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Pham NQ, Duong TA, Wingfield BD, Barnes I, Durán A, Wingfield MJ. Characterisation of the mating-type loci in species of Elsinoe causing scab diseases. Fungal Biol 2023; 127:1484-1490. [PMID: 38097322 DOI: 10.1016/j.funbio.2023.11.003] [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: 06/30/2023] [Revised: 11/08/2023] [Accepted: 11/10/2023] [Indexed: 12/18/2023]
Abstract
The genus Elsinoe includes many aggressive plant pathogens that infect various economically important agricultural, horticultural and forestry plants. Significant diseases include citrus scab caused by E. fawcettii and E. australis, grapevine spot anthracnose by E. ampelina, and the emerging Eucalyptus scab and shoot malformation disease caused by the recently described E. necatrix. Despite their importance as plant pathogens, little is known regarding the biology of many Elsinoe spp. To gain insights into the reproductive biology of these fungi, we characterized the mating-type loci of seven species using whole genome sequence data. Results showed that the MAT1 locus organization and its flanking genes is relatively conserved in most cases. All seven species manifested a typical heterothallic mating system characterized by having either the MAT1-1 or MAT1-2 idiomorph present in an isolate. These idiomorphs were defined by the MAT1-1-1 or the MAT1-2-1 gene, respectively. A unique MAT1-1 idiomorph containing a truncated MAT1-2-1 gene, and a MAT1-1-1 gene, was identified in E. necatrix and E. fawcettii genomes. Additionally, two idiomorph-specific proteins were found in the MAT1-1 and MAT1-2 idiomorphs of E. australis. Universal mating-type markers confirmed heterothallism across 21 Elsinoe spp., are poised to advance future studies regarding the biology of these fungi.
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Affiliation(s)
- N Q Pham
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0028, South Africa.
| | - T A Duong
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0028, South Africa
| | - B D Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0028, South Africa
| | - I Barnes
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0028, South Africa
| | - A Durán
- Plant Health Program, Research and Development, Asia Pacific Resources International Holdings Ltd. (APRIL), Pangkalan Kerinci, 28300, Riau, Indonesia
| | - M J Wingfield
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0028, South Africa
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Ujat AH, Ono T, Hattori Y, Nakashima C. Re-Examination of Several Elsinoë Species Reported from Japan. MYCOBIOLOGY 2023; 51:122-138. [PMID: 37359956 PMCID: PMC10288934 DOI: 10.1080/12298093.2023.2219049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/11/2023] [Accepted: 05/21/2023] [Indexed: 06/28/2023]
Abstract
Elsinoë are plant pathogenic fungi that cause scabs, spotted anthracnose, and some morphological distortions on various plants, including woody plants, economically important crops, and ornamental plants. Taxonomical reexamination of Elsinoë species in Japan has not yet been conducted based on the modern species criteria. In this study, several Japanese isolates were reexamine based on the morphological and molecular-phylogenetic analysis of the internal transcribed spacer region (ITS), large subunit gene (LSU)m and protein-coding gene such as RNA polymerase II subunit (rpb2) and Translation elongation factor 1-alpha (tef). Japanese isolates were divided into four clades and three new species, Elsinoë hydrangeae, E. sumire, and E. tanashiensis were proposed. One species, Sphaceloma akebiae, was transferred to the genus Elsinoë.
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Affiliation(s)
- Anysia Hedy Ujat
- Graduate School of Bioresources, Mie University, Tsu, Mie, Japan
| | - Tsuyoshi Ono
- Tokyo Metropolitan Agriculture and Forestry Research Center, Tachikawa, Tokyo, Japan
| | - Yukako Hattori
- Department of Mushroom Science and Forest Microbiology, Forestry and Forest Product Research Institute, Tsukuba, Ibaraki, Japan
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Nigar Q, Cadle-Davidson L, Gadoury DM, Hassan MU. First Report of Colletotrichum fioriniae Causing Grapevine Anthracnose in New York. PLANT DISEASE 2022; 107:223. [PMID: 35771116 DOI: 10.1094/pdis-03-22-0604-pdn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Grapevine is one of the most widely-planted fruit crops in the world, and is the most economically important fruit crop in the state of New York, USA. Symptoms of anthracnose on grapevine are similarly widely-reported on grapevine fruit and foliage, and such symptoms are commonly attributed to Elsinöe ampelina (Wilcox et al., 2015). However, similar symptoms, if not identical, to those associated with E. ampelina have been sporadically attributed to various species in the genus Colletotrichum. In September 2021, a survey was conducted in three research vineyards at Cornell AgriTech in Geneva, NY. Symptoms of anthracnose werebserved on four Vitis interspecific hybrid breeding lines in a 1 ha vineyard. Leaves, fruit, and petioles showing symptoms of anthracnose, i.e., sunken necrotic lesions with grayish centers and brownish margins, were collected. Symptomatic