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Afridi MS, Kumar A, Javed MA, Dubey A, de Medeiros FHV, Santoyo G. Harnessing root exudates for plant microbiome engineering and stress resistance in plants. Microbiol Res 2024; 279:127564. [PMID: 38071833 DOI: 10.1016/j.micres.2023.127564] [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: 08/28/2023] [Revised: 11/02/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023]
Abstract
A wide range of abiotic and biotic stresses adversely affect plant's growth and production. Under stress, one of the main responses of plants is the modulation of exudates excreted in the rhizosphere, which consequently leads to alterations in the resident microbiota. Thus, the exudates discharged into the rhizospheric environment play a preponderant role in the association and formation of plant-microbe interactions. In this review, we aimed to provide a synthesis of the latest and most pertinent literature on the diverse biochemical and structural compositions of plant root exudates. Also, this work investigates into their multifaceted role in microbial nutrition and intricate signaling processes within the rhizosphere, which includes quorum-sensing molecules. Specifically, it explores the contributions of low molecular weight compounds, such as carbohydrates, phenolics, organic acids, amino acids, and secondary metabolites, as well as the significance of high molecular weight compounds, including proteins and polysaccharides. It also discusses the state-of-the-art omics strategies that unveil the vital role of root exudates in plant-microbiome interactions, including defense against pathogens like nematodes and fungi. We propose multiple challenges and perspectives, including exploiting plant root exudates for host-mediated microbiome engineering. In this discourse, root exudates and their derived interactions with the rhizospheric microbiota should receive greater attention due to their positive influence on plant health and stress mitigation.
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Affiliation(s)
- Muhammad Siddique Afridi
- Department of Plant Pathology, Federal University of Lavras, CP3037, 37200-900 Lavras, MG, Brazil.
| | - Ashwani Kumar
- Metagenomics and Secretomics Research Laboratory, Department of Botany, Dr. Harisingh Gour University (A Central University), Sagar 470003, MP, India
| | - Muhammad Ammar Javed
- Institute of Industrial Biotechnology, Government College University, Lahore 54000, Pakistan
| | - Anamika Dubey
- Metagenomics and Secretomics Research Laboratory, Department of Botany, Dr. Harisingh Gour University (A Central University), Sagar 470003, MP, India
| | | | - Gustavo Santoyo
- Instituto de Investigaciones Químico Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, 58030 Morelia, Mexico.
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de Souza Gouveia A, Monteiro TSA, Balbino HM, de Magalhães FC, Ramos MES, Silva de Moura VA, Luiz PHD, de Almeida Oliveira MG, de Freitas LG, de Oliveira Ramos HJ. Inoculation of Pochonia chlamydosporia triggers a defense response in tomato roots, affecting parasitism by Meloidogyne javanica. Microbiol Res 2022; 266:127242. [DOI: 10.1016/j.micres.2022.127242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 10/20/2022] [Accepted: 10/23/2022] [Indexed: 11/07/2022]
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3
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Zhao Y, Zhou Q, Zou C, Zhang K, Huang X. Repulsive response of Meloidogyne incognita induced by biocontrol bacteria and its effect on interspecific interactions. Front Microbiol 2022; 13:994941. [PMID: 36187996 PMCID: PMC9520663 DOI: 10.3389/fmicb.2022.994941] [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: 07/15/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
The aversive behavior of Caenorhabditis elegans is an important strategy that increases their survival under pathogen infection, and the molecular mechanisms underlying this behavior have been described. However, whether this defensive response occurs in plant-parasitic nematodes (PPNs), which have quite different life cycles and genomic sequences from the model nematode, against biocontrol microbes and affects interspecific interactions in ecological environments remains unclear. Here, we showed that Meloidogyne incognita, one of the most common PPNs, engaged in lawn-leaving behavior in response to biocontrol bacteria such as Bacillus nematocida B16 and B. thuringiensis Bt79. Genomic analysis revealed that the key genes responsible for the aversive behavior of C. elegans, such as serotonin-and TGF-β-related genes in canonical signaling pathways, were homologous to those of M. incognita, and the similarity between these sequences ranged from 30% to 67%. Knockdown of the homologous genes impaired avoidance of M. incognita to varying degrees. Calcium ion imaging showed that the repulsive response requires the involvement of the multiple amphid neurons of M. incognita. In situ hybridization specifically localized Mi-tph-1 of the serotonin pathway to ADF/NSM neurons and Mi-dbl-1 of the TGF-β pathway to AVA neurons. Our data suggested that the repulsive response induced by different biocontrol bacteria strongly suppresses the invasion of tomato host plants by M. incognita. Overall, our study is the first to clarify the pathogen-induced repulsive response of M. incognita and elucidate its underlying molecular mechanisms. Our findings provide new insights into interspecific interactions among biocontrol bacteria, PPNs, and host plants.
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Affiliation(s)
- Yanli Zhao
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and College of Life Science, Yunnan University, Kunming, China
- Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming, China
| | - Qinying Zhou
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and College of Life Science, Yunnan University, Kunming, China
| | - Chenggang Zou
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and College of Life Science, Yunnan University, Kunming, China
| | - Keqin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and College of Life Science, Yunnan University, Kunming, China
| | - Xiaowei Huang
- State Key Laboratory for Conservation and Utilization of Bio-Resources, and College of Life Science, Yunnan University, Kunming, China
- School of Medicine, Yunnan University, Kunming, China
- *Correspondence: Xiaowei Huang,
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Rutter WB, Franco J, Gleason C. Rooting Out the Mechanisms of Root-Knot Nematode-Plant Interactions. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:43-76. [PMID: 35316614 DOI: 10.1146/annurev-phyto-021621-120943] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Root-knot nematodes (RKNs; Meloidogyne spp.) engage in complex parasitic interactions with many different host plants around the world, initiating elaborate feeding sites and disrupting host root architecture. Although RKNs have been the focus of research for many decades, new molecular tools have provided useful insights into the biological mechanisms these pests use to infect and manipulate their hosts. From identifying host defense mechanisms underlying resistance to RKNs to characterizing nematode effectors that alter host cellular functions, the past decade of research has significantly expanded our understanding of RKN-plant interactions, and the increasing number of quality parasite and host genomes promises to enhance future research efforts into RKNs. In this review, we have highlighted recent discoveries, summarized the current understanding within the field, and provided links to new and useful resources for researchers. Our goal is to offer insights and tools to support the study of molecular RKN-plant interactions.
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Affiliation(s)
- William B Rutter
- US Vegetable Laboratory, USDA Agricultural Research Service, Charleston, South Carolina, USA
| | - Jessica Franco
- Department of Plant Pathology, Washington State University, Pullman, Washington, USA;
| | - Cynthia Gleason
- Department of Plant Pathology, Washington State University, Pullman, Washington, USA;
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Elkobrosy DH, Aseel DG, Hafez EE, El-Saedy MA, Al-Huqail AA, Ali HM, Jebril J, Shama S, Abdelsalam NR, Elnahal AS. Quantitative detection of induced systemic resistance genes of potato roots upon ethylene treatment and cyst nematode, Globodera rostochiensis, infection during plant–nematode interactions. Saudi J Biol Sci 2022; 29:3617-3625. [PMID: 35844398 PMCID: PMC9280246 DOI: 10.1016/j.sjbs.2022.02.045] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/13/2022] [Accepted: 02/27/2022] [Indexed: 11/02/2022] Open
Abstract
Potato cyst nematodes caused by Globodera rostochiensis, are quarantine-restricted pests causing significant yield losses to potato growers. The phytohormone ethylene play significant roles in various plant-pathogen interactions, however, the molecular knowledge of how ethylene influences potato–nematode interaction is still lacking. Precise detection of potato-induced genes is essential for recognizing plant-induced systemic resistance (ISR). Candidate genes or PR- proteins with putative functions in modulating the response to potato cyst nematode stress were selected and functionally characterized. Using real-time polymerase chain reaction (RT-PCR), we measured the quantified expression of four pathogenesis-related (PR) genes, PR2, PR3, peroxidase, and polyphenol oxidase. The activation of these genes is intermediate during the ISR signaling in the root tissues. Using different ethylene concentrations could detect and induce defense genes in infected potato roots compared to the control treatment. The observed differences in the gene expression of treated infected plants are because of different concentrations of ethylene treatment and pathogenicity. Besides, the overexpressed or suppressed of defense- related genes during developmental stages and pathogen infection. We concluded that ethylene treatments positively affected potato defensive genes expression levels against cyst nematode infection. The results emphasize the necessity of studying molecular signaling pathways controlling biotic stress responses. Understanding such mechanisms will be critical for the development of broad-spectrum and stress-tolerant crops in the future.
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Mwamba S, Kihika-Opanda R, Murungi LK, Losenge T, Beck JJ, Torto B. Identification of Repellents from Four Non-Host Asteraceae Plants for the Root Knot Nematode, Meloidogyne incognita. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:15145-15156. [PMID: 34882384 DOI: 10.1021/acs.jafc.1c06500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Olfactory cues guide plant parasitic nematodes (PPNs) to their host plants. We tested the hypothesis that non-host plant root volatiles repel PPNs. To achieve this, we compared the olfactory responses of infective juveniles (J2s) of the PPN Meloidogyne incognita to four non-host Asteraceae plants, namely, black-jack (Bidens pilosa), pyrethrum (Chrysanthemum cinerariifolium), marigold (Tagetes minuta), and sweet wormwood (Artemisia annua), traditionally used in sub-Saharan Africa for the management of PPNs. Chemical analysis by coupled gas chromatography-mass spectrometry (GC/MS) combined with random forest analysis, followed by behavioral assays, identified the repellents in the root volatiles of B. pilosa, T. minuta, and A. annua as (E)-β-farnesene and 1,8-cineole, whereas camphor was attractive. In contrast, random forest analysis predicted repellents for C. cinerariifolium and A. annua as β-patchoulene and isopropyl hexadecanoate. Our results suggested that terpenoids generally account for the repellency of non-host Asteraceae plants used in PPN management.
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Affiliation(s)
- Sydney Mwamba
- Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772, Nairobi 00100, Kenya
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000, Nairobi 00200, Kenya
- Ministry of Agriculture, Seed Control and Certification Institute, P.O. Box 350199, Chilanga 00100, Zambia
| | - Ruth Kihika-Opanda
- Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772, Nairobi 00100, Kenya
| | - Lucy K Murungi
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000, Nairobi 00200, Kenya
| | - Turoop Losenge
- Department of Horticulture, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000, Nairobi 00200, Kenya
| | - John J Beck
- Chemistry Research Unit, Center for Medical, Agricultural and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture, 1700 SW 23rd Drive, Gainesville, Florida 32608, United States
| | - Baldwyn Torto
- Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772, Nairobi 00100, Kenya
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Sikder MM, Vestergård M, Kyndt T, Kudjordjie EN, Nicolaisen M. Phytohormones selectively affect plant parasitic nematodes associated with Arabidopsis roots. THE NEW PHYTOLOGIST 2021; 232:1272-1285. [PMID: 34115415 DOI: 10.1111/nph.17549] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 06/07/2021] [Indexed: 06/12/2023]
Abstract
Phytohormones may affect plant-nematode interactions directly as chemo-attractants or -repellents, or indirectly through the root-associated microbiome or through host defense mechanisms. However, the exact roles of phytohormones in these complex plant-soil-nematode interactions are not well understood. We used Arabidopsis thaliana mutants impaired in phytohormone synthesis or sensitivity to elucidate their role in root-nematode interactions. As root-associated microorganisms may modulate these interactions, we explored correlations between the relative abundances of root-associated nematodes, and bacteria and fungi using amplicon sequencing. We found distinct shifts in relative abundances of a range of nematode taxa in the A. thaliana phytohormone mutants. The root knot nematode Meloidogyne hapla, a sedentary endoparasitic species that is in intimate contact with the host, was highly enriched in JA-, SA- and SL-impaired lines, and in an ET-insensitive line. Positive or negative correlations between specific microbial and nematode taxa were observed, but, as the inference of causal relationships between microbiome responses and effects on nematode communities is premature, this should be studied in detail in future studies. In conclusion, genetic derailment of hormonal balances generally rendered plants vulnerable to endoparasitic nematode attack. Furthermore, preliminary data suggest that this effect may be partially modulated by the associated microbiome.
