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Andronis CE, Jacques S, Lopez-Ruiz FJ, Lipscombe R, Tan KC. Proteomic analysis revealed that the oomyceticide phosphite exhibits multi-modal action in an oomycete pathosystem. J Proteomics 2024; 301:105181. [PMID: 38670258 DOI: 10.1016/j.jprot.2024.105181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 04/17/2024] [Accepted: 04/23/2024] [Indexed: 04/28/2024]
Abstract
Phytopathogenic oomycetes constitute some of the most devastating plant pathogens and cause significant crop and horticultural yield and economic losses. The phytopathogen Phytophthora cinnamomi causes dieback disease in native vegetation and several crops. The most commonly used chemical to control P. cinnamomi is the oomyceticide phosphite. Despite its widespread use, the mode of action of phosphite is not well understood and it is unclear whether it targets the pathogen, the host, or both. Resistance to phosphite is emerging in P. cinnamomi isolates and other oomycete phytopathogens. The mode of action of phosphite on phosphite-sensitive and resistant isolates of the pathogen and through a model host was investigated using label-free quantitative proteomics. In vitro treatment of sensitive P. cinnamomi isolates with phosphite hinders growth by interfering with metabolism, signalling and gene expression; traits that are not observed in the resistant isolate. When the model host Lupinus angustifolius was treated with phosphite, proteins associated with photosynthesis, carbon fixation and lipid metabolism in the host were enriched. Increased production of defence-related proteins was also observed in the plant. We hypothesise the multi-modal action of phosphite and present two models constructed using comparative proteomics that demonstrate mechanisms of pathogen and host responses to phosphite. SIGNIFICANCE: Phytophthora cinnamomi is a significant phytopathogenic oomycete that causes root rot (dieback) in a number of horticultural crops and a vast range of native vegetation. Historically, areas infected with phosphite have been treated with the oomyceticide phosphite despite its unknown mode of action. Additionally, overuse of phosphite has driven the emergence of phosphite-resistant isolates of the pathogen. We conducted a comparative proteomic study of a sensitive and resistant isolate of P. cinnamomi in response to treatment with phosphite, and the response of a model host, Lupinus angustifolius, to phosphite and its implications on infection. The present study has allowed for a deeper understanding of the bimodal action of phosphite, suggested potential biochemical factors contributing to chemical resistance in P. cinnamomi, and unveiled possible drivers of phosphite-induced host plant immunity to the pathogen.
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Affiliation(s)
- Christina E Andronis
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia; Proteomics International, Nedlands, WA, Australia.
| | - Silke Jacques
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia
| | | | | | - Kar-Chun Tan
- Centre for Crop and Disease Management, Curtin University, Bentley, WA, Australia.
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2
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Lopes UP, Alonzo G, Onofre RB, Mello PP, Gadoury DM, Vallad GE, Peres NA. Effective Management of Powdery Mildew in Cantaloupe Plants Using Nighttime Applications of UV Light. PLANT DISEASE 2023; 107:2483-2489. [PMID: 36726003 DOI: 10.1094/pdis-08-22-1941-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Ultraviolet light at wavelengths from 254 to 283 nm/has been reported to effectively suppress powdery mildews in several crops, including some cucurbits. Its use to suppress powdery mildew (Podosphaera xanthii) specifically in cantaloupe has not been previously reported. We evaluated the foregoing technology in cantaloupe fields for suppression of powdery mildew and possible effects on plant growth and yield. In a controlled laboratory study, greenhouse-grown cantaloupe plants were exposed to a gradient of UV-C (254 nm) doses during darkness, and the effects upon powdery mildew development and the plant were evaluated. We also evaluated the efficacy of nighttime applications of UV-C at 100 and 200 J/m2 against powdery mildew on adaxial leaf surfaces in greenhouse, high-tunnel, and open-field plantings. UV-C at the foregoing doses reduced sporulation and germination of P. xanthii conidia without damaging plants. On cantaloupe seedlings in the greenhouse, disease severity was equivalently suppressed at all doses and frequencies of applications of the light. In high-tunnel and open-field experiments, the most effective control of powdery mildew was provided by UV-C applied at 200 J/m2 twice every week, where suppression provided by UV-C was generally equal to and sometimes better than the fungicide treatment. The foregoing UV-C dose and frequency of application also provided the highest yield under field conditions, indicating that UV-C treatment is a promising technology for commercially relevant suppression of powdery mildew on cantaloupe in a variety of growing systems.