and healthy portions of surface-sterilized tissues were placed on PDA medium and incubated at 23oC for 7 days. Several petiole samples yielded colonies of white to greyish mycelium, with some red to orange pigmentation (Fig. 1A and 1B), similar to those described by Chowdappa et al. (2009) for Colletotrichum species isolated from grapevine in India. Cultures were allowed to sporulate. Slides from cultures were prepared and examined at 400X magnification. Conidia from cultures were cylindrical with rounded ends, 13.5-15.2 μm in length and 7.6-9.0 μm in width (Fig. 1C). Koch's postulates were fulfilled by inoculating detached healthy leaves of V. vinifera 'Chardonnay' that had been surface sterilized in 10% sodium hypochlorite and triple-rinsed in sterile distilled water. Drop inoculation was used from a suspension of 105 conidia/ml from the foregoing pure cultures as five 2 µL droplets per leaf. Inoculated detached leaves were maintained on water agar in a Petri dish at 23oC. Four days after inoculation, symptoms were observed and compared with the originally collected samples. Inoculated leaves displayed symptoms typically found on the collected tissues, and the original pathogen, as confirmed by colony morphology and conidial characteristics and dimensions, was reisolated from inoculated leaves, and not from non-inoculated controls. For molecular characterization, fungal DNA was isolated by using Qiagen DNeasy kit and amplified using the following primer pairs: ITS1/ITS4, TEF (Hyun et al., 2009), E. ampelina F/R (Santos et al. 2018), TUB2, ACT, HIS3, GAPDH and CHS1 (Damm et al., 2001). PCR products were purified using ExoSAP-IT, and samples were Sanger sequenced. Sequences were analyzed using Geneious Prime software, and the resulting sequences (NCBI accessions OL720215, OL720216, OL720217, OL720218, OL853836, OM982612, OM982613, OM982614, OM982615 and OM982616) had 94 to 100% identity to Colletotrichum fioriniae NCBI accessions MN944922.1, MK646015.1, MN944922.1, MN856415.1, KU847413.1, MN520490.1, MN544294.1, KY695259.1, MN535117.1 and MN544295.1. Symptoms of grapevine anthracnose caused by Colletotrichum species have been reported from India (Chowdappa et al., 2009) and Korea (Kim et al., 2021). To our knowledge this is the first report of grapevine anthracnose caused by C. fioriniae Anthracnose and ripe rot are diseases of increasing importance, particularly as new grapevine cultivars with resistance to powdery mildew or downy mildew are adopted. Taxonomy of the causal agents (E. ampelina and Colletotrichum spp.) has undergone considerable revision. Consequently, distribution and relative prevalence of the various taxa will require further study.
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Affiliation(s)
- Qandeela Nigar
- Pir Mehr Ali Shah Arid Agriculture University, 72599, Department of Plant Breeding and Genetics, Rawalpindi, Punjab, Pakistan
- Cornell AgriTech, 116317, Plant Pathology and Plant Microbe Biology, Geneva, New York, United States;
| | - Lance Cadle-Davidson
- USDA Agricultural Research Service, 17123, Grape Genetics Research Unit, Geneva, New York, United States
- Cornell AgriTech, 116317, Plant Pathology and Plant Microbe Biology, Geneva, New York, United States;
| | - David M Gadoury
- Cornell AgriTech, 116317, Plant Pathology and Plant Microbe Biology, Geneva, New York, United States;
| | - Mahmood Ul Hassan
- Pir Mehr Ali Shah Arid Agriculture University, 72599, Department of Plant Breeding and Genetics, Rawalpindi, Punjab, Pakistan;
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Chaisiri C, Liu X, Lin Y, Luo C. Diaporthe citri: A Fungal Pathogen Causing Melanose Disease. PLANTS 2022; 11:plants11121600. [PMID: 35736750 PMCID: PMC9227384 DOI: 10.3390/plants11121600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/25/2022] [Accepted: 06/12/2022] [Indexed: 11/16/2022]
Abstract
Citrus melanose is a fungal disease caused by Diaporthe citri F.A. Wolf. It is found in various citrus-growing locations across the world. The host range of D. citri is limited to plants of the Citrus genus. The most economically important hosts are Citrus reticulata (mandarin), C. sinensis (sweet orange), C. grandis or C. maxima (pumelo), and C. paradisi (grapefruit). In the life cycle of D. citri throughout the citrus growing season, pycnidia can be seen in abundance on dead branches, especially after rain, with conidia appearing as slimy masses discharged from the dead twigs. Raindrops can transmit conidia to leaves, twigs, and fruits, resulting in disease dispersion throughout small distances. Persistent rains and warm climatic conditions generally favor disease onset and development. The melanose disease causes a decline in fruit quality, which lowers the value of fruits during marketing and exportation. High rainfall areas should avoid planting susceptible varieties. In this article, information about the disease symptoms, history, geographic distribution, epidemiology, impact, and integrated management practices, as well as the pathogen morphology and identification, was reviewed and discussed.
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Affiliation(s)
- Chingchai Chaisiri
- Key Lab of Horticultural Plant Biology, Ministry of Education, Wuhan 430070, China; (C.C.); (X.L.)
