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Li Z, Wang R, Wang L, Tan C, Xu J, Fang J, Xian J. Machine Learning-Based MRI Radiogenomics for Evaluation of Response to Induction Chemotherapy in Head and Neck Squamous Cell Carcinoma. Acad Radiol 2024; 31:2464-2475. [PMID: 37985290 DOI: 10.1016/j.acra.2023.10.054] [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: 09/20/2023] [Revised: 10/16/2023] [Accepted: 10/28/2023] [Indexed: 11/22/2023]
Abstract
RATIONALE AND OBJECTIVES To develop and validate a radiogenomics model integrating clinical data, radiomics-based machine learning (RBML) classifiers, and transcriptomics data for predicting the response to induction chemotherapy (IC) in patients with head and neck squamous cell carcinoma (HNSCC). MATERIALS AND METHODS Radiomics features derived from T2-weighted, pre- and post-contrast-enhanced T1-weighted MRI sequences, clinical data, and RNA sequencing data of 150 patients with HNSCC were included in the study. Analysis of variance or recursive feature elimination was used to reduce radiomics features. Three RBML classifiers were developed to distinguish non-responders from responders. Weighted correlation network analysis (WGCNA) was performed to identify the correlation between clinical data or radiomics features and molecular features; subsequently, protein interaction and functional enrichment analyses were performed. The predictive performance of the radiogenomics model integrating significant clinical variables, RBML classifiers, and molecular features was evaluated using receiver operating characteristic curve analysis. RESULTS Five radiomics features and two conventional MRI findings significantly stratified HNSCC patients into responders and non-responders. On WGCNA analysis, 809 genes showed a significant correlation with two radiomics features. Functional enrichment analysis suggested that our proposed radiomics features could reflect the T cell-mediated immune response and immune infiltration of HNSCC. The radiogenomics model showed the highest area under the curve (0.88[95%CI 0.75-0.96]) for predicting IC response, which was better than MRI findings(p = 0.0407) or molecular features(p = 0.004) alone, but showed no significant difference with that of RBML model (p = 0.2254) in test cohort. CONCLUSION Merging imaging phenotypes with transcriptomic data improved the prediction of IC response in HNSCC.
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Affiliation(s)
- Zheng Li
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China (Z.L., J.X.).
| | - Ru Wang
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China (R.W., L.W., C.T., J.X., J.F.).
| | - Lingwa Wang
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China (R.W., L.W., C.T., J.X., J.F.).
| | - Chen Tan
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China (R.W., L.W., C.T., J.X., J.F.).
| | - Jiaqi Xu
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China (R.W., L.W., C.T., J.X., J.F.).
| | - Jugao Fang
- Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital, Capital Medical University, Beijing, China (R.W., L.W., C.T., J.X., J.F.).
| | - Junfang Xian
- Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China (Z.L., J.X.).
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2
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Young J, Oakley WRM, Fox G. Humulus lupulus and microbes: Exploring biotic causes for hop creep. Food Microbiol 2023; 114:104298. [PMID: 37290874 DOI: 10.1016/j.fm.2023.104298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/19/2023] [Accepted: 04/25/2023] [Indexed: 06/10/2023]
Abstract
BACKGROUND Hop creep continues to present an unresolved issue for the brewing industry, specifically stemming from those hops added to beer during fermentation. Hops have been found to contain four dextrin-degrading enzymes: alpha amylase, beta amylase, limit dextrinase, and an amyloglucosidase. One recent hypothesis predicts that these dextrin-degrading enzymes could originate from microbes rather than the hop plant itself. SCOPE AND APPROACH This review begins by describing how hops are processed and used in the brewing industry. It will then discuss hop creep's origins with a new beer style, antimicrobial factors from hops and resistance mechanisms that bacteria use to counter them, and finally microbial communities that inhabit hops, focusing on whether they can produce the starch degrading enzymes which drive hop creep. After initial identification, microbes with possible links to hop creep were then run through several databases to search the genomes (if available) and for those specific enzymes. KEY FINDINGS AND CONCLUSIONS Several bacteria and fungi contain alpha amylase as well as unspecified glycosyl hydrolases, but only one contains beta amylase. Finally, this paper closes with a short summary of how abundant these organisms typically are in other flowers.
