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Peil A, Howard NP, Bühlmann-Schütz S, Hiller I, Schouten H, Flachowsky H, Patocchi A. Rvi4 and Rvi15 are the same apple scab resistance genes. Mol Breed 2023; 43:74. [PMID: 37830083 PMCID: PMC10564682 DOI: 10.1007/s11032-023-01421-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 10/02/2023] [Indexed: 10/14/2023]
Abstract
The apple (Malus x domestica) scab (Venturia inaequalis) resistance genes Rvi4 and Rvi15 were mapped to a similar region on the top of linkage group 2 and both resistance genes elicit the same type of resistance reaction, i.e., a hypersensitive response; hence, it is suspected that the two genes may be the same. As the two resistance genes Rvi4 and Rvi15 are currently used in apple breeding, it is important to clarify whether the two resistance genes are the same or not. Several approaches were used to make this determination. First, the pedigree of the genotype GMAL 2473, the source of Rvi15, was reconstructed. GMAL 2473 was found to be an F1 of 'Russian seedling', the genotype, which is known to also be the source of Rvi4. Next, it was further demonstrated that 'Regia', a cultivar known to carry Rvi4 (and Rvi2), carries the same gene (Vr2-C), which was demonstrated to be the gene inducing Rvi15 resistance. Finally, it was shown that transgenic lines carrying Vr2-C are compatible with race 4 apple scab isolates. Taken all together, these results definitively demonstrate that Rvi4 and Rvi15 are the same resistance gene. For future studies, we suggest referring to this resistance with the first name that was assigned to this gene, namely Rvi4. Supplementary Information The online version contains supplementary material available at 10.1007/s11032-023-01421-0.
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Affiliation(s)
- Andreas Peil
- Julius Kühn Institut (JKI)—Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden, Pillnitz Germany
| | - Nicholas P Howard
- Fresh Forward Breeding and Marketing B.V., Hogewoerd 1C, 6851 ET Huissen, The Netherlands
| | - Simone Bühlmann-Schütz
- Research Division Plant Breeding, Agroscope, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
| | - Ines Hiller
- Julius Kühn Institut (JKI)—Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden, Pillnitz Germany
| | - Henk Schouten
- Department of Plant Breeding, Wageningen University & Research, Droevendaalsesteeg 1, P.O. Box 386, 6700 AJ Wageningen, The Netherlands
| | - Henryk Flachowsky
- Julius Kühn Institut (JKI)—Federal Research Centre for Cultivated Plants, Institute for Breeding Research on Fruit Crops, Pillnitzer Platz 3a, 01326 Dresden, Pillnitz Germany
| | - Andrea Patocchi
- Research Division Plant Breeding, Agroscope, Müller-Thurgau-Strasse 29, 8820 Wädenswil, Switzerland
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Bhagta S, Bhardwaj V, Kant A. Exogenous dsRNA trigger RNAi in Venturia inaequalis resulting in down regulation of target genes and growth reduction. Mol Biol Rep 2023; 50:8421-8429. [PMID: 37620739 DOI: 10.1007/s11033-023-08736-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 08/02/2023] [Indexed: 08/26/2023]
Abstract
BACKGROUND Venturia inaequalis is an apple scab causing fungal pathogen. It is a highly contagious and destructive pathogen which rapidly spreads infection in the surrounding orchards if not managed. The management and control of disease require multiple fungicides to be sprayed at different development stages of the apple. Persistent applications of fungicides also raises environmental concerns. Here, we demonstrate the potential of using spray induced gene silencing (SIGS) by developing target specific gene constructs for the synthesis of corresponding double-stranded RNA (dsRNA). METHODS AND RESULTS The exogenous application of dsRNAs was found to reduce mycelial growth and spore formation of V. inaequalis on culture plates. Four genes of V. inaequalis viz. CIN1, CE5, VICE12 and VICE16 which get upregulated during infection, were selected as targets for the development of gene construct expressing the corresponding dsRNA. The effect of exogenously supplied in vitro synthesized dsRNA on V. inaequalis was assessed in culture bioassay experiments with respect to growth, and spore formation. The expression level of the target genes in treated and control fungus was evaluated using quantitative PCR. Fungus treated with VICE12 targeted dsRNA showed maximum reduction in colony size (~ 55%), conidia formation (~ 93%) and expression level of the corresponding gene (2.2 fold), which was followed by CIN1-dsRNA. VICE16-dsRNA treatment was least effective with 32% reduction in growth, the non-significant effect of conidial spore formation and 1.13 fold down regulation of corresponding target gene expression level. CONCLUSION The result of this investigation validates the hypothesis that RNAi is evoked in V. inaequalis by exogenously supplied dsRNA and spray induced gene silencing (SIGS) based solutions may reduce burden of fungicide usage on apple crop against apple scab disease in future.
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Affiliation(s)
- Suhani Bhagta
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh, 173234, India
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh, 171001, India
| | - Vinay Bhardwaj
- ICAR-Central Potato Research Institute, Shimla, Himachal Pradesh, 171001, India
| | - Anil Kant
- Department of Biotechnology and Bioinformatics, Jaypee University of Information Technology, Waknaghat, Solan, Himachal Pradesh, 173234, India.
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Dar MS, Ahmad M, Yetoo NUN, Bhatt B, Bhat SN, Altaf H, Rafiqee S, Nabi A, Mohiddin FA, Gaafar ARZ, Mansoor S, Shah MD, Mushtaq M. Genetic footprint of population diversity and genetic structure of Venturia inaequalis infecting apple (Malus × domestica Borkh.). 3 Biotech 2023; 13:273. [PMID: 37449250 PMCID: PMC10335993 DOI: 10.1007/s13205-023-03672-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 06/13/2023] [Indexed: 07/18/2023] Open
Abstract
Apple scab instigated by Venturia inaequalis impels remarkable losses to apple fruit production. In an effort to comprehend the key mechanisms of evolutionary potential defining V. inaequalis population, 132 isolates of V. inaequalis from five commercial apple orchards were collected and assayed using 14 microsatellite markers. The average diversity was observed within the individuals of populations based on the Shannon-Wieners index (I) and observed heterozygosity (Ho) was average but considerably lower than expected heterozygosity (He). The genetic differentiation based on FST values was revealed as an average measure of divergence between populations and had varying proportions of gene flow and migration among themselves. Analysis of Molecular Variance (AMOVA) revealed that variance (94%) was dispersed across individuals with a significant (6%) variation between populations from different regions. To examine host specialization within the V. inaequalis population, the assignment approach based on K-means of clustering (an unsupervised machine learning approach), revealed that the clustering method supported three clusters at (K = 3) and three major clusters were also observed in Principle Component Analysis (PCA). Additionally, Nei's genetic distance values, pairwise estimates of genetic differentiation, dendrogram using the neighbor-joining and PCoA revealed the random distribution of V. Inaequalis isolates that depicted a high proportion of genotypic diversity within populations and population genetic structure. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-023-03672-2.
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Affiliation(s)
- Mohammad Saleem Dar
- Division of Plant Pathology, Faculty of Agriculture, SKUAST-Kashmir, Wadura, Sopore, Jammu and Kashmir 193201 India
| | - Mushtaq Ahmad
- Division of Plant Pathology, Faculty of Horticulture, SKUAST-Kashmir, Shalimar, Srinagar, Jammu and Kashmir 190025 India
| | - Nakeeb-Un-Nisa Yetoo
- Division of Genetics and Plant Breeding, FoA, SKUAST-K, Wadura, Sopore, Jammu and Kashmir 193201 India
| | - Bhagyshree Bhatt
- MS Swaminathan School of Agriculture, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan, Himachal Pradesh 173229 India
| | - Suhail Nazir Bhat
- Division of Fruit Science, Faculty of Horticulture, SKUAST-Kashmir, Shalimar, Srinagar, Jammu and Kashmir 190025 India
| | - Heena Altaf
- Division of Plant Pathology, Faculty of Agriculture, SKUAST-Kashmir, Wadura, Sopore, Jammu and Kashmir 193201 India
| | - Sumira Rafiqee
- Division of Genetics and Plant Breeding, FoA, SKUAST-K, Wadura, Sopore, Jammu and Kashmir 193201 India
| | - Asha Nabi
- Division of Plant Pathology, Faculty of Agriculture, SKUAST-Kashmir, Wadura, Sopore, Jammu and Kashmir 193201 India
| | - F. A. Mohiddin
- Mountain Research Centre for Field Crops, SKUAST-Kashmir, Khudwani, Kulgam, Jammu and Kashmir 192101 India
| | - Abdel-Rhman Z. Gaafar
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 11451, Riyadh, Saudi Arabia
| | - Sheikh Mansoor
- Department of Plant Resources and Environment, Jeju National University, Jeju, 63243 Republic of Korea
| | - Mehraj D. Shah
- Division of Plant Pathology, Faculty of Horticulture, SKUAST-Kashmir, Shalimar, Srinagar, Jammu and Kashmir 190025 India
| | - Muntazir Mushtaq
- MS Swaminathan School of Agriculture, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan, Himachal Pradesh 173229 India
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Schneider K, Barreiro-Hurle J, Vossen J, Schouten HJ, Kessel G, Andreasson E, Kieu NP, Strassemeyer J, Hristov J, Rodriguez-Cerezo E. Insights on cisgenic plants with durable disease resistance under the European Green Deal. Trends Biotechnol 2023; 41:1027-1040. [PMID: 37419837 DOI: 10.1016/j.tibtech.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 01/26/2023] [Accepted: 02/17/2023] [Indexed: 07/09/2023]
Abstract
Significant shares of harvests are lost to pests and diseases, therefore, minimizing these losses could solve part of the supply constraints to feed the world. Cisgenesis is defined as the insertion of genetic material into a recipient organism from a donor that is sexually compatible. Here, we review (i) conventional plant breeding, (ii) cisgenesis, (iii) current pesticide-based disease management, (iv) potential economic implications of cultivating cisgenic crops with durable disease resistances, and (v) potential environmental implications of cultivating such crops; focusing mostly on potatoes, but also apples, with resistances to Phytophthora infestans and Venturia inaequalis, respectively. Adopting cisgenic varieties could provide benefits to farmers and to the environment through lower pesticide use, thus contributing to the European Green Deal target.
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Affiliation(s)
- Kevin Schneider
- Joint Research Centre, European Commission, Calle Inca Garcilaso 3, 41092, Sevilla, Spain.
| | - Jesus Barreiro-Hurle
- Joint Research Centre, European Commission, Calle Inca Garcilaso 3, 41092, Sevilla, Spain
| | - Jack Vossen
- Plant Breeding, Wageningen University & Research, Droevendaalsesteeg 1, 6700, AJ, Wageningen, The Netherlands
| | - Henk J Schouten
- Plant Breeding, Wageningen University & Research, Droevendaalsesteeg 1, 6700, AJ, Wageningen, The Netherlands
| | - Geert Kessel
- Field Crops, Wageningen University & Research, Edelhertweg 1, 8219, PH, Lelystad, The Netherlands
| | - Erik Andreasson
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp Campus, Sweden
| | - Nam Phuong Kieu
- Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp Campus, Sweden
| | - Jörn Strassemeyer
- Julius Kühn-Institut, Federal Research Centre for Cultivated Plants, Institute for Strategies and Technology Assessment, 14532, Kleinmachnow, Germany
| | - Jordan Hristov
- Joint Research Centre, European Commission, Calle Inca Garcilaso 3, 41092, Sevilla, Spain
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Moureu S, Jacquin J, Samaillie J, Deweer C, Rivière C, Muchembled J. Antifungal Activity of Hop Leaf Extracts and Xanthohumol on Two Strains of Venturia inaequalis with Different Sensitivities to Triazoles. Microorganisms 2023; 11:1605. [PMID: 37375106 DOI: 10.3390/microorganisms11061605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Hop cones are well-known for their antimicrobial properties, attributed to their specialized metabolites. Thus, this study aimed to determine the in vitro antifungal activity of different hop parts, including by-products such as leaves and stems, and some metabolites against Venturia inaequalis, the causal agent of apple scab. For each plant part, two types of extracts, a crude hydro-ethanolic extract and a dichloromethane sub-extract, were tested on spore germination of two strains with different sensitivities to triazole fungicides. Both extracts of cones, leaves and stems were able to inhibit the two strains, whereas rhizomes did not show activity. The apolar sub-extract of leaves appeared as the most active modality tested with half maximal inhibitory concentrations (IC50) of 5 and 10.5 mg·L-1 on the sensitive strain and the strain with reduced sensitivity, respectively. Differences in activity level between strains were noticed for all active modalities tested. Sub-extracts of leaves were then separated into seven fractions by preparative HPLC and tested on V. inaequalis. One fraction, containing xanthohumol, was especially active on both strains. This prenylated chalcone was then purified by preparative HPLC and showed significant activity against both strains, with IC50 of 1.6 and 5.1 mg·L-1. Therefore, xanthohumol seems to be a promising compound to control V. inaequalis.