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Affiliation(s)
- Ueder P Lopes
- Universidade Federal do Agreste de Pernambuco, Garanhuns, Pernambuco 55292-270, Brazil
- Plant Pathology Department, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, U.S.A
| | - Galvin Alonzo
- Plant Pathology Department, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, U.S.A
| | - Rodrigo B Onofre
- Plant Pathology Department, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, U.S.A
| | - Paulo P Mello
- Plant Pathology Department, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, U.S.A
| | - David M Gadoury
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456, U.S.A
| | - Gary E Vallad
- Plant Pathology Department, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, U.S.A
| | - Natalia A Peres
- Plant Pathology Department, Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, U.S.A
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3
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Zanni R, Martínez-Cruz J, Gálvez-Llompart M, Fernández-Ortuño D, Romero D, García-Domènech R, Pérez-García A, Gálvez J. Rational Design of Chitin Deacetylase Inhibitors for Sustainable Agricultural Use Based on Molecular Topology. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:13118-13131. [PMID: 36194443 PMCID: PMC10389753 DOI: 10.1021/acs.jafc.2c02377] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Fungicide resistance is a major concern in modern agriculture; therefore, there is a pressing demand to develop new, greener chemicals. Chitin is a major component of the fungal cell wall and a well-known elicitor of plant immunity. To overcome chitin recognition, fungal pathogens developed different strategies, with chitin deacetylase (CDA) activity being the most conserved. This enzyme is responsible for hydrolyzing the N-acetamido group in N-acetylglucosamine units of chitin to convert it to chitosan, a compound that can no longer be recognized by the plant. In previous works, we observed that treatments with CDA inhibitors, such as carboxylic acids, reduced the symptoms of cucurbit powdery mildew and induced rapid activation of chitin-triggered immunity, indicating that CDA could be an interesting target for fungicide development. In this work, we developed an in silico strategy based on QSAR (quantitative structure-activity relationship) and molecular topology (MT) to discover new, specific, and potent CAD inhibitors. Starting with the chemical structures of few carboxylic acids, with and without disease control activity, three predictive equations based on the MT paradigm were developed to identify a group of potential molecules. Their fungicidal activity was experimentally tested, and their specificity as CDA inhibitors was studied for the three best candidates by molecular docking simulations. To our knowledge, this is the first time that MT has been used for the identification of potential CDA inhibitors to be used against resistant powdery mildew strains. In this sense, we consider of special interest the discovery of molecules capable of stimulating the immune system of plants by triggering a defensive response against fungal species that are highly resistant to fungicides such as powdery mildew.
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Affiliation(s)
- Riccardo Zanni
- Molecular Topology and Drug Design Unit, Department of Physical Chemistry, University of Valencia, 46010Valencia, Spain
| | - Jesús Martínez-Cruz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga29071, Spain
| | - María Gálvez-Llompart
- Molecular Topology and Drug Design Unit, Department of Physical Chemistry, University of Valencia, 46010Valencia, Spain
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga29071, Spain
| | - Diego Romero
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga29071, Spain
| | - Ramón García-Domènech
- Molecular Topology and Drug Design Unit, Department of Physical Chemistry, University of Valencia, 46010Valencia, Spain
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Universidad de Málaga, Málaga29071, Spain
| | - Jorge Gálvez
- Molecular Topology and Drug Design Unit, Department of Physical Chemistry, University of Valencia, 46010Valencia, Spain
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4
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Gao S, Xu L, Zeng R, Gao P, Song Z, Dai F. Baseline sensitivity of
Rhizoctonia solani
to four DMI fungicides. J Basic Microbiol 2022; 62:701-710. [DOI: 10.1002/jobm.202100642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Shigang Gao
- Shanghai Engineering Research Centre of Low‐Carbon Agriculture, Institute of Eco‐Environment and Plant Protection Shanghai Academy of Agricultural Sciences Shanghai China
| | - Lihui Xu
- Shanghai Engineering Research Centre of Low‐Carbon Agriculture, Institute of Eco‐Environment and Plant Protection Shanghai Academy of Agricultural Sciences Shanghai China
| | - Rong Zeng
- Shanghai Engineering Research Centre of Low‐Carbon Agriculture, Institute of Eco‐Environment and Plant Protection Shanghai Academy of Agricultural Sciences Shanghai China
| | - Ping Gao
- Shanghai Engineering Research Centre of Low‐Carbon Agriculture, Institute of Eco‐Environment and Plant Protection Shanghai Academy of Agricultural Sciences Shanghai China
| | - Zhiwei Song
- Shanghai Engineering Research Centre of Low‐Carbon Agriculture, Institute of Eco‐Environment and Plant Protection Shanghai Academy of Agricultural Sciences Shanghai China
| | - Fuming Dai
- Shanghai Engineering Research Centre of Low‐Carbon Agriculture, Institute of Eco‐Environment and Plant Protection Shanghai Academy of Agricultural Sciences Shanghai China
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5
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Martínez-Cruz JM, Polonio Á, Zanni R, Romero D, Gálvez J, Fernández-Ortuño D, Pérez-García A. Chitin Deacetylase, a Novel Target for the Design of Agricultural Fungicides. J Fungi (Basel) 2021; 7:jof7121009. [PMID: 34946992 PMCID: PMC8706340 DOI: 10.3390/jof7121009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 12/23/2022] Open
Abstract
Fungicide resistance is a serious problem for agriculture. This is particularly apparent in the case of powdery mildew fungi. Therefore, there is an urgent need to develop new agrochemicals. Chitin is a well-known elicitor of plant immunity, and fungal pathogens have evolved strategies to overcome its detection. Among these strategies, chitin deacetylase (CDA) is responsible for modifying immunogenic chitooligomers and hydrolysing the acetamido group in the N-acetylglucosamine units to avoid recognition. In this work, we tested the hypothesis that CDA can be an appropriate target for antifungals using the cucurbit powdery mildew pathogen Podosphaera xanthii. According to our hypothesis, RNAi silencing of PxCDA resulted in a dramatic reduction in fungal growth that was linked to a rapid elicitation of chitin-triggered immunity. Similar results were obtained with treatments with carboxylic acids such as EDTA, a well-known CDA inhibitor. The disease-suppression activity of EDTA was not associated with its chelating activity since other chelating agents did not suppress disease. The binding of EDTA to CDA was confirmed by molecular docking studies. Furthermore, EDTA also suppressed green and grey mould-causing pathogens applied to oranges and strawberries, respectively. Our results conclusively show that CDA is a promising target for control of phytopathogenic fungi and that EDTA could be a starting point for fungicide design.
