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Babu S, Vineeth VK, Reshma TR, Philip S. Integrating multilocus phylogeny and morphological analysis reveals the prevalence of Phytophthora meadii (McRae) associated with abnormal leaf fall disease of Hevea brasiliensis in India. Fungal Biol 2024; 128:2042-2053. [PMID: 39174239 DOI: 10.1016/j.funbio.2024.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 07/18/2024] [Accepted: 07/31/2024] [Indexed: 08/24/2024]
Abstract
The Oomycetes fungus Phytophthora spp. which causes Abnormal leaf fall (ALF) disease poses a significant threat as one of the most devastating diseases affecting rubber trees in India. A total of 30 Phytophthora isolates were obtained from ALF-affected samples collected during the Southwest monsoon season of Kerala. The colony morphology of Phytophthora isolates revealed eight different types of growth patterns, with stellate, stellate striated, and petaloid patterns growing rapidly, whereas chrysanthemum pattern grew slowly. Sporangia were papillate to non-papillate in various shapes, and sporangiophores exhibited simple, simple sympodial, or irregularly branching patterns. Highly virulent isolates exhibited petaloid morphology and rapid growth rates. Regardless of their virulence, all isolates showed susceptibility to the fungicide metalaxyl. Under in vitro conditions, the highly virulent isolate (R17) from rubber caused severe infections in chili, brinjal, and tomato with brown water-soaked lesions. Sequence analysis and multi-locus phylogeny of Internal transcribed spacer (ITS), cCytochrome c oxidase 1 (COX 1), Heat shock protein 90 (HSP 90), and Ribosomal protein L10 (RPL 10) confirmed the pathogen as Phytophthora meadii. A comprehensive understanding of both morphological and molecular traits of P. meadii is crucial for precise identification and future genetic variability studies.
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Affiliation(s)
- Shilpa Babu
- Plant Pathology Division, Rubber Research Institute of India, Rubber Board P.O, Kottayam, Kerala, 686009, India.
| | - V K Vineeth
- Plant Pathology Division, Rubber Research Institute of India, Rubber Board P.O, Kottayam, Kerala, 686009, India.
| | - T R Reshma
- Plant Pathology Division, Rubber Research Institute of India, Rubber Board P.O, Kottayam, Kerala, 686009, India.
| | - Shaji Philip
- Plant Pathology Division, Rubber Research Institute of India, Rubber Board P.O, Kottayam, Kerala, 686009, India.
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Wang L, Zhao F, Liu H, Chen H, Zhang F, Li S, Sun T, Nekrasov V, Huang S, Dong S. A modified Agrobacterium-mediated transformation for two oomycete pathogens. PLoS Pathog 2023; 19:e1011346. [PMID: 37083862 PMCID: PMC10156060 DOI: 10.1371/journal.ppat.1011346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 05/03/2023] [Accepted: 04/06/2023] [Indexed: 04/22/2023] Open
Abstract
Oomycetes are a group of filamentous microorganisms that include some of the biggest threats to food security and natural ecosystems. However, much of the molecular basis of the pathogenesis and the development in these organisms remains to be learned, largely due to shortage of efficient genetic manipulation methods. In this study, we developed modified transformation methods for two important oomycete species, Phytophthora infestans and Plasmopara viticola, that bring destructive damage in agricultural production. As part of the study, we established an improved Agrobacterium-mediated transformation (AMT) method by prokaryotic expression in Agrobacterium tumefaciens of AtVIP1 (VirE2-interacting protein 1), an Arabidopsis bZIP gene required for AMT but absent in oomycetes genomes. Using the new method, we achieved an increment in transformation efficiency in two P. infestans strains. We further obtained a positive GFP transformant of P. viticola using the modified AMT method. By combining this method with the CRISPR/Cas12a genome editing system, we successfully performed targeted mutagenesis and generated loss-of-function mutations in two P. infestans genes. We edited a MADS-box transcription factor-encoding gene and found that a homozygous mutation in MADS-box results in poor sporulation and significantly reduced virulence. Meanwhile, a single-copy avirulence effector-encoding gene Avr8 in P. infestans was targeted and the edited transformants were virulent on potato carrying the cognate resistance gene R8, suggesting that loss of Avr8 led to successful evasion of the host immune response by the pathogen. In summary, this study reports on a modified genetic transformation and genome editing system, providing a potential tool for accelerating molecular genetic studies not only in oomycetes, but also other microorganisms.
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Affiliation(s)
- Luyao Wang
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
- Department of Plant Pathology and Key Laboratory of Integrated Management of Crop Disease and Pests (Ministry of Education), Nanjing Agricultural University, Nanjing, China
| | - Fei Zhao
- Department of Plant Pathology and Key Laboratory of Integrated Management of Crop Disease and Pests (Ministry of Education), Nanjing Agricultural University, Nanjing, China
| | - Haohao Liu
- Department of Plant Pathology and Key Laboratory of Integrated Management of Crop Disease and Pests (Ministry of Education), Nanjing Agricultural University, Nanjing, China
| | - Han Chen
- Department of Plant Pathology and Key Laboratory of Integrated Management of Crop Disease and Pests (Ministry of Education), Nanjing Agricultural University, Nanjing, China
| | - Fan Zhang
- Department of Plant Pathology and Key Laboratory of Integrated Management of Crop Disease and Pests (Ministry of Education), Nanjing Agricultural University, Nanjing, China
| | - Suhua Li
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Tongjun Sun
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Vladimir Nekrasov
- Plant Sciences and the Bioeconomy, Rothamsted Research, Harpenden, United Kingdom
| | - Sanwen Huang
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Suomeng Dong
- Department of Plant Pathology and Key Laboratory of Integrated Management of Crop Disease and Pests (Ministry of Education), Nanjing Agricultural University, Nanjing, China
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3
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Myo-D-inositol Trisphosphate Signalling in Oomycetes. Microorganisms 2022; 10:microorganisms10112157. [DOI: 10.3390/microorganisms10112157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 10/21/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022] Open
Abstract
Oomycetes are pathogens of plants and animals, which cause billions of dollars of global losses to the agriculture, aquaculture and forestry sectors each year. These organisms superficially resemble fungi, with an archetype being Phytophthora infestans, the cause of late blight of tomatoes and potatoes. Comparison of the physiology of oomycetes with that of other organisms, such as plants and animals, may provide new routes to selectively combat these pathogens. In most eukaryotes, myo-inositol 1,4,5 trisphosphate is a key second messenger that links extracellular stimuli to increases in cytoplasmic Ca2+, to regulate cellular activities. In the work presented in this study, investigation of the molecular components of myo-inositol 1,4,5 trisphosphate signaling in oomycetes has unveiled similarities and differences with that in other eukaryotes. Most striking is that several oomycete species lack detectable phosphoinositide-selective phospholipase C homologues, the enzyme family that generates this second messenger, but still possess relatives of myo-inositol 1,4,5 trisphosphate-gated Ca2+-channels.
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Situ J, Xi P, Lin L, Huang W, Song Y, Jiang Z, Kong G. Signal and regulatory mechanisms involved in spore development of Phytophthora and Peronophythora. Front Microbiol 2022; 13:984672. [PMID: 36160220 PMCID: PMC9500583 DOI: 10.3389/fmicb.2022.984672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/23/2022] [Indexed: 11/13/2022] Open
Abstract
Oomycetes cause hundreds of destructive plant diseases, threatening agricultural production and food security. These fungus-like eukaryotes show multiple sporulation pattern including the production of sporangium, zoospore, chlamydospore and oospore, which are critical for their survival, dispersal and infection on hosts. Recently, genomic and genetic technologies have greatly promoted the study of molecular mechanism of sporulation in the genus Phytophthora and Peronophythora. In this paper, we characterize the types of asexual and sexual spores and review latest progress of these two genera. We summarize the genes encoding G protein, mitogen-activated protein kinase (MAPK) cascade, transcription factors, RNA-binding protein, autophagy-related proteins and so on, which function in the processes of sporangium production and cleavage, zoospore behaviors and oospore formation. Meanwhile, various molecular, chemical and electrical stimuli in zoospore behaviors are also discussed. Finally, with the molecular mechanism of sporulation in Phytophthora and Peronophythora is gradually being revealed, we propose some thoughts for the further research and provide the alternative strategy for plant protection against phytopathogenic oomycetes.
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Affiliation(s)
- Junjian Situ
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Pinggen Xi
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Long Lin
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Weixiong Huang
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Yu Song
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Zide Jiang
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
| | - Guanghui Kong
- Department of Plant Pathology, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou, China
- *Correspondence: Guanghui Kong,
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Baysal-Gurel F, Bika R, Simmons T, Avin F. Identification and Management of Phytophthora Aerial Blight Caused by Phytophthora nicotianae on Catharanthus roseus. PLANT DISEASE 2022; 106:1271-1277. [PMID: 34854759 DOI: 10.1094/pdis-06-21-1342-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Phytophthora nicotianae is the most common pathogen in nurseries and gardens, infecting both woody and herbaceous ornamental plants. Phytophthora aerial blight symptoms such dull water-soaked lesions on shoot tips and leaf petioles, girdling on the main stem, necrosis, and wilting of annual vinca were observed in a commercial greenhouse in Warren County, TN, U.S.A., in May 2016. The objective of this study was to identify the causal agent of Phytophthora aerial blight and develop a fungicide management recommendation for ornamental producers. Attempts to isolate the pathogen from symptomatic leaf tissue were conducted, and excised leaf pieces were embedded in V8 agar medium. Morphological characterization, PCR, sequencing, and pathogenicity test of the isolate FBG2016_444 were conducted to confirm the pathogen identification. The sequence identity was 100% identical to P. nicotianae, and a combined phylogenetic tree (internal transcribed spacer, large subunit of rDNA, and ras-related protein gene) grouped isolate FBG2016_444 within the clade of P. nicotianae. In the pathogenicity study, all inoculated annual vinca plant showed Phytophthora aerial blight symptoms, and P. nicotianae was reisolated, whereas noninoculated annual vinca plant remained symptomless. These findings confirmed P. nicotianae as the causal agent of Phytophthora aerial blight of annual vinca. In addition, two rates (0.078 and 0.156 ml·liter-1) and three application intervals (7, 14, and 21 days before inoculation [DBI]) of oxathiapiprolin (Segovis) were evaluated for their ability to reduce the Phytophthora aerial blight severity on annual vinca plants. The control groups were positive (nontreated inoculated) and negative (nontreated noninoculated) plants. Both rates and application timings of oxathiapiprolin significantly reduced Phytophthora aerial blight severity and disease progress (area under disease progress curve [AUDPC]) on annual vinca plants compared with the positive control. However, 0.078 and 0.156 ml·liter-1 of oxathiapiprolin applied at 7 or 14 DBI were the most effective treatments in reducing the disease severity and AUDPC on annual vinca plants. The plant growth parameters such as increase in height and width, total plant weight, and root weight were not influenced by the application of oxathiapiprolin. The findings reported in this study will help ornamental producers with better management of Phytophthora aerial blight of annual vinca.