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Affiliation(s)
- Sophie Moureu
- Joint Research Unit 1158 BioEcoAgro, INRAE, University of Lille, JUNIA, University of Liège, UPJV, University of Artois, ULCO, 59000 Lille, France
| | - Justine Jacquin
- Joint Research Unit 1158 BioEcoAgro, INRAE, University of Lille, JUNIA, University of Liège, UPJV, University of Artois, ULCO, 59000 Lille, France
| | - Jennifer Samaillie
- Joint Research Unit 1158 BioEcoAgro, INRAE, University of Lille, JUNIA, University of Liège, UPJV, University of Artois, ULCO, 59000 Lille, France
| | - Caroline Deweer
- Joint Research Unit 1158 BioEcoAgro, INRAE, University of Lille, JUNIA, University of Liège, UPJV, University of Artois, ULCO, 59000 Lille, France
| | - Céline Rivière
- Joint Research Unit 1158 BioEcoAgro, INRAE, University of Lille, JUNIA, University of Liège, UPJV, University of Artois, ULCO, 59000 Lille, France
| | - Jérôme Muchembled
- Joint Research Unit 1158 BioEcoAgro, INRAE, University of Lille, JUNIA, University of Liège, UPJV, University of Artois, ULCO, 59000 Lille, France
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Rocafort M, Srivastava V, Bowen JK, Díaz-Moreno SM, Guo Y, Bulone V, Plummer KM, Sutherland PW, Anderson MA, Bradshaw RE, Mesarich CH. Cell Wall Carbohydrate Dynamics during the Differentiation of Infection Structures by the Apple Scab Fungus, Venturia inaequalis. Microbiol Spectr 2023; 11:e0421922. [PMID: 37039647 PMCID: PMC10269774 DOI: 10.1128/spectrum.04219-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 03/15/2023] [Indexed: 04/12/2023] Open
Abstract
Scab, caused by the biotrophic fungal pathogen Venturia inaequalis, is the most economically important disease of apples. During infection, V. inaequalis colonizes the subcuticular host environment, where it develops specialized infection structures called runner hyphae and stromata. These structures are thought to be involved in nutrient acquisition and effector (virulence factor) delivery, but also give rise to conidia that further the infection cycle. Despite their importance, very little is known about how these structures are differentiated. Likewise, nothing is known about how these structures are protected from host defenses or recognition by the host immune system. To better understand these processes, we first performed a glycosidic linkage analysis of sporulating tubular hyphae from V. inaequalis developed in culture. This analysis revealed that the V. inaequalis cell wall is mostly composed of glucans (44%) and mannans (37%), whereas chitin represents a much smaller proportion (4%). Next, we used transcriptomics and confocal laser scanning microscopy to provide insights into the cell wall carbohydrate composition of runner hyphae and stromata. These analyses revealed that, during subcuticular host colonization, genes of V. inaequalis putatively associated with the biosynthesis of immunogenic carbohydrates, such as chitin and β-1,6-glucan, are downregulated relative to growth in culture, while on the surface of runner hyphae and stromata, chitin is deacetylated to the less-immunogenic carbohydrate chitosan. These changes are anticipated to enable the subcuticular differentiation of runner hyphae and stromata by V. inaequalis, as well as to protect these structures from host defenses and recognition by the host immune system. IMPORTANCE Plant-pathogenic fungi are a major threat to food security. Among these are subcuticular pathogens, which often cause latent asymptomatic infections, making them difficult to control. A key feature of these pathogens is their ability to differentiate specialized subcuticular infection structures that, to date, remain largely understudied. This is typified by Venturia inaequalis, which causes scab, the most economically important disease of apples. In this study, we show that, during subcuticular host colonization, V. inaequalis downregulates genes associated with the biosynthesis of two immunogenic cell wall carbohydrates, chitin and β-1,6-glucan, and coats its subcuticular infection structures with a less-immunogenic carbohydrate, chitosan. These changes are anticipated to enable host colonization by V. inaequalis and provide a foundation for understanding subcuticular host colonization by other plant-pathogenic fungi. Such an understanding is important, as it may inform the development of novel control strategies against subcuticular plant-pathogenic fungi.
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Affiliation(s)
- Mercedes Rocafort
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
| | - Vaibhav Srivastava
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm, Sweden
| | - Joanna K. Bowen
- The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland, New Zealand
| | - Sara M. Díaz-Moreno
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm, Sweden
| | - Yanan Guo
- Laboratory of Molecular Plant Pathology, School of Natural Sciences, Massey University, Palmerston North, New Zealand
| | - Vincent Bulone
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology (KTH), AlbaNova University Centre, Stockholm, Sweden
- School of Food, Agriculture and Wine, The University of Adelaide, Waite Campus, Adelaide, South Australia, Australia
| | - Kim M. Plummer
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, La Trobe University, Bundoora, Melbourne, Victoria, Australia
| | - Paul W. Sutherland
- The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland, New Zealand
| | - Marilyn A. Anderson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Melbourne, Victoria, Australia
| | - Rosie E. Bradshaw
- Laboratory of Molecular Plant Pathology, School of Natural Sciences, Massey University, Palmerston North, New Zealand
- Bioprotection Aotearoa, Massey University, Palmerston North, New Zealand
| | - Carl H. Mesarich
- Laboratory of Molecular Plant Pathology, School of Agriculture and Environment, Massey University, Palmerston North, New Zealand
- Bioprotection Aotearoa, Massey University, Palmerston North, New Zealand
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Khajuria YP, Akhoon BA, Kaul S, Dhar MK. Secretomic Insights into the Pathophysiology of Venturia inaequalis: The Causative Agent of Scab, a Devastating Apple Tree Disease. Pathogens 2022; 12. [PMID: 36678413 DOI: 10.3390/pathogens12010066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/10/2022] [Accepted: 12/27/2022] [Indexed: 01/04/2023] Open
Abstract
Apple scab, caused by Venturia inaequalis, is one of the world's most commercially significant apple diseases. The fungi have a catastrophic impact on apples, causing considerable losses in fruit quality and productivity in many apple-growing locations despite numerous control agents. Fungi secrete various effectors and other virulence-associated proteins that suppress or alter the host's immune system, and several such proteins were discovered in this work. Using state-of-the-art bioinformatics techniques, we examined the V. inaequalis reference genome (EU-B04), resulting in the identification of 647 secreted proteins, of which 328 were classified as small secreted proteins (SSPs), with 76.52% of SSPs identified as anticipated effector proteins. The more prevalent CAZyme proteins were the enzymes engaged in plant cell wall disintegration (targeting pectin and xylanase), adhesion and penetration (Cutinases/acetyl xylan esterase), and reactive oxygen species formation (multicopper oxidases). Furthermore, members of the S9 prolyl oligopeptidase family were identified as the most abundant host defense peptidases. Several known effector proteins were discovered to be expressed during the V. inaequalis infection process on apple leaves. The present study provides valuable data that can be used to develop new strategies for controlling apple scab.
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Chatzidimopoulos M, Zambounis A, Lioliopoulou F, Vellios E. Detection of Venturia inaequalis Isolates with Multiple Resistance in Greece. Microorganisms 2022; 10. [PMID: 36557607 DOI: 10.3390/microorganisms10122354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 11/30/2022] Open
Abstract
The excessive use of fungicides against Venturia inaequalis, the causal agent of apple scab, has led to the emergence of resistant populations to multiple fungicides over the years. In Greece, there is no available information on fungicide resistance, despite the fact that control failures have been reported on certain areas. An amount of 418 single-spore isolates were collected from three major apple production areas and tested for their sensitivity to eight commonly used fungicides from unrelated chemical groups. The isolates were tested on malt extract agar media enriched with the discriminatory dose of each fungicide using the point inoculation method. To define the discriminatory dose for assessing the levels of resistance, EC50 values on both spore germination and mycelial growth assays were previously determined. Isolates exhibiting high resistance to trifloxystrobin (92% in total) and difenoconazole (3%); and moderate resistance to cyprodinil (75%), dodine (28%), difenoconazole (36%), boscalid (5%), and fludioxonil (7%) were found for the first time in Greece. A small percentage of the isolates were also found less sensitive to captan (8%) and dithianon (6%). Two isolates showed various levels of resistance to all eight fungicides. Despite the occurrence of strains with multiple resistances to many fungicides, we concluded that this practical resistance in the field arose mainly due to the poor control of apple scab with trifloxystrobin and difenoconazole.
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Rocafort M, Bowen JK, Hassing B, Cox MP, McGreal B, de la Rosa S, Plummer KM, Bradshaw RE, Mesarich CH. The Venturia inaequalis effector repertoire is dominated by expanded families with predicted structural similarity, but unrelated sequence, to avirulence proteins from other plant-pathogenic fungi. BMC Biol 2022; 20:246. [PMID: 36329441 PMCID: PMC9632046 DOI: 10.1186/s12915-022-01442-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022] Open
Abstract
Background Scab, caused by the biotrophic fungus Venturia inaequalis, is the most economically important disease of apples worldwide. During infection, V. inaequalis occupies the subcuticular environment, where it secretes virulence factors, termed effectors, to promote host colonization. Consistent with other plant-pathogenic fungi, many of these effectors are expected to be non-enzymatic proteins, some of which can be recognized by corresponding host resistance proteins to activate plant defences, thus acting as avirulence determinants. To develop durable control strategies against scab, a better understanding of the roles that these effector proteins play in promoting subcuticular growth by V. inaequalis, as well as in activating, suppressing, or circumventing resistance protein-mediated defences in apple, is required. Results We generated the first comprehensive RNA-seq transcriptome of V. inaequalis during colonization of apple. Analysis of this transcriptome revealed five temporal waves of gene expression that peaked during early, mid, or mid-late infection. While the number of genes encoding secreted, non-enzymatic proteinaceous effector candidates (ECs) varied in each wave, most belonged to waves that peaked in expression during mid-late infection. Spectral clustering based on sequence similarity determined that the majority of ECs belonged to expanded protein families. To gain insights into function, the tertiary structures of ECs were predicted using AlphaFold2. Strikingly, despite an absence of sequence similarity, many ECs were predicted to have structural similarity to avirulence proteins from other plant-pathogenic fungi, including members of the MAX, LARS, ToxA and FOLD effector families. In addition, several other ECs, including an EC family with sequence similarity to the AvrLm6 avirulence effector from Leptosphaeria maculans, were predicted to adopt a KP6-like fold. Thus, proteins with a KP6-like fold represent another structural family of effectors shared among plant-pathogenic fungi. Conclusions Our study reveals the transcriptomic profile underpinning subcuticular growth by V. inaequalis and provides an enriched list of ECs that can be investigated for roles in virulence and avirulence. Furthermore, our study supports the idea that numerous sequence-unrelated effectors across plant-pathogenic fungi share common structural folds. In doing so, our study gives weight to the hypothesis that many fungal effectors evolved from ancestral genes through duplication, followed by sequence diversification, to produce sequence-unrelated but structurally similar proteins. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01442-9.