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Affiliation(s)
- Md Maniruzzaman Sikder
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Slagelse, 4200, Denmark
- Department of Botany, Faculty of Biological Sciences, Jahangirnagar University, Savar, Dhaka, 1342, Bangladesh
| | - Mette Vestergård
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Slagelse, 4200, Denmark
| | - Tina Kyndt
- Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University, Gent, 9000, Belgium
| | - Enoch Narh Kudjordjie
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Slagelse, 4200, Denmark
| | - Mogens Nicolaisen
- Department of Agroecology, Faculty of Technical Sciences, Aarhus University, Slagelse, 4200, Denmark
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Li X, Sun Y, Yang Y, Yang X, Xue W, Wu M, Chen P, Weng Y, Chen S. Transcriptomic and Histological Analysis of the Response of Susceptible and Resistant Cucumber to Meloidogyne incognita Infection Revealing Complex Resistance via Multiple Signaling Pathways. FRONTIERS IN PLANT SCIENCE 2021; 12:675429. [PMID: 34194451 PMCID: PMC8236822 DOI: 10.3389/fpls.2021.675429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 05/18/2021] [Indexed: 05/24/2023]
Abstract
The root-knot nematode (RKN), Meloidogyne incognita, is a devastating pathogen for cucumber (Cucumis sativus L.) specially in production under protected environments or continuous cropping. High level RKN resistance has been identified in African horned melon Cucumis metuliferus (CM). However, the resistance mechanism remains unclear. In this study, the comparative analysis on phenotypic and transcriptomic responses in the susceptible cucumber inbred line Q24 and the resistant CM, after M. incognita infection, was performed. The results showed that, in comparison with Q24, the CM was able to significantly reduce penetration numbers of second stage juveniles (J2), slow its development in the roots resulting in fewer galls and smaller giant cells suggesting the presence of host resistance in CM. Comparative transcriptomes analysis of Q24 and CM before and after M. incognita infection was conducted and differentially expressed genes (DEGs) associated with host resistance were identified in CM. Enrichment analyses revealed most enriched DEGs in Ca2+ signaling, salicylic acid (SA)/jamonate signaling (JA), as well as auxin (IAA) signaling pathways. In particular, in CM, DEGs in the Ca2+ signaling pathway such as those for the calmodulin and calcium-binding proteins were upregulated at the early stage of M. incognita infection; genes for SA/JA synthesis/signal transduction were markedly activated, whereas the IAA signaling pathway genes were inhibited upon infection suggesting the importance of SA/JA signaling pathways in mediating M. incognita resistance in CM. A model was established to explain the different molecular mechanisms on M. incognita susceptibility in cucumber and resistance to M. incognita infection in CM.
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Affiliation(s)
- Xvzhen Li
- College of Horticulture, Northwest A&F University/Shaanxi Engineering Research Center for Vegetables, Yangling, China
| | - Yinhui Sun
- College of Horticulture, Northwest A&F University/Shaanxi Engineering Research Center for Vegetables, Yangling, China
| | - Yuting Yang
- College of Horticulture, Northwest A&F University/Shaanxi Engineering Research Center for Vegetables, Yangling, China
| | - Xiaopei Yang
- College of Horticulture, Northwest A&F University/Shaanxi Engineering Research Center for Vegetables, Yangling, China
| | - Wanyu Xue
- College of Horticulture, Northwest A&F University/Shaanxi Engineering Research Center for Vegetables, Yangling, China
| | - Meiqian Wu
- College of Horticulture, Northwest A&F University/Shaanxi Engineering Research Center for Vegetables, Yangling, China
| | - Panpan Chen
- College of Horticulture, Northwest A&F University/Shaanxi Engineering Research Center for Vegetables, Yangling, China
| | - Yiqun Weng
- United States Department of Agriculture, Agriculture Research Service, Vegetable Crops Research Unit, Horticulture Department, University of Wisconsin, Madison, WI, United States
| | - Shuxia Chen
- College of Horticulture, Northwest A&F University/Shaanxi Engineering Research Center for Vegetables, Yangling, China
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Fujimoto T, Abe H, Mizukubo T, Seo S. Phytol, a Constituent of Chlorophyll, Induces Root-Knot Nematode Resistance in Arabidopsis via the Ethylene Signaling Pathway. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:279-285. [PMID: 33166202 DOI: 10.1094/mpmi-07-20-0186-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Root-knot nematodes (RKNs; Meloidogyne spp.) parasitize the roots or stems of a wide range of plant species, resulting in severe damage to the parasitized plant. The phytohormone ethylene (ET) plays an important role in signal transduction pathways leading to resistance against RKNs. However, little is currently known about the induction mechanisms of ET-dependent RKN resistance. Inoculation of Arabidopsis thaliana roots with RKNs decreased chlorophyll contents in aerial parts of the plant. We observed accumulation of phytol, a constituent of chlorophyll and a precursor of tocopherols, in RKN-parasitized roots. Application of sclareol, a diterpene that has been shown to induce ET-dependent RKN resistance, to the roots of Arabidopsis plants increased phytol contents in roots accompanied by a decrease in chlorophyll in aerial parts. Exogenously applied phytol inhibited RKN penetration of roots without exhibiting nematicidal activity. This phytol-induced inhibition of RKN penetration was attenuated in the ET-insensitive Arabidopsis mutant ein2-1. Exogenously applied phytol enhanced the production of α-tocopherol and expression of VTE5, a gene involved in tocopherol production, in Arabidopsis roots. α-Tocopherol exerted induction of RKN resistance similar to that of phytol and showed increased accumulation in roots inoculated with RKNs. Furthermore, the Arabidopsis vte5 mutant displayed no inhibition of RKN penetration in response to phytol. These results suggest that exogenously applied phytol induces EIN2-dependent RKN resistance, possibly via tocopherol production.[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)
- Taketo Fujimoto
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8602, Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo
| | - Hiroshi Abe
- Experimental Plant Division, RIKEN BioResource Research Center, Tsukuba, Ibaraki, 305-0074, Japan
| | - Takayuki Mizukubo
- National Agricultural Research Center, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, 305-8666, Japan
| | - Shigemi Seo
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8602, Japan
- Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, 305-8602, Japan
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Gupta S, Kumble ALK, Dey K, Bessière JM, Borges RM. The Scent of Life: Phoretic Nematodes Use Wasp Volatiles and Carbon Dioxide to Choose Functional Vehicles for Dispersal. J Chem Ecol 2021; 47:139-152. [PMID: 33475939 DOI: 10.1007/s10886-021-01242-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/18/2020] [Accepted: 01/04/2021] [Indexed: 10/22/2022]
Abstract
Hitchhikers (phoretic organisms) need vehicles to disperse out of unsuitable habitats. Therefore, finding vehicles with the right functional attributes is essential for phoretic organisms. To locate these vehicles, phoretic organisms employ cues within modalities, ranging from visual to chemical senses. However, how hitchhikers discriminate between individual vehicles has rarely been investigated. Using a phoretic nematode community associated with an obligate fig-fig wasp pollination mutualism, we had earlier established that hitchhiking nematodes make decisions based on vehicle species identity and number of conspecific hitchhikers already present on the vehicle. Here we investigate if hitchhikers can differentiate between physiological states of vehicles. We asked whether phoretic nematodes choose between live or dead vehicles present in a chemically crowded environment and we investigated the basis for any discrimination. We conducted two-choice and single-choice behavioral assays using single nematodes and found that plant- and animal-parasitic nematodes preferred live over dead vehicles and used volatiles as a sensory cue to make this decision. However, in single-choice assays, animal-parasitic nematodes were also attracted towards naturally dead or freeze-killed wasps. The volatile profile of the wasps was dominated by terpenes and spiroketals. We examined the volatile blend emitted by the different wasp physiological states and determined a set of volatiles that the phoretic nematodes might use to discriminate between these states which is likely coupled with respired CO2. We determined that CO2 levels emitted by single wasps are sufficient to attract nematodes, demonstrating the high sensitivity of nematodes to this metabolic product.
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Affiliation(s)
- Satyajeet Gupta
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560012, India
| | - Anusha L K Kumble
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560012, India
| | - Kaveri Dey
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560012, India
| | | | - Renee M Borges
- Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560012, India.
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Fröschel C, Komorek J, Attard A, Marsell A, Lopez-Arboleda WA, Le Berre J, Wolf E, Geldner N, Waller F, Korte A, Dröge-Laser W. Plant roots employ cell-layer-specific programs to respond to pathogenic and beneficial microbes. Cell Host Microbe 2020; 29:299-310.e7. [PMID: 33378688 DOI: 10.1016/j.chom.2020.11.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 10/02/2020] [Accepted: 11/25/2020] [Indexed: 12/12/2022]
Abstract
Plant roots are built of concentric cell layers that are thought to respond to microbial infections by employing specific, genetically defined programs. Yet, the functional impact of this radial organization remains elusive, particularly due to the lack of genome-wide techniques for monitoring expression at a cell-layer resolution. Here, cell-type-specific expression of tagged ribosomes enabled the isolation of ribosome-bound mRNA to obtain cell-layer translatomes (TRAP-seq, translating ribosome affinity purification and RNA sequencing). After inoculation with the vascular pathogen Verticillium longisporum, pathogenic oomycete Phytophthora parasitica, or mutualistic endophyte Serendipita indica, root cell-layer responses reflected the fundamentally different colonization strategies of these microbes. Notably, V. longisporum specifically suppressed the endodermal barrier, which restricts fungal progression, allowing microbial access to the root central cylinder. Moreover, localized biosynthesis of antimicrobial compounds and ethylene differed in response to pathogens and mutualists. These examples highlight the power of this resource to gain insights into root-microbe interactions and to develop strategies in crop improvement.
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Affiliation(s)
- Christian Fröschel
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute, Julius-Maximilians-Universität Würzburg, Julius-von-Sachs Platz 2, 97082 Würzburg, Germany
| | - Jaqueline Komorek
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute, Julius-Maximilians-Universität Würzburg, Julius-von-Sachs Platz 2, 97082 Würzburg, Germany
| | - Agnès Attard
- INRAE, CNRS, ISA, Université Côte d'Azur, 400 Route des Chappes, 06903 Sophia Antipolis, France
| | - Alexander Marsell
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute, Julius-Maximilians-Universität Würzburg, Julius-von-Sachs Platz 2, 97082 Würzburg, Germany
| | - William A Lopez-Arboleda
- Center for Computational and Theoretical Biology, CCTB, Julius-Maximilians-Universität Würzburg, Klara-Oppenheimer-Weg 32, 97074 Würzburg, Germany
| | - Joëlle Le Berre
- INRAE, CNRS, ISA, Université Côte d'Azur, 400 Route des Chappes, 06903 Sophia Antipolis, France
| | - Elmar Wolf
- Department of Biochemistry and Molecular Biology, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Niko Geldner
- Department of Plant Molecular Biology, Université de Lausanne, Biophore Building, Unil-Sorge, 1015 Lausanne, Switzerland
| | - Frank Waller
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute, Julius-Maximilians-Universität Würzburg, Julius-von-Sachs Platz 2, 97082 Würzburg, Germany
| | - Arthur Korte
- Center for Computational and Theoretical Biology, CCTB, Julius-Maximilians-Universität Würzburg, Klara-Oppenheimer-Weg 32, 97074 Würzburg, Germany
| | - Wolfgang Dröge-Laser
- Department of Pharmaceutical Biology, Julius-von-Sachs-Institute, Julius-Maximilians-Universität Würzburg, Julius-von-Sachs Platz 2, 97082 Würzburg, Germany.