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Affiliation(s)
- Fulya Baysal-Gurel
- Otis L. Floyd Nursery Research Center, Department of Agricultural and Environmental Sciences, Tennessee State University, McMinnville, TN 37110
| | - Ravi Bika
- Otis L. Floyd Nursery Research Center, Department of Agricultural and Environmental Sciences, Tennessee State University, McMinnville, TN 37110
| | - Terri Simmons
- Otis L. Floyd Nursery Research Center, Department of Agricultural and Environmental Sciences, Tennessee State University, McMinnville, TN 37110
| | - Farhat Avin
- Otis L. Floyd Nursery Research Center, Department of Agricultural and Environmental Sciences, Tennessee State University, McMinnville, TN 37110
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6
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Tran QD, Galiana E, Thomen P, Cohen C, Orange F, Peruani F, Noblin X. Coordination of two opposite flagella allows high-speed swimming and active turning of individual zoospores. eLife 2022; 11:e71227. [PMID: 35343437 PMCID: PMC9068220 DOI: 10.7554/elife.71227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Accepted: 03/25/2022] [Indexed: 11/13/2022] Open
Abstract
Phytophthora species cause diseases in a large variety of plants and represent a serious agricultural threat, leading, every year, to multibillion dollar losses. Infection occurs when their biflagellated zoospores move across the soil at their characteristic high speed and reach the roots of a host plant. Despite the relevance of zoospore spreading in the epidemics of plant diseases, individual swimming of zoospores have not been fully investigated. It remains unknown about the characteristics of two opposite beating flagella during translation and turning, and the roles of each flagellum on zoospore swimming. Here, combining experiments and modeling, we show how these two flagella contribute to generate thrust when beating together, and identify the mastigonemes-attached anterior flagellum as the main source of thrust. Furthermore, we find that turning involves a complex active process, in which the posterior flagellum temporarily stops, while the anterior flagellum keeps on beating and changes its gait from sinusoidal waves to power and recovery strokes, similar to Chlamydomonas's breaststroke, to reorient its body to a new direction. Our study is a fundamental step toward a better understanding of the spreading of plant pathogens' motile forms, and shows that the motility pattern of these biflagellated zoospores represents a distinct eukaryotic version of the celebrated 'run-and-tumble' motility class exhibited by peritrichous bacteria.
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Affiliation(s)
- Quang D Tran
- Université Côte d’Azur, CNRS UMR 7010, Institut de Physique de Nice (INPHYNI)NiceFrance
| | - Eric Galiana
- Université Côte d’Azur, INRAE UMR 1355, CNRS UMR 7254, Institut Sophia Agrobiotech (ISA)Sophia AntipolisFrance
| | - Philippe Thomen
- Université Côte d’Azur, CNRS UMR 7010, Institut de Physique de Nice (INPHYNI)NiceFrance
| | - Céline Cohen
- Université Côte d’Azur, CNRS UMR 7010, Institut de Physique de Nice (INPHYNI)NiceFrance
| | - François Orange
- Université Côte d’Azur, Centre Commun de Microscopie Appliquée (CCMA)NiceFrance
| | - Fernando Peruani
- Université Côte d’Azur, CNRS UMR 7351, Laboratoire J.A. Dieudonné (LJAD)NiceFrance
- CY Cergy Paris Université, CNRS UMR 8089, Laboratoire de Physique Théorique et ModélisationCergy-PontoiseFrance
| | - Xavier Noblin
- Université Côte d’Azur, CNRS UMR 7010, Institut de Physique de Nice (INPHYNI)NiceFrance
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Pavić D, Grbin D, Gregov M, Ćurko J, Vladušić T, Šver L, Miljanović A, Bielen A. Variations in the Sporulation Efficiency of Pathogenic Freshwater Oomycetes in Relation to the Physico-Chemical Properties of Natural Waters. Microorganisms 2022; 10:microorganisms10030520. [PMID: 35336096 PMCID: PMC8955207 DOI: 10.3390/microorganisms10030520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 02/16/2022] [Accepted: 02/25/2022] [Indexed: 01/27/2023] Open
Abstract
Oomycete pathogens in freshwaters, such as Saprolegnia parasitica and Aphanomyces astaci, are responsible for fish/crayfish population declines in the wild and disease outbreaks in aquaculture. Although the formation of infectious zoospores in the laboratory can be triggered by washing their mycelium with natural water samples, the physico-chemical properties of the water that might promote sporulation are still unexplored. We washed the mycelia of A. astaci and S. parasitica with a range of natural water samples and observed differences in sporulation efficiency. The results of Partial Least Squares Regression (PLS-R) multivariate analysis showed that SAC (spectral absorption coefficient measured at 254 nm), DOC (dissolved organic carbon), ammonium-N and fluoride had the strongest positive effect on sporulation of S. parasitica, while sporulation of A. astaci was not significantly correlated with any of the analyzed parameters. In agreement with this, the addition of environmentally relevant concentrations of humic acid, an important contributor to SAC and DOC, to the water induced sporulation of S. parasitica but not of A. astaci. Overall, our results point to the differences in ecological requirements of these pathogens, but also present a starting point for optimizing laboratory protocols for the induction of sporulation.
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Lacalendola N, Tayagui A, Ting M, Malmstrom J, Nock V, Willmott GR, Garrill A. Biomechanical responses of encysted zoospores of the oomycete Achlya bisexualis to hyperosmotic stress are consistent with an ability to turgor regulate. Fungal Genet Biol 2022; 159:103676. [DOI: 10.1016/j.fgb.2022.103676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 02/20/2022] [Accepted: 02/21/2022] [Indexed: 11/27/2022]
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Kaczmarek A, Boguś MI. Fungi of entomopathogenic potential in Chytridiomycota and Blastocladiomycota, and in fungal allies of the Oomycota and Microsporidia. IMA Fungus 2021; 12:29. [PMID: 34635188 PMCID: PMC8504053 DOI: 10.1186/s43008-021-00074-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 07/25/2021] [Indexed: 11/10/2022] Open
Abstract
The relationship between entomopathogenic fungi and their insect hosts is a classic example of the co-evolutionary arms race between pathogen and target host. The present review describes the entomopathogenic potential of Chytridiomycota and Blastocladiomycota fungi, and two groups of fungal allies: Oomycota and Microsporidia. The Oomycota (water moulds) are considered as a model biological control agent of mosquito larvae. Due to their shared ecological and morphological similarities, they had long been considered a part of the fungal kingdom; however, phylogenetic studies have since placed this group within the Straminipila. The Microsporidia are parasites of economically-important insects, including grasshoppers, lady beetles, bumblebees, colorado potato beetles and honeybees. They have been found to display some fungal characteristics, and phylogenetic studies suggest that they are related to fungi, either as a basal branch or sister group. The Blastocladiomycota and Chytridiomycota, named the lower fungi, historically were described together; however, molecular phylogenetic and ultrastructural research has classified them in their own phylum. They are considered parasites of ants, and of the larval stages of black flies, mosquitoes and scale insects.
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Affiliation(s)
- Agata Kaczmarek
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Twarda 51/55, 00-818, Warsaw, Poland.
| | - Mieczysława I Boguś
- Witold Stefański Institute of Parasitology, Polish Academy of Sciences, Twarda 51/55, 00-818, Warsaw, Poland
- Biomibo, Strzygłowska 15, 04-872, Warsaw, Poland
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Becking T, Kiselev A, Rossi V, Street-Jones D, Grandjean F, Gaulin E. Pathogenicity of animal and plant parasitic Aphanomyces spp and their economic impact on aquaculture and agriculture. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Sabbadin F, Henrissat B, Bruce NC, McQueen-Mason SJ. Lytic Polysaccharide Monooxygenases as Chitin-Specific Virulence Factors in Crayfish Plague. Biomolecules 2021; 11:biom11081180. [PMID: 34439846 PMCID: PMC8393829 DOI: 10.3390/biom11081180] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 11/19/2022] Open
Abstract
The oomycete pathogen Aphanomyces astaci, also known as “crayfish plague”, is an obligate fungal-like parasite of freshwater crustaceans and is considered responsible for the ongoing decline of native European crayfish populations. A. astaci is thought to secrete a wide array of effectors and enzymes that facilitate infection, however their molecular mechanisms have been poorly characterized. Here, we report the identification of AA15 lytic polysaccharide monooxygenases (LPMOs) as a new group of secreted virulence factors in A. astaci. We show that this enzyme family has greatly expanded in A. astaci compared to all other oomycetes, and that it may facilitate infection through oxidative degradation of crystalline chitin, the most abundant polysaccharide found in the crustacean exoskeleton. These findings reveal new roles for LPMOs in animal–pathogen interactions, and could help inform future strategies for the protection of farmed and endangered species.
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Affiliation(s)
- Federico Sabbadin
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, UK;
- Correspondence: (F.S.); (S.J.M.-M.)
| | - Bernard Henrissat
- DTU Bioengineering, Technical University of Denmark, Søltofts Plads, 2800 Kongens Lyngby, Denmark;
- Department of Biological Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Neil C. Bruce
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, UK;
| | - Simon J. McQueen-Mason
- Centre for Novel Agricultural Products, Department of Biology, University of York, York YO10 5DD, UK;
- Correspondence: (F.S.); (S.J.M.-M.)
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Atallah OO, Osman A, Ali MA, Sitohy M. Soybean β-conglycinin and catfish cutaneous mucous p22 glycoproteins deteriorate sporangial cell walls of Pseudoperonospora cubensis and suppress cucumber downy mildew. PEST MANAGEMENT SCIENCE 2021; 77:3313-3324. [PMID: 33763975 DOI: 10.1002/ps.6375] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 03/13/2021] [Accepted: 03/25/2021] [Indexed: 05/25/2023]
Abstract
BACKGROUND Cucumber plants suffer from a serious threatening disease, downy mildew, throughout the growing seasons irrespective of the weather temperature. The causal agent, Pseudoperonospora cubensis, tends to evolve rapidly upon sequential applications of chemical fungicides and generate new progeny possessing tolerance to such fungicides. Glycoproteins represent an environmentally safe alternative for chemically synthetized fungicides and do not trigger fungicide resistance. We studied the antifungal activity of four glycoproteins namely soybean β-conglycinin, chickpea vicilin, duck egg ovomucin and catfish p22 against P. cubensis. Ten commercial fungicides of different chemical groups were used as positive controls of glycoprotein treatments. RESULTS The results revealed that soybean β-conglycinin and catfish p22 glycoproteins possess significant antifungal activity against P. cubensis. The amount of disease suppression caused by β-conglycinin and p22 was comparable to the highly efficient chemical fungicides containing copper oxychloride, cymoxanil and fosetyl Al as active ingredients. Vicilin and ovomucin were less efficient biocides as they gave moderate suppression of disease severity. However, all tested glycoproteins provided full protection for the newly emerged cucumber leaves. Microscopic examination of glycoprotein-treated leaves inferred the ability of catfish p22 and soybean β-conglycinin to disrupt the integrity of sporangial cell walls of P. cubensis rendering them non-viable compared to untreated ones. Expression levels of total phenolic compounds and the antioxidant enzymes catalase, superoxide dismutase and peroxidase were elevated upon glycoproteins application, which infers their involvement in disease suppression. CONCLUSION This report emphasizes the direct and indirect roles of glycoproteins in safe management of cucumber downy mildew disease. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Osama O Atallah
- Department of Plant Pathology, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Ali Osman
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Mohamed As Ali
- Department of Plant Pathology, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Mahmoud Sitohy
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
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Mohammadi MA, Cheng Y, Aslam M, Jakada BH, Wai MH, Ye K, He X, Luo T, Ye L, Dong C, Hu B, Priyadarshani SVGN, Wang-Pruski G, Qin Y. ROS and Oxidative Response Systems in Plants Under Biotic and Abiotic Stresses: Revisiting the Crucial Role of Phosphite Triggered Plants Defense Response. Front Microbiol 2021; 12:631318. [PMID: 34276579 PMCID: PMC8281016 DOI: 10.3389/fmicb.2021.631318] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 05/10/2021] [Indexed: 11/30/2022] Open
Abstract
Phosphite (Phi) is a chemical analog of orthophosphate [HPO4 3-]. It is a systemic pesticide generally known to control the prevalence of oomycetes and soil-borne diseases such as Phytophthora, Pythium, and Plasmopora species. Phi can also control disease symptoms and the spread of pathogenic bacteria, fungi, and nematodes. Phi plays critical roles as a fungicide, pesticide, fertilizer, or biostimulator. Overall, Phi can alleviate the severity of the disease caused by oomycete, fungi, pathogenic bacteria, and nematodes (leave, stem, fruit, tuber, and root) in various plants (vegetables, fruits, crops, root/tuber crops, ornamental plants, and forests). Advance research in molecular, physiological, and biochemical approaches has approved the key role of Phi in enhancing crop growth, quantity, and quality of several plant species. Phi is chemically similar to orthophosphate, and inside the cells, it is likely to get involved in different features of phosphate metabolism in both plants and pathogens. In plants, a range of physiobiochemical alterations are induced by plant pathogen stress, which causes lowered photosynthesis activities, enzymatic activities, increased accumulation of reactive oxygen species (ROS), and modification in a large group of genes. To date, several attempts have been made to study plant-pathogen interactions with the intent to minimize the loss of crop productivity. Phi's emerging function as a biostimulant in plants has boost plant yield and tolerance against various stress factors. This review discusses Phi-mediated biostimulant effects against biotic and abiotic stresses.