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Affiliation(s)
- Mercedes Rocafort
- Laboratory of Molecular Plant Pathology/Bioprotection Aotearoa, School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand
| | - Joanna K Bowen
- The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland, 1025, New Zealand
| | - Berit Hassing
- Laboratory of Molecular Plant Pathology/Bioprotection Aotearoa, School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand
| | - Murray P Cox
- Bioprotection Aotearoa, School of Natural Sciences, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand
| | - Brogan McGreal
- The New Zealand Institute for Plant and Food Research Limited, Mount Albert Research Centre, Auckland, 1025, New Zealand
| | - Silvia de la Rosa
- Laboratory of Molecular Plant Pathology/Bioprotection Aotearoa, School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand
| | - Kim M Plummer
- Department of Animal, Plant and Soil Sciences, La Trobe University, AgriBio, Centre for AgriBiosciences, La Trobe University, Bundoora, Victoria, 3086, Australia
| | - Rosie E Bradshaw
- Bioprotection Aotearoa, School of Natural Sciences, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand
| | - Carl H Mesarich
- Laboratory of Molecular Plant Pathology/Bioprotection Aotearoa, School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North, 4442, New Zealand.
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10
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Leconte A, Tournant L, Muchembled J, Paucellier J, Héquet A, Deracinois B, Deweer C, Krier F, Deleu M, Oste S, Jacques P, Coutte F. Assessment of Lipopeptide Mixtures Produced by Bacillus subtilis as Biocontrol Products against Apple Scab ( Venturia inaequalis). Microorganisms 2022; 10:1810. [PMID: 36144412 DOI: 10.3390/microorganisms10091810] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/29/2022] [Accepted: 09/05/2022] [Indexed: 02/03/2023] Open
Abstract
Apple scab is an important disease conventionally controlled by chemical fungicides, which should be replaced by more environmentally friendly alternatives. One of these alternatives could be the use of lipopeptides produced by Bacillus subtilis. The objective of this work is to study the action of the three families of lipopeptides and different mixtures of them in vitro and in vivo against Venturia inaequalis. Firstly, the antifungal activity of mycosubtilin/surfactin and fengycin/surfactin mixtures was determined in vitro by measuring the median inhibitory concentration. Then, the best lipopeptide mixture ratio was produced using Design of Experiment (DoE) to optimize the composition of the culture medium. Finally, the lipopeptides mixtures efficiency against V. inaequalis was assessed in orchards as well as the evaluation of the persistence of lipopeptides on apple. In vitro tests show that the use of fengycin or mycosubtilin alone is as effective as a mixture, with the 50–50% fengycin/surfactin mixture being the most effective. Optimization of culture medium for the production of fengycin/surfactin mixture shows that the best composition is glycerol coupled with glutamic acid. Finally, lipopeptides showed in vivo antifungal efficiency against V. inaequalis regardless of the mixture used with a 70% reduction in the incidence of scab for both mixtures (fengycin/surfactin or mycosubtilin/surfactin). The reproducibility of the results over the two trial campaigns was significantly better with the mycosubtilin/surfactin mixture. The use of B. subtilis lipopeptides to control this disease is very promising.
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11
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Rocafort M, Arshed S, Hudson D, Sidhu JS, Bowen JK, Plummer KM, Bradshaw RE, Johnson RD, Johnson LJ, Mesarich CH. CRISPR-Cas9 gene editing and rapid detection of gene-edited mutants using high-resolution melting in the apple scab fungus, Venturia inaequalis. Fungal Biol 2022; 126:35-46. [PMID: 34930557 DOI: 10.1016/j.funbio.2021.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 09/27/2021] [Accepted: 10/07/2021] [Indexed: 11/24/2022]
Abstract
Apple scab, caused by the fungal pathogen Venturia inaequalis, is the most economically important disease of apple (Malus x domestica) worldwide. To develop durable control strategies against this disease, a better understanding of the genetic mechanisms underlying the growth, reproduction, virulence and pathogenicity of V. inaequalis is required. A major bottleneck for the genetic characterization of V. inaequalis is the inability to easily delete or disrupt genes of interest using homologous recombination. Indeed, no gene deletions or disruptions in V. inaequalis have yet been published. Using the melanin biosynthesis pathway gene trihydroxynaphthalene reductase (THN) as a target for inactivation, which has previously been shown to result in a light-brown colony phenotype when transcriptionally silenced using RNA interference, we show, for the first time, that the CRISPR-Cas9 gene editing system can be successfully applied to the apple scab fungus. More specifically, using a CRISPR-Cas9 single guide RNA (sgRNA) targeted to the THN gene, delivered by a single autonomously replicating Golden Gate-compatible plasmid, we were able to identify six of 36 stable transformants with a light-brown phenotype, indicating an ∼16.7% gene inactivation efficiency. Notably, of the six THN mutants, five had an independent mutation. As part of our pipeline, we also report a high-resolution melting (HRM) curve protocol for the rapid detection of CRISPR-Cas9 gene-edited mutants of V. inaequalis. This protocol identified a single base pair deletion mutation in a sample containing only 5% mutant genomic DNA, indicating high sensitivity for mutant screening. In establishing CRISPR-Cas9 as a tool for gene editing in V. inaequalis, we have provided a strong starting point for studies aiming to decipher gene function in this fungus. The associated HRM curve protocol will enable CRISPR-Cas9 transformants to be screened for gene inactivation in a high-throughput and low-cost manner, which will be particularly powerful in cases where the CRISPR-Cas9-mediated gene inactivation efficiency is low.
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12
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Ayer KM, Strickland DA, Choi M, Cox KD. Optimizing the Integration of a Biopesticide ( Bacillus subtilis QST 713) with a Single-Site Fungicide (Benzovindiflupyr) to Reduce Reliance on Synthetic Multisite Fungicides (Captan and Mancozeb) for Management of Apple Scab. Plant Dis 2021; 105:3545-3553. [PMID: 34142850 DOI: 10.1094/pdis-02-21-0426-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Apple scab is one of the most economically important diseases of apple in temperate production regions. In the absence of durable host resistance in commercially preferred cultivars, considerable applications of fungicides are needed to manage this disease. With the sequential development of resistance to nearly all classes of single-site fungicides in the apple scab pathogen Venturia inaequalis, synthetic multisite fungicides, such as mancozeb and captan, often comprise the core of chemical management programs for apple scab. Although these fungicides have demonstrable benefits for both disease and fungicide resistance management, the sustainability movement within agriculture aims to reduce reliance on such fungicides because of their broader environmental impacts. In this study, we establish a framework to enhance the feasibility of chemical management programs that do not rely on use of synthetic multisite protectant fungicides to manage apple scab. Specifically, we wish to evaluate chemical programs that integrate the biopesticide Bacillus subtilis QST 713 (Serenade Opti) in rotation with benzovindiflupyr (Aprovia), a single-site fungicide belonging to the class of succinate dehydrogenase inhibitors (SDHI), to circumvent the need for applications of synthetic multisite fungicides. During implementation of these programs, disease incidence data were taken at biweekly intervals. Regardless of the seasonal challenges presented in the 2 years of this study, when Bacillus subtilis QST 713 was used in place of captan and mancozeb mixtures, we did not observe any significant differences (P > 0.05) in development of apple scab symptoms between any of the management programs for the vertical axis or super spindle orchards in either year. This potential for substituting synthetic multisite fungicides with biopesticides is best realized when the programs are used with a decision support system in a super spindle planting system, where trees have reduced canopy densities. This 2-year study shows the potential to achieve adequate disease control using the integration of SDHI fungicides and biological controls without the use of synthetic multisite fungicides.
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Affiliation(s)
- K M Ayer
- Section of Plant Pathology and Plant-Microbe Biology, Cornell AgriTech, Cornell University, Geneva, NY 14456
| | - D A Strickland
- Section of Plant Pathology and Plant-Microbe Biology, Cornell AgriTech, Cornell University, Geneva, NY 14456
| | - M Choi
- Section of Plant Pathology and Plant-Microbe Biology, Cornell AgriTech, Cornell University, Geneva, NY 14456
| | - K D Cox
- Section of Plant Pathology and Plant-Microbe Biology, Cornell AgriTech, Cornell University, Geneva, NY 14456
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13
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Padder SA, Mansoor S, Bhat SA, Baba TR, Rather RA, Wani SM, Popescu SM, Sofi S, Aziz MA, Hefft DI, Alzahrani OM, Noureldeen A, Darwish H. Bacterial Endophyte Community Dynamics in Apple ( Malus domestica Borkh.) Germplasm and Their Evaluation for Scab Management Strategies. J Fungi (Basel) 2021; 7:jof7110923. [PMID: 34829212 PMCID: PMC8623955 DOI: 10.3390/jof7110923] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/21/2021] [Accepted: 09/21/2021] [Indexed: 12/11/2022] Open
Abstract
The large genetic evolution due to the sexual reproduction-mediated gene assortments and propensities has made Venturia inaequalis (causing apple scab) unique with respect to its management strategies. The resistance in apple germplasm against the scab, being controlled for by more than fifteen genes, has limited gene alteration-based investigations. Therefore, a biological approach of bacterial endophyte community dynamics was envisioned across the apple germplasm in context to the fungistatic behavior against V. inaequalis. A total of 155 colonies of bacterial endophytes were isolated from various plant parts of the apple, comprising 19 varieties, and after screening for antifungal behavior followed by morphological, ARDRA, and sequence analysis, a total of 71 isolates were selected for this study. The alpha diversity indices were seen to fluctuate greatly among the isolation samples in context to microflora with antifungal behavior. As all the isolates were screened for the presence of various metabolites and some relevant genes that directly or indirectly influence the fungistatic behavior of the isolated microflora, a huge variation among the isolated microflora was observed. The outstanding isolates showing highest percentage growth inhibition of V. inaequalis were exploited to raise a bio-formulation, which was tested against the scab prevalence in eight apple varieties under controlled growth conditions. The formulation at all the concentrations caused considerable reductions in both the disease severity and disease incidence in all the tested apple varieties. Red Delicious being most important cultivar of the northwestern Himalayas was further investigated for its biochemical behavior in formulation and the investigation revealed different levels of enzyme production, chlorophyll, and sugars against the non-inoculated control.
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Affiliation(s)
- Shahid A. Padder
- Division of Basic Sciences and Humanities, FoH, Sher-e—Kashmir University of Agricultural Sciences & Technology of Kashmir, Srinagar 190025, Jammu and Kashmir, India; (S.A.B.); (S.M.W.); (S.S.)
