scholarly journals Fungicide Resistance Evolution and Detection in Plant Pathogens: Plasmopara viticola as a Case Study

2021 ◽  
Vol 9 (1) ◽  
pp. 119
Author(s):  
Federico Massi ◽  
Stefano F. F. Torriani ◽  
Lorenzo Borghi ◽  
Silvia L. Toffolatti
Keyword(s):  
Fungicide Resistance ◽  
Plant Pathogens ◽  
Control Plant ◽  
Plasmopara Viticola ◽  
Life Cycles ◽  
Grapevine Downy Mildew ◽  
Resistance Evolution ◽  
Evolution Of Resistance ◽  
Monitoring Activities

The use of single-site fungicides to control plant pathogens in the agroecosystem can be associated with an increased selection of resistance. The evolution of resistance represents one of the biggest challenges in disease control. In vineyards, frequent applications of fungicides are carried out every season for multiple years. The agronomic risk of developing fungicide resistance is, therefore, high. Plasmopara viticola, the causal agent of grapevine downy mildew, is a high risk pathogen associated with the development of fungicide resistance. P. viticola has developed resistance to most of the fungicide classes used and constitutes one of the most important threats for grapevine production. The goals of this review are to describe fungicide resistance evolution in P. viticola populations and how to conduct proper monitoring activities. Different methods have been developed for phenotyping and genotyping P. viticola for fungicide resistance and the different phases of resistance evolution and life cycles of the pathogen are discussed, to provide a full monitoring toolkit to limit the spread of resistance. A detailed revision of the available tools will help in shaping and harmonizing the monitoring activities between countries and organizations.

scholarly journals At Least Two Origins of Fungicide Resistance in Grapevine Downy Mildew Populations

2007 ◽  
Vol 73 (16) ◽  
pp. 5162-5172 ◽  
Author(s):  
Wei-Jen Chen ◽  
François Delmotte ◽  
Sylvie Richard Cervera ◽  
Lisette Douence ◽  
Charles Greif ◽  
...  
Keyword(s):  
Plant Pathogen ◽  
Fungicide Resistance ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Plasmopara Viticola ◽  
Isolated Populations ◽  
Grapevine Downy Mildew ◽  
First Case ◽  
Wide Range ◽  
Pathogen Populations

ABSTRACT Quinone outside inhibiting (QoI) fungicides represent one of the most widely used groups of fungicides used to control agriculturally important fungal pathogens. They inhibit the cytochrome bc 1 complex of mitochondrial respiration. Soon after their introduction onto the market in 1996, QoI fungicide-resistant isolates were detected in field plant pathogen populations of a large range of species. However, there is still little understanding of the processes driving the development of QoI fungicide resistance in plant pathogens. In particular, it is unknown whether fungicide resistance occurs independently in isolated populations or if it appears once and then spreads globally by migration. Here, we provide the first case study of the evolutionary processes that lead to the emergence of QoI fungicide resistance in the plant pathogen Plasmopara viticola. Sequence analysis of the complete cytochrome b gene showed that all resistant isolates carried a mutation resulting in the replacement of glycine by alanine at codon 143 (G143A). Phylogenetic analysis of a large mitochondrial DNA fragment including the cytochrome b gene (2,281 bp) across a wide range of European P. viticola isolates allowed the detection of four major haplotypes belonging to two distinct clades, each of which contains a different QoI fungicide resistance allele. This is the first demonstration that a selected substitution conferring resistance to a fungicide has occurred several times in a plant-pathogen system. Finally, a high population structure was found when the frequency of QoI fungicide resistance haplotypes was assessed in 17 French vineyards, indicating that pathogen populations might be under strong directional selection for local adaptation to fungicide pressure.

scholarly journals Evidence of Selection for Fungicide Resistance in Zymoseptoria tritici Populations on Wheat in Western Oregon

Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 483-489 ◽  
Author(s):  
Laura E. Hayes ◽  
Kathryn E. Sackett ◽  
Nicole P. Anderson ◽  
Michael D. Flowers ◽  
Christopher C. Mundt
Keyword(s):  
Fungicide Resistance ◽  
Fungal Pathogen ◽  
Plant Pathogens ◽  
Septoria Tritici Blotch ◽  
Septoria Tritici ◽  
Zymoseptoria Tritici ◽  
Resistance Evolution ◽  
Regional Control ◽  
Selection For ◽  
Moderately Resistant

Plant pathogens pose a major challenge to maintaining food security in many parts of the world. Where major plant pathogens are fungal, fungicide resistance can often thwart regional control efforts. Zymoseptoria tritici, causal agent of Septoria tritici blotch, is a major fungal pathogen of wheat that has evolved resistance to chemical control products in four fungicide classes in Europe. Compared with Europe, however, fungicide use has been less and studies of fungicide resistance have been infrequent in North American Z. tritici populations. Here, we confirm first reports of Z. tritici fungicide resistance evolution in western Oregon through analysis of the effects of spray applications of propiconazole and an azoxystrobin + propiconazole mixture during a single growing season. Frequencies of strobilurin-resistant isolates, quantified as proportions of G143A mutants, were significantly higher in azoxystrobin-sprayed plots compared with plots with no azoxystrobin treatment at two different locations and were significantly higher in plots of a moderately resistant cultivar than in plots of a susceptible cultivar. Thus, it appears that western Oregon Z. tritici populations have the potential to evolve levels of strobilurin resistance similar to those observed in Europe. Although the concentration of propiconazole required to reduce pathogen growth by 50% values were numerically greater for isolates collected from plots receiving propiconazole than in control plots, this effect was not significant (P > 0.05).