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Affiliation(s)
- Mohammad Aqa Mohammadi
- Joint FAFU-Dalhousie Lab, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Lab of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning, China
- Department of Horticulture, College of Agriculture, Alberoni University, Kohistan, Afghanistan
| | - Yan Cheng
- Joint FAFU-Dalhousie Lab, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Mohammad Aslam
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Lab of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning, China
| | - Bello Hassan Jakada
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Myat Hnin Wai
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Kangzhuo Ye
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaoxue He
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Tiantian Luo
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Li Ye
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chunxing Dong
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Bin Hu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, China
| | - S. V. G. N. Priyadarshani
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- National Education Commission, Nugegoda, Sri Lanka
| | - Gefu Wang-Pruski
- Joint FAFU-Dalhousie Lab, College of Horticulture, Fujian Agriculture and Forestry University, Fuzhou, China
- Department of Plant, Food, and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS, Canada
| | - Yuan Qin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, College of Life Sciences, Center for Genomics and Biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources, Guangxi Key Lab of Sugarcane Biology, College of Agriculture, Guangxi University, Nanning, China
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Jara M, Holcomb K, Wang X, Goss EM, Machado G. The Potential Distribution of Pythium insidiosum in the Chincoteague National Wildlife Refuge, Virginia. Front Vet Sci 2021; 8:640339. [PMID: 33681336 PMCID: PMC7933582 DOI: 10.3389/fvets.2021.640339] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 01/27/2021] [Indexed: 02/06/2023] Open
Abstract
Pythium insidiosum is a widespread pathogen that causes pythiosis in mammals. Recent increase in cases reported in North America indicates a need to better understand the distribution and persistence of the pathogen in the environment. In this study, we reconstructed the distribution of P. insidiosum in the Chincoteague National Wildlife Refuge, located on Assateague Island, Virginia, and based on 136 environmental water samples collected between June and September of 2019. The Refuge hosts two grazing areas for horses, also known as the Chincoteague Ponies. In the past 3 years, 12 horses have succumbed to infection by P. insidiosum. Using an ecological niche model framework, we estimated and mapped suitable areas for P. insidiosum throughout the Refuge. We found P. insidiosum throughout much of the study area. Our results showed significant monthly variation in the predicted suitability, where the most influential environmental predictors were land-surface water and temperature. We found that June, July, and August were the months with the highest suitability for P. insidiosum across the Refuge, while December through March were less favorable months. Likewise, significant differences in suitability were observed between the two grazing areas. The suitability map provided here could also be used to make management decisions, such as monitoring horses for lesions during high risk months.
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Affiliation(s)
- Manuel Jara
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
| | - Kevin Holcomb
- U.S. Fish & Wildlife Service, Chincoteague National Wildlife Refuge, Chincoteague, VA, United States
| | - Xuechun Wang
- Mount Vernon Northwestern Washington Research & Extension Center Mount Vernon, Mount Vernon, WA, United States
| | - Erica M Goss
- Mount Vernon Northwestern Washington Research & Extension Center Mount Vernon, Mount Vernon, WA, United States
| | - Gustavo Machado
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, United States
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Bassani I, Larousse M, Tran QD, Attard A, Galiana E. Phytophthora zoospores: From perception of environmental signals to inoculum formation on the host-root surface. Comput Struct Biotechnol J 2020; 18:3766-3773. [PMID: 33304469 PMCID: PMC7718214 DOI: 10.1016/j.csbj.2020.10.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 12/13/2022] Open
Abstract
To explore moist soils and to target host plants, phytopathogenic Phytophthora species utilize the sensory and propulsion capabilities of the biflagellate unicellular zoospores they produce. Zoospore motion and interactions with the microenvironment are of primary importance for Phytophthora physiology. These are also of critical significance for plant pathology in early infection sequential events and their regulation: the directed zoospore migration toward the host, the local aggregation and adhesion at the host penetration site. In the soil, these early events preceding the root colonization are orchestrated by guidance factors, released from the soil particles in water films, or emitted within microbiota and by host plants. This signaling network is perceived by zoospores and results in coordinated behavior and preferential localization in the rhizosphere. Recent computational and structural studies suggest that rhizospheric ion and plant metabolite sensing is a key determinant in driving zoospore motion, orientation and aggregation. To reach their target, zoospores respond to various molecular, chemical and electrical stimuli. However, it is not yet clear how these signals are generated in local soil niches and which gene functions govern the sensing and subsequent responses of zoospores. Here we review studies on the soil, microbial and host-plant factors that drive zoospore motion, as well as the adaptations governing zoospore behavior. We propose several research directions that could be explored to characterize the role of zoospore microbial ecology in disease.
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Affiliation(s)
- Ilaria Bassani
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Marie Larousse
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Quang D Tran
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Nice 06108, France
| | - Agnès Attard
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
| | - Eric Galiana
- Université Côte d'Azur, INRAE, CNRS, ISA, Sophia Antipolis 06903, France
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Wu J, Handique U, Graham J, Johnson E. Phytophthora nicotianae Infection of Citrus Leaves and Host Defense Activation Compared to Root Infection. PHYTOPATHOLOGY 2020; 110:1437-1448. [PMID: 32228377 DOI: 10.1094/phyto-09-19-0343-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Currently, little is known about the host pathogen interaction between Phytophthora spp. and citrus roots versus leaves. Therefore, we compared the molecular events occurring in citrus roots and leaves after zoospore inoculation with Phytophthora nicotianae. We analyzed the physical characteristics and genetic responses to P. nicotianae infection of leaves and roots for susceptible and tolerant citrus rootstocks to examine the potential for leaves to model root responses to P. nicotianae infection. Leaves responded faster and stronger to P. nicotianae infection than roots, and leaves showed greater differential response than roots. In addition to differences in hormonal responses, sugar, phospholipase D (PLD), and phospholipase A (PLA) involvement in the interaction between citrus and P. nicotianae was identified. This work, for the first time, creates a solid P. nicotianae zoospore infection protocol, reports P. nicotianae infection on citrus leaves through stomata, and provides evidence that different host organs respond to the pathogen differentially in timing and magnitude. This work identifies the hormones, sugars, pathogenesis-related genes, PLDs, and PLAs that are involved in the molecular events occurring in citrus under infection of P. nicotianae zoospore, and advances our understanding of the mechanisms underlying the interaction.
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Affiliation(s)
- Jian Wu
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, U.S.A
- Potato Engineering & Technology Research Center, Inner Mongolia University, 235 University Road, Hohhot, Inner Mongolia, China
| | - Utpal Handique
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, U.S.A
- Potato Engineering & Technology Research Center, Inner Mongolia University, 235 University Road, Hohhot, Inner Mongolia, China
| | - James Graham
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, U.S.A
| | - Evan Johnson
- Citrus Research and Education Center, University of Florida, 700 Experiment Station Road, Lake Alfred, FL, U.S.A
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Transcriptomic and Ultrastructural Signatures of K +-Induced Aggregation in Phytophthora parasitica Zoospores. Microorganisms 2020; 8:microorganisms8071012. [PMID: 32645882 PMCID: PMC7409359 DOI: 10.3390/microorganisms8071012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/03/2020] [Accepted: 07/04/2020] [Indexed: 11/17/2022] Open
Abstract
Most pathogenic oomycetes of the genus Phytophthora spread in water films as flagellated zoospores. Zoospores perceive and produce signals attracting other zoospores, resulting in autoaggregation in vitro or biofilm formation on plant surface. The mechanisms underlying intercellular communication and consequent attraction, adhesion and aggregation are largely unknown. In Phytophthora parasitica, the perception of a K+ gradient induces coordinated motion and aggregation. To define cellular and molecular events associated with oomycete aggregation, we combined transcriptomic and ultrastructural analyses. Results indicate involvement of electroception in K+ sensing. They establish that the transcriptome repertoire required for swimming and aggregation is already fully functional at zoospore release. At the time points analyzed, aggregates are mainly constituted of zoospores. They produce vesicular and fibrillary material discharged at cell-to-cell contacts. Consistently, the signature of transcriptome dynamics during transition to aggregates is an upregulation of genes potentially related to vesicular trafficking. Moreover, transcriptomic and functional analyses show a strong enhancement of carbonic anhydrase activity, indicating that pH homeostasis may contribute to aggregation by acting on both zoospore movement and adhesion. This study poses the molecular and cellular bases of aggregative behavior within oomycetes and expands the current knowledge of ion perception-mediated dissemination of propagules in the rhizosphere.
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Yuzon JD, Travadon R, Malar C M, Tripathy S, Rank N, Mehl HK, Rizzo DM, Cobb R, Small C, Tang T, McCown HE, Garbelotto M, Kasuga T. Asexual Evolution and Forest Conditions Drive Genetic Parallelism in Phytophthora ramorum. Microorganisms 2020; 8:E940. [PMID: 32580470 PMCID: PMC7357085 DOI: 10.3390/microorganisms8060940] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 11/16/2022] Open
Abstract
It is commonly assumed that asexual lineages are short-lived evolutionarily, yet many asexual organisms can generate genetic and phenotypic variation, providing an avenue for further evolution. Previous work on the asexual plant pathogen Phytophthora ramorum NA1 revealed considerable genetic variation in the form of Structural Variants (SVs). To better understand how SVs arise and their significance to the California NA1 population, we studied the evolutionary histories of SVs and the forest conditions associated with their emergence. Ancestral state reconstruction suggests that SVs arose by somatic mutations among multiple independent lineages, rather than by recombination. We asked if this unusual phenomenon of parallel evolution between isolated populations is transmitted to extant lineages and found that SVs persist longer in a population if their genetic background had a lower mutation load. Genetic parallelism was also found in geographically distant demes where forest conditions such as host density, solar radiation, and temperature, were similar. Parallel SVs overlap with genes involved in pathogenicity such as RXLRs and have the potential to change the course of an epidemic. By combining genomics and environmental data, we identified an unexpected pattern of repeated evolution in an asexual population and identified environmental factors potentially driving this phenomenon.