- Correspondence: (S.A.P.); (S.M.)
| | - Sheikh Mansoor
- Division of Biochemistry, FBSc, SKUAST-J, Jammu 180009, Jammu and Kashmir, India
- Correspondence: (S.A.P.); (S.M.)
| | - Sajad A. Bhat
- Division of Basic Sciences and Humanities, FoH, Sher-e—Kashmir University of Agricultural Sciences & Technology of Kashmir, Srinagar 190025, Jammu and Kashmir, India; (S.A.B.); (S.M.W.); (S.S.)
| | - Tawseef Rehman Baba
- Division of Fruit Science, SKUAST-Kashmir, Srinagar 190025, Jammu and Kashmir, India;
| | - Rauoof Ahmad Rather
- Division of Environmental Sciences, FoH, Sher-e—Kashmir University of Agricultural Sciences & Technology of Kashmir, Srinagar 190025, Jammu and Kashmir, India;
| | - Saima M. Wani
- Division of Basic Sciences and Humanities, FoH, Sher-e—Kashmir University of Agricultural Sciences & Technology of Kashmir, Srinagar 190025, Jammu and Kashmir, India; (S.A.B.); (S.M.W.); (S.S.)
| | - Simona Mariana Popescu
- Department of Biology and Environmental Engineering, University of Craiova, 13, A.I. Cuza, 200585 Craiova, Romania;
| | - Shakeela Sofi
- Division of Basic Sciences and Humanities, FoH, Sher-e—Kashmir University of Agricultural Sciences & Technology of Kashmir, Srinagar 190025, Jammu and Kashmir, India; (S.A.B.); (S.M.W.); (S.S.)
| | - Malik Asif Aziz
- Division of Basic Sciences and Humanities FoA, Sher-e—Kashmir University of Agricultural Sciences & Technology of Kashmir, Wadura Sopore 193201, Jammu and Kashmir, India;
| | - Daniel Ingo Hefft
- University Centre Reaseheath, Reaseheath College, Nantwich CW5 6DF, UK;
| | - Othman M. Alzahrani
- Department of Biology, College of Science, Taif University, P.O. Box 110099, Taif 21944, Saudi Arabia; (O.M.A.); (A.N.)
| | - Ahmed Noureldeen
- Department of Biology, College of Science, Taif University, P.O. Box 110099, Taif 21944, Saudi Arabia; (O.M.A.); (A.N.)
| | - Hadeer Darwish
- Department of Biotechnology, College of Sciences, Taif University, P.O. Box 110099, Taif 21944, Saudi Arabia;
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Bénéjam J, Ravon E, Gaucher M, Brisset MN, Durel CE, Perchepied L. Acibenzolar- S-Methyl and Resistance Quantitative Trait Loci Complement Each Other to Control Apple Scab and Fire Blight. Plant Dis 2021; 105:1702-1710. [PMID: 33190613 DOI: 10.1094/pdis-07-20-1439-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Diversifying disease control methods is a key strategy to sustainably reduce pesticides. Plant genetic resistance has long been used to create resistant varieties. Plant resistance inducers (PRI) are also considered to promote crop health, but their effectiveness is partial and can vary according to the environment and the plant genotype. We investigated the putative interaction between intrinsic (genetic) and PRI-induced resistance in apple when affected by scab and fire blight diseases. A large F1 mapping population was challenged by each disease after a pre-treatment with acibenzolar-S-methyl (ASM) and compared with the water control. Apple scab and fire blight resistance quantitative trait loci (QTLs) were detected in both conditions and compared. ASM exhibited a strong effectiveness in reducing both diseases. When combined, QTL-controlled and ASM-induced resistance acted complementarily to reduce the symptoms from 85 to 100%, depending on the disease. In our conditions, resistance QTLs were only slightly or rarely affected by ASM treatment, despite their probable implication in various stages of the resistance buildup. Implications of these results are discussed considering already known results, the underlying mechanisms, cross protection of both types of resistance against pathogen adaptation, and practical application in orchard conditions.
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Affiliation(s)
- Juliette Bénéjam
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Elisa Ravon
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Matthieu Gaucher
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | | | - Charles-Eric Durel
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Laure Perchepied
- Univ Angers, INRAE, Institut Agro, IRHS, SFR QUASAV, F-49000 Angers, France
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15
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Cordero-Limon L, Shaw MW, Passey TA, Robinson JD, Xu X. Cross-resistance between myclobutanil and tebuconazole and the genetic basis of tebuconazole resistance in Venturia inaequalis. Pest Manag Sci 2021; 77:844-850. [PMID: 32926586 DOI: 10.1002/ps.6088] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/05/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Myclobutanil is one of the most widely used demethylation inhibitor (DMI) fungicides for the management of apple scab, caused by Venturia inaequalis. Strains of V. inaequalis resistant to myclobutanil have been reported across the world. Tebuconazole, another DMI fungicide, has been proposed as an alternative to myclobutanil, and the extent of cross-resistance with myclobutanil therefore needs to be evaluated. The sensitivity to tebuconazole and myclobutanil of a total of 40 isolates was determined. Half the isolates came from an isolated orchard which had never been sprayed with fungicides and half from orchards sprayed regularly with myclobutanil, but still with disease control problems. The progeny of a tebuconazole resistant (R) × sensitive (S) V. inaequalis cross were analyzed in order to improve understanding of the genetic control of tebuconazole sensitivity. RESULTS There is cross-resistance between myclobutanil and tebuconazole (r = 0.91; P < 0.001). Sensitivity to tebuconazole of the progeny of a R × S cross varied quantitatively in a pattern which implied at least two gene loci differing between the parental strains. In addition, the asymmetric distribution of the sensitivity in the progeny implied possible epistatic effects. CONCLUSION Resistance to myclobutanil and tebuconazole is strongly correlated. At least two genes are involved in the control of tebuconazole resistance in V. inaequalis.
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Affiliation(s)
- Laura Cordero-Limon
- School of Agriculture, Policy and Development, University of Reading, Reading, UK
- NIAB EMR, Kent, UK
| | - Michael W Shaw
- School of Agriculture, Policy and Development, University of Reading, Reading, UK
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16
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Podwyszyńska M, Markiewicz M, Broniarek-Niemiec A, Matysiak B, Marasek-Ciolakowska A. Apple Autotetraploids with Enhanced Resistance to Apple Scab ( Venturia inaequalis) Due to Genome Duplication-Phenotypic and Genetic Evaluation. Int J Mol Sci 2021; 22:E527. [PMID: 33430246 DOI: 10.3390/ijms22020527] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/04/2021] [Accepted: 01/05/2021] [Indexed: 11/16/2022] Open
Abstract
Among the fungal diseases of apple trees, serious yield losses are due to an apple scab caused by Venturia inaequalis. Protection against this disease is based mainly on chemical treatments, which are currently very limited. Therefore, it is extremely important to introduce cultivars with reduced susceptibility to this pathogen. One of the important sources of variability for breeding is the process of polyploidization. Newly obtained polyploids may acquire new features, including increased resistance to diseases. In our earlier studies, numerous tetraploids have been obtained for several apple cultivars with 'Free Redstar' tetraploids manifesting enhanced resistance to apple scab. In the present study, tetraploids of 'Free Redstar' were assessed in terms of phenotype and genotype with particular emphasis on the genetic background of their increased resistance to apple scab. Compared to diploid plants, tetraploids (own-rooted plants) were characterized with poor growth, especially during first growing season. They had considerably shorter shoots, fewer branches, smaller stem diameter, and reshaped leaves. In contrast to own-rooted plants, in M9-grafted three-year old trees, no significant differences between diplo- and tetraploids were observed, either in morphological or physiological parameters, with the exceptions of the increased leaf thickness and chlorophyll content recorded in tetraploids. Significant differences between sibling tetraploid clones were recorded, particularly in leaf shape and some physiological parameters. The amplified fragment length polymorphism (AFLP) analysis confirmed genetic polymorphism of tetraploid clones. Methylation-sensitive amplification polymorphism (MSAP) analysis showed that the level of DNA methylation was twice as high in young tetraploid plants as in a diploid donor tree, which may explain the weaker vigour of neotetraploids in the early period of their growth in the juvenile phase. Molecular analysis showed that 'Free Redstar' cultivar and their tetraploids bear six Rvi genes (Rvi5, Rvi6, Rvi8, Rvi11, Rvi14 and Rvi17). Transcriptome analysis confirmed enhanced resistance to apple scab of 'Free Redstar' tetraploids since the expression levels of genes related to resistance were strongly enhanced in tetraploids compared to their diploid counterparts.
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17
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Mansoor S, Sharma V, Mir MA, Mir JI, Un Nabi S, Ahmed N, Alkahtani J, Alwahibi MS, Masoodi KZ. Quantification of polyphenolic compounds and relative gene expression studies of phenylpropanoid pathway in apple ( Malus domestica Borkh) in response to Venturia inaequalis infection. Saudi J Biol Sci 2020; 27:3397-3404. [PMID: 33304148 PMCID: PMC7715465 DOI: 10.1016/j.sjbs.2020.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 08/19/2020] [Accepted: 09/02/2020] [Indexed: 12/26/2022] Open
Abstract
Apple (Malus domestica Borkh) is rich in phenolic compounds, which may enhance resistance to scab disease caused by Venturia inaequalis. In present study, apple cv. Golden Delicious was used for estimation of total phenols, flavonoids and quantification of six individual phenolic compounds. between control vs inoculated samples at different inoculation stages. The relative gene expression of phenylalanine ammonia lyase, chalcone synthase and flavanone 3 hydroxylase increased and polyphenolic compounds were constitutively upregulated at different post-inoculation stages. Data suggest that synthesis and accumulation of polyphenols is closely related with disease resistance against Venturia inaequalis. This study may play a vital role in understanding and finding out the governing mechanisms of scab resistance.
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Affiliation(s)
- Sheikh Mansoor
- Division of Biochemistry, Faculty of Basic Sciences, SKUAST, Jammu 180009, India
| | - Vikas Sharma
- Division of Biochemistry, Faculty of Basic Sciences, SKUAST, Jammu 180009, India
| | - Mudasir A Mir
- Division of Plant Biotechnology, SKUAST, Shalimar, Kashmir 190025, India
| | - Javid I Mir
- ICAR - Cental Institute of Temperate Horticulture, Rangreth, Srinagar, India
| | - Sajad Un Nabi
- ICAR - Cental Institute of Temperate Horticulture, Rangreth, Srinagar, India
| | - Nazeer Ahmed
- Division of Plant Biotechnology, SKUAST, Shalimar, Kashmir 190025, India
| | - Jawaher Alkahtani
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Mona S Alwahibi
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Khalid Z Masoodi
- Division of Plant Biotechnology, SKUAST, Shalimar, Kashmir 190025, India
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18
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Prencipe S, Sillo F, Garibaldi A, Gullino ML, Spadaro D. Development of a Sensitive TaqMan qPCR Assay for Detection and Quantification of Venturia inaequalis in Apple Leaves and Fruit and in Air Samples. Plant Dis 2020; 104:2851-2859. [PMID: 32902358 DOI: 10.1094/pdis-10-19-2160-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A TaqMan quantitative PCR (qPCR) assay based on the translation elongation factor 1-α gene was developed for the quantification of Venturia inaequalis in leaves and fruits of Malus × domestica and in spore trap samples. The designed primers and hydrolysis probe amplified a specific 86-bp fragment for V. inaequalis. The specificity of the assay was tested using 35 strains of V. inaequalis and 20 different fungal species, including common pathogens of apple and other species of Venturia. The limit of detection was 20 fg, which is lower than a single genome of V. inaequalis. The selectivity of the assay was tested using DNA from three cultivars of Malus × domestica, and no influence on pathogen amplification was found. The assay was also validated for repeatability and reproducibility. With this assay, it was possible to detect and quantify V. inaequalis in four cultivars (Ambrosia, Florina, Golden Delicious, and Mondial Gala) in both symptomatic and asymptomatic leaves and in symptomatic Golden Delicious apple fruit stored for 2 months. Furthermore, the assay was successfully tested on spore trap samples originating from apple orchards. The quantification of the molecular assay when compared with the estimated number of V. inaequalis cells, using an optical microscope, showed a correlation coefficient of 0.8186. The developed technique could be used to detect V. inaequalis in asymptomatic samples without any cross-reaction with other fungal species. Furthermore, to improve the efficacy of disease management with a timely application of fungicides, this assay could be used for the analysis of spore trap samples by using an implemented extraction method.