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Affiliation(s)
- Jesús M. Martínez-Cruz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
| | - Álvaro Polonio
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
| | - Riccardo Zanni
- Molecular Topology and Drug Design Unit, Department of Physical Chemistry, University of Valencia, 46010 Valencia, Spain; (R.Z.); (J.G.)
| | - Diego Romero
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
| | - Jorge Gálvez
- Molecular Topology and Drug Design Unit, Department of Physical Chemistry, University of Valencia, 46010 Valencia, Spain; (R.Z.); (J.G.)
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
- Correspondence:
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
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6
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Resistance to the SDHI Fungicides Boscalid and Fluopyram in Podosphaera xanthii Populations from Commercial Cucurbit Fields in Spain. J Fungi (Basel) 2021; 7:jof7090733. [PMID: 34575771 PMCID: PMC8464660 DOI: 10.3390/jof7090733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 08/27/2021] [Accepted: 09/06/2021] [Indexed: 01/23/2023] Open
Abstract
Powdery mildew is caused by Podosphaera xanthii, and is one of the most important diseases that attacks Spanish cucurbit crops. Fungicide application is the primary control tool; however, its effectiveness is hampered by the rapid development of resistance to these compounds. In this study, the EC50 values of 26 isolates were determined in response to the succinate dehydrogenase inhibitor (SDHI) fungicides boscalid and fluopyram. From these data, the discriminatory doses were deduced and used for SDHI resistance monitoring during the 2018 and 2019 growing seasons. Of the 298 isolates analysed, 37.9% showed resistance to boscalid and 44% to fluopyram. Although different phenotypes were observed in leaf disc assays, the resistant isolates showed the same phenotype in plant assays. Compared to sensitive isolates, two amino acid changes were found in the SdhC subunit, A86V and G151R, which are associated mostly with resistance patterns to fluopyram and boscalid, respectively. Furthermore, no significant differences were observed in terms of fitness cost between the selected sensitive and resistant isolates analysed here. Lastly, a loop-mediated isothermal amplification (LAMP) assay was developed to detect A86V and G151R mutations using conidia obtained directly from infected material. Our results show that growers could continue to use boscalid and fluopyram, but resistance management practices must be implemented.
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Kelly LA, Vaghefi N, Bransgrove K, Fechner NA, Stuart K, Pandey AK, Sharma M, Németh MZ, Liu SY, Tang SR, Nair RM, Douglas CA, Kiss L. One Crop Disease, How Many Pathogens? Podosphaera xanthii and Erysiphe vignae sp. nov. Identified as the Two Species that Cause Powdery Mildew of Mungbean ( Vigna radiata) and Black Gram ( V. mungo) in Australia. PHYTOPATHOLOGY 2021; 111:1193-1206. [PMID: 33487024 DOI: 10.1094/phyto-12-20-0554-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Powdery mildew is a significant threat to mungbean (Vigna radiata) and black gram (V. mungo) production across Australia and overseas. Although they have been present in Australia for at least six decades and are easily recognized in the field, the precise identification of the pathogens causing this disease has remained unclear. Our goal was to identify the powdery mildew species infecting mungbean, black gram, and wild mungbean (V. radiata ssp. sublobata) in Australia. The internal transcribed spacer (ITS) and large subunit sequences of the ribosomal DNA and/or morphology of 57 Australian specimens were examined. Mungbean and black gram were infected by two species: Podosphaera xanthii and a newly recognized taxon, Erysiphe vignae sp. nov. Wild mungbean was infected only with P. xanthii. Mungbean and black gram powdery mildew ITS sequences from China, India, and Taiwan revealed the presence of only P. xanthii on these crops despite controversial reports of an Erysiphe species on both crops in India. Sequence analyses indicated that the closest relative of E. vignae is E. diffusa, which infects soybean (Glycine max) and other plants. E. vignae did not infect soybean in cross-inoculation tests. In turn, E. diffusa from soybean infected black gram and provoked hypersensitive response in mungbean. The recognition of a second species, E. vignae, as another causal agent of mungbean and black gram powdery mildew in Australia may complicate plant breeding efforts and control of the disease with fungicide applications.