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Ghaemi R, Pourjam E, Safaie N, Verstraeten B, Mahmoudi SB, Mehrabi R, De Meyer T, Kyndt T. Molecular insights into the compatible and incompatible interactions between sugar beet and the beet cyst nematode. BMC PLANT BIOLOGY 2020; 20:483. [PMID: 33092522 PMCID: PMC7583174 DOI: 10.1186/s12870-020-02706-8] [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] [Received: 11/07/2019] [Accepted: 10/18/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND Sugar beet (Beta vulgaris subsp. vulgaris) is an economically important crop that provides nearly one third of the global sugar production. The beet cyst nematode (BCN), Heterodera schachtii, causes major yield losses in sugar beet and other crops worldwide. The most effective and economic approach to control this nematode is growing tolerant or resistant cultivars. To identify candidate genes involved in susceptibility and resistance, the transcriptome of sugar beet and BCN in compatible and incompatible interactions at two time points was studied using mRNA-seq. RESULTS In the susceptible cultivar, most defense-related genes were induced at 4 dai while suppressed at 10 dai but in the resistant cultivar Nemakill, induction of genes involved in the plant defense response was observed at both time points. In the compatible interaction, alterations in phytohormone-related genes were detected. The effect of exogenous application of Methyl Jasmonate and ET-generator ethephon on susceptible plants was therefore investigated and the results revealed significant reduction in plant susceptibility. Genes putatively involved in the resistance of Nemakill were identified, such as genes involved in phenylpropanoid pathway and genes encoding CYSTM domain-containing proteins, F-box proteins, chitinase, galactono-1,4-lactone dehydrogenase and CASP-like protein. Also, the transcriptome of the BCN was analyzed in infected root samples and several novel potential nematode effector genes were found. CONCLUSIONS Our data provides detailed insights into the plant and nematode transcriptional changes occurring during compatible and incompatible interactions between sugar beet and BCN. Many important genes playing potential roles in susceptibility or resistance of sugar beet against BCN, as well as some BCN effectors with a potential role as avr proteins were identified. In addition, our findings indicate the effective role of jasmonate and ethylene in enhancing sugar beet defense response against BCN. This research provides new molecular insights into the plant-nematode interactions that can be used to design novel management strategies against BCN.
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Affiliation(s)
- Razieh Ghaemi
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Ebrahim Pourjam
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
| | - Naser Safaie
- Department of Plant Pathology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
| | - Bruno Verstraeten
- Department of Biotechnology, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium
| | - Seyed Bagher Mahmoudi
- Sugar Beet Seed Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Rahim Mehrabi
- Department of Biotechnology, College of Agriculture, Isfahan University of Technology, P.O. Box 8415683111, Isfahan, Iran
| | - Tim De Meyer
- Department of Data Analysis and Mathematical Modelling, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium
| | - Tina Kyndt
- Department of Biotechnology, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
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13
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Kihika R, Tchouassi DP, Ng'ang'a MM, Hall DR, Beck JJ, Torto B. Compounds Associated with Infection by the Root-Knot Nematode, Meloidogyne javanica, Influence the Ability of Infective Juveniles to Recognize Host Plants. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:9100-9109. [PMID: 32786872 DOI: 10.1021/acs.jafc.0c03386] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Plant root chemistry is altered by the parasitism of plant-parasitic nematodes (PPN). Here, we investigated the influence of the infective stage juveniles (J2) of Meloidogyne javanica in inducing tomato (Solanum lycopersicum) root volatiles and chemotactic effect on conspecifics. In olfactometer assays, J2 avoided the roots of 2-day infected plants but preferred 7-day-infected tomato compared to healthy plants. Chemical analysis showed a 2-7-fold increase in the amounts of monoterpenes emitted from tomato roots infected with M. javanica relative to healthy roots. In further bioassays, the monoterpenes β-pinene, (+)-(2)-carene, α-phellandrene, and β-phellandrene differentially attracted (51-87%) J2 relative to control. Concurrent reduction and increase in the levels of methyl salicylate and (Z)-methyl dihydrojasmonate, respectively, in the root volatiles reduced J2 responses. These results demonstrate that the host plant can alter its root volatile composition to inhibit PPN attack. The observed plant-produced inhibition of J2 warrants further investigation as a potential management tool for growers.
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Affiliation(s)
- Ruth Kihika
- Behavioral and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
- Department of Chemistry, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya
| | - David P Tchouassi
- Behavioral and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
| | - Margaret M Ng'ang'a
- Department of Chemistry, Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya
| | - David R Hall
- Natural Resources Institute, University of Greenwich-Medway Campus, Central Avenue, Chatham Maritime, Kent ME4 4TB, United Kingdom
| | - John J Beck
- Chemistry Research Unit, Center for Medical, Agricultural, and Veterinary Entomology, Agricultural Research Service, U.S. Department of Agriculture, 1700 SW 23rd Drive, Gainesville, Florida 32608, United States
| | - Baldwyn Torto
- Behavioral and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology (icipe), P.O. Box 30772-00100, Nairobi, Kenya
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14
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Dihydroxyacetone of wheat root exudates serves as an attractant for Heterodera avenae. PLoS One 2020; 15:e0236317. [PMID: 32702002 PMCID: PMC7377440 DOI: 10.1371/journal.pone.0236317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/03/2020] [Indexed: 12/26/2022] Open
Abstract
Heterodera avenae, as an obligate endoparasite, causes severe yield loss in wheat (Triticum aestivum). Investigation on the mechanisms how H. avenae perceives wheat roots is limited. Here, the attractiveness of root exudates from eight plant genotypes to H. avenae were evaluated on agar plates. Results showed that the attraction of H. avenae to the root exudates from the non-host Brachypodium distachyon variety Bd21-3 was the highest, approximately 50 infective second-stage juveniles (J2s) per plate, followed by that from three H. avenae-susceptible wheat varieties, Zhengmai9023, Yanmai84 and Xiangmai25, as well as the resistant one of Xinyuan958, whereas the lowest attractive activity was observed in the two H. avenae-resistant wheat varieties, Xianmai20 (approximately 12 J2s/plate) and Liangxing66 (approximately 11 J2s/plate). Then Bd21-3, Zhengmai9023 and Heng4399 were selected for further assays as their different attractiveness and resistance to H. avenae, and attractants for H. avenae in their root exudates were characterized to be heat-labile and low-molecular compounds (LM) by behavioral bioassay. Based on these properties of the attractants, a principle of identifying attractants for H. avenae was set up. Then LM of six root exudates from the three plants with and without heating were separated and analyzed by HPLC-MS. Finally, dihydroxyacetone (DHA), methylprednisolone succinate, embelin and diethylpropionin in the root exudates were identified to be putative attractants for H. avenae according to the principle, and the attraction of DHA to H. avenae was validated by behavioral bioassay on agar. Our study enhances the recognition to the orientation mechanism of H. avenae towards wheat roots.
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15
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Costa SR, Chin S, Mathesius U. Infection of Medicago truncatula by the Root-Knot Nematode Meloidogyne javanica Does Not Require Early Nodulation Genes. FRONTIERS IN PLANT SCIENCE 2020; 11:1050. [PMID: 32733526 PMCID: PMC7363973 DOI: 10.3389/fpls.2020.01050] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/25/2020] [Indexed: 05/27/2023]
Abstract
Because of the developmental similarities between root nodules induced by symbiotic rhizobia and root galls formed by parasitic nematodes, we investigated the involvement of nodulation genes in the infection of Medicago truncatula by the root knot nematode (RKN), Meloidogyne javanica. We found that gall formation, including giant cell formation, pericycle and cortical cell division, as well as egg laying, occurred successfully in the non-nodulating mutants nfp1 (nod factor perception1), nin1 (nodule inception1) and nsp2 (nodulation signaling pathway2) and the cytokinin perception mutant cre1 (cytokinin receptor1). Gall and egg formation were significantly reduced in the ethylene insensitive, hypernodulating mutant skl (sickle), and to a lesser extent, in the low nodulation, abscisic acid insensitive mutant latd/nip (lateral root-organ defective/numerous infections and polyphenolics). Despite its supernodulation phenotype, the sunn4 (super numeric nodules4) mutant, which has lost the ability to autoregulate nodule numbers, did not form excessive numbers of galls. Co-inoculation of roots with nematodes and rhizobia significantly reduced nodule numbers compared to rhizobia-only inoculated roots, but only in the hypernodulation mutant skl. Thus, this effect is likely to be influenced by ethylene signaling, but is not likely explained by resource competition between galls and nodules. Co-inoculation with rhizobia also reduced gall numbers compared to nematode-only infected roots, but only in the wild type. Therefore, the protective effect of rhizobia on nematode infection does not clearly depend on nodule number or on Nod factor signaling. Our study demonstrates that early nodulation genes that are essential for successful nodule development are not necessary for nematode-induced gall formation, that gall formation is not under autoregulation of nodulation control, and that ethylene signaling plays a positive role in successful RKN parasitism in M. truncatula.
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Affiliation(s)
- Sofia R. Costa
- Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, ACT, Australia
- CBMA—Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Braga, Portugal
| | - Sabrina Chin
- Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Ulrike Mathesius
- Division of Plant Sciences, Research School of Biology, Australian National University, Canberra, ACT, Australia
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16
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Castro-Moretti FR, Gentzel IN, Mackey D, Alonso AP. Metabolomics as an Emerging Tool for the Study of Plant-Pathogen Interactions. Metabolites 2020; 10:E52. [PMID: 32013104 PMCID: PMC7074241 DOI: 10.3390/metabo10020052] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/16/2020] [Accepted: 01/27/2020] [Indexed: 12/19/2022] Open
Abstract
Plants defend themselves from most microbial attacks via mechanisms including cell wall fortification, production of antimicrobial compounds, and generation of reactive oxygen species. Successful pathogens overcome these host defenses, as well as obtain nutrients from the host. Perturbations of plant metabolism play a central role in determining the outcome of attempted infections. Metabolomic analyses, for example between healthy, newly infected and diseased or resistant plants, have the potential to reveal perturbations to signaling or output pathways with key roles in determining the outcome of a plant-microbe interaction. However, application of this -omic and its tools in plant pathology studies is lagging relative to genomic and transcriptomic methods. Thus, it is imperative to bring the power of metabolomics to bear on the study of plant resistance/susceptibility. This review discusses metabolomics studies that link changes in primary or specialized metabolism to the defense responses of plants against bacterial, fungal, nematode, and viral pathogens. Also examined are cases where metabolomics unveils virulence mechanisms used by pathogens. Finally, how integrating metabolomics with other -omics can advance plant pathology research is discussed.
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Affiliation(s)
- Fernanda R. Castro-Moretti
- BioDiscovery Institute, University of North Texas, TX 76201, USA;
- Department of Biological Sciences, University of North Texas, TX 76201, USA
| | - Irene N. Gentzel
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, USA;
| | - David Mackey
- Department of Horticulture and Crop Science, The Ohio State University, Columbus, OH 43210, USA;
| | - Ana P. Alonso
- BioDiscovery Institute, University of North Texas, TX 76201, USA;
- Department of Biological Sciences, University of North Texas, TX 76201, USA
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17
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Molinari S, Leonetti P. Bio-control agents activate plant immune response and prime susceptible tomato against root-knot nematodes. PLoS One 2019; 14:e0213230. [PMID: 31794550 PMCID: PMC6890175 DOI: 10.1371/journal.pone.0213230] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 11/15/2019] [Indexed: 11/18/2022] Open
Abstract
Beneficial microorganisms are generally known to activate plant defense against biotic challenges. However, the molecular mechanisms by which activated plants react more rapidly and actively to pests remain still largely unclear. Tomato plants pre-treated with a mixture of beneficial bio-control agents (BCAs), as soil-drenches, were less sensitive to infection of the root-knot nematode (RKN) Meloidogyne incognita. To unravel the molecular mechanisms of this induced resistance against RKNs, we used qRT-PCR to monitor the expression, in tomato roots and leaves, of 6 key defense genes. Gene transcripts were detected until the 12th day after BCA treatment(3, 7, 8, 12 dpt) and3 and 7 days after nematode inoculation of pre-treated plants. Early after BCA treatment, the salicylic acid (SA)-dependent pathogenesis related gene (PR-gene), PR-1b, marker of the systemic acquired resistance (SAR), was systemically over-expressed. Another PR-gene, PR-5, was over-expressed at later stages of BCA-plant interaction, and only in roots. Activation of defense against RKNs was attested by the early up-regulation of 4 genes (PR-1, PR-3, PR-5, ACO) in pre-treated plants after inoculation. Conversely, the expression of the JA/ET-dependent gene JERF3 did not increase after nematode inoculation in primed plants. A catalase gene (CAT)was highly over-expressed by nematode infection, however, this over-expression was annulled at the earliest stages or limited at the later stages of infection toBCA-treated roots. Enzyme activities, such as glucanase and endochitinase, were enhanced in roots of pre-treated inoculated plants with respect to plants left not inoculated as a control. These findings indicate that BCA interaction with roots primes plants against RKNs. BCA-mediated immunity seems to rely on SA-mediated SAR and to be associated with both the activation of chitinase and glucanase enzyme activities and the inhibition of the plant antioxidant enzyme system. Immunity is triggered at the penetration and movements inside the roots of the invading nematode juveniles but probably acts at the feeding site building stage of nematode infection.