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Affiliation(s)
- Simona Prencipe
- Department of Agricultural, Forestry and Food Sciences (DiSAFA), University of Torino, via Paolo Braccini 2, 10095, Grugliasco, Italy
| | - Fabiano Sillo
- Department of Agricultural, Forestry and Food Sciences (DiSAFA), University of Torino, via Paolo Braccini 2, 10095, Grugliasco, Italy
| | - Angelo Garibaldi
- Centre of Competence for the Innovation in the Agro-environmental Sector-AGROINNOVA, University of Turin, via Paolo Braccini 2, 10095, Grugliasco, Italy
| | - Maria Lodovica Gullino
- Department of Agricultural, Forestry and Food Sciences (DiSAFA), University of Torino, via Paolo Braccini 2, 10095, Grugliasco, Italy
- Centre of Competence for the Innovation in the Agro-environmental Sector-AGROINNOVA, University of Turin, via Paolo Braccini 2, 10095, Grugliasco, Italy
| | - Davide Spadaro
- Department of Agricultural, Forestry and Food Sciences (DiSAFA), University of Torino, via Paolo Braccini 2, 10095, Grugliasco, Italy
- Centre of Competence for the Innovation in the Agro-environmental Sector-AGROINNOVA, University of Turin, via Paolo Braccini 2, 10095, Grugliasco, Italy
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Patocchi A, Wehrli A, Dubuis PH, Auwerkerken A, Leida C, Cipriani G, Passey T, Staples M, Didelot F, Philion V, Peil A, Laszakovits H, Rühmer T, Boeck K, Baniulis D, Strasser K, Vávra R, Guerra W, Masny S, Ruess F, Le Berre F, Nybom H, Tartarini S, Spornberger A, Pikunova A, Bus VGM. Ten Years of VINQUEST: First Insight for Breeding New Apple Cultivars With Durable Apple Scab Resistance. Plant Dis 2020; 104:2074-2081. [PMID: 32525450 DOI: 10.1094/pdis-11-19-2473-sr] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Apple scab, caused by Venturia inaequalis, is a major fungal disease worldwide. Cultivation of scab-resistant cultivars would reduce the chemical footprint of apple production. However, new apple cultivars carrying durable resistances should be developed to prevent or at least slow the breakdown of resistance against races of V. inaequalis. One way to achieve durable resistance is to pyramid multiple scab resistance genes in a cultivar. The choice of the resistance genes to be combined in the pyramids should take into account the frequency of resistance breakdown and the geographical distribution of apple scab isolates able to cause such breakdowns. In order to acquire this information and to make it available to apple breeders, the VINQUEST project (www.vinquest.ch) was initiated in 2009. Ten years after launching this project, 24 partners from 14 countries regularly contribute data. From 2009 to 2018, nearly 9,000 data points have been collected. This information has been used to identify the most promising apple scab resistance genes for developing cultivars with durable resistance, which to date are: Rvi5, Rvi11, Rvi12, Rvi14, and Rvi15. As expected, Rvi1, together with Rvi3 and Rvi8, were often overcome, and have little value for scab resistance breeding. Rvi10 may also belong to this group. On the other hand, Rvi2, Rvi4, Rvi6, Rvi7, Rvi9, and Rvi13 are still useful for breeding, but their use is recommended only in extended pyramids of ≥3 resistance genes.
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Affiliation(s)
| | - Andreas Wehrli
- Agroscope, Breeding Research, 8820 Wädenswil, Switzerland
| | | | | | - Carmen Leida
- Consorzio Italiano Vivaisti CIV, 44022 San Giuseppe di Comacchio, Italy
| | - Guido Cipriani
- Dipartimento di Scienze Agroalimentari, Ambientali e Animali, University of Udine, 33100 Udine, Italy
| | - Tom Passey
- NIAB EMR, East Malling, West Malling ME19 6BJ, United Kingdom
| | - Martina Staples
- Höhere Bundeslehranstalt und Bundesamt für Wein- und Obstbau Klosterneuburg, 3400 Klosterneuburg, Austria
| | - Frédérique Didelot
- IRHS, Agrocampus-Ouest, INRA, Université d'Angers, 49071 Beaucouzé, France
| | - Vincent Philion
- Institut de Recherche et de Développement en Agroenvironnement, Saint-Bruno-de-Montarville, QC J3V 0G7, Canada
| | - Andreas Peil
- Julius Kühn-Institut (JKI), Bundesforschungsinstitut für Kulturpflanzen, Institut für Züchtungsforschung an Obst, 01326 Dresden, Germany
| | | | - Thomas Rühmer
- Versuchsstation Obst- und Weinbau Haidegg, 8047 Graz, Austria
| | - Klemens Boeck
- Landwirtschaftskammer Tirol, 6020 Innsbruck, Austria
| | - Danas Baniulis
- Lithuanian Research Centre for Agriculture and Forestry, 54333 Babtai, Lithuania
| | | | - Radek Vávra
- Research and Breeding Institute of Pomology, Holovousy 129, 508 01 Horice, Czech Republic
| | - Walter Guerra
- Laimburg Research Centre, Laimburg 6, 39040 Ora, Italy
| | | | - Franz Ruess
- Staatliche Lehr- und Versuchsanstalt für Wein und Obstbau Weinsberg, 74189 Weinsberg, Germany
| | - Fanny Le Berre
- Station d'études et d'expérimentations fruitières de La Morinière, La Morinière, 37800 Saint Epain, France
| | - Hilde Nybom
- Swedish University of Agricultural Sciences, Balsgård, 29194 Kristianstad, Sweden
| | - Stefano Tartarini
- Department of Agricultural and Food Sciences, University of Bologna, 40126 Bologna, Italy
| | | | - Anna Pikunova
- VNIISPK - Russian Research Institute of Fruit Crop Breeding, 302530 Zilina, Russia
| | - Vincent G M Bus
- The New Zealand Institute for Plant and Food Research Limited, 4157 Havelock North, New Zealand
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Dar MS, Padder BA, Ahmad M, Sofi TA, Mir AA, Nabi A, Shah MD. Population structure of Venturia inaequalis, a hemibiotrophic fungus, under different host resistance specificities in the Kashmir valley. Arch Microbiol 2020; 202:2245-2253. [PMID: 32533207 DOI: 10.1007/s00203-020-01950-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/08/2020] [Accepted: 05/11/2020] [Indexed: 11/25/2022]
Abstract
Venturia inaequalis is a notorious fungal pathogen and show classical gene for gene interaction with its apple host. Neutral markers provide clues about history, evolutionary potential, genetic diversity and population structure of V. inaequalis. The genetic diversity and population structure of fungus indicates that the pathogen is highly diverse with the capacity to breach the scab resistance genes. In the present study, we collected 108 V. inaequalis isolates from three apple cultivars differing in Rvi1 resistance gene. Based on the AMOVA, the variation was mostly distributed among the isolates, providing evidence of non-existence of subpopulation in orchards thus founder population is difficult to arise in Kashmir apple orchards. Pair wise genetic differentiation is less due to regular occurrence of gene flow between the populations residing on different orchard as infected material is transported without stringent quarantine measures. Based on principal coordinate analysis and clustering algorithm as implemented in STRUCTURE, we observed admixture between the two subpopulations, which is quite low, suggesting the existence of pre-zygotic and post-zygotic barriers to gene flow and we cannot rule out the existence of other structures shared by accessions belonging to different varieties. Due to the continuous increase in introduction and monoculture of apple varieties, mixed orchard with different host resistance specificities are more suitable for managing the apple scab in Kashmir valley.
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Affiliation(s)
- M S Dar
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, SKUAST-Kashmir, Shalimar, Srinagar, 190025, India
| | - Bilal A Padder
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, SKUAST-Kashmir, Shalimar, Srinagar, 190025, India.
| | - Mushtaq Ahmad
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, SKUAST-Kashmir, Shalimar, Srinagar, 190025, India
| | - T A Sofi
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, SKUAST-Kashmir, Shalimar, Srinagar, 190025, India
| | - A A Mir
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, SKUAST-Kashmir, Shalimar, Srinagar, 190025, India
| | - Asha Nabi
- Division of Plant Pathology, Faculty of Agriculture, SKUAST-K, Sopore, Wadura, 193201, India
| | - M D Shah
- Plant Virology and Molecular Plant Pathology Laboratory, Division of Plant Pathology, SKUAST-Kashmir, Shalimar, Srinagar, 190025, India
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21
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Rebel P, Poblete-Echeverría C, van Zyl JG, Wessels JPB, Coetzer C, McLeod A. Determining Mancozeb Deposition Benchmark Values on Apple Leaves for the Management of Venturia inaequalis. Plant Dis 2020; 104:168-178. [PMID: 31697224 DOI: 10.1094/pdis-04-19-0873-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Apple scab, caused by Venturia inaequalis, is the most common fruit and foliar disease in commercial apple production worldwide. Early in the production season, preventative contact fungicide sprays are essential for protecting highly susceptible continuously unfolding and expanding young leaves. In South Africa, mancozeb is a key contact fungicide used for controlling apple scab early in the season. The current study developed deposition benchmarks indicative of the biological efficacy of mancozeb against apple scab, using a laboratory-based apple seedling model system. The model system employed a yellow fluorescent pigment that is known to be an effective tracer of mancozeb deposition. A concentration range of mancozeb (0.15 to 1 times the registered dosage) and fluorescent pigment concentrations was sprayed onto seedling leaves, which yielded various fluorescent particle coverage (FPC%) levels. Modeling of the FPC% values versus percent disease control yielded different benchmark values when disease quantification was conducted using two different methods. Thermal infrared imaging (TIRI) disease quantification resulted in a benchmark model where 0.40%, 0.79%, and 1.35 FPC% yielded 50, 75, and 90% apple scab control, respectively. These FPC% values were higher than the benchmarks (0.10, 0.20, and 0.34 FPC%, respectively) obtained with quantitative real-time PCR (qPCR) disease quantification. The qPCR benchmark model is recommended as a guideline for evaluating the efficacy of mancozeb sprays on leaves in apple orchards since the TIRI benchmark model underestimated disease control. The TIRI benchmark model yielded 68% disease control at the lowest mancozeb dosage, yet no visible lesion developed at this dosage. Both benchmark models showed that mancozeb yielded high levels of disease control at very low concentrations; for the qPCR benchmark model the FPC% value of the FPC90 (90% control) corresponded to 0.15 times that of the registered mancozeb concentration in South Africa, i.e., 85% lower than the registered dosage.