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Affiliation(s)
- Jennifer David Yuzon
- Department of Plant Pathology, University of California, Davis, CA 95616, USA; (R.T.); (H.K.M.); (D.M.R.); (C.S.); (T.T.); (H.E.M.)
| | - Renaud Travadon
- Department of Plant Pathology, University of California, Davis, CA 95616, USA; (R.T.); (H.K.M.); (D.M.R.); (C.S.); (T.T.); (H.E.M.)
| | - Mathu Malar C
- CSIR Indian Institute of Chemical Biology, Kolkata 700032, India; (M.M.C.); (S.T.)
| | - Sucheta Tripathy
- CSIR Indian Institute of Chemical Biology, Kolkata 700032, India; (M.M.C.); (S.T.)
| | - Nathan Rank
- Department of Biology, Sonoma State University, Rohnert Park, CA 94928, USA;
| | - Heather K. Mehl
- Department of Plant Pathology, University of California, Davis, CA 95616, USA; (R.T.); (H.K.M.); (D.M.R.); (C.S.); (T.T.); (H.E.M.)
| | - David M. Rizzo
- Department of Plant Pathology, University of California, Davis, CA 95616, USA; (R.T.); (H.K.M.); (D.M.R.); (C.S.); (T.T.); (H.E.M.)
| | - Richard Cobb
- Department of Natural Resources and Environmental Science, California Polytechnic State University, San Luis Obispo, CA 93407, USA;
| | - Corinn Small
- Department of Plant Pathology, University of California, Davis, CA 95616, USA; (R.T.); (H.K.M.); (D.M.R.); (C.S.); (T.T.); (H.E.M.)
| | - Tiffany Tang
- Department of Plant Pathology, University of California, Davis, CA 95616, USA; (R.T.); (H.K.M.); (D.M.R.); (C.S.); (T.T.); (H.E.M.)
| | - Haley E. McCown
- Department of Plant Pathology, University of California, Davis, CA 95616, USA; (R.T.); (H.K.M.); (D.M.R.); (C.S.); (T.T.); (H.E.M.)
| | - Matteo Garbelotto
- Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, USA;
| | - Takao Kasuga
- Crops Pathology and Genetics Research Unit, USDA Agricultural Research Service, Davis, CA 95616, USA
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Organize, Don't Agonize: Strategic Success of Phytophthora Species. Microorganisms 2020; 8:microorganisms8060917. [PMID: 32560346 PMCID: PMC7355776 DOI: 10.3390/microorganisms8060917] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 12/20/2022] Open
Abstract
Plants are constantly challenged by various environmental stressors ranging from abiotic-sunlight, elevated temperatures, drought, and nutrient deficits, to biotic factors-microbial pathogens and insect pests. These not only affect the quality of harvest but also the yield, leading to substantial annual crop losses, worldwide. Although plants have a multi-layered immune system, phytopathogens such as species of the oomycete genus Phytophthora, can employ elaborate mechanisms to breach this defense. For the last two decades, researchers have focused on the co-evolution between Phytophthora and interacting hosts to decouple the mechanisms governing their molecular associations. This has provided a comprehensive understanding of the pathobiology of plants affected by oomycetes. Ultimately, this is important for the development of strategies to sustainably improve agricultural production. Therefore, this paper discusses the present-day state of knowledge of the strategic mode of operation employed by species of Phytophthora for successful infection. Specifically, we consider motility, attachment, and host cell wall degradation used by these pathogenic species to obtain nutrients from their host. Also discussed is an array of effector types from apoplastic (hydrolytic proteins, protease inhibitors, elicitins) to cytoplastic (RxLRs, named after Arginine-any amino acid-Leucine-Arginine consensus sequence and CRNs, for CRinkling and Necrosis), which upon liberation can subvert the immune response and promote diseases in plants.
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Ramírez JE, Pajares C, Martínez MI, Rodríguez Fernández R, Molina-Gayosso E, Lozada-Lechuga J, Fernández Téllez A. Site-bond percolation solution to preventing the propagation of Phytophthora zoospores on plantations. Phys Rev E 2020; 101:032301. [PMID: 32289901 DOI: 10.1103/physreve.101.032301] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 01/30/2020] [Indexed: 06/11/2023]
Abstract
We propose a strategy based on the site-bond percolation to minimize the propagation of Phytophthora zoospores on plantations, consisting in introducing physical barriers between neighboring plants. Two clustering processes are distinguished: (i) one of cells with the presence of the pathogen, detected on soil analysis, and (ii) that of diseased plants, revealed from a visual inspection of the plantation. The former is well described by the standard site-bond percolation. In the latter, the percolation threshold is fitted by a Tsallis distribution when no barriers are introduced. We provide, for both cases, the formulas for the minimal barrier density to prevent the emergence of the spanning cluster. Though this work is focused on a specific pathogen, the model presented here can also be applied to prevent the spreading of other pathogens that disseminate, by other means, from one plant to the neighboring ones. Finally, the application of this strategy to three types of commercially important Mexican chili plants is also shown.
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Affiliation(s)
- J E Ramírez
- Departamento de Física de Partículas, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, España
- Instituto Galego de Física de Altas Enerxías, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, España
| | - C Pajares
- Departamento de Física de Partículas, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, España
- Instituto Galego de Física de Altas Enerxías, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, España
| | - M I Martínez
- Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Apartado Postal 165, 72000 Puebla, Puebla, México
| | - R Rodríguez Fernández
- Instituto Galego de Física de Altas Enerxías, Universidad de Santiago de Compostela, E-15782 Santiago de Compostela, España
| | - E Molina-Gayosso
- Universidad Politécnica de Puebla, Tercer carril del Ejido Serrano, 72640, Juan C. Bonilla, Puebla, México
| | - J Lozada-Lechuga
- Universidad Politécnica de Puebla, Tercer carril del Ejido Serrano, 72640, Juan C. Bonilla, Puebla, México
| | - A Fernández Téllez
- Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Apartado Postal 165, 72000 Puebla, Puebla, México
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Sancheti A, Ju LK. Eco-friendly rhamnolipid based fungicides for protection of soybeans from Phytophthora sojae. PEST MANAGEMENT SCIENCE 2019; 75:3031-3038. [PMID: 30891859 DOI: 10.1002/ps.5418] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/03/2019] [Accepted: 03/15/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Excessive use of chemical fungicides over the years for plant pathogen control has caused unwanted damage to non-target organisms and resistance buildup in the target organisms. These harmful effects have prompted the industry to look for more sustainable and eco-friendly solutions. Rhamnolipid is a naturally occurring surfactant that is biodegradable, relatively innocuous to non-target species and can effectively lyse zoospores, the life form responsible for the spread of Phytophthora. In this study, rhamnolipid based coatings were developed and evaluated for protection of soybeans from P. sojae zoospores. RESULTS Pure (acidic) rhamnolipid, when coated on the soybeans, affects the germination negatively. However, sodium and calcium complexed rhamnolipids do not interfere with germination. Seeds coated with 15-20 mg of developed formulation were planted in soil pots and then subjected to P. sojae infection by simulating flooding conditions and zoospore inoculation. Statistical analysis showed that sodium rhamnolipid based coating significantly improved the germination in presence of P. sojae from 42% to 73% (P = 0.017) while the germination of stress-free control was 85% (statistically similar to coated seeds, P = 1). CONCLUSION Neutralized rhamnolipid can protect soybeans from P. sojae without any negative effect on germination. This work illustrates the strategy to use rhamnolipid as effective fungicide. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Ashwin Sancheti
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH, USA
| | - Lu-Kwang Ju
- Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, OH, USA
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Leesutthiphonchai W, Judelson HS. Phytophthora infestans Sporangia Produced in Artificial Media and Plant Lesions Have Subtly Divergent Transcription Profiles but Equivalent Infection Potential and Aggressiveness. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2019; 32:1077-1087. [PMID: 30908943 DOI: 10.1094/mpmi-12-18-0349-ta] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Sporangia of the potato late blight agent Phytophthora infestans are often used in studies of pathogen biology and plant responses to infection. Investigations of spore biology can be challenging in oomycetes because their sporangia are physiologically active and change in response to environmental factors and aging. Whether sporangia from artificial media and plant lesions are functionally equivalent has been a topic of debate. To address these issues, we compared the transcriptomes and infection ability of sporangia from rye-sucrose media, potato and tomato leaflets, and potato tubers. Small differences were observed between the mRNA profiles of sporangia from all sources, including variation in genes encoding metabolic enzymes, cell-wall-degrading enzymes, and ABC transporters. Small differences in sporangia age also resulted in variation in the transcriptome. Taking care to use sporangia of similar maturity, we observed that those sourced from media or plant lesions had similar rates of zoospore release and cyst germination. There were also no differences in infection rates or aggressiveness on leaflets, based on single-spore inoculation assays. Such results are discordant with those of a recent publication in this journal. Nevertheless, we conclude that sporangia from plant and media cultures are functionally similar and emphasize the importance of using "best practices" in experiments with sporangia to obtain reliable results.
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Affiliation(s)
| | - Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, U.S.A
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Galiana E, Cohen C, Thomen P, Etienne C, Noblin X. Guidance of zoospores by potassium gradient sensing mediates aggregation. J R Soc Interface 2019; 16:20190367. [PMID: 31387479 DOI: 10.1098/rsif.2019.0367] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The biflagellate zoospores of some phytopathogenic Phytophthora species spontaneously aggregate within minutes in suspension. We show here that Phytophthora parasitica zoospores can form aggregates in response to a K+ gradient with a particular geometric arrangement. Using time-lapse live imaging in macro- and microfluidic devices, we defined (i) spatio-temporal and concentration-scale changes in the gradient, correlated with (ii) the cell distribution and (iii) the metrics of zoospore motion (velocity, trajectory). In droplets, we found that K+-induced aggregates resulted from a single biphasic temporal sequence involving negative chemotaxis followed by bioconvection over a K+ gradient concentration scale [0-17 mM]. Each K+-sensing cell moved into a region in which potassium concentration is below the threshold range of 1-4 mM, resulting in swarming. Once a critical population density had been achieved, the zoospores formed a plume that migrated downward, with fluid advection in its wake and aggregate formation on the support surface. In the microfluidic device, the density of zoospores escaping potassium was similar to that achieved in droplets. We discuss possible sources of K+ gradients in the natural environment (zoospore population, microbiota, plant roots, soil particles), and implications for the events preceding inoculum formation on host plants.
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Affiliation(s)
- Eric Galiana
- Université Côte d'Azur, INRA, CNRS, ISA, Sophia Antipolis, France
| | - Celine Cohen
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Parc Valrose, 06108 Nice, France
| | - Philippe Thomen
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Parc Valrose, 06108 Nice, France
| | | | - Xavier Noblin
- Université Côte d'Azur, CNRS, UMR 7010, Institut de Physique de Nice, Parc Valrose, 06108 Nice, France
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Fletcher K, Gil J, Bertier LD, Kenefick A, Wood KJ, Zhang L, Reyes-Chin-Wo S, Cavanaugh K, Tsuchida C, Wong J, Michelmore R. Genomic signatures of heterokaryosis in the oomycete pathogen Bremia lactucae. Nat Commun 2019; 10:2645. [PMID: 31201315 PMCID: PMC6570648 DOI: 10.1038/s41467-019-10550-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 05/14/2019] [Indexed: 12/26/2022] Open
Abstract
Lettuce downy mildew caused by Bremia lactucae is the most important disease of lettuce globally. This oomycete is highly variable and rapidly overcomes resistance genes and fungicides. The use of multiple read types results in a high-quality, near-chromosome-scale, consensus assembly. Flow cytometry plus resequencing of 30 field isolates, 37 sexual offspring, and 19 asexual derivatives from single multinucleate sporangia demonstrates a high incidence of heterokaryosis in B. lactucae. Heterokaryosis has phenotypic consequences on fitness that may include an increased sporulation rate and qualitative differences in virulence. Therefore, selection should be considered as acting on a population of nuclei within coenocytic mycelia. This provides evolutionary flexibility to the pathogen enabling rapid adaptation to different repertoires of host resistance genes and other challenges. The advantages of asexual persistence of heterokaryons may have been one of the drivers of selection that resulted in the loss of uninucleate zoospores in multiple downy mildews.