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Affiliation(s)
- Sergio Molinari
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Bari, Italy
- * E-mail:
| | - Paola Leonetti
- Institute for Sustainable Plant Protection, National Research Council of Italy (IPSP-CNR), Bari, Italy
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18
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Kaloshian I, Teixeira M. Advances in Plant-Nematode Interactions with Emphasis on the Notorious Nematode Genus Meloidogyne. PHYTOPATHOLOGY 2019; 109:1988-1996. [PMID: 31613704 DOI: 10.1094/phyto-05-19-0163-ia] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Plant infections by plant-parasitic nematodes (PPNs) continue to be one of the major limitations in agricultural systems. Root-knot nematodes (RKNs), belonging to the genus Meloidogyne, are one of the most important groups of PPNs worldwide. Their wide host range combined with ubiquitous presence, continues to provide challenges for their control and breeding for resistance. Although resistance to RKNs has been identified, incorporation of these resistances into crops and durability of the resistance remains challenging. In addition, progress in cloning of RKN resistance genes has been dismal. Recent identification of pattern-triggered immunity in roots against nematodes, an ascaroside as a nematode-associated molecular pattern (NAMP) and the discovery of a NAMP plant receptor, provide tools and opportunities to develop durable host resistance against nematodes including RKNs.
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Affiliation(s)
- Isgouhi Kaloshian
- Department of Nematology, University of California, Riverside, CA 92521
- Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
| | - Marcella Teixeira
- Department of Nematology, University of California, Riverside, CA 92521
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19
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Dyer S, Weir R, Cox D, Cheseto X, Torto B, Dalzell JJ. Ethylene Response Factor (ERF) genes modulate plant root exudate composition and the attraction of plant parasitic nematodes. Int J Parasitol 2019; 49:999-1003. [PMID: 31726058 DOI: 10.1016/j.ijpara.2019.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 09/17/2019] [Accepted: 09/19/2019] [Indexed: 01/30/2023]
Abstract
Plant root exudates are compositionally diverse, plastic and adaptive. Ethylene signalling influences the attraction of plant parasitic nematodes, presumably through the modulation of root exudate composition. Understanding this pathway could lead to new sources of crop parasite resistance. Here we used Virus-Induced Gene Silencing to knock down the expression of two Ethylene Response Factor (ERF) genes, ERF-E2 and ERF-E3, in tomato. Root exudates were significantly more attractive to the PPNs Meloidogyne incognita and Globodera pallida following knockdown of ERF-E2, which had no impact on the attraction of Meloidogyne javanica. Knockdown of ERF-E3 had no impact on the attraction of Meloidogyne or Globodera spp. Gas Chromatography Mass Spectrometry analysis revealed major changes in root exudate composition relative to controls. However, these changes did not alter the attraction of rhizosphere microbes Bacillus subtilis or Agrobacterium tumefaciens. This study further supports the potential of engineering plant root exudate for parasite control, through the modulation of plant genes.
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Affiliation(s)
- Steven Dyer
- School of Biological Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Ryan Weir
- School of Biological Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Deborah Cox
- School of Biological Sciences, Queen's University Belfast, Northern Ireland, United Kingdom
| | - Xavier Cheseto
- The International Center of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
| | - Baldwyn Torto
- The International Center of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya
| | - Johnathan J Dalzell
- School of Biological Sciences, Queen's University Belfast, Northern Ireland, United Kingdom.
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20
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Abdelsamad NA, MacIntosh GC, Leandro LFS. Induction of ethylene inhibits development of soybean sudden death syndrome by inducing defense-related genes and reducing Fusarium virguliforme growth. PLoS One 2019; 14:e0215653. [PMID: 31116746 PMCID: PMC6530837 DOI: 10.1371/journal.pone.0215653] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 04/07/2019] [Indexed: 12/31/2022] Open
Abstract
Ethylene is a gaseous hormone that regulates plant responses to biotic and abiotic stresses. To investigate the importance of ethylene in soybean resistance to Fusarium virguliforme (Fv), the causal agent of sudden death syndrome (SDS), soybean cultivars Williams 82 (SDS-susceptible) and MN1606 (SDS-resistant) were treated 24 h before and 24h after Fv inoculation with either ethephon (ethylene inducer), cobalt chloride (ethylene biosynthesis inhibitor), or 1-MCP (ethylene perception inhibitor). Inoculated plants were grown for 21 days at 24°C in the greenhouse and then evaluated for SDS severity and expression of soybean defense genes. In both cultivars, plants treated with ethephon showed lower SDS foliar severity compared to the other treatments, whereas those treated with cobalt chloride or 1-MCP showed the same or higher SDS foliar severity compared to the water-treated control. Ethephon application resulted in activation of genes involved in ethylene biosynthesis, such as ethylene synthase (ACS) and ethylene oxidase (ACO), and genes involved in soybean defense response, such as pathogenesis-related protein (PR), basic peroxidase (IPER), chalcone synthase (CHS), and defense-associated transcription factors. Cobalt chloride and 1-MCP treatments had little or no effect on the expression of these genes. In addition, ethephon had a direct inhibitory effect on in-vitro growth of Fv on PDA media. Our results suggest that ethephon application inhibits SDS development directly by slowing Fv growth and/or by inducing soybean ethylene signaling and the expression of defense related genes.
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Affiliation(s)
- Noor A. Abdelsamad
- San Joaquin Valley Agricultural Sciences Center, USDA-ARS, Parlier, CA, United States of America
| | - Gustavo C. MacIntosh
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States of America
| | - Leonor F. S. Leandro
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States of America
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21
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Bell CA, Lilley CJ, McCarthy J, Atkinson HJ, Urwin PE. Plant-parasitic nematodes respond to root exudate signals with host-specific gene expression patterns. PLoS Pathog 2019; 15:e1007503. [PMID: 30707749 PMCID: PMC6373980 DOI: 10.1371/journal.ppat.1007503] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/13/2019] [Accepted: 12/03/2018] [Indexed: 12/20/2022] Open
Abstract
Plant parasitic nematodes must be able to locate and feed from their host in order to survive. Here we show that Pratylenchus coffeae regulates the expression of selected cell-wall degrading enzyme genes relative to the abundance of substrate in root exudates, thereby tailoring gene expression for root entry of the immediate host. The concentration of cellulose or xylan within the exudate determined the level of β-1,4-endoglucanase (Pc-eng-1) and β-1,4-endoxylanase (Pc-xyl) upregulation respectively. Treatment of P. coffeae with cellulose or xylan or with root exudates deficient in cellulose or xylan conferred a specific gene expression response of Pc-eng-1 or Pc-xyl respectively with no effect on expression of another cell wall degrading enzyme gene, a pectate lyase (Pc-pel). RNA interference confirmed the importance of regulating these genes as lowered transcript levels reduced root penetration by the nematode. Gene expression in this plant parasitic nematode is therefore influenced, in a host-specific manner, by cell wall components that are either secreted by the plant or released by degradation of root tissue. Transcriptional plasticity may have evolved as an adaptation for host recognition and increased root invasion by this polyphagous species. Plant parasitic nematodes feed from plant roots to support their development. In order to enter and reproduce within the host the nematode must interact with the components exuded by the root. The components are known to vary between individual plant species thus presenting different challenges for the nematode. We observe upregulation of two cell wall degrading enzyme genes in Pratylenchus coffeae upon exposure to root exudates. The nematode genes are differentially expressed dependent upon the identity of the plant. The relative expression of each gene correlates with the abundance of the encoded enzyme substrate in the nematode environment, indicating that the nematode perceives these components and responds by tailoring gene expression for what is currently required for host-parasitism. This ability may explain the wide host range of this nematode species and may be shared by other parasites.
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Affiliation(s)
| | | | | | - Howard J. Atkinson
- Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - P. E. Urwin
- Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- * E-mail:
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22
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Li C, Zhou X, Lewis EE, Yu Y, Wang C. Study on host-seeking behavior and chemotaxis of entomopathogenic nematodes using Pluronic F-127 gel. J Invertebr Pathol 2019; 161:54-60. [PMID: 30707919 DOI: 10.1016/j.jip.2019.01.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/31/2018] [Accepted: 01/26/2019] [Indexed: 10/27/2022]
Abstract
Pluronic F-127 gel (PF127) has proven to be a powerful medium in which to study host-finding behavior and chemotaxis for plant-parasitic nematodes. Pluronic gel can also be used to study host-habitat seeking behavior of entomopathogenic nematodes (EPN), which are natural enemies of root-feeding insect pests. In this study, PF127 was used to study tritrophic interactions among EPNs, host-habitat roots and insects. We also tested whether EPN aggregated to acetic acid (pH gradient) which mimicked the conditions near the roots. The chive root gnat Bradysia odoriphaga alone significantly attracted more nematodes than chive roots alone or the combination of roots plus insects. The attractiveness of B. odoriphaga differed (3.7-15.4%) among all tested species/strains of EPNs. In addition, we found that Heterorhabditis spp. and Steinernema spp. infective juveniles responded to pH gradients formed by acetic acid in Pluronic gel. The preferred pH ranges for strains of H. bacteriophora and H. megidis were from 4.32-5.04, and from 5.37-6.92 for Steinernema species, indicating that Heterorhabditis spp. prefer low pH conditions than Steinernema species. A narrow pH gradient between 6.84 and 7.05 was detected around chive root tips in which EPN was attracted. These results suggest that Pluronic gel can be broadly used for the study of host or host-habitat seeking behaviors and chemotaxis of nematodes.
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Affiliation(s)
- Chunjie Li
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
| | - Xianhong Zhou
- Shandong Key Laboratory of Plant Virology, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Edwin E Lewis
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, ID 83844, USA
| | - Yi Yu
- Shandong Key Laboratory of Plant Virology, Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China.
| | - Congli Wang
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China.
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23
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Sato K, Kadota Y, Shirasu K. Plant Immune Responses to Parasitic Nematodes. FRONTIERS IN PLANT SCIENCE 2019; 10:1165. [PMID: 31616453 PMCID: PMC6775239 DOI: 10.3389/fpls.2019.01165] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 08/26/2019] [Indexed: 05/19/2023]
Abstract
Plant-parasitic nematodes (PPNs), such as root-knot nematodes (RKNs) and cyst nematodes (CNs), are among the most devastating pests in agriculture. RKNs and CNs induce redifferentiation of root cells into feeding cells, which provide water and nutrients to these nematodes. Plants trigger immune responses to PPN infection by recognizing PPN invasion through several different but complementary systems. Plants recognize pathogen-associated molecular patterns (PAMPs) sderived from PPNs by cell surface-localized pattern recognition receptors (PRRs), leading to pattern-triggered immunity (PTI). Plants can also recognize tissue and cellular damage caused by invasion or migration of PPNs through PRR-based recognition of damage-associated molecular patterns (DAMPs). Resistant plants have the added ability to recognize PPN effectors via intracellular nucleotide-binding domain leucine-rich repeat (NLR)-type immune receptors, leading to NLR-triggered immunity. Some PRRs may also recognize apoplastic PPN effectors and induce PTI. Plant immune responses against PPNs include the secretion of anti-nematode enzymes, the production of anti-nematode compounds, cell wall reinforcement, production of reactive oxygen species and nitric oxide, and hypersensitive response-mediated cell death. In this review, we summarize the recognition mechanisms for PPN infection and what is known about PPN-induced immune responses in plants.