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Affiliation(s)
- Jessica Young
- University of California, Davis, Department of Food Science and Technology Davis, California, USA.
| | | | - Glen Fox
- University of California, Davis, Department of Food Science and Technology Davis, California, USA
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3
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Bakhat N, Vielba-Fernández A, Padilla-Roji I, Martínez-Cruz J, Polonio Á, Fernández-Ortuño D, Pérez-García A. Suppression of Chitin-Triggered Immunity by Plant Fungal Pathogens: A Case Study of the Cucurbit Powdery Mildew Fungus Podosphaera xanthii. J Fungi (Basel) 2023; 9:771. [PMID: 37504759 PMCID: PMC10381495 DOI: 10.3390/jof9070771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/17/2023] [Accepted: 07/17/2023] [Indexed: 07/29/2023] Open
Abstract
Fungal pathogens are significant plant-destroying microorganisms that present an increasing threat to the world's crop production. Chitin is a crucial component of fungal cell walls and a conserved MAMP (microbe-associated molecular pattern) that can be recognized by specific plant receptors, activating chitin-triggered immunity. The molecular mechanisms underlying the perception of chitin by specific receptors are well known in plants such as rice and Arabidopsis thaliana and are believed to function similarly in many other plants. To become a plant pathogen, fungi have to suppress the activation of chitin-triggered immunity. Therefore, fungal pathogens have evolved various strategies, such as prevention of chitin digestion or interference with plant chitin receptors or chitin signaling, which involve the secretion of fungal proteins in most cases. Since chitin immunity is a very effective defensive response, these fungal mechanisms are believed to work in close coordination. In this review, we first provide an overview of the current understanding of chitin-triggered immune signaling and the fungal proteins developed for its suppression. Second, as an example, we discuss the mechanisms operating in fungal biotrophs such as powdery mildew fungi, particularly in the model species Podosphaera xanthii, the main causal agent of powdery mildew in cucurbits. The key role of fungal effector proteins involved in the modification, degradation, or sequestration of immunogenic chitin oligomers is discussed in the context of fungal pathogenesis and the promotion of powdery mildew disease. Finally, the use of this fundamental knowledge for the development of intervention strategies against powdery mildew fungi is also discussed.
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Affiliation(s)
- Nisrine Bakhat
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Alejandra Vielba-Fernández
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Isabel Padilla-Roji
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Jesús Martínez-Cruz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Álvaro Polonio
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Malaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Malaga, Spain
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Suppression of Chitin-Triggered Immunity by a New Fungal Chitin-Binding Effector Resulting from Alternative Splicing of a Chitin Deacetylase Gene. J Fungi (Basel) 2022; 8:jof8101022. [PMID: 36294587 PMCID: PMC9605236 DOI: 10.3390/jof8101022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 09/24/2022] [Accepted: 09/25/2022] [Indexed: 11/16/2022] Open
Abstract
Phytopathogenic fungi have evolved mechanisms to manipulate plant defences, such as chitin-triggered immunity, a plant defensive response based on the recognition of chitin oligomers by plant-specific receptors. To cope with chitin resistance, fungal pathogens have developed different strategies to prevent chitin recognition, such as binding, breaking, or modifying immunogenic oligomers. In powdery mildew fungi, the activity of chitin deacetylase (CDA) is crucial for this purpose, since silencing of the CDA gene leads to a rapid activation of chitin signalling and the subsequent suppression of fungal growth. In this work, we have identified an unusually short CDA transcript in Podosphaera xanthii, the cucurbit powdery mildew pathogen. This transcript, designated PxCDA3, appears to encode a truncated version of CDA resulting from an alternative splicing of the PxCDA gene, which lacked most of the chitin deacetylase activity domain but retained the carbohydrate-binding module. Experiments with the recombinant protein showed its ability to bind to chitin oligomers and prevent the activation of chitin signalling. Furthermore, the use of fluorescent fusion proteins allowed its localization in plant papillae at pathogen penetration sites. Our results suggest the occurrence of a new fungal chitin-binding effector, designated CHBE, involved in the manipulation of chitin-triggered immunity in powdery mildew fungi.