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Affiliation(s)
- Kyle Fletcher
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Juliana Gil
- Genome Center, University of California, Davis, CA, 95616, USA
- Plant Pathology Graduate Group, University of California, Davis, CA, 95616, USA
| | - Lien D Bertier
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Aubrey Kenefick
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Kelsey J Wood
- Genome Center, University of California, Davis, CA, 95616, USA
- Integrated Genetics and Genomics Graduate Group, University of California, Davis, CA, 95616, USA
| | - Lin Zhang
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Sebastian Reyes-Chin-Wo
- Genome Center, University of California, Davis, CA, 95616, USA
- Integrated Genetics and Genomics Graduate Group, University of California, Davis, CA, 95616, USA
- Bayer Crop Science, 37437 CA-16, Woodland, CA, 95695, USA
| | - Keri Cavanaugh
- Genome Center, University of California, Davis, CA, 95616, USA
| | - Cayla Tsuchida
- Genome Center, University of California, Davis, CA, 95616, USA
- Plant Pathology Graduate Group, University of California, Davis, CA, 95616, USA
- Arcadia Biosciences, Davis, CA, 95616, USA
| | - Joan Wong
- Genome Center, University of California, Davis, CA, 95616, USA
- Plant Biology Graduate Group, University of California, Davis, CA, 95616, USA
- Pacific Biosciences of California, Inc., Menlo Park, CA, 94025, USA
| | - Richard Michelmore
- Genome Center, University of California, Davis, CA, 95616, USA.
- Departments of Plant Sciences, Molecular and Cellular Biology, Medical Microbiology and Immunology, University of California, Davis, CA, 95616, USA.
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25
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Hargreaves J, van West P. Oomycete-Root Interactions. METHODS IN RHIZOSPHERE BIOLOGY RESEARCH 2019. [DOI: 10.1007/978-981-13-5767-1_6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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26
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Lang-Yona N, Pickersgill DA, Maurus I, Teschner D, Wehking J, Thines E, Pöschl U, Després VR, Fröhlich-Nowoisky J. Species Richness, rRNA Gene Abundance, and Seasonal Dynamics of Airborne Plant-Pathogenic Oomycetes. Front Microbiol 2018; 9:2673. [PMID: 30498479 PMCID: PMC6249755 DOI: 10.3389/fmicb.2018.02673] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/19/2018] [Indexed: 12/14/2022] Open
Abstract
Oomycetes, also named Peronosporomycetes, are one of the most important and widespread groups of plant pathogens, leading to significant losses in the global agricultural productivity. They have been studied extensively in ground water, soil, and host plants, but their atmospheric transport vector is not well characterized. In this study, the occurrence of airborne Oomycetes was investigated by Sanger sequencing and quantitative PCR of coarse and fine aerosol particle samples (57 filter pairs) collected over a 1-year period (2006-2007) and full seasonal cycle in Mainz, Germany. In coarse particulate matter, we found 55 different hypothetical species (OTUs), of which 54 were plant pathogens and 29 belonged to the genus Peronospora (downy mildews). In fine particulate matter (<3 μm), only one species of Hyaloperonospora was found in one sample. Principal coordinate analysis of the species composition revealed three community clusters with a dependence on ambient temperature. The abundance of Oomycetes rRNA genes was low in winter and enhanced during spring, summer, and fall, with a dominance of Phytophthora, reaching a maximum concentration of ∼1.6 × 106 rRNA genes per cubic meter of sampled air in summer. The presence and high concentration of rRNA genes in air suggests that atmospheric transport, which can lead to secondary infection, may be more important than currently estimated. This illustrates the need for more current and detailed datasets, as potential seasonal shifts due to changing meteorological conditions may influence the composition of airborne Oomycetes. An insight into the dynamics of airborne plant pathogens and their major drivers should be useful for improved forecasting and management of related plant diseases.
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Affiliation(s)
- Naama Lang-Yona
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
| | - Daniel A Pickersgill
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany.,Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Isabel Maurus
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
| | - David Teschner
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany.,Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jörn Wehking
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany.,Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Eckhard Thines
- Institute for Microbiology and Wine Research, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Ulrich Pöschl
- Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
| | - Viviane R Després
- Institute of Molecular Physiology, Johannes Gutenberg University Mainz, Mainz, Germany
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Kagda MS, Vu AL, Ah-Fong AMV, Judelson HS. Phosphagen kinase function in flagellated spores of the oomycete Phytophthora infestans integrates transcriptional regulation, metabolic dynamics and protein retargeting. Mol Microbiol 2018; 110:296-308. [PMID: 30137656 DOI: 10.1111/mmi.14108] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2018] [Indexed: 11/30/2022]
Abstract
Flagellated spores play important roles in the infection of plants and animals by many eukaryotic microbes. The oomycete Phytophthora infestans, which causes potato blight, expresses two phosphagen kinases (PKs). These enzymes store energy in taurocyamine, and are hypothesized to resolve spatial and temporal imbalances between rates of ATP creation and use in zoospores. A dimeric PK is found at low levels in vegetative mycelia, but high levels in ungerminated sporangia and zoospores. In contrast, a monomeric PK protein is at similar levels in all tissues, although is transcribed primarily in mycelia. Subcellular localization studies indicate that the monomeric PK is mitochondrial. In contrast, the dimeric PK is cytoplasmic in mycelia and sporangia but is retargeted to flagellar axonemes during zoosporogenesis. This supports a model in which PKs shuttle energy from mitochondria to and through flagella. Metabolite analysis indicates that deployment of the flagellar PK is coordinated with a large increase in taurocyamine, synthesized by sporulation-induced enzymes that were lost during the evolution of zoospore-lacking oomycetes. Thus, PK function is enabled by coordination of the transcriptional, metabolic and protein targeting machinery during the life cycle. Since plants lack PKs, the enzymes may be useful targets for inhibitors of oomycete plant pathogens.
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Affiliation(s)
- Meenakshi S Kagda
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Andrea L Vu
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Audrey M V Ah-Fong
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
| | - Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, CA, 92521, USA
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Leesutthiphonchai W, Vu AL, Ah-Fong AMV, Judelson HS. How Does Phytophthora infestans Evade Control Efforts? Modern Insight Into the Late Blight Disease. PHYTOPATHOLOGY 2018; 108:916-924. [PMID: 29979126 DOI: 10.1094/phyto-04-18-0130-ia] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The infamous oomycete Phytophthora infestans has been a persistent threat to potato and tomato production worldwide, causing the diseases known as late blight. This pathogen has proved to be remarkably adept at overcoming control strategies including host-based resistance and fungicides. This review describes the features of P. infestans that make it such a daunting challenge to agriculture. These include a stealthy lifestyle that helps P. infestans evade plant defenses, effectors that suppress host defenses and promote susceptibility, profuse sporulation with a short latent period that enables rapid dissemination, and a genome structure that promotes the adaptive evolution of P. infestans by fostering genetic diversity. Nevertheless, there is reason to be optimistic that accumulated knowledge about the biology of P. infestans and its hosts will lead to improved management of late blight.
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Affiliation(s)
| | - Andrea L Vu
- Department of Microbiology and Plant Pathology, University of California, Riverside 92521
| | - Audrey M V Ah-Fong
- Department of Microbiology and Plant Pathology, University of California, Riverside 92521
| | - Howard S Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside 92521
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29
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What has happened to the “aquatic phycomycetes” (sensu Sparrow)? Part II: Shared properties of zoosporic true fungi and fungus-like microorganisms. FUNGAL BIOL REV 2018. [DOI: 10.1016/j.fbr.2017.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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30
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Rezinciuc S, Sandoval-Sierra JV, Ruiz-León Y, van West P, Diéguez-Uribeondo J. Specialized attachment structure of the fish pathogenic oomycete Saprolegnia parasitica. PLoS One 2018; 13:e0190361. [PMID: 29342156 PMCID: PMC5771568 DOI: 10.1371/journal.pone.0190361] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 12/13/2017] [Indexed: 12/18/2022] Open
Abstract
The secondary cysts of the fish pathogen oomycete Saprolegnia parasitica possess bundles of long hooked hairs that are characteristic to this economically important pathogenic species. Few studies have been carried out on elucidating their specific role in the S. parasitica life cycle and the role they may have in the infection process. We show here their function by employing several strategies that focus on descriptive, developmental and predictive approaches. The strength of attachment of the secondary cysts of this pathogen was compared to other closely related species where bundles of long hooked hairs are absent. We found that the attachment of the S. parasitica cysts was around three times stronger than that of other species. The time sequence and influence of selected factors on morphology and the number of the bundles of long hooked hairs conducted by scanning electron microscopy study revealed that these are dynamic structures. They are deployed early after encystment, i.e., within 30 sec of zoospore encystment, and the length, but not the number, of the bundles steadily increased over the encystment period. We also observed that the number and length of the bundles was influenced by the type of substrate and encystment treatment applied, suggesting that these structures can adapt to different substrates (glass or fish scales) and can be modulated by different signals (i.e., protein media, 50 mM CaCl2 concentrations, carbon particles). Immunolocalization studies evidenced the presence of an adhesive extracellular matrix. The bioinformatic analyses of the S. parasitica secreted proteins showed that there is a high expression of genes encoding domains of putative proteins related to the attachment process and cell adhesion (fibronectin and thrombospondin) coinciding with the deployment stage of the bundles of long hooked hairs formation. This suggests that the bundles are structures that might contribute to the adhesion of the cysts to the host because they are composed of these adhesive proteins and/or by increasing the surface of attachment of this extracellular matrix.
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Affiliation(s)
| | | | | | - Pieter van West
- International Centre for Aquaculture Research and Development at the University of Aberdeen, Aberdeen Oomycete Laboratory, Institute of Medical Sciences, Foresterhill, Aberdeen, United Kingdom
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31
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Huchzermeyer CF, Huchzermeyer KDA, Christison KW, Macey BM, Colly PA, Hang'ombe BM, Songe MM. First record of epizootic ulcerative syndrome from the Upper Congo catchment: An outbreak in the Bangweulu swamps, Zambia. JOURNAL OF FISH DISEASES 2018; 41:87-94. [PMID: 28745838 DOI: 10.1111/jfd.12680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 06/02/2017] [Accepted: 06/06/2017] [Indexed: 06/07/2023]
Abstract
We report on the first outbreak of epizootic ulcerative syndrome (EUS) amongst wild fish populations in the Bangweulu swamps, an inland delta, in the north of Zambia during 2014. The area supports a large and diverse fish fauna related to, but distinct from, that of the Zambezi River system where EUS outbreaks have occurred since 2006. A sizeable artisanal fishery, based on extensive fish weirs, is sustained by the annual flooding of the swamps, and observations of the disease outbreak by fishermen were recorded. Signs typical of infection with Aphanomyces invadans were observed in a number of species. Clinical observations, histology and molecular diagnostic methods were used to confirm infection with A. invadans in two of the most commonly and severely affected species. Several features of the wetland may have contributed to the outbreak and the annual recurrence of the disease. Modes by which the disease may have been introduced into the swamps are discussed. The outbreak is of great significance as the Bangweulu swamps drain into the Congo River in neighbouring Democratic Republic of Congo, Africa's largest drainage system with an extensive and diverse fish fauna previously unaffected by EUS.