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Affiliation(s)
- Kazuki Sato
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
| | - Yasuhiro Kadota
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- *Correspondence: Yasuhiro Kadota, ; Ken Shirasu,
| | - Ken Shirasu
- RIKEN Center for Sustainable Resource Science, Yokohama, Japan
- Graduate School of Science, University of Tokyo, Bunkyo, Japan
- *Correspondence: Yasuhiro Kadota, ; Ken Shirasu,
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Piya S, Binder BM, Hewezi T. Canonical and noncanonical ethylene signaling pathways that regulate Arabidopsis susceptibility to the cyst nematode Heterodera schachtii. THE NEW PHYTOLOGIST 2019; 221:946-959. [PMID: 30136723 DOI: 10.1111/nph.15400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/13/2018] [Indexed: 05/29/2023]
Abstract
Plant-parasitic cyst nematodes successfully exploit various phytohormone signaling pathways to establish a new hormonal equilibrium that facilitates nematode parasitism. Although it is largely accepted that ethylene regulates plant responses to nematode infection, a mechanistic understanding of how ethylene shapes plant-nematode interactions remains largely unknown. In this study, we examined the involvement of various components regulating ethylene perception and signaling in establishing Arabidopsis susceptibility to the cyst nematode Heterodera schachtii using a large set of well-characterized single and higher order mutants. Our analyses revealed the existence of two pathways that separately engage ethylene with salicylic acid (SA) and cytokinin signaling during plant response to nematode infection. One pathway involves the canonical ethylene signaling pathway in which activation of ethylene signaling results in suppression of SA-based immunity. The second pathway involves the ethylene receptor ETR1, which signals independently of SA acid to affect immunity, instead altering cytokinin-mediated regulation of downstream components. Our results reveal important mechanisms through which cyst nematodes exploit components of ethylene perception and signaling to affect the balance of hormonal signaling through ethylene interaction with SA and cytokinin networks. This hormonal interaction overcomes plant defense and provokes a susceptible response.
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Affiliation(s)
- Sarbottam Piya
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Brad M Binder
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Tarek Hewezi
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
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Sikder MM, Vestergård M. Impacts of Root Metabolites on Soil Nematodes. FRONTIERS IN PLANT SCIENCE 2019; 10:1792. [PMID: 32082349 PMCID: PMC7005220 DOI: 10.3389/fpls.2019.01792] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 12/23/2019] [Indexed: 05/20/2023]
Abstract
Plant parasitic nematodes cause significant crop damage globally. Currently, many nematicides have been banned or are being phased out in Europe and other parts of the world because of environmental and human health concerns. Therefore, we need to focus on sustainable and alternative methods of nematode control to protect crops. Plant roots contain and release a wide range of bioactive secondary metabolites, many of which are known defense compounds. Hence, profound understanding of the root mediated interactions between plants and plant parasitic nematodes may contribute to efficient control and management of pest nematodes. In this review, we have compiled literature that documents effects of root metabolites on plant parasitic nematodes. These chemical compounds act as either nematode attractants, repellents, hatching stimulants or inhibitors. We have summarized the few studies that describe how root metabolites regulate the expression of nematode genes. As non-herbivorous nematodes contribute to decomposition, nutrient mineralization, microbial community structuring and control of herbivorous insect larvae, we also review the impact of plant metabolites on these non-target organisms.
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Affiliation(s)
- Md Maniruzzaman Sikder
- Department of Agroecology, AU-Flakkebjerg, Aarhus University, Slagelse, Denmark
- Mycology and Plant Pathology, Department of Botany, Jahangirnagar University, Dhaka, Bangladesh
| | - Mette Vestergård
- Department of Agroecology, AU-Flakkebjerg, Aarhus University, Slagelse, Denmark
- *Correspondence: Mette Vestergård,
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Hu Y, You J, Li J, Wang C. Loss of cytosolic glucose-6-phosphate dehydrogenase increases the susceptibility of Arabidopsis thaliana to root-knot nematode infection. ANNALS OF BOTANY 2019; 123:37-46. [PMID: 29992234 PMCID: PMC6344109 DOI: 10.1093/aob/mcy124] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 06/14/2018] [Indexed: 05/14/2023]
Abstract
BACKGROUND AND AIMS Root knot nematodes (RKNs, Meloidogyne spp.) are microscopic roundworms with a wide host range causing great economic losses worldwide. Understanding how metabolic pathways function within the plant upon RKN infection will provide insight into the molecular aspects of plant-RKN interactions. Glucose-6-phosphate dehydrogenase (G6PDH), the key regulatory enzyme of the oxidative pentose phosphate pathway (OPPP), is involved in plant responses to abiotic stresses and pathogenesis. In this study, the roles of Arabidopsis cytosolic G6PDH in plant-RKN interactions were investigated. METHODS Enzyme assays and western blotting were used to characterize changes in total G6PDH activity and protein abundance in wild-type Arabidopsis in response to RKN infection. The susceptibility of wild-type plants and the double mutant g6pd5/6 to RKNs was analysed and the expression of genes associated with the basal defence response was tested after RKN infection using quantitative reverse transcription PCR. KEY RESULTS RKN infection caused a marked increase in total G6PDH activity and protein abundance in wild-type Arabidopsis roots. However, the transcript levels of G6PDH genes except G6PD6 were not significantly induced following RKN infection, suggesting that the increase in G6PDH activity may occur at the post-transcriptional level. The double mutant g6pd5/6 with loss-of-function of the two cytosolic isoforms G6PD5 and G6PD6 displayed enhanced susceptibility to RKNs. Moreover, reactive oxygen species (ROS) production and gene expression involved in the defence response including jasmonic acid and salicylic acid pathways were suppressed in the g6pd5/6 mutant at the early stage of RKN infection when compared to the wild-type plants. CONCLUSIONS The results demonstrated that the G6PDH-mediated OPPP plays an important role in the plant-RKN interaction. In addition, a new aspect of G6PDH activity involving NADPH production by the OPPP in plant basal defence against RKNs is defined, which may be involved in ROS signalling.
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Affiliation(s)
- Yanfeng Hu
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Jia You
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
| | - Jisheng Li
- College of Life Sciences, Northwest A&F University, Yangling, Shanxi, China
| | - Congli Wang
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin, China
- For correspondence. E-mail
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Wang C, Masler EP, Rogers ST. Responses of Heterodera glycines and Meloidogyne incognita Infective Juveniles to Root Tissues, Root Exudates, and Root Extracts from Three Plant Species. PLANT DISEASE 2018; 102:1733-1740. [PMID: 30125180 DOI: 10.1094/pdis-09-17-1445-re] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The infective juvenile (J2) stage of endoparasitic plant nematodes uses plant chemical signals, released from roots, to localize and infect hosts. We examined the behaviors of soybean cyst nematode (Heterodera glycines) and root-knot nematode (Meloidogyne incognita) J2 in the presence of root signals from marigold (Tagetes patula), soybean (Glycine max), and pepper (Capsicum annuum). Signals were obtained from sources commonly used in phytoparasitic nematode chemotaxis studies: root tips, root exudates, and root extracts. Root tips from each plant species attracted M. incognita but H. glycines was attracted only to soybean. In contrast, root exudates prepared from marigold, pepper, or soybean seedlings were attractive to H. glycines but were repellent to M. incognita. Root extracts had the same effect as exudates. Fractionation of exudates by reversed-phase high-performance liquid chromatography (HPLC) (acetonitrile [CH3CN] and 0.1% trifluoroacetic acid) revealed highly polar and less polar components affecting behaviors. Fractions eluting at 12% CH3CN from all three plants attracted H. glycines and repelled M. incognita. None of the less polar HPLC fractions (>15% CH3CN) affected H. glycines but those from G. max and T. patula repelled M. incognita. Differences among exudates and effects of fractionation on behavior are discussed.
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Affiliation(s)
- Congli Wang
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, China
| | - Edward P Masler
- United States Department of Agriculture, Agricultural Research Service, Mycology and Nematology Genetic Diversity and Biology Laboratory, Beltsville, MD, 20705
| | - Stephen T Rogers
- United States Department of Agriculture, Agricultural Research Service, Mycology and Nematology Genetic Diversity and Biology Laboratory, Beltsville, MD, 20705
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Coyne DL, Cortada L, Dalzell JJ, Claudius-Cole AO, Haukeland S, Luambano N, Talwana H. Plant-Parasitic Nematodes and Food Security in Sub-Saharan Africa. ANNUAL REVIEW OF PHYTOPATHOLOGY 2018; 56:381-403. [PMID: 29958072 PMCID: PMC7340484 DOI: 10.1146/annurev-phyto-080417-045833] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Sub-Saharan Africa (SSA) is a region beset with challenges, not least its ability to feed itself. Low agricultural productivity, exploding populations, and escalating urbanization have led to declining per capita food availability. In order to reverse this trend, crop production systems must intensify, which brings with it an elevated threat from pests and diseases, including plant-parasitic nematodes. A holistic systems approach to pest management recognizes disciplinary integration. However, a critical under-representation of nematology expertise is a pivotal shortcoming, especially given the magnitude of the threat nematodes pose under more intensified systems. With more volatile climates, efficient use of water by healthy root systems is especially crucial. Within SSA, smallholder farming systems dominate the agricultural landscape, where a limited understanding of nematode problems prevails. This review provides a synopsis of current nematode challenges facing SSA and presents the opportunities to overcome current shortcomings, including a means to increase nematology capacity.
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Affiliation(s)
- Danny L Coyne
- International Institute of Tropical Agriculture, Kasarani, Nairobi, Kenya;
| | - Laura Cortada
- International Institute of Tropical Agriculture, Kasarani, Nairobi, Kenya;
| | - Johnathan J Dalzell
- Queen's University Belfast, School of Biological Sciences, Medical Biology Centre, Belfast, BT9 7BL, United Kingdom
| | - Abiodun O Claudius-Cole
- Department of Crop Protection and Environmental Biology, University of Ibadan, Ibadan, Nigeria
| | - Solveig Haukeland
- International Centre for Insect Physiology and Ecology, Kasarani, Nairobi, Kenya
| | | | - Herbert Talwana
- Department of Agricultural Production, School of Agricultural Sciences, Makerere University, Kampala, Uganda
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Torto B, Cortada L, Murungi LK, Haukeland S, Coyne DL. Management of Cyst and Root Knot Nematodes: A Chemical Ecology Perspective. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:8672-8678. [PMID: 30037217 DOI: 10.1021/acs.jafc.8b01940] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plant parasitic nematode infection of crops can be highly detrimental to agricultural production. Since the discovery that plant roots release chemicals that attract the infective stage of plant parasitic nematodes some 80 years ago, significant progress in identifying the signaling molecules has occurred only relatively recently. Here, we review the literature on chemical ecological studies of two major plant parasitic nematode groups: root knot nematodes in the genus Meloidogyne and cyst nematodes in the genus Globodera because of the negative impact their parasitism has on farming systems in Africa. We then highlight perspectives for future directions for their management.
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Affiliation(s)
- Baldwyn Torto
- International Centre of Insect Physiology and Ecology ( icipe), P.O. Box 30772-00100, Nairobi , Kenya
| | - Laura Cortada
- International Institute of Tropical Agriculture (IITA) , P.O. Box 30772-00100, Nairobi , Kenya
| | - Lucy K Murungi
- Department of Horticulture , Jomo Kenyatta University of Agriculture and Technology (JKUAT) , P.O. Box 62000-00200, Nairobi , Kenya
| | - Solveig Haukeland
- International Centre of Insect Physiology and Ecology ( icipe), P.O. Box 30772-00100, Nairobi , Kenya
| | - Danny L Coyne
- International Institute of Tropical Agriculture (IITA) , P.O. Box 30772-00100, Nairobi , Kenya
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Potent Attractant for Root-Knot Nematodes in Exudates from Seedling Root Tips of Two Host Species. Sci Rep 2018; 8:10847. [PMID: 30022095 PMCID: PMC6052019 DOI: 10.1038/s41598-018-29165-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 07/06/2018] [Indexed: 11/24/2022] Open
Abstract
Root-knot nematodes (RKN; Meloidogyne spp.) can parasitize over 2,000 plant species and are generally considered to be the most agriculturally damaging group of plant-parasitic nematodes worldwide. Infective juveniles (J2) are non-feeding and must locate and invade a host before their reserves are depleted. However, what attracts J2 to appropriate root entry sites is not known. An aim of this research is to identify semiochemicals that attract RKN to roots. J2 of the three RKN species tested are highly attracted to root tips of both tomato and Medicago truncatula. For both hosts, mutants defective in ethylene signaling were found to be more attractive than those of wild type. We determined that cell-free exudates collected from tomato and M. truncatula seedling root tips were highly attractive to M. javanica J2. Using a pluronic gel-based microassay to monitor chemical fractionation, we determined that for both plant species the active component fractionated similarly and had a mass of ~400 based on size-exclusion chromatography. This characterization is a first step toward identification of a potent and specific attractant from host roots that attracts RKN. Such a compound is potentially a valuable tool for developing novel and safe control strategies.