scholarly journals Responses to Drought Stress Modulate the Susceptibility to Plasmopara Viticola in Grapevine

2020 ◽  
Author(s):  
Lisa Heyman ◽  
Antonios Chrysargyris ◽  
Kristof Demeestere ◽  
Nikolaos Tzortzakis ◽  
Monica Höfte
Keyword(s):  
Drought Stress ◽  
Deficit Irrigation ◽  
Plant Pathogens ◽  
Plasmopara Viticola ◽  
In Planta ◽  
Grapevine Downy Mildew ◽  
Combined Stresses ◽  
Controlled Conditions ◽  
Infection Stage ◽  
Leaf Disks

Abstract Climate change will increase the occurrence of plants simultaneously suffering drought and pathogen stress. Although it is well-known that drought can alter the way plants respond to pathogens, the knowledge about the effect of concurrent drought and biotic stress in grapevine is scarce. This is especially true for Plasmopara viticola, the causal agent of grapevine downy mildew. This research addresses how vines with different drought tolerance respond to the challenge with P. viticola, drought stress or their combination, and how one stress affects the other. An artificial inoculation was performed on two cultivars, exposed to full or deficit irrigation, in the Mediterranean climate of Cyprus. In parallel, leaf disks from these plants were inoculated in controlled conditions. Leaves were sampled at an early infection stage to determine the influence of the single and combined stresses on oxidative parameters, chlorophyll and phytohormones. Under irrigation, the local Cypriot cultivar Xynisteri was more susceptible to P. viticola than the drought-sensitive Chardonnay. Drought stress increased their susceptibility in leaves inoculated in controlled conditions. Conversely, both cultivars showed resistance against P. viticola when inoculated in planta under continued deficit irrigation. Despite their resistance, the pathogen-associated responses in auxin, antioxidant enzyme activity and proline still occurred in these drought-stressed plants. Surprisingly, abscisic acid, rather than the generally implicated jasmonic and salicylic acid, seemed to play a prominent role in this resistance. The irrigation-dependent susceptibility highlights that the changing climate and the practices used to mitigate its effects, may have a profound impact on plant pathogens.

scholarly journals Monitoring of a Single Point Mutation in the PvCesA3 Allele Conferring Resistance to Carboxylic Acid Amide Fungicides in Plasmopara viticola Populations In Yamanashi Prefecture, Japan

2015 ◽  
Vol 16 (2) ◽  
pp. 84-87 ◽  
Author(s):  
Yoshinao Aoki ◽  
Yumi Kawagoe ◽  
Nozomi Fujimori ◽  
Sayumi Tanaka ◽  
Shunji Suzuki
Keyword(s):  
Carboxylic Acid ◽  
Point Mutation ◽  
Fungicide Resistance ◽  
Single Point ◽  
Acid Amide ◽  
Plasmopara Viticola ◽  
Single Point Mutation ◽  
Carboxylic Acid Amide ◽  
Grapevine Downy Mildew ◽  
Quinone Outside Inhibitor

The use of the carboxylic acid amide (CAA) fungicide mandipropamid to manage grapevine downy mildew in vineyards in Japan has been increasing since 2010, because of widespread quinone outside inhibitor fungicide resistance in the Plasmopara viticola population. However, CAA fungicide resistance in P. viticola is becoming a serious problem worldwide. In 2013, we monitored for the presence of a single point mutation at codon 1105 of the cellulose synthase gene PvCesA3, which confers resistance to mandipropamid in P. viticola samples collected from four vineyards in Yamanashi prefecture in Japan. Five out of 157 samples were found to be heterozygotes, carrying both the mutated and nonmutated PvCesA3 alleles. Although CAA fungicide-resistant P. viticola isolates have not been reported yet in Japan, the emergence of heterozygous P. viticola populations indicates the potential risk of emergence of resistant homozygotes. Accepted for publication 14 March 2015. Published 1 May 2015

Soft selective sweeps in fungicide resistance evolution: recurrent mutations without fitness costs in grapevine downy mildew

2017 ◽  
Vol 26 (7) ◽  
pp. 1936-1951 ◽  
Author(s):  
Chloé E. L. Delmas ◽  
Yann Dussert ◽  
Laurent Delière ◽  
Carole Couture ◽  
Isabelle D. Mazet ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Fungicide Resistance ◽  
Selective Sweeps ◽  
Fitness Costs ◽  
Grapevine Downy Mildew ◽  
Resistance Evolution ◽  
Recurrent Mutations ◽  
Soft Selective Sweeps

scholarly journals A High-Quality Grapevine Downy Mildew Genome Assembly Reveals Rapidly Evolving and Lineage-Specific Putative Host Adaptation Genes