- Hubei Key Lab of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China;
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiangyu Liu
- Key Lab of Horticultural Plant Biology, Ministry of Education, Wuhan 430070, China; (C.C.); (X.L.)
- Hubei Key Lab of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China;
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yang Lin
- Hubei Key Lab of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China;
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Chaoxi Luo
- Key Lab of Horticultural Plant Biology, Ministry of Education, Wuhan 430070, China; (C.C.); (X.L.)
- Hubei Key Lab of Plant Pathology, Huazhong Agricultural University, Wuhan 430070, China;
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, China
- Correspondence:
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Shin K, Kwon SH, Lee SC, Moon YE. Sensitive and Rapid Detection of Citrus Scab Using an RPA-CRISPR/Cas12a System Combined with a Lateral Flow Assay. PLANTS 2021; 10:plants10102132. [PMID: 34685941 PMCID: PMC8539466 DOI: 10.3390/plants10102132] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 10/02/2021] [Accepted: 10/02/2021] [Indexed: 12/14/2022]
Abstract
Citrus is the most extensively produced fruit tree crop in the world and is grown in over 130 countries. Fungal diseases in citrus can cause significant losses in yield and quality. An accurate diagnosis is critical for determining the best management practices and preventing future losses. In this study, a Recombinase polymerase amplification (RPA)-clustered regularly interspaced short palindromic repeats (CRISPR)/associated (Cas) system was established with the integration of a lateral flow assay (LFA) readout system for diagnosis of citrus scab. This detection can be completed within 1 h, is highly sensitive and prevents cross-reactions with other common fungal citrus diseases. Furthermore, the detection system is compatible with crude DNA extracted from infected plant tissue. This RPA-CRISPR/Cas12a-LFA system provides a sensitive, rapid, and cost-effective method with promising and significant practical value for point-of-care diagnosis of citrus scab. To our knowledge, this is the first report to establish an RPA- and CRISPR-based method with LFA for fungal diseases in plants.
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Shin K, Paudyal DP, Lee SC, Hyun JW. Different Phytohormonal Responses on Satsuma Mandarin (Citrus unshiu) Leaves Infected with Host-Compatible or Host-Incompatible Elsinoë fawcettii. THE PLANT PATHOLOGY JOURNAL 2021; 37:268-279. [PMID: 34111916 PMCID: PMC8200574 DOI: 10.5423/ppj.oa.12.2020.0224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/05/2021] [Accepted: 04/23/2021] [Indexed: 06/12/2023]
Abstract
Citrus scab, caused by the fungal pathogen Elsinoë fawcettii, is one of the most important fungal diseases affecting Citrus spp. Citrus scab affects young tissues, including the leaves, twigs, and fruits, and produces severe fruit blemishes that reduce the market value of fresh fruits. To study the molecular responses of satsuma mandarin (C. unshiu) to E. fawcettii, plant hormone-related gene expression was analyzed in response to host-compatible (SM16-1) and host-incompatible (DAR70024) isolates. In the early phase of infection by E. fawcettii, jasmonic acid- and salicylic acid-related gene expression was induced in response to infection with the compatible isolate. However, as symptoms advanced during the late phase of the infection, the jasmonic acid- and salicylic acid-related gene expression was downregulated. The gene expression patterns were compared between compatible and incompatible interactions. As scabs were accompanied by altered tissue growth surrounding the infection site, we conducted gibberellic acid- and abscisic acid-related gene expression analysis and assessed the content of these acids during scab symptom development. Our results showed that gibberellic and abscisic acid-related gene expression and hormonal changes were reduced and induced in response to the infection, respectively. Accordingly, we propose that jasmonic and salicylic acids play a role in the early response to citrus scab, whereas gibberellic and abscisic acids participate in symptom development.