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Affiliation(s)
- P Rebel
- Department of Plant Pathology, Stellenbosch University, Matieland, 7600, South Africa
| | - C Poblete-Echeverría
- Department of Viticulture and Oenology, Stellenbosch University, 7600, South Africa
| | | | | | - C Coetzer
- Department of Plant Pathology, Stellenbosch University, Matieland, 7600, South Africa
| | - A McLeod
- Department of Plant Pathology, Stellenbosch University, Matieland, 7600, South Africa
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Sarkate A, Saini SS, Gaid M, Teotia D, Mir JI, Agrawal PK, Beerhues L, Sircar D. Molecular cloning and functional analysis of a biphenyl phytoalexin-specific O-methyltransferase from apple cell suspension cultures. Planta 2019; 249:677-691. [PMID: 30357505 DOI: 10.1007/s00425-018-3031-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 10/18/2018] [Indexed: 06/08/2023]
Abstract
This manuscript describes the cloning and functional characterization of a biphenyl phytoalexin biosynthetic gene, 3,5-dihydroxybiphenyl O-methyltransferase from elicitor-treated cell cultures of scab resistant apple cultivar 'Florina'. Apples belong to the subtribe Malinae of the Rosaceae family. Biphenyls and dibenzofurans are the specialized phytoalexins of Malinae, of which aucuparin is the most widely distributed biphenyl. The precursor of aucuparin, 3,5-dihydroxybiphenyl, is a benzoate-derived polyketide, which is formed by the sequential condensation of three molecules of malonyl-CoA and one molecule of benzoyl-CoA in a reaction catalyzed by biphenyl synthase (BIS). This 3,5-dihydroxybiphenyl then undergoes sequential 5-O-methylation, 4-hydroxylation, and finally 3-O-methylation to form aucuparin. A cDNA encoding O-methyltransferase (OMT) was isolated and functionally characterized from the cell cultures of scab-resistant apple cultivar 'Florina' (Malus domestica cultivar 'Florina'; MdOMT) after treatment with elicitor prepared from the apple scab causing fungus Venturia inaequalis. MdOMT catalyzed the regiospecific O-methylation of 3,5-dihydroxybiphenyl at the 5-position to form 3-hydroxy-5-methoxybiphenyl. The enzyme showed absolute substrate preference for 3,5-dihydroxybiphenyl. The elicitor-treated apple cell cultures showed transient increases in the MdOMT (GenBank ID MF740747) and MdBIS3 (GenBank ID JQ390523) transcript levels followed by the accumulation of biphenyls (aucuparin and noraucuparin) and dibenzofuran (eriobofuran) phytoalexins. MdOMT fused with N- and C-terminal yellow fluorescent protein showed cytoplasmic localization in the epidermis of Nicotiana benthamiana leaves. In scab inoculated greenhouse-grown 'Florina' plants, the expression of MdOMT was transiently induced in the stem followed by the accumulation of biphenyl phytoalexins.
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Affiliation(s)
- Amol Sarkate
- Plant Molecular Biology Group, Biotechnology Department, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Shashank Sagar Saini
- Plant Molecular Biology Group, Biotechnology Department, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Mariam Gaid
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstrasse 1, 38106, Braunschweig, Germany
| | - Deepa Teotia
- Plant Molecular Biology Group, Biotechnology Department, Indian Institute of Technology Roorkee, Roorkee, 247667, India
| | - Javid Iqbal Mir
- Plant Biotechnology Department, Central Institute of Temperate Horticulture (ICAR-CITH), Srinagar, 190005, Jammu and Kashmir, India
| | | | - Ludger Beerhues
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstrasse 1, 38106, Braunschweig, Germany
| | - Debabrata Sircar
- Plant Molecular Biology Group, Biotechnology Department, Indian Institute of Technology Roorkee, Roorkee, 247667, India.
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Frank DL. Evaluation of Fruit Bagging as a Pest Management Option for Direct Pests of Apple. Insects 2018; 9:E178. [PMID: 30513746 DOI: 10.3390/insects9040178] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/16/2018] [Accepted: 11/28/2018] [Indexed: 11/29/2022]
Abstract
Bagging fruit with plastic, paper, and two-layer commercial bags was evaluated for control of insect pests and diseases in an experimental apple orchard planted with ‘Red Delicious’ trees. Results from fruit damage evaluations at harvest showed that bagging significantly reduced fruit damage from direct apple pests compared with non-bagged control plots, and generally provided similar levels of fruit protection when compared with a conventional pesticide spray program. Of the three bagging materials evaluated, plastic bags provided numerically higher levels of fruit protection from insect pests, and two-layer commercial bags provided numerically higher levels of fruit protection from fruit diseases. Fruit quality as measured by percentage Brix was higher in non-bagged control plots than all other treatment plots. Fruit quality as measured by fruit diameter was not significantly different among treatments. Plastic and two-layer commercial bags generally required less time to secure around apple fruit than paper bags. The proportion of bags that remained on fruit until harvest ranged from 0.54–0.71 (commercial bags), 0.64–0.82 (plastic bags), and 0.32–0.60 (paper bags), depending on the year.
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Muchembled J, Deweer C, Sahmer K, Halama P. Antifungal activity of essential oils on two Venturia inaequalis strains with different sensitivities to tebuconazole. Environ Sci Pollut Res Int 2018; 25:29921-29928. [PMID: 29098578 DOI: 10.1007/s11356-017-0507-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 10/18/2017] [Indexed: 05/09/2023]
Abstract
The antifungal activity of seven essential oils (eucalyptus, clove, mint, oregano, savory, tea tree, and thyme) was studied on Venturia inaequalis, the fungus responsible for apple scab. The composition of the essential oils was checked by gas chromatography-mass spectrometry. Each essential oil had its main compound. Liquid tests were performed to calculate the IC50 of essential oils as well as their majority compounds. The tests were made on two strains with different sensitivities to tebuconazole: S755, the sensitive strain, and rs552, the strain with reduced sensitivity. Copper sulfate was selected as the reference mineral fungicidal substance. IC50 with confidence intervals were calculated after three independent experiments. The results showed that all essential oils and all major compounds had in vitro antifungal activities. Moreover, it was highlighted that the effectiveness of four essential oils (clove, eucalyptus, mint, and savory) was higher than copper sulfate on both strains. For each strain, the best activity was obtained using clove and eucalyptus essential oils. For clove, the IC50 obtained on the sensitive strain (5.2 mg/L [4.0-6.7 mg/L]) was statistically lower than the IC50 of reduced sensitivity strain (14 mg/L [11.1-17.5 mg/L]). In contrast, for eucalyptus essential oil, the IC50 were not different with respectively 9.4-13.0 and 12.2-17.9 mg/L for S755 and rs552 strains. For mint, origano, savory, tea tree, and thyme, IC50 were always the best on rs552 strain. The majority compounds were not necessarily more efficient than their corresponding oils; only eugenol (for clove) and carvacrol (for oregano and savory) seemed to be more effective on S755 strain. On the other hand, rs552 strain seemed to be more sensitive to essential oils than S755 strain. In overall, it was shown that essential oils have different antifungal activities but do not have the same antifungal activities depending on the fungus strain used.
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Affiliation(s)
- Jérôme Muchembled
- Charles Viollette Research Institute, EA 7394, SFR Condorcet FR CNRS 3417, ISA-Yncréa, 48 boulevard Vauban, 59014, Lille Cedex, France.
| | - Caroline Deweer
- Charles Viollette Research Institute, EA 7394, SFR Condorcet FR CNRS 3417, ISA-Yncréa, 48 boulevard Vauban, 59014, Lille Cedex, France
| | - Karin Sahmer
- Civil and Geo-Environmental Engineering Laboratory (LGCgE), ISA-Yncréa, 48 boulevard Vauban, 59014, Lille Cedex, France
| | - Patrice Halama
- Charles Viollette Research Institute, EA 7394, SFR Condorcet FR CNRS 3417, ISA-Yncréa, 48 boulevard Vauban, 59014, Lille Cedex, France
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Ehlert K, Piepenbring M, Kollar A. Ascospore release in apple scab underlies infrared sensation. Fungal Biol 2017; 121:1054-1062. [PMID: 29122177 DOI: 10.1016/j.funbio.2017.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/11/2017] [Accepted: 09/18/2017] [Indexed: 12/29/2022]
Abstract
The agent of apple scab disease (Venturia inaequalis) is the most common pathogen in apple cultivation. Its ascospores are released in spring, mainly during daylight hours and triggered by rain events. To investigate the causes of diurnal rhythm of ascospore dissemination of the apple scab fungus ascospore releases were examined continuously with spore traps in the orchard and with laboratory assays. One of the spore traps was illuminated at night with different light sources in each year during 2011-2015. The laboratory assays were performed with different light sources with varying wavelengths and intensities. In field and laboratory conditions only light including infrared radiation stimulated ascospore release, but not with light in the visible spectrum only. Artificial illumination during night was correlated with an increase of up to 46 % of ascospores released overnight in the field. We proved that infrared radiation induces V. inaequalis to release its spores. This is the first report in which spore discharge could be stimulated during night under field conditions.
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Affiliation(s)
- Katja Ehlert
- Julius Kuehn-Institut, Federal Research Center for Cultivated Plants, Institute for Plant Protection in Fruit Crops and Viticulture, Schwabenheimer Straße 101, 69221 Dossenheim, Germany.
| | - Meike Piepenbring
- Department of Mycology, Cluster for Integrative Fungal Research (IPF), Institute for Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Straße 13, 60438 Frankfurt am Main, Germany
| | - Andreas Kollar
- Julius Kuehn-Institut, Federal Research Center for Cultivated Plants, Institute for Plant Protection in Fruit Crops and Viticulture, Schwabenheimer Straße 101, 69221 Dossenheim, Germany
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Deng CH, Plummer KM, Jones DAB, Mesarich CH, Shiller J, Taranto AP, Robinson AJ, Kastner P, Hall NE, Templeton MD, Bowen JK. Comparative analysis of the predicted secretomes of Rosaceae scab pathogens Venturia inaequalis and V. pirina reveals expanded effector families and putative determinants of host range. BMC Genomics 2017; 18:339. [PMID: 28464870 PMCID: PMC5412055 DOI: 10.1186/s12864-017-3699-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/11/2017] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Fungal plant pathogens belonging to the genus Venturia cause damaging scab diseases of members of the Rosaceae. In terms of economic impact, the most important of these are V. inaequalis, which infects apple, and V. pirina, which is a pathogen of European pear. Given that Venturia fungi colonise the sub-cuticular space without penetrating plant cells, it is assumed that effectors that contribute to virulence and determination of host range will be secreted into this plant-pathogen interface. Thus the predicted secretomes of a range of isolates of Venturia with distinct host-ranges were interrogated to reveal putative proteins involved in virulence and pathogenicity. RESULTS Genomes of Venturia pirina (one European pear scab isolate) and Venturia inaequalis (three apple scab, and one loquat scab, isolates) were sequenced and the predicted secretomes of each isolate identified. RNA-Seq was conducted on the apple-specific V. inaequalis isolate Vi1 (in vitro and infected apple leaves) to highlight virulence and pathogenicity components of the secretome. Genes encoding over 600 small secreted proteins (candidate effectors) were identified, most of which are novel to Venturia, with expansion of putative effector families a feature of the genus. Numerous genes with similarity to Leptosphaeria maculans AvrLm6 and the Verticillium spp. Ave1 were identified. Candidates for avirulence effectors with cognate resistance genes involved in race-cultivar specificity were identified, as were putative proteins involved in host-species determination. Candidate effectors were found, on average, to be in regions of relatively low gene-density and in closer proximity to repeats (e.g. transposable elements), compared with core eukaryotic genes. CONCLUSIONS Comparative secretomics has revealed candidate effectors from Venturia fungal plant pathogens that attack pome fruit. Effectors that are putative determinants of host range were identified; both those that may be involved in race-cultivar and host-species specificity. Since many of the effector candidates are in close proximity to repetitive sequences this may point to a possible mechanism for the effector gene family expansion observed and a route to diversification via transposition and repeat-induced point mutation.