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31
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Zhan LP, Peng DL, Wang XL, Kong LA, Peng H, Liu SM, Liu Y, Huang WK. Priming effect of root-applied silicon on the enhancement of induced resistance to the root-knot nematode Meloidogyne graminicola in rice. BMC PLANT BIOLOGY 2018; 18:50. [PMID: 29580214 PMCID: PMC5870084 DOI: 10.1186/s12870-018-1266-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 03/12/2018] [Indexed: 05/23/2023]
Abstract
BACKGROUND Silicon (Si) can confer plant resistance to both abiotic and biotic stress. In the present study, the priming effect of Si on rice (Oryza sativa cv Nipponbare) against the root-knot nematode Meloidogyne graminicola and its histochemical and molecular impact on plant defense mechanisms were evaluated. RESULTS Si amendment significantly reduced nematodes in rice roots and delayed their development, while no obvious negative effect on giant cells was observed. Increased resistance in rice was correlated with higher transcript levels of defense-related genes (OsERF1, OsEIN2 and OsACS1) in the ethylene (ET) pathway. Si amendment significantly reduced nematode numbers in rice plants with enhanced ET signaling but had no effect in plants deficient in ET signaling, indicating that the priming effects of Si were dependent on the ET pathway. A higher deposition of callose and accumulation of phenolic compounds were observed in rice roots after nematode attack in Si-amended plants than in the controls. CONCLUSION These findings indicate that the priming effect may partially depend on the production of phenolic compounds and hydrogen peroxide. Further research is required to model the ethylene signal transduction pathway that occurs in the Si-plant-nematode interaction system and gain a better understanding of Si-induced defense in rice.
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Affiliation(s)
- Li-Ping Zhan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China
| | - De-Liang Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China
| | - Xu-Li Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China
| | - Ling-An Kong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China
| | - Huan Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China
| | - Shi-Ming Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China
| | - Ying Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China
| | - Wen-Kun Huang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China
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Zhao W, Zhou X, Lei H, Fan J, Yang R, Li Z, Hu C, Li M, Zhao F, Wang S. Transcriptional evidence for cross talk between JA and ET or SA during root-knot nematode invasion in tomato. Physiol Genomics 2018; 50:197-207. [PMID: 29341868 DOI: 10.1152/physiolgenomics.00079.2017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
studies have demonstrated that jasmonic acid (JA) reduces root-knot nematode (RKN) infections in tomato plants. RKN invasion is sensed by roots, and root-derived JA signaling activates systemic defense responses, though this is poorly understood. Here, we investigate variations in the RKN-induced transcriptome in scion phloem between two tomato plant grafts: CM/CM ( Lycopersicum esculentum Mill. cv. Castlemart) and CM/ spr2 (a JA-deficient mutant). A total of 8,716 genes were differentially expressed in the scion phloem of the plants with JA-deficient rootstock via RNA sequencing. Among these genes, 535 upregulated and 153 downregulated genes with high copy numbers were identified as significantly differentially expressed. Among them, 34 predicted transcription factor genes were identified. Additionally, we used real-time quantitative PCR to analyze the expression patterns of 42 genes involved in the JA, ethylene, or salicylic acid pathway in phloem under RKN infection. The results suggested that in the absence of JA signaling, the ET signaling pathway is enhanced after RKN infection; however, alterations in the SA signaling pathway were not observed.
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Affiliation(s)
- Wenchao Zhao
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Xiaoxuan Zhou
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Hui Lei
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Jingwei Fan
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Rui Yang
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Zilong Li
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Canli Hu
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Mengyan Li
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Fukuan Zhao
- College of Biotechnology, Beijing University of Agriculture, Beijing, China
| | - Shaohui Wang
- Beijing Key Laboratory for Agricultural Applications and New Techniques, Plant Science and Technology College, Beijing University of Agriculture, Beijing, China
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Smant G, Helder J, Goverse A. Parallel adaptations and common host cell responses enabling feeding of obligate and facultative plant parasitic nematodes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:686-702. [PMID: 29277939 DOI: 10.1111/tpj.13811] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 12/10/2017] [Accepted: 12/14/2017] [Indexed: 05/08/2023]
Abstract
Parallel adaptations enabling the use of plant cells as the primary food source have occurred multiple times in distinct nematode clades. The hallmark of all extant obligate and facultative plant-feeding nematodes is the presence of an oral stylet, which is required for penetration of plant cell walls, delivery of pharyngeal gland secretions into host cells and selective uptake of plant assimilates. Plant parasites from different clades, and even within a single clade, display a large diversity in feeding behaviours ranging from short feeding cycles on single cells to prolonged feeding on highly sophisticated host cell complexes. Despite these differences, feeding of nematodes frequently (but certainly not always) induces common responses in host cells (e.g. endopolyploidization and cellular hypertrophy). It is thought that these host cell responses are brought about by the interplay of effectors and other biological active compounds in stylet secretions of feeding nematodes, but this has only been studied for the most advanced sedentary plant parasites. In fact, these responses are thought to be fundamental for prolonged feeding of sedentary plant parasites on host cells. However, as we discuss in this review, some of these common plant responses to independent lineages of plant parasitic nematodes might also be generic reactions to cell stress and as such their onset may not require specific inputs from plant parasitic nematodes. Sedentary plant parasitic nematodes may utilize effectors and their ability to synthesize other biologically active compounds to tailor these common responses for prolonged feeding on host cells.
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Affiliation(s)
- Geert Smant
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708PB, The Netherlands
| | - Johannes Helder
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708PB, The Netherlands
| | - Aska Goverse
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708PB, The Netherlands
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The Role of Sugar Transporter Genes during Early Infection by Root-Knot Nematodes. Int J Mol Sci 2018; 19:ijms19010302. [PMID: 29351253 PMCID: PMC5796247 DOI: 10.3390/ijms19010302] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 01/16/2018] [Accepted: 01/17/2018] [Indexed: 12/28/2022] Open
Abstract
Although pathogens such as nematodes are known to hijack nutrients from host plants, the mechanisms whereby nematodes obtain sugars from plants remain largely unknown. To determine the effects of nematode infection on host plant sugar allocation, soluble sugar (fructose, glucose, sucrose) content was investigated using high-performance liquid chromatography with refractive index detection and was found to increase significantly in tomato (Solanum lycopersicum, Sl) leaves and roots during early infection by root-knot nematodes (RKNs). To further analyze whether sugar transporters played a role in this process, the expression levels of sucrose transporter (SUT/SUC), Sugars Will Eventually be Exported Transporter (SWEET), tonoplast monosaccharide transporter (TMT), and vacuolar glucose transporter (VGT) gene family members were examined by qRT-PCR analysis after RKN infection. The results showed that three SlSUTs, 17 SlSWEETs, three SlTMTs, and SlVGT1 were upregulated in the leaves, whereas three SlSUTs, 17 SlSWEETs, two SlTMTs, and SlVGT1 were induced in the roots. To determine the function of the sugar transporters in the RKN infection process, we examined post-infection responses in the Atsuc2 mutant and pAtSUC2-GUS lines. β-glucuronidase expression was strongly induced at the infection sites, and RKN development was significantly arrested in the Atsuc2 mutant. Taken together, our analyses provide useful information for understanding the sugar transporter responses during early infection by RKNs in tomato.
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Wu X, Zhu X, Wang Y, Liu X, Chen L, Duan Y. The cold tolerance of the northern root-knot nematode, Meloidogyne hapla. PLoS One 2018; 13:e0190531. [PMID: 29293608 PMCID: PMC5749844 DOI: 10.1371/journal.pone.0190531] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 12/15/2017] [Indexed: 01/09/2023] Open
Abstract
The northern root-knot nematode, Meloidogyne hapla, is one of the most important nematode pathogens occurring in cold regions. It is a sedentary, biotrophic parasites of plants and overwinter in the soil or in diseased roots. This study showed that the cold tolerance for the second-stage juveniles (J2) of M. hapla was moderate with the 50% survival temperature (S50) of -2.22°C and the fatal temperature was -6°C when cooling at 0.5°C min-1. Cryoprotective dehydration significantly enhance cold tolerance of M. hapla J2 with the lowest S50 of -3.28°C after held being at -1°C for 6 h. Moreover, cold shock and cold acclimation had significant effects on the freezing survival of M. hapla J2. The lethal temperature of eggs was -18°C. Therefore, the cold tolerance of M. hapla is sufficiently favorable to withstand winters in cold temperature environments.
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Affiliation(s)
- Xiaojing Wu
- College of Plant Protection, Shenyang Agricultural University, Shenyang, Liaoning, China
| | - Xiaofeng Zhu
- College of Plant Protection, Shenyang Agricultural University, Shenyang, Liaoning, China
| | - Yuanyuan Wang
- College of Biology science and technology, Shenyang Agricultural University, Shenyang, Liaoning, China
| | - Xiaoyu Liu
- College of Science, Shenyang Agricultural University, Shenyang, Liaoning, China
| | - Lijie Chen
- College of Plant Protection, Shenyang Agricultural University, Shenyang, Liaoning, China
| | - Yuxi Duan
- College of Plant Protection, Shenyang Agricultural University, Shenyang, Liaoning, China
- * E-mail:
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Chen C, Cui L, Chen Y, Zhang H, Liu P, Wu P, Qiu D, Zou J, Yang D, Yang L, Liu H, Zhou Y, Li H. Transcriptional responses of wheat and the cereal cyst nematode Heterodera avenae during their early contact stage. Sci Rep 2017; 7:14471. [PMID: 29101332 PMCID: PMC5670130 DOI: 10.1038/s41598-017-14047-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/04/2017] [Indexed: 01/22/2023] Open
Abstract
Cereal cyst nematode (Heterodera avenae) is attracted to and aggregated around wheat roots to initiate infection, but this interaction between wheat and the nematode is not fully understood. The transcriptional responses of both wheat and H. avenae were examined during their early contact stage by mRNA sequencing analysis; certain numbers of the differentially expressed genes (DEGs) were validated using quantitative real-time PCR. The immobile host wheat root only had 93 DEGs (27 up-regulated and 66 down-regulated), while the mobile plant parasitic nematode reacted much more actively with 879 DEGs (867 up-regulated and 12 down-regulated). Among them, a number of wheat DEGs (mostly down-regulated) were involved in biotic stress pathways, while several putative effector genes were up-regulated in the nematode DEGs. One putative chitinase-like effector gene of H. avenae was able to suppress BAX-triggered programmed cell death in Nicotiana benthamiana. Results of these experiments demonstrated that nematode responded more actively than wheat during the contact stage of parasitism. The parasite's responses mainly involved up-regulation of genes including at least one anti-plant-defence effector gene, whereas the host responses mainly involved down-regulation of certain defence-related genes.