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Affiliation(s)
- Lisa A Kelly
- University of Southern Queensland, Centre for Crop Health, QLD 4350 Toowoomba, Australia
- Queensland Government, Department of Agriculture and Fisheries, QLD 4350 Toowoomba, Australia
| | - Niloofar Vaghefi
- University of Southern Queensland, Centre for Crop Health, QLD 4350 Toowoomba, Australia
| | - Kaylene Bransgrove
- Queensland Plant Pathology Herbarium, Department of Agriculture and Fisheries, QLD 4102 Dutton Park, Australia
| | - Nigel A Fechner
- Queensland Government, Department of Environment and Science, Queensland Herbarium, Mt. Coot-tha Botanic Gardens, QLD 4066 Toowong, Australia
| | - Kara Stuart
- Biosecurity Queensland, Department of Agriculture and Fisheries, QLD 4102 Dutton Park, Australia
| | - Abhay K Pandey
- World Vegetable Center, South Asia, ICRISAT Campus, Patancheru, Hyderabad 502324, India
| | - Mamta Sharma
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad 502324, India
| | - Márk Z Németh
- Plant Protection Institute, Centre for Agricultural Research, Eötvös Loránd Research Network, H-1525 Budapest, Hungary
| | - Shu-Yan Liu
- Jilin Agricultural University, College of Plant Protection, Changchun 130118, Jilin Province, China
| | - Shu-Rong Tang
- Jilin Agricultural University, College of Plant Protection, Changchun 130118, Jilin Province, China
| | - Ramakrishnan M Nair
- World Vegetable Center, South Asia, ICRISAT Campus, Patancheru, Hyderabad 502324, India
| | - Colin A Douglas
- Queensland Government, Department of Agriculture and Fisheries, QLD 4370 Warwick, Australia
| | - Levente Kiss
- University of Southern Queensland, Centre for Crop Health, QLD 4350 Toowoomba, Australia
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Ishii H, Bryson PK, Kayamori M, Miyamoto T, Yamaoka Y, Schnabel G. Cross-resistance to the new fungicide mefentrifluconazole in DMI-resistant fungal pathogens. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 171:104737. [PMID: 33357559 DOI: 10.1016/j.pestbp.2020.104737] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/15/2020] [Accepted: 10/16/2020] [Indexed: 06/12/2023]
Abstract
In the European Union (EU), regulation of sterol demethylation inhibiting (DMI) fungicides is tightened due to their suspected endocrine disrupting properties. However, the new DMI fungicide mefentrifluconazole was reported to have high fungicidal activity with minimal adverse side effects. In addition, some evidence suggests inconsistent cross resistance between mefentrifluconazole and other azoles. In this study, mefentrifluconazole and other triazoles were examined for activity to select pathogens sensitive or resistant to DMIs using mycelial growth tests on fungicide-treated culture medium or spray trials using cucumber plants. Cross-resistance was confirmed for all of the fungal species tested but activity levels varied. The sensitivity of Monilinia fructicola from peach to mefentrifluconazole was higher compared to other DMIs. In contrast, the inhibitory activity of mefentrifluconazole was equal or slightly inferior compared to difenoconazole, tebuconazole, propiconazole in Colletotrichum spp., Alternaria alternaria sp. complex and Cercospora beticola isolated from peach and sugar beet, respectively. Similar tendencies (i.e. equal or slightly inferior activity and cross-resistance) were observed for cucumber powdery mildew (Podosphaera xanthii) resistant to triflumizole, myclobutanil, and difenoconazole. Despite cross-resistance to other DMIs, mefentrifluconazole is a promising fungicide for fungal disease control on peach and other crops, with a reportedly more favorable toxicity profile.
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Affiliation(s)
- Hideo Ishii
- University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan; Clemson University, 105 Collings St., Clemson, SC 29634, USA.
| | | | - Miyuki Kayamori
- Tokachi Agricultural Experiment Station, Hokkaido Research Organization, Memuro, Kasai, Hokkaido 082-0081, Japan
| | - Takuya Miyamoto
- Horticultural Research Institute, Ibaraki Agricultural Centre, 3165-1 Ago, Kasama, Ibaraki 312-0292, Japan
| | - Yuichi Yamaoka
- University of Tsukuba, Tennodai 1-1-1, Tsukuba, Ibaraki 305-8572, Japan
| | - Guido Schnabel
- Clemson University, 105 Collings St., Clemson, SC 29634, USA.
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9
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Fungicide Resistance in Powdery Mildew Fungi. Microorganisms 2020; 8:microorganisms8091431. [PMID: 32957583 PMCID: PMC7564317 DOI: 10.3390/microorganisms8091431] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/07/2020] [Accepted: 09/14/2020] [Indexed: 11/17/2022] Open
Abstract
Powdery mildew fungi (Erysiphales) are among the most common and important plant fungal pathogens. These fungi are obligate biotrophic parasites that attack nearly 10,000 species of angiosperms, including major crops, such as cereals and grapes. Although cultural and biological practices may reduce the risk of infection by powdery mildew, they do not provide sufficient protection. Therefore, in practice, chemical control, including the use of fungicides from multiple chemical groups, is the most effective tool for managing powdery mildew. Unfortunately, the risk of resistance development is high because typical spray programs include multiple applications per season. In addition, some of the most economically destructive species of powdery mildew fungi are considered to be high-risk pathogens and are able to develop resistance to several chemical classes within a few years. This situation has decreased the efficacy of the major fungicide classes, such as sterol demethylation inhibitors, quinone outside inhibitors and succinate dehydrogenase inhibitors, that are employed against powdery mildews. In this review, we present cases of reduction in sensitivity, development of resistance and failure of control by fungicides that have been or are being used to manage powdery mildew. In addition, the molecular mechanisms underlying resistance to fungicides are also outlined. Finally, a number of recommendations are provided to decrease the probability of resistance development when fungicides are employed.