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RoyChowdhury M, Sternhagen J, Xin Y, Lou B, Li X, Li C. Evolution of pathogenicity in obligate fungal pathogens and allied genera. PeerJ 2022; 10:e13794. [PMID: 36042858 PMCID: PMC9420410 DOI: 10.7717/peerj.13794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 07/06/2022] [Indexed: 01/17/2023] Open
Abstract
Obligate fungal pathogens (ascomycetes and basidiomycetes) and oomycetes are known to cause diseases in cereal crop plants. They feed on living cells and most of them have learned to bypass the host immune machinery. This paper discusses some of the factors that are associated with pathogenicity drawing examples from ascomycetes, basidiomycetes and oomycetes, with respect to their manifestation in crop plants. The comparisons have revealed a striking similarity in the three groups suggesting convergent pathways that have arisen from three lineages independently leading to an obligate lifestyle. This review has been written with the intent, that new information on adaptation strategies of biotrophs, modifications in pathogenicity strategies and population dynamics will improve current strategies for breeding with stable resistance.
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Affiliation(s)
- Moytri RoyChowdhury
- Infectious Diseases Program, California Department of Public Health, Richmond, California, United States of America
| | - Jake Sternhagen
- Riverside School of Medicine, University of California, Riverside, Riverside, CA, United States of America
| | - Ya Xin
- Hangzhou Academy of Agricultural Sciences, Hangzhou, P.R. China
| | - Binghai Lou
- Guangxi Academy of Specialty Crops, Guilin, Guangxi, P.R. China
| | - Xiaobai Li
- Zhejiang Academy of Agricultural Sciences, Hangzhou, P.R. China
| | - Chunnan Li
- Hangzhou Academy of Agricultural Sciences, Hangzhou, P.R. China
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6
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GWAS Reveals a Novel Candidate Gene CmoAP2/ERF in Pumpkin ( Cucurbita moschata) Involved in Resistance to Powdery Mildew. Int J Mol Sci 2022; 23:ijms23126524. [PMID: 35742978 PMCID: PMC9223685 DOI: 10.3390/ijms23126524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/08/2022] [Accepted: 06/08/2022] [Indexed: 12/10/2022] Open
Abstract
Pumpkin (Cucurbita moschata Duchesne ex Poir.) is a multipurpose cash crop rich in antioxidants, minerals, and vitamins; the seeds are also a good source of quality oils. However, pumpkin is susceptible to the fungus Podosphaera xanthii, an obligate biotrophic pathogen, which usually causes powdery mildew (PM) on both sides of the leaves and reduces photosynthesis. The fruits of infected plants are often smaller than usual and unpalatable. This study identified a novel gene that involves PM resistance in pumpkins through a genome-wide association study (GWAS). The allelic variation identified in the CmoCh3G009850 gene encoding for AP2-like ethylene-responsive transcription factor (CmoAP2/ERF) was proven to be involved in PM resistance. Validation of the GWAS data revealed six single nucleotide polymorphism (SNP) variations in the CmoAP2/ERF coding sequence between the resistant (IT 274039 [PMR]) and the susceptible (IT 278592 [PMS]). A polymorphic marker (dCAPS) was developed based on the allelic diversity to differentiate these two haplotypes. Genetic analysis in the segregating population derived from PMS and PMR parents provided evidence for an incomplete dominant gene-mediated PM resistance. Further, the qRT-PCR assay validated the elevated expression of CmoAP2/ERF during PM infection in the PMR compared with PMS. These results highlighted the pivotal role of CmoAP2/ERF in conferring resistance to PM and identifies it as a valuable molecular entity for breeding resistant pumpkin cultivars.