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Affiliation(s)
- Cecilia H. Deng
- The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand
| | - Kim M. Plummer
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Plant Biosecurity Cooperative Research Centre, Bruce, ACT Australia
| | - Darcy A. B. Jones
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Present Address: The Centre for Crop and Disease Management, Curtin University, Bentley, Australia
| | - Carl H. Mesarich
- The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand
- The School of Biological Sciences, University of Auckland, Auckland, New Zealand
- Present Address: Institute of Agriculture & Environment, Massey University, Palmerston North, New Zealand
| | - Jason Shiller
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Present Address: INRA-Angers, Beaucouzé, Cedex, France
| | - Adam P. Taranto
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Plant Sciences Division, Research School of Biology, The Australian National University, Canberra, Australia
| | - Andrew J. Robinson
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative (VLSCI), Victoria, Australia
| | - Patrick Kastner
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
| | - Nathan E. Hall
- Animal, Plant & Soil Sciences Department, AgriBio Centre for AgriBioscience, La Trobe University, Melbourne, Victoria Australia
- Life Sciences Computation Centre, Victorian Life Sciences Computation Initiative (VLSCI), Victoria, Australia
| | - Matthew D. Templeton
- The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand
- The School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Joanna K. Bowen
- The New Zealand Institute for Plant & Food Research Limited (PFR), Auckland, New Zealand
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Hutabarat OS, Flachowsky H, Regos I, Miosic S, Kaufmann C, Faramarzi S, Alam MZ, Gosch C, Peil A, Richter K, Hanke MV, Treutter D, Stich K, Halbwirth H. Transgenic apple plants overexpressing the chalcone 3-hydroxylase gene of Cosmos sulphureus show increased levels of 3-hydroxyphloridzin and reduced susceptibility to apple scab and fire blight. Planta 2016; 243:1213-24. [PMID: 26895335 PMCID: PMC4837221 DOI: 10.1007/s00425-016-2475-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 01/26/2016] [Indexed: 05/10/2023]
Abstract
MAIN CONCLUSION Overexpression of chalcone-3-hydroxylase provokes increased accumulation of 3-hydroxyphloridzin in Malus . Decreased flavonoid concentrations but unchanged flavonoid class composition were observed. The increased 3-hydroxyphlorizin contents correlate well with reduced susceptibility to fire blight and scab. The involvement of dihydrochalcones in the apple defence mechanism against pathogens is discussed but unknown biosynthetic steps in their formation hamper studies on their physiological relevance. The formation of 3-hydroxyphloretin is one of the gaps in the pathway. Polyphenol oxidases and cytochrome P450 dependent enzymes could be involved. Hydroxylation of phloretin in position 3 has high similarity to the B-ring hydroxylation of flavonoids catalysed by the well-known flavonoid 3'-hydroxylase (F3'H). Using recombinant F3'H and chalcone 3-hydroxylase (CH3H) from Cosmos sulphureus we show that F3'H and CH3H accept phloretin to some extent but higher conversion rates are obtained with CH3H. To test whether CH3H catalyzes the hydroxylation of dihydrochalcones in planta and if this could be of physiological relevance, we created transgenic apple trees harbouring CH3H from C. sulphureus. The three transgenic lines obtained showed lower polyphenol concentrations but no shift between the main polyphenol classes dihydrochalcones, flavonols, hydroxycinnamic acids and flavan 3-ols. Increase of 3-hydroxyphloridzin within the dihydrochalcones and of epicatechin/catechin within soluble flavan 3-ols were observed. Decreased activity of dihydroflavonol 4-reductase and chalcone synthase/chalcone isomerase could partially explain the lower polyphenol concentrations. In comparison to the parent line, the transgenic CH3H-lines showed a lower disease susceptibility to fire blight and apple scab that correlated with the increased 3-hydroxyphlorizin contents.
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Affiliation(s)
- Olly Sanny Hutabarat
- Institute of Chemical Engineering, Technical University of Vienna, Getreidemarkt 9, 1060, Vienna, Austria
| | - Henryk Flachowsky
- Federal Research Centre for Cultivated Plants, Institute of Breeding Research on Horticultural and Fruit Crops, Julius Kühn-Institut, Pillnitzer Platz 3a, 01326, Dresden, Germany
| | - Ionela Regos
- Unit of Fruit Science, Technical University of Munich, Dürnast 2, 85350, Freising, Germany
| | - Silvija Miosic
- Institute of Chemical Engineering, Technical University of Vienna, Getreidemarkt 9, 1060, Vienna, Austria
| | - Christine Kaufmann
- Chair of Urban Water Systems Engineering, Technical University of Munich, Am Coulombwall, 85748, Garching, Germany
| | - Shadab Faramarzi
- Institute of Chemical Engineering, Technical University of Vienna, Getreidemarkt 9, 1060, Vienna, Austria
| | - Mohammed Zobayer Alam
- Institute of Chemical Engineering, Technical University of Vienna, Getreidemarkt 9, 1060, Vienna, Austria
| | - Christian Gosch
- Institute of Chemical Engineering, Technical University of Vienna, Getreidemarkt 9, 1060, Vienna, Austria
| | - Andreas Peil
- Federal Research Centre for Cultivated Plants, Institute of Breeding Research on Horticultural and Fruit Crops, Julius Kühn-Institut, Pillnitzer Platz 3a, 01326, Dresden, Germany
| | - Klaus Richter
- Federal Research Centre for Cultivated Plants, Institute for Resistance Research and Stress Tolerance, Julius Kühn-Institut, Erwin-Baur-Str. 27, 06484, Quedlinburg, Germany
| | - Magda-Viola Hanke
- Federal Research Centre for Cultivated Plants, Institute of Breeding Research on Horticultural and Fruit Crops, Julius Kühn-Institut, Pillnitzer Platz 3a, 01326, Dresden, Germany
| | - Dieter Treutter
- Unit of Fruit Science, Technical University of Munich, Dürnast 2, 85350, Freising, Germany
| | - Karl Stich
- Institute of Chemical Engineering, Technical University of Vienna, Getreidemarkt 9, 1060, Vienna, Austria
| | - Heidi Halbwirth
- Institute of Chemical Engineering, Technical University of Vienna, Getreidemarkt 9, 1060, Vienna, Austria.
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28
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Chizzali C, Gusberti M, Schouten HJ, Gessler C, Broggini GAL. Cisgenic Rvi6 scab-resistant apple lines show no differences in Rvi6 transcription when compared with conventionally bred cultivars. Planta 2016; 243:635-644. [PMID: 26586177 DOI: 10.1007/s00425-015-2432-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 11/09/2015] [Indexed: 06/05/2023]
Abstract
The expression of the apple scab resistance gene Rvi6 in different apple cultivars and lines is not modulated by biotic or abiotic factors. All commercially important apple cultivars are susceptible to Venturia inaequalis, the causal organism of apple scab. A limited number of apple cultivars were bred to express the resistance gene Vf from the wild apple genotype Malus floribunda 821. Positional cloning of the Vf locus allowed the identification of the Rvi6 (formerly HcrVf2) scab resistance gene that was subsequently used to generate cisgenic apple lines. It is important to understand and compare how this resistance gene is transcribed and modulated during infection in conventionally bred cultivars and in cisgenic lines. The aim of this work was to study the transcription pattern of Rvi6 in three classically bred apple cultivars and six lines of 'Gala' genetically modified to express Rvi6. Rvi6 transcription was analyzed at two time points using quantitative real-time PCR (RT-qPCR) following inoculation with V. inaequalis conidia or water. Rvi6 transcription was assessed in relation to five reference genes. β-Actin, RNAPol, and UBC were the most suited to performing RT-qPCR experiments on Malus × domestica. Inoculation with V. inaequalis conidia under conditions conducive to scab infection failed to produce any significant changes to the transcription level of Rvi6. Rvi6 expression levels were inconsistent in response to external treatments in the different apple cultivars, and transgenic, intragenic or cisgenic lines.
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Affiliation(s)
- Cornelia Chizzali
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitaetstrasse 2, 8092, Zurich, Switzerland.
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, Beutenbergstrasse 11a, 07745, Jena, Germany.
| | - Michele Gusberti
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitaetstrasse 2, 8092, Zurich, Switzerland
| | - Henk J Schouten
- Wageningen UR Plant Breeding, Wageningen University and Research Centre, PO Box 16, 6700 AA, Wageningen, The Netherlands
| | - Cesare Gessler
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitaetstrasse 2, 8092, Zurich, Switzerland
| | - Giovanni A L Broggini
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Universitaetstrasse 2, 8092, Zurich, Switzerland
- Agroscope, Institute for Plant Production Sciences, Schloss 1, 8820, Wädenswil, Switzerland
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Lemaire C, De Gracia M, Leroy T, Michalecka M, Lindhard-Pedersen H, Guerin F, Gladieux P, Le Cam B. Emergence of new virulent populations of apple scab from nonagricultural disease reservoirs. New Phytol 2016; 209:1220-9. [PMID: 26428268 DOI: 10.1111/nph.13658] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 08/15/2015] [Indexed: 05/11/2023]
Abstract
Plant pathogens adapt readily to new crop varieties in agrosystems, and it is crucial to understand the factors underlying the epidemic spread of new virulent strains if we are to develop more efficient strategies to control them. In this study we used multilocus microsatellite typing, molecular epidemiology tools and a large collection of isolates from cultivated, wild and ornamental apples to investigate the origin of new virulent populations of Venturia inaequalis, an ascomycete fungus causing apple scab on varieties carrying the Rvi6 resistance gene. We demonstrated a common origin at the European scale of populations infecting apples (Malus × domestica) carrying the Rvi6 resistance and Malus floribunda, the progenitor of the Rvi6 resistance. Demographic modeling indicated that the Rvi6-virulent lineage separated several thousands of years ago from populations infecting non-Rvi6 hosts, without detectable gene flow between the two lineages. These findings show that 'breakdowns' of plant resistance genes can be caused by the selection and migration of virulent genotypes from standing genetic variation maintained in environmental disease reservoirs, here ornamental crabapples. This work stresses the need to take better account of pathogen diversity in resistance screenings of breeding lines and in resistance deployment strategies, in order to enhance sustainable disease management.
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Affiliation(s)
- Christophe Lemaire
- Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences (IRHS), SFR4207 QUASAV, PRES L'UNAM, Angers, 49075, France
| | - Marie De Gracia
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences (IRHS), Beaucouzé, 49071, France
| | - Thibault Leroy
- Université d'Angers, UMR1345 Institut de Recherche en Horticulture et Semences (IRHS), SFR4207 QUASAV, PRES L'UNAM, Angers, 49075, France
- INRA, UMR 1202 BIOGECO, Cestas, 33612, France
| | - Monika Michalecka
- Department of Plant Pathology, Institute of Horticulture, Skierniewice, 96-100, Poland
| | | | - Fabien Guerin
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences (IRHS), Beaucouzé, 49071, France
- Université de la Réunion, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), Saint Pierre, 97715, La Réunion, France
| | - Pierre Gladieux
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences (IRHS), Beaucouzé, 49071, France
- INRA, UMR BGPI, Montpellier, 34398, France
- CIRAD, UMR BGPI, Montpellier, 34398, France
| | - Bruno Le Cam
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences (IRHS), Beaucouzé, 49071, France
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Bastiaanse H, Bassett HCM, Kirk C, Gardiner SE, Deng C, Groenworld R, Chagné D, Bus VGM. Scab resistance in 'Geneva' apple is conditioned by a resistance gene cluster with complex genetic control. Mol Plant Pathol 2016; 17:159-72. [PMID: 25892110 PMCID: PMC6638522 DOI: 10.1111/mpp.12269] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Apple scab, caused by the fungal pathogen Venturia inaequalis, is one of the most severe diseases of apple worldwide. It is the most studied plant-pathogen interaction involving a woody species using modern genetic, genomic, proteomic and bioinformatic approaches in both species. Although 'Geneva' apple was recognized long ago as a potential source of resistance to scab, this resistance has not been characterized previously. Differential interactions between various monoconidial isolates of V. inaequalis and six segregating F1 and F2 populations indicate the presence of at least five loci governing the resistance in 'Geneva'. The 17 chromosomes of apple were screened using genotyping-by-sequencing, as well as single marker mapping, to position loci controlling the V. inaequalis resistance on linkage group 4. Next, we fine mapped a 5-cM region containing five loci conferring both dominant and recessive scab resistance to the distal end of the linkage group. This region corresponds to 2.2 Mbp (from 20.3 to 22.5 Mbp) on the physical map of 'Golden Delicious' containing nine candidate nucleotide-binding site leucine-rich repeat (NBS-LRR) resistance genes. This study increases our understanding of the complex genetic basis of apple scab resistance conferred by 'Geneva', as well as the gene-for-gene (GfG) relationships between the effector genes in the pathogen and resistance genes in the host.