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10
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Lammari HI, Rehfus A, Stammler G, Benslimane H. Sensitivity of the Pyrenophora teres Population in Algeria to Quinone outside Inhibitors, Succinate Dehydrogenase Inhibitors and Demethylation Inhibitors. THE PLANT PATHOLOGY JOURNAL 2020; 36:218-230. [PMID: 32547338 PMCID: PMC7272849 DOI: 10.5423/ppj.oa.09.2019.0237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 03/25/2020] [Accepted: 04/21/2020] [Indexed: 05/27/2023]
Abstract
Net blotch of barley caused by Pyrenophora teres (Died.) Drechsler, is one of the most destructive diseases on barley in Algeria. It occurs in two forms: P. teres f. teres and P. teres f. maculata. A total of 212 isolates, obtained from 58 fields sampled in several barley growing areas, were assessed for fungicide sensitivity by target gene analysis. F129L and G137R mitochondrial cytochrome b substitution associated with quinone outside inhibitors (QoIs) resistance, and succinate dehydrogenase inhibitors (SDHIs) related mutations (B-H277, C-N75S, C-G79R, C-H134R, and C-S135R), were analyzed by pyrosequencing. In vitro sensitivity of 45 isolates, towards six fungicides belonging to three chemical groups (QoI, demethylase inhibitor, and SDHI) was tested by microtiter technique. Additionally, sensitivity towards three fungicides (azoxystrobin, fluxapyroxad, and epoxiconazole) was assessed in planta under glasshouse conditions. All tested isolates were QoI-sensitive and SDHI-sensitive, no mutation that confers resistance was identified. EC50 values showed that pyraclostrobin and azoxystrobin are the most efficient fungicides in vitro, whereas fluxapyroxad displayed the best disease inhibition in planta (81% inhibition at 1/9 of the full dose). The EC50 values recorded for each form of net blotch showed no significant difference in efficiency of QoI treatments and propiconazole on each form. However, in the case of fluxapyroxad, epoxiconazole and tebuconazole treatments, analysis showed significant differences in their efficiency. To our knowledge, this study is the first investigation related to mutations associated to QoI and SDHI fungicide resistance in Algerian P. teres population, as well as it is the first evaluation of the sensitivity of P. teres population towards these six fungicides.
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Affiliation(s)
- Hamama-Imène Lammari
- Phytopathology and Molecular Biology Laboratory, Department of Botany, National High College of Agriculture, Algiers, Algeria
| | | | - Gerd Stammler
- BASF SE, Agricultural Centre, 67117 Limburgerhof, Germany
| | - Hamida Benslimane
- Integrative Improvement of Crop Production Laboratory (Amélioration Intégrative des Productions Végétales), Department of Botany, National High College of Agriculture, Algiers C2711100, Algeria
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11
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He L, Li X, Gao Y, Li B, Mu W, Liu F. Oil Adjuvants Enhance the Efficacy of Pyraclostrobin in Managing Cucumber Powdery Mildew ( Podosphaera xanthii) by Modifying the Affinity of Fungicide Droplets on Diseased Leaves. PLANT DISEASE 2019; 103:1657-1664. [PMID: 31082320 DOI: 10.1094/pdis-09-18-1606-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Adding adjuvants improved the affinity of fungicide droplets to cucumber leaves infected with powdery mildew (Podosphaera xanthii) and subsequent efficacy of fungicide treatments in reducing the disease. The affinity of oil adjuvants was quantified by adhesional tension and "work of adhesion". Oil adjuvant-fungicide mixtures were applied to plants in field experiments to evaluate their effectiveness in disease prevention. Both the adhesional tension and work of adhesion of the adjuvants at selected concentrations increased on powdery-mildew-infected cucumber leaves more than on healthy cucumber leaves. The adjuvant GY-Tmax (GYT) displayed the best surface activity or "surfactivity" in enhancing the affinity and adherence of droplets to powdery-mildew-infected cucumber leaves, while epoxidized soybean oil (ESO), methyl oleate, and biodiesel exhibited much lower effects in terms of the surface tension, contact angle, adhesional tension, and work of adhesion. Field experiments determined that the combination of GYT at 1,000 mg liter-1 and pyraclostrobin (150 g a.i. ha-1) was most effective (91.52%) in controlling cucumber powdery mildew. Pyraclostrobin with ESO was also highly effective (ranging from 77.54 to 89.65%). The addition of oil adjuvants, especially GYT and ESO, to fungicide applications can be an effective strategy to enhance the efficacy of pesticides in controlling plant diseases by modifying the affinity of fungicide droplets to symptomatic leaves.
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Affiliation(s)
- Lifei He
- 1 Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
- 2 Key Laboratory of Pesticide Toxicology & Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
| | - Xiaoxu Li
- 1 Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
- 2 Key Laboratory of Pesticide Toxicology & Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
| | - Yangyang Gao
- 1 Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
- 2 Key Laboratory of Pesticide Toxicology & Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
| | - Beixing Li
- 2 Key Laboratory of Pesticide Toxicology & Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
- 3 Research Center of Pesticide Environmental Toxicology, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
| | - Wei Mu
- 1 Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
- 3 Research Center of Pesticide Environmental Toxicology, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
| | - Feng Liu
- 2 Key Laboratory of Pesticide Toxicology & Application Technique, College of Plant Protection, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
- 3 Research Center of Pesticide Environmental Toxicology, Shandong Agricultural University, Tai'an, Shandong 271018, P. R. China
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12
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Vielba-Fernández A, de Vicente A, Pérez-García A, Fernández-Ortuño D. Monitoring Methyl Benzimidazole Carbamate-Resistant Isolates of the Cucurbit Powdery Mildew Pathogen, Podosphaera xanthii, Using Loop-Mediated Isothermal Amplification. PLANT DISEASE 2019; 103:1515-1524. [PMID: 31059385 DOI: 10.1094/pdis-12-18-2256-re] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Powdery mildew, caused by the fungus Podosphaera xanthii, is one of the most economically important diseases affecting cucurbit crops in Spain. Currently, chemical control offers the most efficient management of the disease; however, P. xanthii isolates resistant to multiple classes of site-specific fungicides have been reported in the Spanish cucurbit powdery mildew population. In previous studies, resistance to the fungicides known as methyl benzimidazole carbamates (MBCs) was found to be caused by the amino acid substitution E198A on β-tubulin. To detect MBC-resistant isolates in a faster, more efficient, and more specific way than the traditional methods used to date, a loop-mediated isothermal amplification (LAMP) system was developed. In this study, three sets of LAMP primers were designed. One set was designed for the detection of the wild-type allele and two sets were designed for the E198A amino acid change. Positive results were only obtained with both mutant sets; however, LAMP reaction conditions were only optimized with primer set 2, which was selected for optimal detection of the E198A amino acid change in P. xanthii-resistant isolates, along with the optimal temperature and duration parameters of 65°C for 75 min, respectively. The hydroxynaphthol blue (HNB) metal indicator was used for quick visualization of results through the color change from violet to sky blue when the amplification was positive. HNB was added before the amplification to avoid opening the lids, thus decreasing the probability of contamination. To confirm that the amplified product corresponded to the β-tubulin gene, the LAMP product was digested with the enzyme LweI and sequenced. Our results show that the LAMP technique is a specific and reproducible method that could be used for monitoring MBC resistance of P. xanthii directly in the field.