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Affiliation(s)
- Kihye Shin
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration, Jeju 63607, Korea
| | - Dilli Prasad Paudyal
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration, Jeju 63607, Korea
- Current address: miniPCR, Amplyus LLC, Arlington, MA 02474, USA
| | - Seong Chan Lee
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration, Jeju 63607, Korea
| | - Jae Wook Hyun
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration, Jeju 63607, Korea
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New multiplex conventional PCR and quadruplex real-time PCR assays for one-tube detection of Phyllosticta citricarpa, Elsinoë fawcettii, Elsinoë australis, and Pseudocercospora angolensis in Citrus: development and validation. Appl Microbiol Biotechnol 2020; 104:9363-9385. [PMID: 32926221 DOI: 10.1007/s00253-020-10880-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 08/17/2020] [Accepted: 09/02/2020] [Indexed: 10/23/2022]
Abstract
Phyllosticta citricarpa, Elsinoë fawcettii, Elsinoë australis, and Pseudocercospora angolensis are major pathogens of citrus crops worldwide and can cause non-characteristic symptoms that may lead to confusion regarding the causative agent. These fungi are subject to international phytosanitary regulations, and testing on fruits or leaves requires accurate and easy-to-use tools. New multiplex conventional PCR and real-time PCR assays were developed here to achieve highly accurate simultaneous detection of all four fungal pathogens in fruit tissues. We designed new oligonucleotide combinations for P. citricarpa, E. fawcettii, and E. australis and combined them with already available primers and hydrolysis probes to be used in either PCR assay. The limit of detection for multiplex conventional PCR was as low as 100 pg μL-1 for P. citricarpa, E. fawcettii, and E. australis and 10 pg μL-1 of target DNA per reaction tube for P. angolensis. The quadruplex real-time PCR assay successfully yielded repeatable positive results with as low as 242, 243, 241, and 242 plasmidic copies of target DNA of P. citricarpa, E. fawcettii, E. australis, and P. angolensis, respectively. Moreover, analysis of 60 naturally infected citrus samples yielded 100% concordant results by both assays. Our validation experiment revealed that the multiplex real-time PCR assay showed high specificity except a cross-reaction with P. paracitricarpa DNA. Sensitivity, repeatability, reproducibility, and robustness were verified, and the assay could be used following different DNA extraction procedures, supporting fitness for routine analysis. These new multiplex tools should be of great interest as cost-effective solutions for regulatory authorities and diagnostic laboratories, enabling testing for four important pathogens in single-tube reactions. KEY POINTS: • Development of new conventional PCR and qPCR assays for four citrus pathogens. • Very low limits of detection were found for multiplex conventional PCR. • qPCR had high specificity, sensitivity, repeatability, reproducibility, and robustness.
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Zhao L, Xiao H, Ma X, Cheng Q. Elsinoë australis Causing Spot Anthracnose on Poplar in China. PLANT DISEASE 2020; 104:2202-2209. [PMID: 32452751 DOI: 10.1094/pdis-11-19-2349-re] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Poplar plantations provide important industrial feedstock in China. Red spot symptoms were observed on leaves of Populus tomentosa and P. deltoides in southeastern China. Based on morphology and molecular phylogenetic analysis, the fungus isolated from disease spots was identified as Elsinoë australis, which has been previously recognized as a pathogen of Citrus spp. and jojoba but has not been reported in China. Pathogenicity tests found that isolates from two poplar species caused red spot symptoms on leaves from different poplar species and also led to scab formation on the fruit of one hybrid citrus but not on fruit of orange, lemon, or grapefruit. The draft genome of one E. australis isolate was generated. The genetic architecture of the MAT1-1 and MAT1-2 loci of E. australis was revealed by genome sequence and long-range PCR analyses. Single isolates carried only one of two opposite mating-types was confirmed by idiomorph-specific PCR, suggesting a heterothallic mating system. Our results not only revealed a new E. australis pathotype causing poplar spot anthracnose in China but also provided its genome and mating system information.
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Affiliation(s)
- Lijuan Zhao
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Hongju Xiao
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Xujie Ma
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
| | - Qiang Cheng
- Key Laboratory of Forest Genetics & Biotechnology of Ministry of Education, Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China
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Jeffress S, Arun-Chinnappa K, Stodart B, Vaghefi N, Tan YP, Ash G. Genome mining of the citrus pathogen Elsinoë fawcettii; prediction and prioritisation of candidate effectors, cell wall degrading enzymes and secondary metabolite gene clusters. PLoS One 2020; 15:e0227396. [PMID: 32469865 PMCID: PMC7259788 DOI: 10.1371/journal.pone.0227396] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 04/17/2020] [Indexed: 11/22/2022] Open
Abstract
Elsinoë fawcettii, a necrotrophic fungal pathogen, causes citrus scab on numerous citrus varieties around the world. Known pathotypes of E. fawcettii are based on host range; additionally, cryptic pathotypes have been reported and more novel pathotypes are thought to exist. E. fawcettii produces elsinochrome, a non-host selective toxin which contributes to virulence. However, the mechanisms involved in potential pathogen-host interactions occurring prior to the production of elsinochrome are unknown, yet the host-specificity observed among pathotypes suggests a reliance upon such mechanisms. In this study we have generated a whole genome sequencing project for E. fawcettii, producing an annotated draft assembly 26.01 Mb in size, with 10,080 predicted gene models and low (0.37%) coverage of transposable elements. A small proportion of the assembly showed evidence of AT-rich regions, potentially indicating genomic regions with increased plasticity. Using a variety of computational tools, we mined the E. fawcettii genome for potential virulence genes as candidates for future investigation. A total of 1,280 secreted proteins and 276 candidate effectors were predicted and compared to those of other necrotrophic (Botrytis cinerea, Parastagonospora nodorum, Pyrenophora tritici-repentis, Sclerotinia sclerotiorum and Zymoseptoria tritici), hemibiotrophic (Leptosphaeria maculans, Magnaporthe oryzae, Rhynchosporium commune and Verticillium dahliae) and biotrophic (Ustilago maydis) plant pathogens. Genomic and proteomic features of known fungal effectors were analysed and used to guide the prioritisation of 120 candidate effectors of E. fawcettii. Additionally, 378 carbohydrate-active enzymes were predicted and analysed for likely secretion and sequence similarity with known virulence genes. Furthermore, secondary metabolite prediction indicated nine additional genes potentially involved in the elsinochrome biosynthesis gene cluster than previously described. A further 21 secondary metabolite clusters were predicted, some with similarity to known toxin producing gene clusters. The candidate virulence genes predicted in this study provide a comprehensive resource for future experimental investigation into the pathogenesis of E. fawcettii.