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Mapuranga J, Zhang L, Zhang N, Yang W. The haustorium: The root of biotrophic fungal pathogens. FRONTIERS IN PLANT SCIENCE 2022; 13:963705. [PMID: 36105706 PMCID: PMC9465030 DOI: 10.3389/fpls.2022.963705] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 08/15/2022] [Indexed: 05/02/2023]
Abstract
Biotrophic plant pathogenic fungi are among the dreadful pathogens that continuously threaten the production of economically important crops. The interaction of biotrophic fungal pathogens with their hosts necessitates the development of unique infection mechanisms and involvement of various virulence-associated components. Biotrophic plant pathogenic fungi have an exceptional lifestyle that supports nutrient acquisition from cells of a living host and are fully dependent on the host for successful completion of their life cycle. The haustorium, a specialized infection structure, is the key organ for biotrophic fungal pathogens. The haustorium is not only essential in the uptake of nutrients without killing the host, but also in the secretion and delivery of effectors into the host cells to manipulate host immune system and defense responses and reprogram the metabolic flow of the host. Although there is a number of unanswered questions in this area yet, results from various studies indicate that the haustorium is the root of biotrophic fungal pathogens. This review provides an overview of current knowledge of the haustorium, its structure, composition, and functions, which includes the most recent haustorial transcriptome studies.
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8
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Martínez-Cruz JM, Polonio Á, Zanni R, Romero D, Gálvez J, Fernández-Ortuño D, Pérez-García A. Chitin Deacetylase, a Novel Target for the Design of Agricultural Fungicides. J Fungi (Basel) 2021; 7:jof7121009. [PMID: 34946992 PMCID: PMC8706340 DOI: 10.3390/jof7121009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 12/23/2022] Open
Abstract
Fungicide resistance is a serious problem for agriculture. This is particularly apparent in the case of powdery mildew fungi. Therefore, there is an urgent need to develop new agrochemicals. Chitin is a well-known elicitor of plant immunity, and fungal pathogens have evolved strategies to overcome its detection. Among these strategies, chitin deacetylase (CDA) is responsible for modifying immunogenic chitooligomers and hydrolysing the acetamido group in the N-acetylglucosamine units to avoid recognition. In this work, we tested the hypothesis that CDA can be an appropriate target for antifungals using the cucurbit powdery mildew pathogen Podosphaera xanthii. According to our hypothesis, RNAi silencing of PxCDA resulted in a dramatic reduction in fungal growth that was linked to a rapid elicitation of chitin-triggered immunity. Similar results were obtained with treatments with carboxylic acids such as EDTA, a well-known CDA inhibitor. The disease-suppression activity of EDTA was not associated with its chelating activity since other chelating agents did not suppress disease. The binding of EDTA to CDA was confirmed by molecular docking studies. Furthermore, EDTA also suppressed green and grey mould-causing pathogens applied to oranges and strawberries, respectively. Our results conclusively show that CDA is a promising target for control of phytopathogenic fungi and that EDTA could be a starting point for fungicide design.
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Affiliation(s)
- Jesús M. Martínez-Cruz
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
| | - Álvaro Polonio
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
| | - Riccardo Zanni
- Molecular Topology and Drug Design Unit, Department of Physical Chemistry, University of Valencia, 46010 Valencia, Spain; (R.Z.); (J.G.)
| | - Diego Romero
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
| | - Jorge Gálvez
- Molecular Topology and Drug Design Unit, Department of Physical Chemistry, University of Valencia, 46010 Valencia, Spain; (R.Z.); (J.G.)
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
- Correspondence:
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain; (J.M.M.-C.); (Á.P.); (D.R.); (A.P.-G.)
- Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29010 Málaga, Spain
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9
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Gene Mining for Conserved, Non-Annotated Proteins of Podosphaera xanthii Identifies Novel Target Candidates for Controlling Powdery Mildews by Spray-Induced Gene Silencing. J Fungi (Basel) 2021; 7:jof7090735. [PMID: 34575773 PMCID: PMC8465782 DOI: 10.3390/jof7090735] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 08/31/2021] [Accepted: 09/06/2021] [Indexed: 11/17/2022] Open
Abstract
The powdery mildew fungus Podosphaera xanthii is one of the most important limiting factors for cucurbit production worldwide. Despite the significant efforts made by breeding and chemical companies, effective control of this pathogen remains elusive to growers. In this work, we examined the suitability of RNAi technology called spray-induced gene silencing (SIGS) for controlling cucurbit powdery mildew. Using leaf disc and cotyledon infiltration assays, we tested the efficacy of dsRNA applications to induce gene silencing in P. xanthii. Furthermore, to identify new target candidate genes, we analyzed sixty conserved and non-annotated proteins (CNAPs) deduced from the P. xanthii transcriptome in silico. Six proteins presumably involved in essential functions, specifically respiration (CNAP8878, CNAP9066, CNAP10905 and CNAP30520), glycosylation (CNAP1048) and efflux transport (CNAP948), were identified. Functional analysis of these CNAP coding genes by dsRNA-induced gene silencing resulted in strong silencing phenotypes with large reductions in fungal growth and disease symptoms. Due to their important contributions to fungal development, the CNAP1048, CNAP10905 and CNAP30520 genes were selected as targets to conduct SIGS assays under plant growth chamber conditions. The spray application of these dsRNAs induced high levels of disease control, supporting that SIGS could be a sustainable approach to combat powdery mildew diseases.
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10
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Mart Nez-Cruz JS, Romero D, Hierrezuelo JS, Thon M, de Vicente A, P Rez-Garc A A. Effectors with chitinase activity (EWCAs), a family of conserved, secreted fungal chitinases that suppress chitin-triggered immunity. THE PLANT CELL 2021; 33:1319-1340. [PMID: 33793825 DOI: 10.1093/plcell/koab011] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 12/11/2020] [Indexed: 05/23/2023]
Abstract
In plants, chitin-triggered immunity is one of the first lines of defense against fungi, but phytopathogenic fungi have developed different strategies to prevent the recognition of chitin. Obligate biotrophs such as powdery mildew fungi suppress the activation of host responses; however, little is known about how these fungi subvert the immunity elicited by chitin. During epiphytic growth, the cucurbit powdery mildew fungus Podosphaera xanthii expresses a family of candidate effector genes comprising nine members with an unknown function. In this work, we examine the role of these candidates in the infection of melon (Cucumis melo L.) plants, using gene expression analysis, RNAi silencing assays, protein modeling and protein-ligand predictions, enzymatic assays, and protein localization studies. Our results show that these proteins are chitinases that are released at pathogen penetration sites to break down immunogenic chitin oligomers, thus preventing the activation of chitin-triggered immunity. In addition, these effectors, designated effectors with chitinase activity (EWCAs), are widely distributed in pathogenic fungi. Our findings reveal a mechanism by which fungi suppress plant immunity and reinforce the idea that preventing the perception of chitin by the host is mandatory for survival and development of fungi in plant environments.
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Affiliation(s)
- Jes S Mart Nez-Cruz
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
| | - Diego Romero
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
| | - Jes S Hierrezuelo
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
| | - Michael Thon
- Instituto Hispano-Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Salamanca 37185, Spain
| | - Antonio de Vicente
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
| | - Alejandro P Rez-Garc A
- Departamento de Microbiolog�a, Facultad de Ciencias, Universidad de M�laga, M�laga 29071, Spain
- Instituto de Hortofruticultura Subtropical y Mediterr�nea "La Mayora", Universidad de M�laga, Consejo Superior de Investigaciones Cient�ficas (IHSM‒UMA‒CSIC), M�laga 29071, Spain
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11
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Polonio Á, Fernández‐Ortuño D, de Vicente A, Pérez‐García A. A haustorial-expressed lytic polysaccharide monooxygenase from the cucurbit powdery mildew pathogen Podosphaera xanthii contributes to the suppression of chitin-triggered immunity. MOLECULAR PLANT PATHOLOGY 2021; 22:580-601. [PMID: 33742545 PMCID: PMC8035642 DOI: 10.1111/mpp.13045] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/04/2021] [Accepted: 02/04/2021] [Indexed: 05/06/2023]
Abstract
Podosphaera xanthii is the main causal agent of cucurbit powdery mildew and a limiting factor of crop productivity. The lifestyle of this fungus is determined by the development of specialized parasitic structures inside epidermal cells, termed haustoria, that are responsible for the acquisition of nutrients and the release of effectors. A typical function of fungal effectors is the manipulation of host immunity, for example the suppression of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). Chitin is a major component of fungal cell walls, and chitin oligosaccharides are well-known PAMP elicitors. In this work, we examined the role of PHEC27213, the most highly expressed, haustorium-specific effector candidate of P. xanthii. According to different computational predictions, the protein folding of PHEC27213 was similar to that of lytic polysaccharide monooxygenases (LPMOs) and included a conserved histidine brace; however, PHEC27213 had low sequence similarity with LPMO proteins and displayed a putative chitin-binding domain that was different from the canonical carbohydrate-binding module. Binding and enzymatic assays demonstrated that PHEC27213 was able to bind and catalyse colloidal chitin, as well as chitooligosaccharides, acting as an LPMO. Furthermore, RNAi silencing experiments showed the potential of this protein to prevent the activation of chitin-triggered immunity. Moreover, proteins with similar features were found in other haustorium-forming fungal pathogens. Our results suggest that this protein is a new fungal LPMO that catalyses chitooligosaccharides, thus contributing to the suppression of plant immunity during haustorium development. To our knowledge, this is the first mechanism identified in the haustorium to suppress chitin signalling.