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Affiliation(s)
- Changlong Chen
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Lei Cui
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Yongpan Chen
- Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Hongjun Zhang
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Pei Liu
- Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Peipei Wu
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Dan Qiu
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Jingwei Zou
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Dan Yang
- Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Li Yang
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Hongwei Liu
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Yang Zhou
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Hongjie Li
- The National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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Xu S, Yang N, Zheng S, Yan F, Jiang C, Yu Y, Guo J, Chai Y, Chen Y. The spo0A-sinI-sinR Regulatory Circuit Plays an Essential Role in Biofilm Formation, Nematicidal Activities, and Plant Protection in Bacillus cereus AR156. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:603-619. [PMID: 28430084 DOI: 10.1094/mpmi-02-17-0042-r] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The rhizosphere bacterium Bacillus cereus AR156 is capable of forming biofilms, killing nematodes, and protecting plants. However, the underlying molecular mechanisms of these processes are not well understood. In this study, we found that the isogenic mutants ΔBcspo0A and ΔBcsinI have significantly reduced colonization and nematicidal activity in vitro and biological control efficacy on the tomato plant under greenhouse conditions. We further investigated the role of the spo0A-sinI-sinR regulatory circuit in biofilm formation, killing against nematodes, and biological control in AR156. Results from mutagenesis of those regulatory genes in AR156 and their heterologous expression in B. subtilis suggested that the spo0A-sinI-sinR genetic circuit is not only essential for biofilm formation and cell differentiation in AR156 but also able to functionally replace their counterparts in B. subtilis in a nearly indistinguishable fashion. Genome-wide transcriptional profiling in the wild type and the ΔBcspo0A and ΔBcsinI mutants further revealed hundreds of differentially expressed genes, likely positively regulated by both Spo0A and SinI (via SinR) in AR156. Among them, 29 genes are predicted to be directly controlled by SinR, whose counterpart in B. subtilis is a biofilm master repressor. Collectively, our studies demonstrated the essential role of the spo0A-sinI-sinR regulatory circuit in biofilm formation, cell differentiation, and bacteria-host interactions in B. cereus AR156.
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Affiliation(s)
- Sunde Xu
- 1 Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Nan Yang
- 1 Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Shiyu Zheng
- 1 Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
| | - Fang Yan
- 2 Department of Biology, Northeastern University, Boston 02115, U.S.A.; and
- 3 Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Chunhao Jiang
- 3 Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yiyang Yu
- 2 Department of Biology, Northeastern University, Boston 02115, U.S.A.; and
- 3 Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Jianhua Guo
- 3 Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunrong Chai
- 2 Department of Biology, Northeastern University, Boston 02115, U.S.A.; and
| | - Yun Chen
- 1 Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China
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38
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Kihika R, Murungi LK, Coyne D, Ng'ang'a M, Hassanali A, Teal PEA, Torto B. Parasitic nematode Meloidogyne incognita interactions with different Capsicum annum cultivars reveal the chemical constituents modulating root herbivory. Sci Rep 2017; 7:2903. [PMID: 28588235 PMCID: PMC5460232 DOI: 10.1038/s41598-017-02379-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 04/10/2017] [Indexed: 11/09/2022] Open
Abstract
Plant volatile signatures are often used as cues by herbivores to locate their preferred hosts. Here, we report on the volatile organic compounds used by the subterranean root-knot nematode (RKN) Meloidogyne incognita for host location. We compared responses of infective second stage juveniles (J2s) to root volatiles of three cultivars and one accession of the solanaceous plant, Capsicum annum against moist sand in dual choice assays. J2s were more attracted to the three cultivars than to the accession, relative to controls. GC/MS analysis of the volatiles identified common constituents in each plant, five of which were identified as α-pinene, limonene, 2-methoxy-3-(1-methylpropyl)-pyrazine, methyl salicylate and tridecane. We additionally identified thymol as being specific to the accession. In dose-response assays, a blend of the five components elicited positive chemotaxis (71-88%), whereas individual components elicited varying responses; Methyl salicylate (MeSA) elicited the highest positive chemotaxis (70-80%), α-pinene, limonene and tridecane were intermediate (54-60%), and 2-methoxy-3-(1-methylpropyl)-pyrazine the lowest (49-55%). In contrast, thymol alone or thymol combined with either the preferred natural plant root volatiles or the five-component synthetic blend induced negative chemotaxis. Our results provide insights into RKN-host plant interactions, creating new opportunities for plant breeding programmes towards management of RKNs.
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Affiliation(s)
- Ruth Kihika
- Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya
- Kenyatta University, P.O. Box 43844- 00100, Nairobi, Kenya
| | - Lucy K Murungi
- Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi, Kenya
| | - Danny Coyne
- International Institute of Tropical Agriculture (IITA), P.O. Box 30772-00100, Nairobi, Kenya
| | | | | | - Peter E A Teal
- USDA/ARS-CMAVE, 1600/1700 SW23rd Dr., Gainesville, FL, 32608, USA
| | - Baldwyn Torto
- Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology, P.O. Box 30772-00100, Nairobi, Kenya.
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39
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Leonetti P, Zonno MC, Molinari S, Altomare C. Induction of SA-signaling pathway and ethylene biosynthesis in Trichoderma harzianum-treated tomato plants after infection of the root-knot nematode Meloidogyne incognita. PLANT CELL REPORTS 2017; 36:621-631. [PMID: 28239746 DOI: 10.1007/s00299-017-2109-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 01/20/2017] [Indexed: 05/10/2023]
Abstract
Salicylic acid-signaling pathway and ethylene biosynthesis were induced in tomato treated with Trichoderma harzianum when infected by root-knot nematodes and limited the infection by activation of SAR and ethylene production. Soil pre-treatment with Trichoderma harzianum (Th) strains ITEM 908 (T908) and T908-5 decreased susceptibility of tomato to Meloidogyne incognita, as assessed by restriction in nematode reproduction and development. The effect of T. harzianum treatments on plant defense was detected by monitoring the expression of the genes PR-1/PR-5 and JERF3/ACO, markers of the SA- and JA/ET-dependent signaling pathways, respectively. The compatible nematode-plant interaction in absence of fungi caused a marked suppression of PR-1, PR-5, and ACO gene expressions, either locally or systemically, whilst expression of JERF3 gene resulted unaffected. Conversely, when plants were pre-treated with Th-strains, over-expression of PR-1, PR-5, and ACO genes was observed in roots 5 days after nematode inoculation. JERF3 gene expression did not change in Th-colonized plants challenged with nematodes. In the absence of nematodes, Trichoderma-root interaction was characterized by the inhibition of both SA-dependent signaling pathway and ET biosynthesis, and, in the case of PR-1 and ACO genes, this inhibition was systemic. JERF3 gene expression was systemically restricted only at the very early stages of plant-fungi interaction. Data presented indicate that Th-colonization primed roots for Systemic Acquired Resistance (SAR) against root-knot nematodes and reacted to nematode infection more efficiently than untreated plants. Such a response probably involves also activation of ET production, through an augmented transcription of the ACO gene, which encodes for the enzyme catalyzing the last step of ET biosynthesis. JA signaling and Induced Systemic Resistance (ISR) do not seem to be involved in the biocontrol action of the tested Th-strains against RKNs.
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Affiliation(s)
- Paola Leonetti
- Institute of Sustainable Plant Protection (IPSP), National Research Council of Italy (CNR), 70126, Bari, Italy.
| | - Maria Chiara Zonno
- Institute of Sciences of Food Production (ISPA), National Research Council of Italy (CNR), 70126, Bari, Italy
| | - Sergio Molinari
- Institute of Sustainable Plant Protection (IPSP), National Research Council of Italy (CNR), 70126, Bari, Italy
| | - Claudio Altomare
- Institute of Sciences of Food Production (ISPA), National Research Council of Italy (CNR), 70126, Bari, Italy
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40
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Hu Y, You J, Li C, Williamson VM, Wang C. Ethylene response pathway modulates attractiveness of plant roots to soybean cyst nematode Heterodera glycines. Sci Rep 2017; 7:41282. [PMID: 28112257 PMCID: PMC5256374 DOI: 10.1038/srep41282] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 12/19/2016] [Indexed: 12/12/2022] Open
Abstract
Plant parasitic nematodes respond to root exudates to locate their host roots. In our studies second stage juveniles of Heterodera glycines, the soybean cyst nematode (SCN), quickly migrated to soybean roots in Pluronic F-127 gel. Roots of soybean and non-host Arabidopsis treated with the ethylene (ET)-synthesis inhibitor aminoethoxyvinylglycine (AVG) were more attractive to SCN than untreated roots, and significantly more nematodes penetrated into roots. Moreover, Arabidopsis ET insensitive mutants (ein2, ein2-1, ein2-5, ein3-1, ein5-1, and ein6) were more attractive than wild-type plants. Conversely, the constitutive triple-response mutant ctr1-1, was less attractive to SCN. While ET receptor gain-of-function mutant ein4-1 attracted more SCN than the wild-type, there were no significant differences in attractiveness between another gain-of-function ET receptor mutant, etr1-3, or the loss-of-function mutants etr1-7 and ers1-3 and the wild type. Expression of the reporter construct EBS: β-glucuronidase (GUS) was detected in Arabidopsis root tips as early as 6 h post infection, indicating that ET signaling was activated in Arabidopsis early by SCN infection. These results suggest that an active ET signaling pathway reduces root attractiveness to SCN in a way similar to that reported for root-knot nematodes, but opposite to that suggested for the sugar beet cyst nematode Heterodera schachtii.
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Affiliation(s)
- Yanfeng Hu
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081 China
| | - Jia You
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081 China
| | - Chunjie Li
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081 China
| | | | - Congli Wang
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081 China
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41
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Abstract
Nematodes and other organisms perceive and respond to plant root exudates. These exudates are affected by the condition and genetic makeup of the plant. Attraction of the root-knot nematode Meloidogyne hapla to roots is altered in plants with mutations affecting ethylene signaling, suggesting that the root exudates to which the nematode responds are modulated by ethylene signaling. Nematode interactions with roots have been difficult to observe directly due to the opaqueness of soil. A medium based on the block copolymer Pluronic F-127 has been useful for studying these interactions. Here, we present protocols for culturing root-knot nematodes, isolating infective juveniles, and measuring their attraction to Arabidopsis seedling roots in this medium.
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42
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43
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Olfactory circuits and behaviors of nematodes. Curr Opin Neurobiol 2016; 41:136-148. [PMID: 27668755 DOI: 10.1016/j.conb.2016.09.002] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/19/2016] [Accepted: 09/05/2016] [Indexed: 12/29/2022]
Abstract
Over one billion people worldwide are infected with parasitic nematodes. Many parasitic nematodes actively search for hosts to infect using volatile chemical cues, so understanding the olfactory signals that drive host seeking may elucidate new pathways for preventing infections. The free-living nematode Caenorhabditis elegans is a powerful model for parasitic nematodes: because sensory neuroanatomy is conserved across nematode species, an understanding of the microcircuits that mediate olfaction in C. elegans may inform studies of olfaction in parasitic nematodes. Here we review circuit mechanisms that allow C. elegans to respond to odorants, gases, and pheromones. We also highlight work on the olfactory behaviors of parasitic nematodes that lays the groundwork for future studies of their olfactory microcircuits.
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44
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Kyndt T, Goverse A, Haegeman A, Warmerdam S, Wanjau C, Jahani M, Engler G, de Almeida Engler J, Gheysen G. Redirection of auxin flow in Arabidopsis thaliana roots after infection by root-knot nematodes. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:4559-70. [PMID: 27312670 PMCID: PMC4973730 DOI: 10.1093/jxb/erw230] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Plant-parasitic root-knot nematodes induce the formation of giant cells within the plant root, and it has been recognized that auxin accumulates in these feeding sites. Here, we studied the role of the auxin transport system governed by AUX1/LAX3 influx proteins and different PIN efflux proteins during feeding site development in Arabidopsis thaliana roots. Data generated via promoter-reporter line and protein localization analyses evoke a model in which auxin is being imported at the basipetal side of the feeding site by the concerted action of the influx proteins AUX1 and LAX3, and the efflux protein PIN3. Mutants in auxin influx proteins AUX1 and LAX3 bear significantly fewer and smaller galls, revealing that auxin import into the feeding sites is needed for their development and expansion. The feeding site development in auxin export (PIN) mutants was only slightly hampered. Expression of some PINs appears to be suppressed in galls, probably to prevent auxin drainage. Nevertheless, a functional PIN4 gene seems to be a prerequisite for proper nematode development and gall expansion, most likely by removing excessive auxin to stabilize the hormone level in the feeding site. Our data also indicate a role of local auxin peaks in nematode attraction towards the root.