2019 ◽  
Vol 11 (3) ◽  
pp. 954-969 ◽  
Author(s):  
Yann Dussert ◽  
Isabelle D Mazet ◽  
Carole Couture ◽  
Jérôme Gouzy ◽  
Marie-Christine Piron ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Genome Assembly ◽  
Population Genomics ◽  
Plasmopara Viticola ◽  
Plant Diseases ◽  
Host Specialization ◽  
Grapevine Downy Mildew ◽  
Downy Mildews ◽  
Genes Encoding ◽  
High Level

Abstract Downy mildews are obligate biotrophic oomycete pathogens that cause devastating plant diseases on economically important crops. Plasmopara viticola is the causal agent of grapevine downy mildew, a major disease in vineyards worldwide. We sequenced the genome of Pl. viticola with PacBio long reads and obtained a new 92.94 Mb assembly with high contiguity (359 scaffolds for a N50 of 706.5 kb) due to a better resolution of repeat regions. This assembly presented a high level of gene completeness, recovering 1,592 genes encoding secreted proteins involved in plant–pathogen interactions. Plasmopara viticola had a two-speed genome architecture, with secreted protein-encoding genes preferentially located in gene-sparse, repeat-rich regions and evolving rapidly, as indicated by pairwise dN/dS values. We also used short reads to assemble the genome of Plasmopara muralis, a closely related species infecting grape ivy (Parthenocissus tricuspidata). The lineage-specific proteins identified by comparative genomics analysis included a large proportion of RxLR cytoplasmic effectors and, more generally, genes with high dN/dS values. We identified 270 candidate genes under positive selection, including several genes encoding transporters and components of the RNA machinery potentially involved in host specialization. Finally, the Pl. viticola genome assembly generated here will allow the development of robust population genomics approaches for investigating the mechanisms involved in adaptation to biotic and abiotic selective pressures in this species.

scholarly journals First Insights into the Effect of Mycorrhizae on the Expression of Pathogen Effectors during the Infection of Grapevine with Plasmopara viticola

2021 ◽  
Vol 13 (3) ◽  
pp. 1226
Author(s):  
Ana Cruz-Silva ◽  
Andreia Figueiredo ◽  
Mónica Sebastiana
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Plasmopara Viticola ◽  
Vitis Vinifera L ◽  
Wine Production ◽  
Grapevine Downy Mildew ◽  
Pathogen Effectors ◽  
Rxlr Effectors ◽  
Mycorrhizal Inoculation ◽  
And Control

Grapevine (Vitis vinifera L.), widely used for berry and wine production, is highly susceptible to the pathogenic oomycete Plasmopara viticola, the etiological agent of grapevine downy mildew disease. The method commonly used to prevent and control P. viticola infection relies on multiple applications of chemical fungicides. However, with European Union goals to lower the usage of such chemicals in viticulture there is a need to develop new and more sustainable strategies. The use of beneficial microorganisms with biocontrol capabilities, such as the arbuscular mycorrhizal fungi (AMF), has been pointed out as a viable alternative. With this study, we intended to investigate the effect of AMF colonization on the expression of P. viticola effectors during infection of grapevine. Grapevine plants were inoculated with the AMF Rhizophagus irregularis and, after mycorrhizae development, plants were infected with P. viticola. The expression of P. viticola RxLR effectors was analyzed by real-time PCR (qPCR) during the first hours of interaction. Results show that pre-mycorrhizal inoculation of grapevine alters the expression of several P. viticola effectors; namely, PvRxLR28, which presented decreased expression in mycorrhizal plants at the two time points post-infection tested. These results suggest that the pre-inoculation of grapevine with AMF could interfere with the pathogen’s ability to infect grapevine by modulation of pathogenicity effectors expression, supporting the hypothesis that AMF can be used to increase plant resistance to pathogens and promote more sustainable agriculture practices, particularly in viticulture.

scholarly journals The Management of Reading Park Case study in Kaba Kamboja Batipuh Panjang

2021 ◽  
Vol 9 (4) ◽  
pp. 493
Author(s):  
Fitri Anggeli ◽  
Solfema Solfema
Keyword(s):  
Human Resources ◽  
Critical Awareness ◽  
Reading Culture ◽  
Monitoring Activities ◽  
Learning Management ◽  
Children's Reading ◽  
Reading Interest ◽  
Children’S Reading

Reading park it means of a place to increase children’s interest in reading which makes reading a daily culture in improving the quality of human resources. In Kaba Kamboja, the withdrawal of interest in reading is carried out by managers the managers is who are collage students. The manager himself which has several strategies in its services, especially learning management in the form of : 1) critical awareness 2) motivating children, 3) two-way communication, 4) monitoring activities, and 5) program providers as needed. In the case of kaba kamboja its focuses on reading interest to make area on Batipuh Panjang are reading culture. The purpose of managing the reading park itself now more focused on children’s reading culture. Kaba Kamboja is opened every times a week and more towards tutoring and becoming a focus for playing and learning areas for the children of the jambak village

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