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Affiliation(s)
- Álvaro Polonio
- Departamento de MicrobiologíaFacultad de CienciasUniversidad de MálagaMálagaSpain
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’Universidad de MálagaConsejo Superior de Investigaciones Científicas (IHSM−UMA−CSIC)MálagaSpain
| | - Dolores Fernández‐Ortuño
- Departamento de MicrobiologíaFacultad de CienciasUniversidad de MálagaMálagaSpain
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’Universidad de MálagaConsejo Superior de Investigaciones Científicas (IHSM−UMA−CSIC)MálagaSpain
| | - Antonio de Vicente
- Departamento de MicrobiologíaFacultad de CienciasUniversidad de MálagaMálagaSpain
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’Universidad de MálagaConsejo Superior de Investigaciones Científicas (IHSM−UMA−CSIC)MálagaSpain
| | - Alejandro Pérez‐García
- Departamento de MicrobiologíaFacultad de CienciasUniversidad de MálagaMálagaSpain
- Instituto de Hortofruticultura Subtropical y Mediterránea ‘La Mayora’Universidad de MálagaConsejo Superior de Investigaciones Científicas (IHSM−UMA−CSIC)MálagaSpain
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12
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Kim S, Subramaniyam S, Jung M, Oh EA, Kim TH, Kim JG. Genome Resource of Podosphaera xanthii, the Host-Specific Fungal Pathogen That Causes Cucurbit Powdery Mildew. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:457-459. [PMID: 33264046 DOI: 10.1094/mpmi-11-20-0307-a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Approximately 33 types of commonly consumed fruits and vegetables are members of the family Cucurbitaceae, making it an important crop family worldwide. However, pathogen resistance to pesticides and fungicides has become a growing problem in cultivation practices. The identification of the effector proteins in each unique fungus-host pair would help toward the development of strategies for preventing the infection of important crops. In this study, we characterized the genome of Podosphaera xanthii, the fungal pathogen that causes powdery mildew disease in cucurbitaceous plants. A first-draft genome of 209.08 MB was assembled and compared with those of 25 other fungal pathogens, particularly for identifying candidate secreted effector proteins. This draft genome can serve as a valuable resource for future genomic and proteomic studies of P. xanthii and its host-specific pathogenesis.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Seunghwan Kim
- Genomics Division, National Institute of Agricultural Science, RDA, 370, Nongsaengmyeong-ro, Jeonju-si 54874, Republic of Korea
| | | | - Myunghee Jung
- Research and Development Center, Insilicogen Inc., Yongin-si 16954, Gyeonggi-do, Republic of Korea
| | - Eun-A Oh
- Genomics Division, National Institute of Agricultural Science, RDA, 370, Nongsaengmyeong-ro, Jeonju-si 54874, Republic of Korea
| | - Tae Ho Kim
- Genomics Division, National Institute of Agricultural Science, RDA, 370, Nongsaengmyeong-ro, Jeonju-si 54874, Republic of Korea
| | - Jeong-Gu Kim
- Genomics Division, National Institute of Agricultural Science, RDA, 370, Nongsaengmyeong-ro, Jeonju-si 54874, Republic of Korea
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13
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Polonio Á, Díaz-Martínez L, Fernández-Ortuño D, de Vicente A, Romero D, López-Ruiz FJ, Pérez-García A. A Hybrid Genome Assembly Resource for Podosphaera xanthii, the Main Causal Agent of Powdery Mildew Disease in Cucurbits. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:319-324. [PMID: 33141618 DOI: 10.1094/mpmi-08-20-0237-a] [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] [Indexed: 05/23/2023]
Abstract