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Affiliation(s)
| | - K D A Huchzermeyer
- Sterkspruit Veterinary Clinic, Lydenburg, South Africa
- Department of Ichthyology and Fisheries Science, Rhodes University, Grahamstown, South Africa
| | - K W Christison
- Department of Agriculture Forestry and Fisheries, Directorate of Aquaculture Research and Development, Roggebaai, South Africa
- Biodiversity and Conservation Biology, University of the Western Cape, Bellville, South Africa
| | - B M Macey
- Department of Agriculture Forestry and Fisheries, Directorate of Aquaculture Research and Development, Roggebaai, South Africa
| | - P A Colly
- Sterkspruit Veterinary Clinic, Lydenburg, South Africa
| | - B M Hang'ombe
- School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - M M Songe
- Ministry of Fisheries and Livestock, Central Veterinary Research Institute, Balmoral, Lusaka, Zambia
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Faggian R, Hanson M, Kennedy R, Petch G, Wakeham A. Assessment of the response of
Plasmodiophora brassicae
in contaminated horticultural land, using lime‐based fertilizer concentrations. Food Energy Secur 2017. [DOI: 10.1002/fes3.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
| | - Mary Hanson
- University of Worcester Henwick Grove Worcester WR2 6AJ
| | - Roy Kennedy
- Warwickshire CollegesPershore College Pershore UK
| | - Geoff Petch
- School of Science and the EnvironmentUniversity of Worcester Worcester UK
| | - Alison Wakeham
- Mologic Ltd Thurleigh Bussiness Park Bedford UK
- Warwickshire CollegesPershore College Pershore UK
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Chen L, Zhang X, Wang W, Geng X, Shi Y, Na R, Dou D, Li H. Network and role analysis of autophagy in Phytophthora sojae. Sci Rep 2017; 7:1879. [PMID: 28500315 PMCID: PMC5431975 DOI: 10.1038/s41598-017-01988-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 04/05/2017] [Indexed: 12/17/2022] Open
Abstract
Autophagy is an evolutionarily conserved mechanism in eukaryotes with roles in development and the virulence of plant fungal pathogens. However, few reports on autophagy in oomycete species have been published. Here, we identified 26 autophagy-related genes (ATGs) belonging to 20 different groups in Phytophthora sojae using a genome-wide survey, and core ATGs in oomycetes were used to construct a preliminary autophagy pathway model. Expression profile analysis revealed that these ATGs are broadly expressed and that the majority of them significantly increase during infection stages, suggesting a central role for autophagy in virulence. Autophagy in P. sojae was detected using a GFP-PsAtg8 fusion protein and the fluorescent dye MDC during rapamycin and starvation treatment. In addition, autophagy was significantly induced during sporangium formation and cyst germination. Silencing PsAtg6a in P. sojae significantly reduced sporulation and pathogenicity. Furthermore, a PsAtg6a-silenced strain showed haustorial formation defects. These results suggested that autophagy might play essential roles in both the development and infection mechanism of P. sojae.
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Affiliation(s)
- Linlin Chen
- Department of Plant Pathology, Henan Agricultural University, Zhengzhou, 450002, China
| | - Xiong Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wen Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xuejing Geng
- Department of Plant Pathology, Henan Agricultural University, Zhengzhou, 450002, China
| | - Yan Shi
- Department of Plant Pathology, Henan Agricultural University, Zhengzhou, 450002, China
| | - Risong Na
- Department of Plant Pathology, Henan Agricultural University, Zhengzhou, 450002, China
| | - Daolong Dou
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Honglian Li
- Department of Plant Pathology, Henan Agricultural University, Zhengzhou, 450002, China.
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An LRR receptor kinase regulates growth, development and pathogenesis in Phytophthora capsici. Microbiol Res 2017; 198:8-15. [DOI: 10.1016/j.micres.2017.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 11/27/2016] [Accepted: 01/23/2017] [Indexed: 11/20/2022]
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Mondol MAM, Farthouse J, Islam MT, Schüffler A, Laatsch H. Metabolites from the Endophytic Fungus Curvularia sp. M12 Act as Motility Inhibitors against Phytophthora capsici Zoospores. JOURNAL OF NATURAL PRODUCTS 2017; 80:347-355. [PMID: 28195475 DOI: 10.1021/acs.jnatprod.6b00785] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The endophytic fungus Curvularia sp., strain M12, was isolated from a leaf of the medicinal plant Murraya koenigii and cultured on rice medium followed by chemical screening of the culture extract. Chromatographic analysis led to the isolation of four new compounds, murranofuran A (1), murranolide A (2), murranopyrone (3a), and murranoic acid A (4a), along with six known metabolites, N-(2-hydroxy-6-methoxyphenyl)acetamide (5), curvularin (6), (S)-dehydrocurvularin (7), pyrenolide A (8), modiolide A (9), and 8-hydroxy-6-methoxy-3-methylisocoumarin (10). The structures of the known compounds were confirmed by comparing ESI HR mass spectra, 1H and 13C NMR, and optical rotation data with values reported in the literature. The planar structures of the new compounds were elucidated by extensive analysis of 1D and 2D NMR and mass data. The absolute configurations of the new compounds were established by coupling constant analysis, modified Mosher's method, and CD data. Compound 8 showed a strong motility impairing activity against Phytophthora capsici zoospores at a low concentration (100% at 0.5 μg/mL) in a short time (30 min). Compounds 2, 3a, 6, 7, 9, and 10 exhibited zoospore motility impairment activity at higher concentrations (IC50: 50-100 μg/mL).
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Affiliation(s)
- Muhammad Abdul Mojid Mondol
- Institute for Organic and Biomolecular Chemistry, Georg-August-University Göttingen , Tamannstrasse 2, D-37077 Göttingen, Germany
| | - Jannatul Farthouse
- Department of Biotechnology, Bangabandhu Sheikh Mujibur Rahman Agricultural University , Gazipur-1706, Bangladesh
| | - Mohammad Tofazzal Islam
- Department of Biotechnology, Bangabandhu Sheikh Mujibur Rahman Agricultural University , Gazipur-1706, Bangladesh
| | - Anja Schüffler
- Institute of Biotechnology and Drug Research , D-67663 Kaiserslautern, Germany
| | - Hartmut Laatsch
- Institute for Organic and Biomolecular Chemistry, Georg-August-University Göttingen , Tamannstrasse 2, D-37077 Göttingen, Germany
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Ah-Fong AMV, Kim KS, Judelson HS. RNA-seq of life stages of the oomycete Phytophthora infestans reveals dynamic changes in metabolic, signal transduction, and pathogenesis genes and a major role for calcium signaling in development. BMC Genomics 2017; 18:198. [PMID: 28228125 PMCID: PMC5322657 DOI: 10.1186/s12864-017-3585-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 02/13/2017] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The oomycete Phytophthora infestans causes the devastating late blight diseases of potato and tomato. P. infestans uses spores for dissemination and infection, like many other filamentous eukaryotic plant pathogens. The expression of a subset of its genes during spore formation and germination were studied previously, but comprehensive genome-wide data have not been available. RESULTS RNA-seq was used to profile hyphae, sporangia, sporangia undergoing zoosporogenesis, motile zoospores, and germinated cysts of P. infestans. Parallel studies of two isolates generated robust expression calls for 16,000 of 17,797 predicted genes, with about 250 transcribed in one isolate but not the other. The largest changes occurred in the transition from hyphae to sporangia, when >4200 genes were up-regulated. More than 1350 of these were induced >100-fold, accounting for 26% of total mRNA. Genes encoding calcium-binding proteins, cation channels, signaling proteins, and flagellar proteins were over-represented in genes up-regulated in sporangia. Proteins associated with pathogenicity were transcribed in waves with subclasses induced during zoosporogenesis, in zoospores, or in germinated cysts. Genes involved in most metabolic pathways were down-regulated upon sporulation and reactivated during cyst germination, although there were exceptions such as DNA replication, where transcripts peaked in zoospores. Inhibitor studies indicated that the transcription of two-thirds of genes induced during zoosporogenesis relied on calcium signaling. A sporulation-induced protein kinase was shown to bind a constitutive Gβ-like protein, which contributed to fitness based on knock-down analysis. CONCLUSIONS Spore formation and germination involves the staged expression of a large subset of the transcriptome, commensurate with the importance of spores in the life cycle. A comparison of the RNA-seq results with the older microarray data indicated that information is now available for about twice the number of genes than before. Analyses based on function revealed dynamic changes in genes involved in pathogenicity, metabolism, and signaling, with diversity in expression observed within members of multigene families and between isolates. The effects of calcium signaling, a spore-induced protein kinase, and an interacting Gβ-like protein were also demonstrated experimentally. The results reveal aspects of oomycete biology that underly their success as pathogens and potential targets for crop protection chemicals.
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Affiliation(s)
- Audrey M. V. Ah-Fong
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521 USA
| | - Kyoung Su Kim
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521 USA
- Present address: Department of Applied Biology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, Korea
| | - Howard S. Judelson
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521 USA
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Sungthong R, van West P, Heyman F, Jensen DF, Ortega-Calvo JJ. Mobilization of Pollutant-Degrading Bacteria by Eukaryotic Zoospores. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:7633-7640. [PMID: 27286642 DOI: 10.1021/acs.est.6b00994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The controlled mobilization of pollutant-degrading bacteria has been identified as a promising strategy for improving bioremediation performance. We tested the hypothesis whether the mobilization of bacterial degraders may be achieved by the action of eukaryotic zoospores. We evaluated zoospores that are produced by the soil oomycete Pythium aphanidermatum as a biological vector, and, respectively, the polycyclic aromatic hydrocarbon (PAH)-degrading bacteria Mycobacterium gilvum VM552 and Pseudomonas putida G7, acting as representative nonflagellated and flagellated species. The mobilization assay was performed with a chemical-in-capillary method, in which zoospores mobilized bacterial cells only when they were exposed to a zoospore homing inducer (5% (v/v) ethanol), which caused the tactic response and settlement of zoospores. The mobilization was strongly linked to a lack of bacterial motility, because the nonflagellated cells from strain M. gilvum VM552 and slightly motile, stationary-phase cells from P. putida G7 were mobilized effectively, but the actively motile, exponentially grown cells of P. putida G7 were not mobilized. The computer-assisted analysis of cell motility in mixed suspensions showed that the swimming rate was enhanced by zoospores in stationary, but not in exponentially grown, cells of P. putida G7. It is hypothesized that the directional swimming of zoospores caused bacterial mobilization through the thrust force of their flagellar propulsion. Our results suggest that, by mobilizing pollutant-degrading bacteria, zoospores can act as ecological amplifiers for fungal and oomycete mycelial networks in soils, extending their potential in bioremediation scenarios.