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Affiliation(s)
- Alejandra Vielba-Fernández
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; and Departamento de Microbiología, Instituto de Hortofruticultura Subtropical y Mediterránea, "La Mayora" Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Campus de Teatinos, 29071 Málaga, Spain
| | - Antonio de Vicente
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; and Departamento de Microbiología, Instituto de Hortofruticultura Subtropical y Mediterránea, "La Mayora" Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Campus de Teatinos, 29071 Málaga, Spain
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; and Departamento de Microbiología, Instituto de Hortofruticultura Subtropical y Mediterránea, "La Mayora" Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Campus de Teatinos, 29071 Málaga, Spain
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; and Departamento de Microbiología, Instituto de Hortofruticultura Subtropical y Mediterránea, "La Mayora" Universidad de Málaga-Consejo Superior de Investigaciones Científicas, Campus de Teatinos, 29071 Málaga, Spain
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13
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Vielba-Fernández A, Bellón-Gómez D, Torés JA, de Vicente A, Pérez-García A, Fernández-Ortuño D. Heteroplasmy for the Cytochrome b Gene in Podosphaera xanthii and its Role in Resistance to QoI Fungicides in Spain. PLANT DISEASE 2018; 102:1599-1605. [PMID: 30673427 DOI: 10.1094/pdis-12-17-1987-re] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In Spain, management of the cucurbit powdery mildew pathogen Podosphaera xanthii is strongly dependent on chemicals such as quinone outside inhibitor (QoI) fungicides. In a previous report, widespread resistance to QoI fungicides in populations of P. xanthii in south-central Spain was documented, but the molecular mechanisms of resistance remained unclear. In this work, the role of the Rieske-FeS (risp) and the cytochrome b (cytb) gene mutations in QoI resistance of P. xanthii were examined. No point mutations in the risp gene were found in the three QoI-resistant isolates analyzed. For cytb, sequence analysis revealed the presence of a G143A substitution that occurs in many QoI-resistant fungi. This mutation was always detected in QoI-resistant isolates of P. xanthii; however, it was also detected in sensitive isolates. To better understand the role of heteroplasmy for cytb in QoI resistance of P. xanthii, an allele-specific quantitative PCR was developed to quantify the relative abundance of the G143 (sensitive) and A143 (resistant) alleles. High relative abundance of A143 allele (70%) was associated with isolates resistant to QoI fungicides; however, QoI-sensitive isolates also carried the mutated allele in frequencies ranged from 10 to 60%. Our data suggest that G143A mutation in cytb is the primary factor involved in QoI resistance of P. xanthii but the proportion of G143 and A143 alleles in an isolate may determine its QoI resistance level.
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Affiliation(s)
- Alejandra Vielba-Fernández
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental "La Mayora", 29750 Algarrobo-Costa (Málaga), Spain
| | - Davinia Bellón-Gómez
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental "La Mayora", 29750 Algarrobo-Costa (Málaga), Spain
| | - Juan A Torés
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental "La Mayora", 29750 Algarrobo-Costa (Málaga), Spain
| | - Antonio de Vicente
- IHSM-UMA-CSIC, Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
| | - Alejandro Pérez-García
- IHSM-UMA-CSIC, Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
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14
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Mair WJ, Deng W, Mullins JGL, West S, Wang P, Besharat N, Ellwood SR, Oliver RP, Lopez-Ruiz FJ. Demethylase Inhibitor Fungicide Resistance in Pyrenophora teres f. sp. teres Associated with Target Site Modification and Inducible Overexpression of Cyp51. Front Microbiol 2016; 7:1279. [PMID: 27594852 PMCID: PMC4990540 DOI: 10.3389/fmicb.2016.01279] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/03/2016] [Indexed: 12/18/2022] Open
Abstract
Pyrenophora teres f. sp. teres is the cause of net form of net blotch (NFNB), an economically important foliar disease in barley (Hordeum vulgare). Net and spot forms of net blotch are widely controlled using site-specific systemic fungicides. Although resistance to succinate dehydrogenase inhibitors and quinone outside inhibitors has been addressed before in net blotches, mechanisms controlling demethylation inhibitor resistance have not yet been reported at the molecular level. Here we report the isolation of strains of NFNB in Australia since 2013 resistant to a range of demethylase inhibitor fungicides. Cyp51A:KO103-A1, an allele with the mutation F489L, corresponding to the archetype F495I in Aspergillus fumigatus, was only present in resistant strains and was correlated with resistance factors to various demethylase inhibitors ranging from 1.1 for epoxiconazole to 31.7 for prochloraz. Structural in silico modeling of the sensitive and resistant CYP51A proteins docked with different demethylase inhibitor fungicides showed how the interaction of F489L within the heme cavity produced a localized constriction of the region adjacent to the docking site that is predicted to result in lower binding affinities. Resistant strains also displayed enhanced induced expression of the two Cyp51A paralogs and of Cyp51B genes. While Cyp51B was found to be constitutively expressed in the absence of fungicide, Cyp51A was only detected at extremely low levels. Under fungicide induction, expression of Cyp51B, Cyp51A2, and Cyp51A1 was shown to be 1.6-, 3,- and 5.3-fold higher, respectively in the resistant isolate compared to the wild type. These increased levels of expression were not supported by changes in the promoters of any of the three genes. The implications of these findings on demethylase inhibitor activity will require current net blotch management strategies to be reconsidered in order to avoid the development of further resistance and preserve the lifespan of fungicides in use.