Podosphaera xanthii is the main causal agent of powdery mildew in cucurbits and, arguably, the most important fungal pathogen of cucurbit crops. Here, we present the first reference genome assembly for P. xanthii. We performed a hybrid genome assembly, using reads from Illumina NextSeq550 and PacBio Sequel S3. The short and long reads were assembled into 1,727 scaffolds with an N50 size of 163,173 bp, resulting in a 142-Mb genome size. The combination of homology-based and ab initio predictions allowed the prediction of 14,911 complete genes. Repetitive sequences comprised 76.2% of the genome. Our P. xanthii genome assembly improves considerably the molecular resources for research on P. xanthii-cucurbit interactions and provides new opportunities for further genomics, transcriptomics, and evolutionary studies in powdery mildew fungi.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Álvaro Polonio
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Luis Díaz-Martínez
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Dolores Fernández-Ortuño
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Antonio de Vicente
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Diego Romero
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
| | - Francisco J López-Ruiz
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia
| | - Alejandro Pérez-García
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
- Instituto de Hortofruticultura Subtropical y Mediterránea 'La Mayora', Universidad de Málaga, Consejo Superior de Investigaciones Científicas (IHSM-UMA-CSIC), 29071 Málaga, Spain
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14
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Jaswal R, Kiran K, Rajarammohan S, Dubey H, Singh PK, Sharma Y, Deshmukh R, Sonah H, Gupta N, Sharma TR. Effector Biology of Biotrophic Plant Fungal Pathogens: Current Advances and Future Prospects. Microbiol Res 2020; 241:126567. [PMID: 33080488 DOI: 10.1016/j.micres.2020.126567] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 07/21/2020] [Accepted: 07/25/2020] [Indexed: 12/13/2022]
Abstract
The interaction of fungal pathogens with their host requires a novel invading mechanism and the presence of various virulence-associated components responsible for promoting the infection. The small secretory proteins, explicitly known as effector proteins, are one of the prime mechanisms of host manipulation utilized by the pathogen to disarm the host. Several effector proteins are known to translocate from fungus to the plant cell for host manipulation. Many fungal effectors have been identified using genomic, transcriptomic, and bioinformatics approaches. Most of the effector proteins are devoid of any conserved signatures, and their prediction based on sequence homology is very challenging, therefore by combining the sequence consensus based upon machine learning features, multiple tools have also been developed for predicting apoplastic and cytoplasmic effectors. Various post-genomics approaches like transcriptomics of virulent isolates have also been utilized for identifying active consortia of effectors. Significant progress has been made in understanding biotrophic effectors; however, most of it is underway due to their complex interaction with host and complicated recognition and signaling networks. This review discusses advances, and challenges in effector identification and highlighted various features of the potential effector proteins and approaches for understanding their genetics and strategies for regulation.
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Affiliation(s)
- Rajdeep Jaswal
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India; Department of Microbiology, Panjab University, Chandigarh, Punjab, 160014, India
| | - Kanti Kiran
- ICAR-National Institute for Plant Biotechnology, Pusa Campus New Delhi, 110012, India
| | | | - Himanshu Dubey
- ICAR-National Institute for Plant Biotechnology, Pusa Campus New Delhi, 110012, India
| | - Pankaj Kumar Singh
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Yogesh Sharma
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Rupesh Deshmukh
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Humira Sonah
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India
| | - Naveen Gupta
- Department of Microbiology, Panjab University, Chandigarh, Punjab, 160014, India.
| | - T R Sharma
- National Agri-Food Biotechnology Institute (NABI), Mohali, Punjab, 140306, India.
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