Cytochrome b gene structure and consequences for resistance to Qo inhibitor fungicides in plant pathogens.

  title={Cytochrome b gene structure and consequences for resistance to Qo inhibitor fungicides in plant pathogens.},
  author={Valeria Grasso and Simona Palermo and Helge Sierotzki and Angelo Garibaldi and Ulrich Gisi},
  journal={Pest management science},
  volume={62 6},
The cytochrome b (cyt b) gene structure was characterized for different agronomically important plant pathogens, such as Puccinia recondita f sp tritici (Erikss) CO Johnston, P graminis f sp tritici Erikss and Hennings, P striiformis f sp tritici Erikss, P coronata f sp avenae P Syd & Syd, P hordei GH Otth, P recondita f sp secalis Roberge, P sorghi Schwein, P horiana Henn, Uromyces appendiculatus (Pers) Unger, Phakopsora pachyrhizi Syd & P Syd, Hemileia vastatrix Berk & Broome, Alternaria… 

Characterization of the cytochrome b (cyt b) gene from Monilinia species causing brown rot of stone and pome fruit and its significance in the development of QoI resistance.

It is suggested that resistance to QoI fungicides based on the G143A mutation is not likely to occur in M. fructicola or M. laxa, and they may be at higher risk for developingQoI resistance owing to the absence of a G143-associated intron.

New insights from short and long reads sequencing to explore cytochrome b variants of Plasmopara viticola populations collected in vineyard and related to resistance to complex III inhibitors

NGS appear promising methods to evaluate pathogen resistance towards fungicides related to cytb modifications at a population scale in the field, and could be rapidly a robust decision-support management tool for vineyard in future.

Field resistance to QoI fungicides in Podosphaera fusca is not supported by typical mutations in the mitochondrial cytochrome b gene.

The results indicate that the mechanism responsible for QoI resistance in P. fusca is not linked to typical mutations in cytochrome b gene and that the absence of the G143A substitution cannot be explained by an intron following codon 143, especially in relation to the possible molecular diagnosis of resistance.

Sequence conservation in the mitochondrial cytochrome b gene and lack of G143A QoI resistance allele in a global sample of Rhynchosporium secalis

A high degree of conservation for the cytb gene is indicated at both intra- and interspecific levels, and complete QoI sensitivity in all R. secalis populations tested.

Characterization of Quinone Outside Inhibitor Fungicide Resistance in Cercospora sojina and Development of Diagnostic Tools for its Identification.

The molecular basis ofQoI fungicide resistance in field isolates of C. sojina was identified as the G143A mutation, and specific molecular approaches were developed to discriminate and to track QoI-resistant and -sensitive isolates.

Resistance to QoI Fungicide and Cytochrome b Diversity in the Hungarian Botrytis cinerea Population

A number of group II field isolates were found to be highly resistant to azoxystrobin although they did not appear to carry the G-to-C mutation generally associated with fungal QoI-resistance.

High frequency of fungicide resistance-associated mutations in the wheat yellow rust pathogen Puccinia striiformis f. sp. tritici.

The identification of resistance-associated alleles confirms that cereal rusts are not immune to fungicides resistance and that selection for resistance evolution is operating at high levels in certain locations, highlighting the need to adopt fungicide resistance management practices and to monitor cereal rust species for development of resistance.

Characterization of the cytochrome [beta] gene in plant pathogenic, basidiomycetes and consequences for QoI resistance

It is demonstrated for the first time that the amino acid sequence of the mitochondrial cytochrome b is a valid tool to study phylogenic relatedness among plant pathogenic Basidiomycetes and supports taxonomic grouping based on morphological structures and host specificity.

Characterization of moderate resistance to QoI fungicides in Pestalotiopsis longiseta and polymorphism in exon–intron structure of cytochrome b gene

Nucleotide sequencing of cytb showed that moderate resistance correlated with a single point mutation; leucine was substituted for phenylalanine at amino acid position 129 (F129L) which suggests that G143A and F129L mutations have each occurred at least twice in the P. longiseta population.

Phylogenetic diversity and sensitivity to MBI and QoI fungicides of Magnaporthe oryzae in Taiwan

Molecular phylogenetic analysis showed that M. oryzae isolates could be classified into nine genetic groups (A–I) based on the DNA polymorphism amplified by CNS1/MP primers, and fungicide tests showed that isolates with low sensitivity to QoIs did not correspond with mutation at codon 129 or 143 in the cyt b gene.



Relatedness Among Agronomically Important Rusts Based on Mitochondrial Cytochrome b Gene and Ribosomal ITS Sequences

The results demonstrate that the amino acid sequence of the mitochondrial cytochrome b is a valid tool to study phylogenic relatedness among plant pathogenic Basidiomycetes and supports taxonomic grouping based on morphological structures and host specificity.

Mechanisms influencing the evolution of resistance to Qo inhibitor fungicides.

The G143A substitution is claimed not to affect the activity of the enzyme, suggesting that resistant individuals may not suffer from a significant fitness penalty, as was demonstrated in B graminis f sp tritici.

Field Resistance to Strobilurin (Q(o)I) Fungicides in Pyricularia grisea Caused by Mutations in the Mitochondrial Cytochrome b Gene.

DNA fingerprinting of resistant isolates revealed that the mutations occurred in just five genetic backgrounds, suggesting that field resistance to the Q(o)I fungicides in Pyricularia grisea is due to a small number of ancestral mutations.

The molecular basis for the natural resistance of the cytochrome bc1 complex from strobilurin-producing basidiomycetes to center Qp inhibitors.

The exon/intron organization was determined and the sequences of cytochromes b from S. tenacellus, M. galopoda and a third basidiomycete, Mycena viridimarginata, which produces no strobilurin A were deduced to be naturally resistant to (E)-beta-methoxyacrylates.

Modeling the Qo site of crop pathogens in Saccharomyces cerevisiae cytochrome b.

Saccharomyces cerevisiae has been used as a model system to characterize the effect of cytochrome b mutations found in fungal and oomycete plant pathogens resistant to Q(o) inhibitors (QoIs),

Point Mutation in Cytochrome b Gene Conferring Resistance to Strobilurin Fungicides in Erysiphe graminis f. sp. tritici Field Isolates

The described mode of resistance and the frequency, migration, and fitness of resistant isolates in field populations have to be considered when strategies concerning the method of delaying resistance buildup under field conditions are defined.

Characterization of the mitochondrial cytochrome b gene from Venturia inaequalis

A new class of agricultural fungicides derived from the group of antifungal strobilurins acts as specific respiration inhibitors by binding to mitochondrial cytochrome b, which was cloned and sequenced from the mitochondrial genome of Venturia inaequalis.

Mode of resistance to respiration inhibitors at the cytochrome bc1 enzyme complex of Mycosphaerella fijiensis field isolates

In sensitive but not in resistant isolates, mixtures of Qo inhibitors and SHAM, an inhibitor of the alternative oxidase (AOX), were more active than the components alone, indicating that the alternative pathway is essential in metabolism, but not causal for resistance.