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Affiliation(s)
- Rungroch Sungthong
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Apartado 1052, Seville 41080, Spain
| | - Pieter van West
- Aberdeen Oomycete Laboratory, University of Aberdeen, Institute of Medical Sciences , Foresterhill, Aberdeen AB25 2ZD, United Kingdom
| | - Fredrik Heyman
- Uppsala BioCenter, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences , Uppsala 750 07, Sweden
| | - Dan Funck Jensen
- Uppsala BioCenter, Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences , Uppsala 750 07, Sweden
| | - Jose Julio Ortega-Calvo
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Apartado 1052, Seville 41080, Spain
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Fu G, Nagasato C, Yamagishi T, Kawai H, Okuda K, Takao Y, Horiguchi T, Motomura T. Ubiquitous distribution of helmchrome in phototactic swarmers of the stramenopiles. PROTOPLASMA 2016; 253:929-941. [PMID: 26202473 DOI: 10.1007/s00709-015-0857-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 07/13/2015] [Indexed: 12/16/2023]
Abstract
Most swarmers (swimming cells) of the stramenopile group, ranging from unicellular protist to giant kelps (brown algae), have two heterogeneous flagella: a long anterior flagellum (AF) and a relatively shorter posterior flagellum (PF). These flagellated cells often exhibit phototaxis upon light stimulation, although the mechanism by which how the phototactic response is regulated remains largely unknown. A flavoprotein concentrating at the paraflagellar body (PFB) on the basal part of the PF, which can emit green autofluorescence under blue light irradiance, has been proposed as a possible blue light photoreceptor for brown algal phototaxis although the nature of the flavoprotein still remains elusive. Recently, we identified helmchrome as a PF-specific flavoprotein protein in a LC-MS/MS-based proteomics study of brown algal flagella (Fu et al. 2014). To verify the conservation of helmchrome, in the present study, the absence or presence and the localization of helmchrome in swarmers of various algal species were investigated. The results showed that helmchrome was only detected in phototactic swarmers but not the non-phototactic ones of the stramenopile group. Electron microscopy further revealed that the helmchrome detectable swarmers bear a conserved PFB-eyespot complex, which may serve as structural basis for light sensing. It is speculated that all three conserved properties: helmchrome, the PFB structure, and the eyespot apparatus, will be essential parts for phototaxis of stramenopile swarmers.
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Affiliation(s)
- Gang Fu
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran, 051-0013, Japan
| | - Chikako Nagasato
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran, 051-0013, Japan
| | - Takahiro Yamagishi
- Research Center for Inland Seas, Kobe University, Rokkodai, Nadaku, Kobe, 657-8501, Japan
| | - Hiroshi Kawai
- Research Center for Inland Seas, Kobe University, Rokkodai, Nadaku, Kobe, 657-8501, Japan
| | - Kazuo Okuda
- Graduate School of Integrated Arts and Sciences, Kochi University, Kochi, 780-8520, Japan
| | - Yoshitake Takao
- Faculty of Marine Bioscience, Fukui Prefectural University, Obama, 917-0003, Japan
| | - Takeo Horiguchi
- Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Taizo Motomura
- Muroran Marine Station, Field Science Center for Northern Biosphere, Hokkaido University, Muroran, 051-0013, Japan.
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Delmas CEL, Mazet ID, Jolivet J, Delière L, Delmotte F. Simultaneous quantification of sporangia and zoospores in a biotrophic oomycete with an automatic particle analyzer: disentangling dispersal and infection potentials. J Microbiol Methods 2015; 107:169-75. [PMID: 25448022 DOI: 10.1016/j.mimet.2014.10.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 10/20/2014] [Accepted: 10/22/2014] [Indexed: 10/24/2022]
Abstract
Quantitative pathogenicity traits drive the fitness and dynamics of pathogens in agricultural ecosystems and are key determinants of the correct management of crop production over time. However, traits relating to infection potential (i.e. zoospore production) have been less thoroughly investigated in oomycetes than traits relating to dispersal (i.e. sporangium production). We simultaneously quantified sporangium and zoospore production in a biotrophic oomycete, for the joint assessment of life-cycle traits relating to dispersal and infection potentials. We used an automatic particle analyzer to count and size the sporangia and/or zoospores produced at t = 0 min (no zoospore release) and t = 100 min (zoospore release) in 43 Plasmopara viticola isolates growing on the susceptible Vitis vinifera cv. Cabernet Sauvignon. We were able to differentiate and quantify three types of propagules from different stages of the pathogen life cycle: full sporangia, empty sporangia and zoospores. The method was validated by comparing the sporangium and zoospore counts obtained with an automatic particle analyzer and under a stereomicroscope (manual counting). Each isolate produced a mean of 5.8 ± 1.9 (SD) zoospores per sporangium. Significant relationships were found between sporangium production and sporangium size (negative) and between sporangium size and the number of zoospores produced per sporangium (positive). However, there was a significant positive correlation between total sporangium production and total zoospore production. This procedure can provide a valid quantification of the production of both sporangia and zoospores by oomycetes in large numbers of samples, facilitating joint estimation of the dispersal and infection potentials of plant pathogens in various agro-ecological contexts.
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Affiliation(s)
- Chloé E L Delmas
- INRA, UMR1065 Santé et Agroécologie du Vignoble, Villenave d'Ornon, France.
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Sungthong R, van West P, Cantos M, Ortega-Calvo JJ. Development of eukaryotic zoospores within polycyclic aromatic hydrocarbon (PAH)-polluted environments: a set of behaviors that are relevant for bioremediation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2015; 511:767-776. [PMID: 25617701 DOI: 10.1016/j.scitotenv.2014.12.089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/26/2014] [Accepted: 12/26/2014] [Indexed: 06/04/2023]
Abstract
In this study, we assessed the development (formation, taxis and settlement) of eukaryotic zoospores under different regimes of exposure to polycyclic aromatic hydrocarbons (PAHs), which imitated environmental scenarios of pollution and bioremediation. With this aim, we used an oomycete, Pythium aphanidermatum, as a source of zoospores and two PAH-degrading bacteria (Mycobacterium gilvum VM552 and Pseudomonas putida G7). The oomycete and both bacteria were not antagonistic, and zoospore formation was diminished only in the presence of the highest bacterial cell density (10(8)-10(10) colony-forming units mL(-1)). A negative influence of PAHs on zoospore formation and taxis was observed when PAHs were exposed in combination with organic solutions and polar solvents. Co-exposure of PAHs with non-polar solvents [hexadecane (HD) and 2,2,4,4,6,8,8-heptamethylnonane (HMN)] did not affect zoospore settlement at the interfaces of the organic solvents and water. However, zoospores settled and created mycelial networks only at HD-water interfaces. Both bacteria diminished the toxic influence of PAHs on zoospore formation and taxis, and they did not interrupt zoospore settlement. The results suggest that zoospore development could be applicable for toxicity assessment of PAHs and enhancement of their bioavailability. Microbial interactions during both swimming modes and community formation at pollutant interfaces were revealed as major factors that have potential relevance to bioremediation.
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Affiliation(s)
- Rungroch Sungthong
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Apartado 1052, 41080 Seville, Spain
| | - Pieter van West
- Aberdeen Oomycete Laboratory, University of Aberdeen, Institute of Medical Sciences, Foresterhill, AB25 2ZD Aberdeen UK
| | - Manuel Cantos
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Apartado 1052, 41080 Seville, Spain
| | - Jose Julio Ortega-Calvo
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), Apartado 1052, 41080 Seville, Spain.
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Meléndez-González C, Murià-González MJ, Anaya AL, Hernández-Bautista BE, Hernández-Ortega S, González MC, Glenn AE, Hanlin RT, Macías-Rubalcava ML. Acremoxanthone E, a Novel Member of Heterodimeric Polyketides with a Bicyclo[3.2.2]nonene Ring, Produced byAcremonium camptosporumW.Gams(Clavicipitaceae) Endophytic Fungus. Chem Biodivers 2015; 12:133-47. [DOI: 10.1002/cbdv.201300370] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Indexed: 10/24/2022]
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Chen L, Shen D, Sun N, Xu J, Wang W, Dou D. Phytophthora sojae TatD nuclease positively regulates sporulation and negatively regulates pathogenesis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:1070-80. [PMID: 24940989 DOI: 10.1094/mpmi-05-14-0153-r] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
During pathogenic interactions, both the host and pathogen are exposed to conditions that induce programmed cell death (PCD). Certain aspects of PCD have been recently examined in eukaryotic microbes but not in oomycetes. Here, we identified conserved TatD proteins in Phytophthora sojae; the proteins are key components of DNA degradation in apoptosis. We selected PsTatD4 for further investigation because the enzyme is unique to the oomycete branch of the phylogenetic tree. The purified protein exhibited DNase activity in vitro. Its expression was upregulated in sporangia and later infective stages but downregulated in cysts and during early infection. Functional analysis revealed that the gene was required for sporulation and zoospore production, and the expression levels were associated with the numbers of hydrogen-peroxide-induced terminal dUTP nick end-labeling-positive cells. Furthermore, overexpression of PsTatD4 gene reduced the virulence in a susceptible soybean cultivar. Together, these data suggest that apoptosis may play different roles in the early and late infective stages of P. sojae, and that PsTatD4 is a key regulator of infection. The association of PsTatD4 and apoptosis will lay a foundation to understanding the basic biology of apoptosis and its roles in P. sojae disease cycle.
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Li A, Zhang M, Wang Y, Li D, Liu X, Tao K, Ye W, Wang Y. PsMPK1, an SLT2-type mitogen-activated protein kinase, is required for hyphal growth, zoosporogenesis, cell wall integrity, and pathogenicity in Phytophthora sojae. Fungal Genet Biol 2014; 65:14-24. [PMID: 24480463 DOI: 10.1016/j.fgb.2014.01.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 01/11/2014] [Accepted: 01/13/2014] [Indexed: 12/13/2022]
Abstract
Mitogen-activated protein kinases (MAPKs) play important roles in the regulation of vegetative and pathogenic growth in plant pathogens. Here, we identified an SLT2-type MAP kinase in Phytophthora sojae, PsMPK1, which was transcriptionally induced in sporulating hyphae and the early stages of infection. Silencing of PsMPK1 caused defects in growth and zoosporogenesis, and increased hyphal swellings after the induction of sporangia formation, along with increasing hypersensitivity to cell wall-degrading enzymes. Transmission electron microscopy showed that the cell wall of PsMPK1-silenced mutants was also deleteriously affected. A dark outermost layer in the cell walls disappeared in the mutants, and an additional layer of the mutant cell wall that was deposited abnormally inside an inner bright layer appeared nonhomogeneous and rough compared to the wild type. Pathogenicity assays showed that PsMPK1-silenced transformants lost their pathogenicity on susceptible soybean host plants and triggered stronger cell death. Overall, PsMPK1 is involved in growth, differentiation, cell wall integrity, and pathogenicity in P. sojae.
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Affiliation(s)
- Aining Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Meng Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yonglin Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Delong Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Xiaoyun Liu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Kai Tao
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Wenwu Ye
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China.
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Gozlan RE, Marshall WL, Lilje O, Jessop CN, Gleason FH, Andreou D. Current ecological understanding of fungal-like pathogens of fish: what lies beneath? Front Microbiol 2014. [PMID: 24600442 DOI: 10.3389/fmicb.2014.00062/bibtex] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
Despite increasingly sophisticated microbiological techniques, and long after the first discovery of microbes, basic knowledge is still lacking to fully appreciate the ecological importance of microbial parasites in fish. This is likely due to the nature of their habitats as many species of fish suffer from living beneath turbid water away from easy recording. However, fishes represent key ecosystem services for millions of people around the world and the absence of a functional ecological understanding of viruses, prokaryotes, and small eukaryotes in the maintenance of fish populations and of their diversity represents an inherent barrier to aquatic conservation and food security. Among recent emerging infectious diseases responsible for severe population declines in plant and animal taxa, fungal and fungal-like microbes have emerged as significant contributors. Here, we review the current knowledge gaps of fungal and fungal-like parasites and pathogens in fish and put them into an ecological perspective with direct implications for the monitoring of fungal fish pathogens in the wild, their phylogeography as well as their associated ecological impact on fish populations. With increasing fish movement around the world for farming, releases into the wild for sport fishing and human-driven habitat changes, it is expected, along with improved environmental monitoring of fungal and fungal-like infections, that the full extent of the impact of these pathogens on wild fish populations will soon emerge as a major threat to freshwater biodiversity.