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Affiliation(s)
- Wesley J Mair
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University Bentley, WA, Australia
| | - Weiwei Deng
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University Bentley, WA, Australia
| | | | - Samuel West
- Institute of Life Science, School of Medicine, Swansea University Swansea, UK
| | - Penghao Wang
- School of Veterinary and Life Sciences, Murdoch University Murdoch, WA, Australia
| | - Naghmeh Besharat
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University Bentley, WA, Australia
| | - Simon R Ellwood
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University Bentley, WA, Australia
| | - Richard P Oliver
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University Bentley, WA, Australia
| | - Francisco J Lopez-Ruiz
- Department of Environment and Agriculture, Centre for Crop and Disease Management, Curtin University Bentley, WA, Australia
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15
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Lamichhane JR, Dachbrodt-Saaydeh S, Kudsk P, Messéan A. Toward a Reduced Reliance on Conventional Pesticides in European Agriculture. PLANT DISEASE 2016; 100:10-24. [PMID: 30688570 DOI: 10.1094/pdis-05-15-0574-fe] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Whether modern agriculture without conventional pesticides will be possible or not is a matter of debate. The debate is meaningful within the context of rising health and environmental awareness on one hand, and the global challenge of feeding a steadily growing human population on the other. Conventional pesticide use has come under pressure in many countries, and some European Union (EU) Member States have adopted policies for risk reduction following Directive 2009/128/EC, the sustainable use of pesticides. Highly diverse crop production systems across Europe, having varied geographic and climatic conditions, increase the complexity of European crop protection. The economic competitiveness of European agriculture is challenged by the current legislation, which banned the use of many previously authorized pesticides that are still available and applied in other parts of the world. This challenge could place EU agricultural production at a disadvantage, so EU farmers are seeking help from the research community to foster and support integrated pest management (IPM). Ensuring stable crop yields and quality while reducing the reliance on pesticides is a challenge facing the farming community is today. Considering this, we focus on several diverse situations in European agriculture in general and in European crop protection in particular. We emphasize that the marked biophysical and socio-economic differences across Europe have led to a situation where a meaningful reduction in pesticide use can hardly be achieved. Nevertheless, improvements and/or adoption of the knowledge and technologies of IPM can still achieve large gains in pesticide reduction. In this overview, the current pest problems and their integrated management are discussed in the context of specific geographic regions of Europe, with a particular emphasis on reduced pesticide use. We conclude that there are opportunities for reduction in many parts of Europe without significant losses in crop yields.
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Affiliation(s)
| | - Silke Dachbrodt-Saaydeh
- Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Stahnsdorfer Damm 81, 14532 Kleinmachnow, Germany
| | - Per Kudsk
- Aarhus University, Department of Agroecology, Forsoegsvej 1, 4200 Slagelse 14 Denmark
| | - Antoine Messéan
- INRA, UAR 1240 Eco-Innov, BP 01, 78850 Thiverval-Grignon, France
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16
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Bellón-Gómez D, Vela-Corcía D, Pérez-García A, Torés JA. Sensitivity of Podosphaera xanthii populations to anti-powdery-mildew fungicides in Spain. PEST MANAGEMENT SCIENCE 2015; 71:1407-13. [PMID: 25418926 DOI: 10.1002/ps.3943] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/12/2014] [Accepted: 11/17/2014] [Indexed: 05/09/2023]
Abstract
BACKGROUND Cucurbit powdery mildew caused by Podosphaera xanthii limits crop production in Spain, where disease control is largely dependent on fungicides. In previous studies, high levels of resistance to QoI and DMI fungicides were documented in south-central Spain. The aim of this study was to investigate the sensitivity of P. xanthii populations to other fungicides and to provide tools for improved disease management. RESULTS Using a leaf-disc assay, sensitivity to thiophanate-methyl, bupirimate and quinoxyfen of 50 isolates of P. xanthii was analysed to determine discriminatory concentrations between sensitive and resistant isolates. With the exception of thiophanate-methyl, no clearly different groups of isolates could be identified, and as a result, discriminatory concentrations were established on the basis of the maximum fungicide field application rate. Subsequently, a survey of P. xanthii resistance to these fungicides was carried out by testing a collection of 237 isolates obtained during the 2002-2011 cucurbit growing seasons. This analysis revealed very high levels of resistance to thiophanate-methyl (95%). By contrast, no resistance to bupirimate and quinoxyfen was found. CONCLUSION Results suggest that thiophanate-methyl has become completely ineffective for controlling cucurbit powdery mildew in Spain. By contrast, bupirimate and quinoxyfen remain as very effective tools for cucurbit powdery mildew management. © 2014 Society of Chemical Industry.