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Affiliation(s)
- Sarah Jeffress
- Centre for Crop Health, Institute for Life Sciences and the Environment, Research and Innovation Division, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Kiruba Arun-Chinnappa
- Centre for Crop Health, Institute for Life Sciences and the Environment, Research and Innovation Division, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Ben Stodart
- Graham Centre for Agricultural Innovation, (Charles Sturt University and NSW Department of Primary Industries), School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Niloofar Vaghefi
- Centre for Crop Health, Institute for Life Sciences and the Environment, Research and Innovation Division, University of Southern Queensland, Toowoomba, QLD, Australia
| | - Yu Pei Tan
- Department of Agriculture and Fisheries, Queensland Government, Brisbane, QLD, Australia
| | - Gavin Ash
- Centre for Crop Health, Institute for Life Sciences and the Environment, Research and Innovation Division, University of Southern Queensland, Toowoomba, QLD, Australia
- Graham Centre for Agricultural Innovation, (Charles Sturt University and NSW Department of Primary Industries), School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
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Shanmugam G, Jeon J, Hyun JW. Draft Genome Sequences of Elsinoë fawcettii and Elsinoë australis Causing Scab Diseases on Citrus. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2020; 33:135-137. [PMID: 31577163 DOI: 10.1094/mpmi-06-19-0169-a] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Elsinoë fawcettii and E. australis (phylum Ascomycota) are phytopathogenic fungi causing scab diseases on citrus plants. We report here the high-quality draft genome sequences and ab initio gene predictions of two E. fawcettii strains and one E. australis strain, which differ in their host range. This genome sequence information will provide valuable resources to underpin genomic attributes for determining host range through comparative genomic analyses of citrus scab fungi.
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Affiliation(s)
- Gnanendra Shanmugam
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Korea
| | - Junhyun Jeon
- Department of Biotechnology, Yeungnam University, Gyeongsan, Gyeongbuk, 38541, Korea
- Plant Immunity Research Center, Seoul National University, Seoul, 08826, Korea
| | - Jae-Wook Hyun
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration, Jeju 63607, Korea
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Ahmed Y, Hubert J, Fourrier-Jeandel C, Dewdney MM, Aguayo J, Ioos R. A Set of Conventional and Multiplex Real-Time PCR Assays for Direct Detection of Elsinoë fawcettii, E. australis, and Pseudocercospora angolensis in Citrus Fruits. PLANT DISEASE 2019; 103:345-356. [PMID: 30566843 DOI: 10.1094/pdis-05-18-0798-re] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Elsinoë fawcettii, E. australis, and Pseudocercospora angolensis are causal agents of citrus scab and spot diseases. The three pathogens are listed as quarantine pests in many countries and are subject to phytosanitary measures to prevent their entry. Diagnosis of these diseases based on visual symptoms is problematic, as they could be confused with other citrus diseases. Isolation of E. fawcettii, E. australis, and P. angolensis from infected tissues is challenging because they grow slowly on culture media. This study developed rapid and specific detection tools for the in planta detection of these pathogens, using either conventional PCR or one-tube multiplex real-time PCR. Primers and hybridization probes were designed to target the single-copy protein-coding gene MS204 for E. fawcettii and E. australis and the translation elongation factor (Tef-1α) gene for P. angolensis. The specificity of the assays was evaluated by testing against DNA extracted from a large number of isolates (102) collected from different citrus-growing areas in the world and from other hosts. The newly described species E. citricola was not included in the specificity test due to its unavailability from the CBS collection. The detection limits of conventional PCR for the three pathogens were 100, 100, and 10 pg μl-1 gDNA per reaction for E. fawcettii, E. australis, and P. angolensis, respectively. The quadruplex qPCR was fully validated assessing the following performance criteria: sensitivity, specificity, repeatability, reproducibility, and robustness. The quadruplex real-time PCR proved to be highly sensitive, detecting as low as 243, 241, and 242 plasmidic copies (pc) μl-1 of E. fawcettii, E. australis, and P. angolensis, respectively. Sensitivity and specificity of this quadruplex assay were further confirmed using 176 naturally infected citrus samples collected from Ethiopia, Cameroon, the United States, and Australia. The quadruplex assay developed in this study is robust, cost-effective, and capable of high-throughput detection of the three targets directly from citrus samples. This new detection tool will substantially reduce the turnaround time for reliable species identification and allow rapid response and appropriate action.