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Affiliation(s)
- Rodolphe E Gozlan
- Unité Mixte de Recherche Biologie des Organismes et Écosystèmes Aquatiques (IRD 207, CNRS 7208, MNHN, UPMC), Muséum National d'Histoire Naturelle Paris Cedex, France ; Centre for Conservation Ecology and Environmental Sciences, School of Applied Sciences, Bournemouth University Poole, Dorset, UK
| | - Wyth L Marshall
- BC Centre for Aquatic Health Sciences Campbell River, BC, Canada
| | - Osu Lilje
- School of Biological Sciences, University of Sydney Sydney, NSW, Australia
| | - Casey N Jessop
- School of Biological Sciences, University of Sydney Sydney, NSW, Australia
| | - Frank H Gleason
- School of Biological Sciences, University of Sydney Sydney, NSW, Australia
| | - Demetra Andreou
- Centre for Conservation Ecology and Environmental Sciences, School of Applied Sciences, Bournemouth University Poole, Dorset, UK
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Savory AIM, Grenville-Briggs LJ, Wawra S, van West P, Davidson FA. Auto-aggregation in zoospores of Phytophthora infestans: the cooperative roles of bioconvection and chemotaxis. J R Soc Interface 2014; 11:20140017. [PMID: 24598206 DOI: 10.1098/rsif.2014.0017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Phytophthora infestans is a highly destructive plant pathogen. It was the cause of the infamous Irish potato famine in the nineteenth century and remains to this day a significant global problem with associated costs estimated at $3 billion annually. Key to the success of this pathogen is the dispersal of free-swimming cells called zoospores. A poorly understood aspect of zoospore behaviour is auto-aggregation--the spontaneous formation of large-scale patterns in cell density. Current competing hypotheses suggest that these patterns are formed by one of two distinct mechanisms: chemotaxis and bioconvection. In this paper, we present mathematical and experimental results that together provide strong evidence that auto-aggregation can only result from a combination of these mechanisms, each having a distinct, time-separated role. A better understanding of the underlying infection mechanisms of P. infestans and potentially other Phytophthora species will in the longer term lead to advances in preventative treatment and thus potentially significant savings in socio-economic costs.
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Saraiva M, de Bruijn I, Grenville-Briggs L, McLaggan D, Willems A, Bulone V, van West P. Functional characterization of a tyrosinase gene from the oomycete Saprolegnia parasitica by RNAi silencing. Fungal Biol 2014; 118:621-9. [PMID: 25088076 PMCID: PMC4152626 DOI: 10.1016/j.funbio.2014.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 01/17/2014] [Accepted: 01/24/2014] [Indexed: 02/04/2023]
Abstract
Here we describe the first application of transient gene silencing in Saprolegnia parasitica, a pathogenic oomycete that infects a wide range of fish, amphibians, and crustaceans. A gene encoding a putative tyrosinase from S. parasitica, SpTyr, was selected to investigate the suitability of RNA-interference (RNAi) to functionally characterize genes of this economically important pathogen. Tyrosinase is a mono-oxygenase enzyme that catalyses the O-hydroxylation of monophenols and subsequent oxidation of O-diphenols to quinines. These enzymes are widely distributed in nature, and are involved in the melanin biosynthesis. Gene silencing was obtained by delivering in vitro synthesized SpTyr dsRNA into protoplasts. Expression analysis, tyrosinase activity measurements, and melanin content analysis confirmed silencing in individual lines. Silencing of SpTyr resulted in a decrease of tyrosinase activity between 38 % and 60 %, dependent on the level of SpTyr-expression achieved. The SpTyr-silenced lines displayed less pigmentation in developing sporangia and occasionally an altered morphology. Moreover, developing sporangia from individual silenced lines possessed a less electron dense cell wall when compared to control lines, treated with GFP-dsRNA. In conclusion, the tyrosinase gene of S. parasitica is required for melanin formation and transient gene silencing can be used to functionally characterize genes in S. parasitica. Successful transient gene silencing in Saprolegnia parasitica through RNAi. Silencing a tyrosinase in S. parasitica results in reduced melanin formation. Silencing a tyrosinase in S. parasitica results in aberrant sporangia formation.
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Affiliation(s)
- Marcia Saraiva
- Aberdeen Oomycete Laboratory, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
| | - Irene de Bruijn
- Aberdeen Oomycete Laboratory, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
| | - Laura Grenville-Briggs
- Aberdeen Oomycete Laboratory, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK; Division of Glycoscience, School of Biotechnology, KTH - Royal Institute of Technology, AlbaNova University Center, SE-106 91 Stockholm, Sweden
| | - Debbie McLaggan
- Aberdeen Oomycete Laboratory, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
| | - Ariane Willems
- Aberdeen Oomycete Laboratory, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK
| | - Vincent Bulone
- Division of Glycoscience, School of Biotechnology, KTH - Royal Institute of Technology, AlbaNova University Center, SE-106 91 Stockholm, Sweden
| | - Pieter van West
- Aberdeen Oomycete Laboratory, University of Aberdeen, Foresterhill, AB25 2ZD Aberdeen, UK.
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Rezinciuc S, Sandoval-Sierra JV, Diéguez-Uribeondo J. Molecular identification of a bronopol tolerant strain of Saprolegnia australis causing egg and fry mortality in farmed brown trout, Salmo trutta. Fungal Biol 2013; 118:591-600. [PMID: 25088073 DOI: 10.1016/j.funbio.2013.11.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/06/2013] [Accepted: 11/20/2013] [Indexed: 10/25/2022]
Abstract
Some species of the genus Saprolegnia, such as Saprolegnia diclina and Saprolegnia ferax are responsible for devastating infections on salmonid eggs. Members of this group cause saprolegniasis, a disease resulting in considerable economic losses in aquaculture. Although both S. diclina and S. ferax have received much attention, the role of other Saprolegnia species in infecting fish eggs is less known. For this purpose, we have investigated the aetiology of chronic egg mortality events occurring in farmed brown trout, Salmo trutta. A total of 48 isolates were obtained from eggs with signs of infection as well as from water samples. A molecular analysis based on nrDNA internal transcribed spacer (ITS) operational taxonomic units indicated that the majority of the isolates correspond to Saprolegnia australis. All isolates of S. australis exhibited the same random amplified polymorphic DNA (RAPD) band patterns suggesting that a single strain is implicated in egg infections. The isolates followed Koch postulates using trout eggs and fry. Under standard concentrations of bronopol commonly used in farms, these isolates could grow, but not sporulate. However, both growth and sporulation were recovered when treatment was removed. This study shows that S. australis can infect and kill salmon eggs, and helps in defining oomycetes core pathogens.
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Affiliation(s)
- Svetlana Rezinciuc
- Department of Mycology, Real Jardín Botánico CSIC, Plaza Murillo 2, 28014 Madrid, Spain
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Phylogenetic and transcriptional analysis of an expanded bZIP transcription factor family in Phytophthora sojae. BMC Genomics 2013; 14:839. [PMID: 24286285 PMCID: PMC4046829 DOI: 10.1186/1471-2164-14-839] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 11/14/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Basic leucine zipper (bZIP) transcription factors are present exclusively in eukaryotes and constitute one of the largest and most diverse transcription factor families. The proteins are responsible for central developmental and physiological processes in plants, animals, and fungi, including the pathogenicity of fungal plant pathogens. However, there is limited understanding of bZIPs in oomycetes, which are fungus-like organisms in the kingdom Stramenopila. Oomycetes include many destructive plant pathogens, including the well-studied species Phytophthora sojae, which causes soybean stem and root rot. RESULTS Candidate bZIPs encoded in the genomes of P. sojae and four other oomycetes, two diatoms, and two fungal species were predicted using bioinformatic methods. Comparative analysis revealed expanded numbers of bZIP candidates in oomycetes, especially the Phytophthora species, due to the expansion of several novel bZIP classes whose highly conserved asparagines in basic DNA-binding regions were substituted by other residues such as cysteine. The majority of these novel bZIP classes were mostly restricted to oomycetes. The large number of novel bZIPs appears to be the result of widespread gene duplications during oomycete evolution. The majority of P. sojae bZIP candidates, including both conventional and novel bZIP classes, were predicted to contain canonical protein secondary structures. Detection of gene transcripts using digital gene expression profiling and qRT-PCR suggested that most of the candidates were not pseudogenes. The major transcriptional shifts of bZIPs occurred during the zoosporangia/zoospore/cyst and host infection stages. Several infection-associated bZIP genes were identified that were positively regulated by H2O2 exposure. CONCLUSIONS The identification of large classes of bZIP proteins in oomycetes with novel bZIP motif variants, that are conserved and developmentally regulated and thus presumably functional, extends our knowledge of this important family of eukaryotic transcription factors. It also lays the foundation for detailed studies of the roles of these proteins in development and infection in P. sojae and other oomycetes.
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Sanju S, Thakur A, Siddappa S, Sreevathsa R, Srivastava N, Shukla P, Singh BP. Pathogen virulence of Phytophthora infestans: from gene to functional genomics. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2013; 19:165-77. [PMID: 24431484 PMCID: PMC3656195 DOI: 10.1007/s12298-012-0157-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The oomycete, Phytophthora infestans, is one of the most important plant pathogens worldwide. Much of the pathogenic success of P. infestans, the potato late blight agent, relies on its ability to generate large amounts of sporangia from mycelia, which release zoospores that encyst and form infection structures. Until recently, little was known about the molecular basis of oomycete pathogenicity by the avirulence molecules that are perceived by host defenses. To understand the molecular mechanisms interplay in the pathogen and host interactions, knowledge of the genome structure was most important, which is available now after genome sequencing. The mechanism of biotrophic interaction between potato and P. infestans could be determined by understanding the effector biology of the pathogen, which is until now poorly understood. The recent availability of oomycete genome will help in understanding of the signal transduction pathways followed by apoplastic and cytoplasmic effectors for translocation into host cell. Finally based on genomics, novel strategies could be developed for effective management of the crop losses due to the late blight disease.
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Affiliation(s)
- Suman Sanju
- />Central potato Research Institute, Shimla, H.P India 171001
| | - Aditi Thakur
- />Central potato Research Institute, Shimla, H.P India 171001
| | | | - Rohini Sreevathsa
- />National Research Centre for Plant Biotechnology, IARI campus, Pusa, New Delhi—12, India
| | - Nidhi Srivastava
- />Department of Biosciences and Biotechnology, Banasthali University (Rajasthan), Tonk, India 304022
| | - Pradeep Shukla
- />Department of Biological Sciences, School of Basic Sciences, SHIATS, Naini, Allahabad, India 211007
| | - B. P. Singh
- />Central potato Research Institute, Shimla, H.P India 171001
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Identification of an isolate of Saprolegnia ferax as the causal agent of saprolegniosis of Yellow catfish (Pelteobagrus fulvidraco) eggs. Vet Res Commun 2012; 36:239-44. [DOI: 10.1007/s11259-012-9536-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/08/2012] [Indexed: 10/28/2022]
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