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Affiliation(s)
- Davinia Bellón-Gómez
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental 'La Mayora', Algarrobo-Costa, Málaga, Spain
| | - David Vela-Corcía
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora' - Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Alejandro Pérez-García
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora' - Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Juan A Torés
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga - Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), Estación Experimental 'La Mayora', Algarrobo-Costa, Málaga, Spain
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17
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Vela-Corcía D, Bellón-Gómez D, López-Ruiz F, Torés JA, Pérez-García A. The Podosphaera fusca TUB2 gene, a molecular “Swiss Army knife” with multiple applications in powdery mildew research. Fungal Biol 2014; 118:228-41. [DOI: 10.1016/j.funbio.2013.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 11/28/2013] [Accepted: 12/04/2013] [Indexed: 10/25/2022]
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18
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Marín F, Santos M, Diánez F, Carretero F, Gea FJ, Yau JA, Navarro MJ. Characters of compost teas from different sources and their suppressive effect on fungal phytopathogens. World J Microbiol Biotechnol 2013; 29:1371-82. [PMID: 23456856 DOI: 10.1007/s11274-013-1300-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Accepted: 02/20/2013] [Indexed: 11/28/2022]
Abstract
Compost teas (CT) are fermented watery extracts of composted materials that are used to control plant diseases and on crop fertilization. In this work, aerated (ACT) and non-aerated compost teas (NCT) were obtained from four different composts: spent mushroom substrate compost, grape marc compost, greenhouse horticultural crop residues compost, and vermicompost. Physico-chemical and microbiological analysis were carried out to determine their properties. In vitro assays were performed to assess their suppressive effect on the mycelial growth of eight fungal phytopathogens. In vivo trials aimed to assess their effect on gummy stem blight (Didymella bryonae) and powdery mildew (Podosphaera fusca) in melon plants. Results showed that ACT and NCT filtrates inhibited the in vitro growth of all tested pathogens while autoclaved CT did not completely lose their inhibitory effect, and CT sterilized by microfiltration had no effect on the pathogen growth. The severity of powdery mildew was highly reduced by ACT and NCT from all sources, though in gummy stem blight assay only a delay in disease development was observed. In general, all compost teas showed a high level of microbial populations and nutrients. Results suggest that the efficacy of ACT and NCT firstly depend on the microbiota present in them. We consider compost teas from the four tested sources as a viable way to manage plant diseases and crop fertilization, throughout its integration in pest management programs and fertirrigation systems under different dilution rates.
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Affiliation(s)
- Francisco Marín
- Departamento de Agronomia, Escuela Superior de Ingeniería, Universidad de Almería, Carretera Sacramento s/n, La Cañada de San Urbano, 04120 Almería, Spain
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19
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Speck-Planche A, Kleandrova VV, Rojas-Vargas JA. QSAR model toward the rational design of new agrochemical fungicides with a defined resistance risk using substructural descriptors. Mol Divers 2011; 15:901-9. [DOI: 10.1007/s11030-011-9320-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 05/17/2011] [Indexed: 11/27/2022]
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20
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Speck-Planche A, Guilarte-Montero L, Yera-Bueno R, Rojas-Vargas JA, García-López A, Uriarte E, Molina-Pérez E. Rational design of new agrochemical fungicides using substructural descriptors. PEST MANAGEMENT SCIENCE 2011; 67:438-445. [PMID: 21394877 DOI: 10.1002/ps.2082] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 09/28/2010] [Accepted: 09/29/2010] [Indexed: 05/30/2023]
Abstract
BACKGROUND The increasing resistance of several phytopathogenic fungal species to existing agrochemical fungicides has alarmed the worldwide scientific community. In an attempt to overcome this problem, a discriminant model based on substructural descriptors was developed from a heterogeneous database of compounds for the design of, search for and prediction of agrochemical fungicides. RESULTS The discriminant model classifies correctly 81.95% of the fungicides and 81.54% of the inactive compounds in the training series, with an accuracy of 81.72%. In the prediction series, the percentage of correct classification was 80.59 and 85.56% for fungicides and inactive compounds respectively, with an accuracy of 83.44%. Some fragments were extracted and their contributions were calculated. From the fragments that were determined to make positive contributions to the fungicidal activity, new molecules such as pyrrole derivatives were designed and the probabilities of their being fungicides were calculated. These molecules were correctly classified as potential fungicides. CONCLUSION The discriminant model based on substructural descriptors provides a promising methodology for the development of molecular patterns to be used in the design of, search for and prediction of agrochemical fungicides of wide spectrum. This constitutes an alternative for the discovery of compounds that are able to decrease crop losses caused by phytopathogenic fungal species.
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Affiliation(s)
- Alejandro Speck-Planche
- Department of Organic Chemistry, Faculty of Pharmacy, University of Santiago de Compostela, Santiago de Compostela, Spain.
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