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Affiliation(s)
- Yosra Ahmed
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (ANSES) Laboratoire de la Santé des Végétaux, Unité de Mycologie, Domaine de Pixérécourt, 54220 Malzéville, France; and Agricultural Research Center, Plant Pathology Research Institute, Giza- Egypt
| | - Jacqueline Hubert
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (ANSES) Laboratoire de la Santé des Végétaux, Unité de Mycologie, Domaine de Pixérécourt, 54220 Malzéville, France
| | - Céline Fourrier-Jeandel
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (ANSES) Laboratoire de la Santé des Végétaux, Unité de Mycologie, Domaine de Pixérécourt, 54220 Malzéville, France
| | - Megan M Dewdney
- Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850
| | - Jaime Aguayo
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (ANSES) Laboratoire de la Santé des Végétaux, Unité de Mycologie, Domaine de Pixérécourt, 54220 Malzéville, France
| | - Renaud Ioos
- Agence Nationale de Sécurité Sanitaire de l'Alimentation, de l'Environnement et du Travail (ANSES) Laboratoire de la Santé des Végétaux, Unité de Mycologie, Domaine de Pixérécourt, 54220 Malzéville, France
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12
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Jeger M, Bragard C, Caffier D, Candresse T, Chatzivassiliou E, Dehnen-Schmutz K, Gilioli G, Grégoire JC, Jaques Miret JA, MacLeod A, Navajas Navarro M, Niere B, Parnell S, Potting R, Rafoss T, Urek G, Van Bruggen A, Van der Werf W, West J, Winter S, Vicent A, Vloutoglou I, Bottex B, Rossi V. Pest categorisation of Elsinoë fawcettii and E. australis. EFSA J 2017; 15:e05100. [PMID: 32625385 PMCID: PMC7010112 DOI: 10.2903/j.efsa.2017.5100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The Panel on Plant Health performed a pest categorisation of Elsinoë fawcettii and E. australis, the causal agents of citrus scab diseases, for the EU. The identities of the pests are well-established and reliable methods exist for their detection/identification. The pests are listed in Annex IIAI of Directive 2000/29/EC as Elsinoë spp. and are not known to occur in the EU. Species and hybrids of citrus (Family Rutaceae) are affected by E. fawcettii and E. australis, with the latter having a more restricted host range and geographical distribution compared to the former. The status of Simmondsia chinensis (jojoba) as a host of E. australis is uncertain. The pests could potentially enter the EU on host plants for planting and fruit originating in infested Third countries. The current distribution of the pests, climate matching and the use of irrigation in the EU citrus-growing areas suggest that the pests could establish and spread in the EU citrus-growing areas. Uncertainty exists on whether cultural practices and control methods, currently applied in the EU, would prevent the establishment of the pests. In the infested areas, the pests cause scab pustules on host leaves and fruit resulting in yield/quality losses. It is expected that the introduction and spread of the pests in the EU could impact citrus production. Cultural practices and chemical control measures may reduce the inoculum sources and to some extent the disease incidence, but they cannot eliminate the pests. Phytosanitary measures are available to mitigate the risk of introduction and spread of the pests in the EU. E. fawcettii and E. australis meet all the criteria assessed by EFSA for consideration as potential Union quarantine pests. As those pests are not known to occur in the EU, this criterion to consider them as Union regulated non-quarantine pests is not met.
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13
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Fan X, Barreto R, Groenewald J, Bezerra J, Pereira O, Cheewangkoon R, Mostert L, Tian C, Crous P. Phylogeny and taxonomy of the scab and spot anthracnose fungus Elsinoë ( Myriangiales, Dothideomycetes). Stud Mycol 2017; 87:1-41. [PMID: 28373739 PMCID: PMC5367849 DOI: 10.1016/j.simyco.2017.02.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Species of Elsinoë are phytopathogens causing scab and spot anthracnose on many plants, including some economically important crops such as avocado, citrus, grapevines, and ornamentals such as poinsettias, field crops and woody hosts. Disease symptoms are often easily recognisable, and referred to as signature-bearing diseases, for the cork-like appearance of older infected tissues with scab-like appearance. In some Elsinoë-host associations the resulting symptoms are better described as spot anthracnose. Additionally the infected plants may also show mild to severe distortions of infected organs. Isolation of Elsinoë in pure culture can be very challenging and examination of specimens collected in the field is often frustrating because of the lack of fertile structures. Current criteria for species recognition and host specificity in Elsinoë are unclear due to overlapping morphological characteristics, and the lack of molecular and pathogenicity data. In the present study we revised the taxonomy of Elsinoë based on DNA sequence and morphological data derived from 119 isolates, representing 67 host genera from 17 countries, including 64 ex-type cultures. Combined analyses of ITS, LSU, rpb2 and TEF1-α DNA sequence data were used to reconstruct the backbone phylogeny of the genus Elsinoë. Based on the single nomenclature for fungi, 26 new combinations are proposed in Elsinoë for species that were originally described in Sphaceloma. A total of 13 species are epitypified with notes on their taxonomy and phylogeny. A further eight new species are introduced, leading to a total of 75 Elsinoë species supported by molecular data in the present study. For the most part species of Elsinoë appear to be host specific, although the majority of the species treated are known only from a few isolates, and further collections and pathogenicity studies will be required to reconfirm this conclusion.
