant, but marked differences were found between locations with percentages of resistant isolates varying from 0.3 to 96.6%. Furthermore, the frequency of CAA-resistant isolates was found to be significantly correlated with the exposure to CAA fungicides (P < 0.05). We further discussed the possibilities to apply the TaqMan-MGB real-time PCR assay to assess the frequency of fungicide-resistant P. viticola isolates in each region or vineyard, which would facilitate the correct choice of fungicide for grape downy mildew and resistance management strategies.

Carboxylic Acid Amide (CAA) Fungicides

2012 ◽  
pp. 807-830 ◽  
Author(s):  
Ulrich Gisi ◽  
Clemens Lamberth ◽  
Andreas Mehl ◽  
Thomas Seitz
Keyword(s):  
Carboxylic Acid ◽  
Acid Amide ◽  
Carboxylic Acid Amide ◽  
Caa Fungicides

The cellulose synthase 3 (CesA3) gene of oomycetes: structure, phylogeny and influence on sensitivity to carboxylic acid amide (CAA) fungicides

2012 ◽  
Vol 116 (4) ◽  
pp. 529-542 ◽  
Author(s):  
Mathias Blum ◽  
Hannes A. Gamper ◽  
Maya Waldner ◽  
Helge Sierotzki ◽  
Ulrich Gisi
Keyword(s):  
Carboxylic Acid ◽  
Acid Amide ◽  
Cellulose Synthase ◽  
Carboxylic Acid Amide ◽  
Caa Fungicides

scholarly journals Generation and Characterization of Isolates of Peronophythora litchii Resistant to Carboxylic Acid Amide Fungicides

2010 ◽  
Vol 100 (5) ◽  
pp. 522-527 ◽  
Author(s):  
Hancheng Wang ◽  
Haiyan Sun ◽  
Gerd Stammler ◽  
Jianxia Ma ◽  
Mingguo Zhou
Keyword(s):  
Carboxylic Acid ◽  
Acid Amide ◽  
Temperature Tolerance ◽  
Cross Resistance ◽  
Carboxylic Acid Amide ◽  
Wild Type ◽  
Fitness Parameters ◽  
Rf Values ◽  
Zoospore Formation ◽  
Caa Fungicides

Four isolates of Peronophythora litchii with resistance to carboxylic acid amide (CAA) fungicides were selected on fungicide-amended agar. These isolates had various levels of resistance, as evidenced by their resistance factor (RF), which is the 50% effective concentration (EC50) value of a particular isolate divided by that of the wild-type parent. RF values to dimethomorph for the four isolates were 15, 24, 141, and >1,500. Resistance was stable for two isolates, while the EC50 values decreased for the other two after repeated subculturing on fungicide-free medium. Cross-resistance occurred with all CAAs tested here (dimethomorph, mandipropamid, flumorph, and pyrimorph), but not with strobilurins (azoxystrobin and famoxadone) or other fungicides (metalaxyl, cymoxanil, and mancozeb). Studies on fitness parameters (mycelial growth, sporulation, spore germination, zoospore formation, aggressiveness, and temperature tolerance) in the parent wild-type and resistant isolates demonstrated that penalties in different parameters may be associated with CAA resistance, depending on the isolate. These studies show that Peronophythora litchii is able to express CAA resistance under laboratory conditions but it is not known if resistant strains could become established in the field and sensitivity monitoring studies are recommended.

Carboxylic Acid Amide (CAA) Fungicides

2008 ◽  
pp. 651-674 ◽  
Author(s):  
Ulrich Gisi ◽  
Clemens Lamberth ◽  
Andreas Mehl ◽  
Thomas Seitz
Keyword(s):  
Carboxylic Acid ◽  
Acid Amide ◽  
Carboxylic Acid Amide ◽  
Caa Fungicides
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