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Affiliation(s)
- Héloïse Bastiaanse
- Plant Pathology Unit, Gembloux Agro-Bio Tech, University of Liège, avenue Maréchal Juin 13, Gembloux 5030, Belgium
- The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
- Plant & Food Research, Private Bag 1401, Havelock North 4157, New Zealand
| | - Heather C M Bassett
- The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
| | - Christopher Kirk
- The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
| | - Susan E Gardiner
- The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
| | - Cecilia Deng
- Plant & Food Research, Private Bag 92169, Auckland 1142, New Zealand
| | - Remmelt Groenworld
- Plant Breeding, Wageningen University & Research, PO Box 386, 6700 AJ Wageningen, the Netherlands
| | - David Chagné
- The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research), Private Bag 11600, Palmerston North 4442, New Zealand
| | - Vincent G M Bus
- Plant & Food Research, Private Bag 1401, Havelock North 4157, New Zealand
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Sciubba F, Di Cocco ME, Gianferri R, Capuani G, De Salvador FR, Fontanari M, Gorietti D, Delfini M. Nuclear Magnetic Resonance-Based Metabolic Comparative Analysis of Two Apple Varieties with Different Resistances to Apple Scab Attacks. J Agric Food Chem 2015; 63:8339-8347. [PMID: 26345382 DOI: 10.1021/acs.jafc.5b03311] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Apple scab, caused by the fungus Venturia inaequalis, is the most serious disease of the apple worldwide. Two cultivars (Malus domestica), having different degrees of resistance against fungi attacks, were analyzed by (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy. Aqueous and organic extracts of both apple flesh and skin were studied, and over 30 metabolites, classified as organic acids, amino acids, carbohydrates, phenolic compounds, lipids, sterols, and other metabolites, were quantified by means of one-dimensional (1D) and two-dimensional (2D) NMR experiments. The metabolic profiles of the two apple cultivars were compared, and the differences were correlated with the different degrees of resistance to apple scab by means of univariate analysis. Levels of metabolites with known antifungal activity were observed not only to be higher in the Almagold cultivar but also to show different correlation patterns in comparison to Golden Delicious, implying a difference in the metabolic network involved in their biosynthesis.
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Affiliation(s)
- Fabio Sciubba
- Department of Chemistry, Sapienza University of Rome , Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Maria Enrica Di Cocco
- Department of Chemistry, Sapienza University of Rome , Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Raffaella Gianferri
- Department of Chemistry, Sapienza University of Rome , Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Giorgio Capuani
- Department of Chemistry, Sapienza University of Rome , Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Flavio Roberto De Salvador
- Fruit Tree Research Centre, Council for Research and Experimentation in Agriculture (CREA) , Via di Fioranello 52, 00134 Rome, Italy
| | - Marco Fontanari
- Edmund Mach Foundation, Research and Innovation Centre (CRI) , Via Edmund Mach 1, 38010 San Michele all'Adige, Trentino, Italy
| | - Daniela Gorietti
- Department of Chemistry, Sapienza University of Rome , Piazzale Aldo Moro 5, 00185 Rome, Italy
| | - Maurizio Delfini
- Department of Chemistry, Sapienza University of Rome , Piazzale Aldo Moro 5, 00185 Rome, Italy
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Stević M, Tamaš N, Miletić N, Vukša P. Different toxicity of the strobilurin fungicides kresoxim-methyl and trifloxistrobin to Venturia inaequalis isolates from Serbia. J Environ Sci Health B 2015; 50:633-637. [PMID: 26079336 DOI: 10.1080/03601234.2015.1038952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Sensitivity of monosporial isolates of V. inaequalis, originated from apple orchards previously exposed (commercial and experimental) and those originated from location where fungicides had never been used (wild type), to strobilurin fungicides kresoxim-methyl and trifloxistrobin was investigated in this study. The experiments were carried out in laboratory using in vitro and in vivo methods. Mycelia growth inhibition on PDA medium with kresoxim-methyl and trifloxistrobin was monitored and sensitivity parameters (EC50 values) were determined using probit analysis. The isolates sensitivity in vivo was tested on apple seedlings using inoculation method. The EC50 values were ranging from 0.066-2.033 and 0.011-0.323 µg mL(-1) for kresoxim-methyl and trifloxistrobin, respectively. The wild type of isolates showed a normal susceptibility to kresoxim-methyl and trifloxistrobin, while isolates originated from experimental and commercial orchard where those fungicides had been used extensively, showed significantly lower sensitivity to the both strobilurin fungicides. The isolate that showed the resistance to kresoxim-methyl and trifloxistrobin in vitro test, also showed reduced sensitivity in vivo test and could not been controlled satisfactory by fungicide concentrations that are commercially used, as well as by double higher, after apple seedlings inoculation.
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Affiliation(s)
- Milan Stević
- a Faculty of Agriculture, University of Belgrade , Belgrade-Zemun , Serbia
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33
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Vanblaere T, Flachowsky H, Gessler C, Broggini GAL. Molecular characterization of cisgenic lines of apple 'Gala' carrying the Rvi6 scab resistance gene. Plant Biotechnol J 2014; 12:2-9. [PMID: 23998808 DOI: 10.1111/pbi.12110] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Revised: 07/16/2013] [Accepted: 07/18/2013] [Indexed: 05/24/2023]
Abstract
Using resistance genes from a crossable donor to obtain cultivars resistant to diseases and the use of such cultivars in production appears an economically and environmentally advantageous approach. In apple, introgression of resistance genes by classical breeding results in new cultivars, while introducing cisgenes by biotechnological methods maintains the original cultivar characteristics. Recently, plants of the popular apple 'Gala' were genetically modified by inserting the apple scab resistance gene Rvi6 (formerly HcrVf2) under control of its own regulatory sequences. This gene is derived from the scab-resistant apple 'Florina' (originally from the wild apple accession Malus floribunda 821). The vector used for genetic modification allowed a postselection marker gene elimination to achieve cisgenesis. In this work, three cisgenic lines were analysed to assess copy number, integration site, expression level and resistance to apple scab. For two of these lines, a single insertion was observed and, despite a very low expression of 0.07- and 0.002-fold compared with the natural expression of 'Florina', this was sufficient to induce plant reaction and reduce fungal growth by 80% compared with the scab-susceptible 'Gala'. Similar results for resistance and expression analysis were obtained also for the third line, although it was impossible to determine the copy number and TDNA integration site-such molecular characterization is requested by the (EC) Regulation No. 1829/2003, but may become unnecessary if cisgenic crops become exempt from GMO regulation.
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Affiliation(s)
- Thalia Vanblaere
- Plant Pathology, Institute of Integrative Biology (IBZ), ETH Zurich, Zurich, Switzerland
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34
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Khalil MNA, Beuerle T, Müller A, Ernst L, Bhavanam VBR, Liu B, Beerhues L. Biosynthesis of the biphenyl phytoalexin aucuparin in Sorbus aucuparia cell cultures treated with Venturia inaequalis. Phytochemistry 2013; 96:101-109. [PMID: 24074553 DOI: 10.1016/j.phytochem.2013.09.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/25/2013] [Accepted: 09/02/2013] [Indexed: 06/02/2023]
Abstract
Aucuparin is the most widely distributed biphenyl phytoalexin in the rosaceous subtribe Pyrinae, which includes the economically important fruit trees apple and pear. The biphenyl scaffold is formed by biphenyl synthase, which catalyzes biosynthesis of 3,5-dihydroxybiphenyl. Conversion of this precursor to aucuparin (3,5-dimethoxy-4-hydroxybiphenyl) was studied in cell cultures of Sorbus aucuparia after treatment with an elicitor preparation from the scab-causing fungus Venturia inaequalis. The sequence of the biosynthetic steps detected was O-methylation - 4-hydroxylation - O-methylation. The two alkylation reactions were catalyzed by distinct methyltransferases, which differed in pH and temperature optima as well as stability. Biphenyl 4-hydroxylase was a microsomal cytochrome P450 monooxygenase, whose activity was appreciably decreased by the addition of established P450 inhibitors. When fed to V. inaequalis-treated S. aucuparia cell cultures, radioactively labeled 3,5-dihydroxybiphenyl was not only incorporated into aucuparin but also into the dibenzofuran eriobofuran, the accumulation of which paralleled that of aucuparin. However, biphenyl 2'-hydroxylase activity proposed to be involved in dibenzofuran formation was detected in neither microsomes nor cell-free extracts in the presence of NADPH and 2-oxoglutarate, respectively. Nevertheless, a basis for studying biphenyl biosynthesis at the gene level is provided.
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Affiliation(s)
- Mohammed N A Khalil
- Institute of Pharmaceutical Biology, Technische Universität Braunschweig, Mendelssohnstr. 1, 38106 Braunschweig, Germany
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35
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Cornille A, Gladieux P, Giraud T. Crop-to-wild gene flow and spatial genetic structure in the closest wild relatives of the cultivated apple. Evol Appl 2013; 6:737-748. [PMID: 29387162 PMCID: PMC5779123 DOI: 10.1111/eva.12059] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 01/21/2013] [Indexed: 11/29/2022] Open
Abstract
Crop‐to‐wild gene flow have important evolutionary and ecological consequences and require careful consideration in conservation programs for wild genetic resources of potential use in breeding programs and in assessments of the risk of transgene escape into natural ecosystems. Using 26 microsatellites and a set of 1181 trees, we investigated the extent of introgression from the cultivated apple, Malus domestica, to its three closest wild relatives, M. sylvestris in Europe, M. orientalis in the Caucasus, and M. sieversii in Central Asia. We found footprints of introgression from M. domestica to M. orientalis (3.2% of hybrids), M. sieversii (14.8%), and M. sylvestris (36.7%). Malus sieversii and M. orientalis presented weak, but significant genetic structures across their geographic range. Malus orientalis displayed genetic differentiation with three differentiated populations in Turkey, Armenia, and Russia. Malus sieversii consisted of a main population spread over Central Asia and a smaller population in the Tian Shan Mountains. The low Sp values suggest high dispersal capacities for the wild apple relatives. High potential for crop‐to‐wild gene flow in apples needs to be considered in the implementation of in situ and ex situ actions for the conservation of wild apple genetic resources potentially useful to plant breeding.
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Affiliation(s)
- Amandine Cornille
- CNRS Laboratoire Ecologie Systématique et Evolution - UMR8079 Orsay France.,University Paris Sud Orsay France
| | - Pierre Gladieux
- CNRS Laboratoire Ecologie Systématique et Evolution - UMR8079 Orsay France.,University Paris Sud Orsay France.,Department of Plant and Microbial Biology University of CaliforniaB erkeley CA 94720-3102 USA
| | - Tatiana Giraud
- CNRS Laboratoire Ecologie Systématique et Evolution - UMR8079 Orsay France.,University Paris Sud Orsay France
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