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Affiliation(s)
- X.L. Fan
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing, 100083, China
| | - R.W. Barreto
- Departmento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil
| | - J.Z. Groenewald
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - J.D.P. Bezerra
- Departamento de Micologia Prof. Chaves Batista, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, s/n, Centro de Biociências, Cidade Universitária, CEP: 50670-901, Recife, PE, Brazil
| | - O.L. Pereira
- Departmento de Fitopatologia, Universidade Federal de Viçosa, Viçosa, MG, 36570-900, Brazil
| | - R. Cheewangkoon
- Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai, 50200, Thailand
| | - L. Mostert
- Department of Plant Pathology, University of Stellenbosch, Private Bag X1, Matieland, 7602, South Africa
| | - C.M. Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing, 100083, China
| | - P.W. Crous
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
- Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai, 50200, Thailand
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, 0002, South Africa
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14
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Rossman AY, Allen WC, Braun U, Castlebury LA, Chaverri P, Crous PW, Hawksworth DL, Hyde KD, Johnston P, Lombard L, Romberg M, Samson RA, Seifert KA, Stone JK, Udayanga D, White JF. Overlooked competing asexual and sexually typified generic names of Ascomycota with recommendations for their use or protection. IMA Fungus 2016; 7:289-308. [PMID: 27990336 PMCID: PMC5159600 DOI: 10.5598/imafungus.2016.07.02.09] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 11/15/2016] [Indexed: 11/10/2022] Open
Abstract
With the change to one scientific name for fungal species, numerous papers have been published with recommendations for use or protection of competing generic names in major groups of ascomycetes. Although genera in each group of fungi were carefully considered, some competing generic names were overlooked. This paper makes recommendations for additional competing genera not considered in previous papers. Chairs of relevant Working Groups of the ICTF were consulted in the development of these recommendations. A number of generic names need protection, specifically Amarenographium over Amarenomyces, Amniculicola over Anguillospora, Balansia over Ephelis, Claviceps over Sphacelia, Drepanopeziza over Gloeosporidiella and Gloeosporium, Golovinomyces over Euoidium, Holwaya over Crinium, Hypocrella over Aschersonia, Labridella over Griphosphaerioma, Metacapnodium over Antennularia, and Neonectria over Cylindrocarpon and Heliscus. The following new combinations are made: Amniculicola longissima, Atichia maunauluana, Diaporthe columnaris, D. liquidambaris, D. longiparaphysata, D. palmicola, D. tersa, Elsinoë bucidae, E.caricae, E. choisyae, E. paeoniae, E. psidii, E. zorniae, Eupelte shoemakeri, Godronia myrtilli, G. raduloides, Sarcinella mirabilis, S. pulchra, Schizothyrium jamaicense, and Trichothallus niger. Finally, one new species name, Diaporthe azadirachte, is introduced to validate an earlier name, and the conservation of Discula with a new type, D. destructiva, is recommended.
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Affiliation(s)
- Amy Y Rossman
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - W Cavan Allen
- Systematic Mycology and Microbiology Laboratory, USDA-ARS, Beltsville, MD 20705, USA
| | - Uwe Braun
- Martin Luther University, Institute of Biology, Department of Geobotany and Botanical Garden, Herbarium, Neuwerk 21, 06099 Halle (Saale), Germany
| | - Lisa A Castlebury
- Systematic Mycology and Microbiology Laboratory, USDA-ARS, Beltsville, MD 20705, USA
| | - Priscila Chaverri
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA; Escuela de Biología, Universidad de Costa Rica, San Pedro San José, Costa Rica
| | - Pedro W Crous
- CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands; Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa; Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - David L Hawksworth
- Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense, Plaza de Ramón y Cajal s/n, Madrid 28040, Spain; Department of Life Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK; Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Surrey TW9 3DS, UK
| | - Kevin D Hyde
- Center of Excellence in Fungal Research, School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand
| | - Peter Johnston
- Landcare Research, Private Bag 92170, Auckland 1142, New Zealand
| | - Lorenzo Lombard
- CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands
| | - Megan Romberg
- USDA-APHIS National Identification Services, Beltsville, MD 20705, USA
| | - Rob A Samson
- CBS-KNAW Fungal Biodiversity Centre, P.O. Box 85167, 3508 AD Utrecht, The Netherlands
| | - Keith A Seifert
- Ottawa Research and Development Centre, Biodiversity (Mycology and Microbiology), Agriculture and Agri-Food Canada, 960 Carling Avenue, Ottawa, Ontario K1A 0C6, Canada
| | - Jeffrey K Stone
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA
| | - Dhanushka Udayanga
- Systematic Mycology and Microbiology Laboratory, USDA-ARS, Beltsville, MD 20705, USA
| | - James F White
- Department of Plant Biology & Pathology, Rutgers University, 59 Dudley Rd., New Brunswick, NJ 08901, USA
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15
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Paudyal DP, Hyun JW. Physical Changes in Satsuma Mandarin Leaf after Infection of Elsinoë fawcettii Causing Citrus Scab Disease. THE PLANT PATHOLOGY JOURNAL 2015; 31:421-7. [PMID: 26674386 PMCID: PMC4677751 DOI: 10.5423/ppj.nt.05.2015.0086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/07/2015] [Accepted: 08/13/2015] [Indexed: 05/29/2023]
Abstract
Citrus scab disease is one of the destructive diseases that reduce the value of fruit for the fresh market. We analyzed the process of symptom development after infection with scab pathogen Elsinoë fawcettii in the susceptible satsuma mandarin leaves to observe the structural modification against pathogen. The cuticle and epidermal cells along with 3-5 layers of mesophyll tissue were degraded 1-2 days post inoculation. Surrounding peripheral cells of degraded tissues grew rapidly and then enveloped the necrotic area along with the growing conidia. Cross sections through the lesion revealed hyphal colonization in epidermis and mesophyll tissues. In response to the pathogen colonization, host cell walls were lignified, inner cells were rapidly compartmentalized and a semi-circular boundary was formed that separated the infected region from the non-infected region, and finally prevented the intercellular pathogen spread.
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Affiliation(s)
- Dilli Prasad Paudyal
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration, Jeju 63607,
Korea
| | - Jae-Wook Hyun
- Citrus Research Institute, National Institute of Horticultural and Herbal Science, Rural Development Administration, Jeju 63607,
Korea
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16
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Ash GJ, Stodart B, Hyun JW. Black Scab of Jojoba (Simmondsia chinensis) in Australia Caused by a Putative New Pathotype of Elsinoë australis. PLANT DISEASE 2012; 96:629-634. [PMID: 30727516 DOI: 10.1094/pdis-06-11-0465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A new disease of jojoba in Australia is described. We have demonstrated that this disease is caused by Elsinoë australis, a pathogen which is normally associated with citrus. This pathogen has not been found previously in Australia on citrus or any other crop. The fungus causes a scab on leaves and stems of jojoba and is widely distributed in eastern Australia. Although molecular analysis of the pathogen indicates that it is closely related to the natsudaidai and the sweet orange pathotypes of E. australis, glasshouse and laboratory experiments demonstrate that it is not pathogenic to a range of citrus cultivars grown in Australia. The data indicate that the isolates from jojoba represent a new pathotype of E. australis.
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Affiliation(s)
- G J Ash
- E. H. Graham Centre for Agricultural Innovation (Department of Primary Industry and Charles Sturt University), School of Agricultural and Wine Sciences, P.O. Box 588 Wagga Wagga, NSW 2678, Australia
| | - B Stodart
- E. H. Graham Centre for Agricultural Innovation (Department of Primary Industry and Charles Sturt University), School of Agricultural and Wine Sciences, P.O. Box 588 Wagga Wagga, NSW 2678, Australia
| | - J-W Hyun
- Citrus Experiment Station, National Institute of Horticultural & Herbal Science, R.D.A. Jeju, 697-943, Korea
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17
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Chung KR. Elsinoë fawcettii and Elsinoë australis: the fungal pathogens causing citrus scab. MOLECULAR PLANT PATHOLOGY 2011; 12:123-35. [PMID: 21199563 PMCID: PMC6640467 DOI: 10.1111/j.1364-3703.2010.00663.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
UNLABELLED Elsinoë fawcettii and E. australis are important pathogens of citrus. Both species are known to produce red or orange pigments, called elsinochrome. Elsinochrome is a nonhost-selective phytotoxin and is required for full fungal virulence and lesion formation. This article discusses the taxonomy, epidemiology, genetics and pathology of the pathogens. It also provides a perspective on the cellular toxicity, biosynthetic regulation and pathological role of elsinochrome phytotoxin. TAXONOMY Elsinoë fawcettii (anamorph: Sphaceloma fawcettii) and E. australis (anamorph: S. australis) are classified in the Phylum Ascomycota, Class Dothideomycetes, Order Myriangiales and Family Elsinoaceae. HOST RANGE Elsinoë fawcettii causes citrus scab (formerly sour orange scab and common scab) on various species and hybrids in the Rutaceae family worldwide, whereas E. australis causes sweet orange scab, primarily on sweet orange and some mandarins, and has a limited geographical distribution. DISEASE SYMPTOMS Citrus tissues infested with Elsinoë often display erumpent scab pustules with a warty appearance. TOXIN PRODUCTION: Elsinochrome and many perylenequinone-containing phytotoxins of fungal origin are grouped as photosensitizing compounds that are able to absorb light energy, react with oxygen molecules and produce reactive oxygen species, such as superoxide and singlet oxygen. Elsinochrome has been documented to cause peroxidation of cell membranes and to induce rapid electrolyte leakage from citrus tissues. Elsinochrome biosynthesis and conidiation are coordinately regulated in E. fawcettii, and the environmental and physiological inducers commonly involved in both processes have begun to be elucidated.
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Affiliation(s)
- Kuang-Ren Chung
- Citrus Research and Education Center, and Department of Plant Pathology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, USA.
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