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Affiliation(s)
- Tina Kyndt
- Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium
| | - Aska Goverse
- Department of Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Annelies Haegeman
- Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium
| | - Sonja Warmerdam
- Department of Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Cecilia Wanjau
- Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium
| | - Mona Jahani
- Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium
| | - Gilbert Engler
- INRA, Univ. Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900 Sophia Antipolis, France
| | - Janice de Almeida Engler
- INRA, Univ. Nice Sophia Antipolis, CNRS, UMR 1355-7254 Institut Sophia Agrobiotech, 06900 Sophia Antipolis, France
| | - Godelieve Gheysen
- Department of Molecular Biotechnology, Ghent University (UGent), Coupure links 653, B-9000 Ghent, Belgium
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45
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Teixeira MA, Wei L, Kaloshian I. Root-knot nematodes induce pattern-triggered immunity in Arabidopsis thaliana roots. THE NEW PHYTOLOGIST 2016; 211:276-87. [PMID: 26892116 DOI: 10.1111/nph.13893] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 01/10/2016] [Indexed: 05/08/2023]
Abstract
Root-knot nematodes (RKNs; Meloidogyne spp.) are plant parasites with a broad host range causing great losses worldwide. To parasitize their hosts, RKNs establish feeding sites in roots known as giant cells. The majority of work studying plant-RKN interactions in susceptible hosts addresses establishment of the giant cells and there is limited information on the early defense responses. Here we characterized early defense or pattern-triggered immunity (PTI) against RKNs in Arabidopsis thaliana. To address PTI, we evaluated known canonical PTI signaling mutants with RKNs and investigated the expression of PTI marker genes after RKN infection using both quantitative PCR and β-glucuronidase reporter transgenic lines. We showed that PTI-compromised plants have enhanced susceptibility to RKNs, including the bak1-5 mutant. BAK1 is a common partner of distinct receptors of microbe- and damage-associated molecular patterns. Furthermore, our data indicated that nematode recognition leading to PTI responses involves camalexin and glucosinolate biosynthesis. While the RKN-induced glucosinolate biosynthetic pathway was BAK1-dependent, the camalexin biosynthetic pathway was only partially dependent on BAK1. Combined, our results indicate the presence of BAK1-dependent and -independent PTI against RKNs in A. thaliana, suggesting the existence of diverse nematode recognition mechanisms.
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Affiliation(s)
- Marcella A Teixeira
- Department of Nematology, University of California, Riverside, CA, 92521, USA
| | - Lihui Wei
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, China
| | - Isgouhi Kaloshian
- Department of Nematology, University of California, Riverside, CA, 92521, USA
- Institute of Integrative Genome Biology, University of California, Riverside, CA, USA
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46
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Gang SS, Hallem EA. Mechanisms of host seeking by parasitic nematodes. Mol Biochem Parasitol 2016; 208:23-32. [PMID: 27211240 DOI: 10.1016/j.molbiopara.2016.05.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 05/13/2016] [Accepted: 05/16/2016] [Indexed: 10/21/2022]
Abstract
The phylum Nematoda comprises a diverse group of roundworms that includes parasites of vertebrates, invertebrates, and plants. Human-parasitic nematodes infect more than one billion people worldwide and cause some of the most common neglected tropical diseases, particularly in low-resource countries [1]. Parasitic nematodes of livestock and crops result in billions of dollars in losses each year [1]. Many nematode infections are treatable with low-cost anthelmintic drugs, but repeated infections are common in endemic areas and drug resistance is a growing concern with increasing therapeutic and agricultural administration [1]. Many parasitic nematodes have an environmental infective larval stage that engages in host seeking, a process whereby the infective larvae use sensory cues to search for hosts. Host seeking is a complex behavior that involves multiple sensory modalities, including olfaction, gustation, thermosensation, and humidity sensation. As the initial step of the parasite-host interaction, host seeking could be a powerful target for preventative intervention. However, host-seeking behavior remains poorly understood. Here we review what is currently known about the host-seeking behaviors of different parasitic nematodes, including insect-parasitic nematodes, mammalian-parasitic nematodes, and plant-parasitic nematodes. We also discuss the neural bases of these behaviors.
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Affiliation(s)
- Spencer S Gang
- Department of Microbiology, Immunology, and Molecular Genetics and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, United States.
| | - Elissa A Hallem
- Department of Microbiology, Immunology, and Molecular Genetics and Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, United States.
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47
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Yang G, Zhou B, Zhang X, Zhang Z, Wu Y, Zhang Y, Lü S, Zou Q, Gao Y, Teng L. Effects of Tomato Root Exudates on Meloidogyne incognita. PLoS One 2016; 11:e0154675. [PMID: 27128659 PMCID: PMC4851295 DOI: 10.1371/journal.pone.0154675] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 04/18/2016] [Indexed: 11/29/2022] Open
Abstract
Plant root exudates affect root-knot nematodes egg hatch. Chemicals in root exudates can attract nematodes to the roots or result in repellence, motility inhibition or even death. However, until recently little was known about the relationship between tomato root exudates chemicals and root-knot nematodes. In this study, root exudates were extracted from three tomato rootstocks with varying levels of nematode resistance: Baliya (highly resistant, HR), RS2 (moderately resistant, MR) and L-402 (highly susceptible, T). The effects of the root exudates on Meloidogyne incognita (M. incognita) egg hatch, survival and chemotaxis of second-stage juveniles (J2) were explored. The composition of the root exudates was analysed by gas chromatography/mass spectrometry (GC/MS) prior to and following M. incognita inoculation. Four compounds in root exudates were selected for further analysis and their allopathic effect on M. incognita were investigated. Root exudates from each tomato rootstocks (HR, MR and T strains) suppressed M. incognita egg hatch and increased J2 mortality, with the highest rate being observed in the exudates from the HR plants. Exudate from HR variety also repelled M. incognita J2 while that of the susceptible plant, T, was demonstrated to be attractive. The relative amount of esters and phenol compounds in root exudates from HR and MR tomato rootstocks increased notably after inoculation. Four compounds, 2,6-Di-tert-butyl-p-cresol, L-ascorbyl 2,6-dipalmitate, dibutyl phthalate and dimethyl phthalate increased significantly after inoculation. The egg hatch of M. incognita was suppressed by each of the compound. L-ascorbyl 2,6-dipalmitate showed the most notable effect in a concentration-dependent manner. All four compounds were associated with increased J2 mortality. The greatest effect was observed with dimethyl phthalate at 2 mmol·L-1. Dibutyl phthalate was the only compound observed to repel M. incognita J2 with no effect being detected in the other compounds. Each of the four compounds were correlated with a reduction in disease index in the susceptible cultivar, T, and tomato seedlings irrigated with L-ascorbyl 2,6-dipalmitate at 2 mmol·L-1 showed the best resistance to M. incognita. Taken together, this study provided a valuable contribution to understanding the underlying mechanism of nematode resistance in tomato cultivars.
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Affiliation(s)
- Guodong Yang
- College of Horticulture, Shenyang Agricultural University, Shenyang, P. R. China
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
| | - Baoli Zhou
- College of Horticulture, Shenyang Agricultural University, Shenyang, P. R. China
- * E-mail:
| | - Xinyu Zhang
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
| | - Zijun Zhang
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
| | - Yuanyuan Wu
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
| | - Yiming Zhang
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
| | - Shuwen Lü
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
| | - Qingdao Zou
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
| | - Yuan Gao
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
| | - Long Teng
- Vegetable Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang, P. R. China
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48
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Favery B, Quentin M, Jaubert-Possamai S, Abad P. Gall-forming root-knot nematodes hijack key plant cellular functions to induce multinucleate and hypertrophied feeding cells. JOURNAL OF INSECT PHYSIOLOGY 2016. [PMID: 26211599 DOI: 10.1016/j.jinsphys.2015.07.013] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Among plant-parasitic nematodes, the root-knot nematodes (RKNs) of the Meloidogyne spp. are the most economically important genus. RKN are root parasitic worms able to infect nearly all crop species and have a wide geographic distribution. During infection, RKNs establish and maintain an intimate relationship with the host plant. This includes the creation of a specialized nutritional structure composed of multinucleate and hypertrophied giant cells, which result from the redifferentiation of vascular root cells. Giant cells constitute the sole source of nutrients for the nematode and are essential for growth and reproduction. Hyperplasia of surrounding root cells leads to the formation of the gall or root-knot, an easily recognized symptom of plant infection by RKNs. Secreted effectors produced in nematode salivary glands and injected into plant cells through a specialized feeding structure called the stylet play a critical role in the formation of giant cells. Here, we describe the complex interactions between RKNs and their host plants. We highlight progress in understanding host plant responses, focusing on how RKNs manipulate key plant processes and functions, including cell cycle, defence, hormones, cellular scaffold, metabolism and transport.
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Affiliation(s)
- Bruno Favery
- INRA, UMR 1355 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France; Univ. Nice Sophia Antipolis, UMR 7254 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France; CNRS, UMR 7254 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France
| | - Michaël Quentin
- INRA, UMR 1355 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France; Univ. Nice Sophia Antipolis, UMR 7254 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France; CNRS, UMR 7254 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France
| | - Stéphanie Jaubert-Possamai
- INRA, UMR 1355 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France; Univ. Nice Sophia Antipolis, UMR 7254 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France; CNRS, UMR 7254 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France
| | - Pierre Abad
- INRA, UMR 1355 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France; Univ. Nice Sophia Antipolis, UMR 7254 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France; CNRS, UMR 7254 Institut Sophia Agrobiotech, 06900 Sophia-Antipolis, France.
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Gleason C, Leelarasamee N, Meldau D, Feussner I. OPDA Has Key Role in Regulating Plant Susceptibility to the Root-Knot Nematode Meloidogyne hapla in Arabidopsis. FRONTIERS IN PLANT SCIENCE 2016; 7:1565. [PMID: 27822219 PMCID: PMC5075541 DOI: 10.3389/fpls.2016.01565] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 10/05/2016] [Indexed: 05/19/2023]
Abstract
Jasmonic acid (JA) is a plant hormone that plays important roles in regulating plant defenses against necrotrophic pathogens and herbivorous insects, but the role of JA in mediating the plant responses to root-knot nematodes has been unclear. Here we show that an application of either methyl jasmonate (MeJA) or the JA-mimic coronatine (COR) on Arabidopsis significantly reduced the number of galls caused by the root-knot nematode Meloidogyne hapla. Interestingly, the MeJA-induced resistance was independent of the JA-receptor COI1 (CORONATINE INSENSITIVE 1). The MeJA-treated plants accumulated the JA precursor cis-(+)-12-oxo-phytodienoic acid (OPDA) in addition to JA/JA-Isoleucine, indicating a positive feedback loop in JA biosynthesis. Using mutants in the JA-biosynthetic pathway, we found that plants deficient in the biosynthesis of JA and OPDA were hyper-susceptible to M. hapla. However, the opr3 mutant, which cannot convert OPDA to JA, exhibited wild-type levels of nematode galling. In addition, mutants in the JA-biosynthesis and perception which lie downstream of opr3 also displayed wild-type levels of galling. The data put OPR3 (OPDA reductase 3) as the branch point between hyper-susceptibility and wild-type like levels of disease. Overall, the data suggests that the JA precursor, OPDA, plays a role in regulating plant defense against nematodes.
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Affiliation(s)
- Cynthia Gleason
- Department of Plant Molecular Biology and Physiology, Georg August University - Albrecht von Haller InstituteGöttingen, Germany
- Department of Plant Molecular Biology and Physiology, Georg August University - Göttingen Center for Molecular BiosciencesGöttingen, Germany
- *Correspondence: Cynthia Gleason,
| | - Natthanon Leelarasamee
- Department of Plant Molecular Biology and Physiology, Georg August University - Albrecht von Haller InstituteGöttingen, Germany
| | - Dorothea Meldau
- Department of Plant Biochemistry, Georg August University - Albrecht von Haller InstituteGöttingen, Germany
| | - Ivo Feussner
- Department of Plant Biochemistry, Georg August University - Albrecht von Haller InstituteGöttingen, Germany
- Department of Plant Biochemistry, Georg August University - Göttingen Center for Molecular BiosciencesGöttingen, Germany
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Huang WK, Ji HL, Gheysen G, Debode J, Kyndt T. Biochar-amended potting medium reduces the susceptibility of rice to root-knot nematode infections. BMC PLANT BIOLOGY 2015; 15:267. [PMID: 26537003 PMCID: PMC4632470 DOI: 10.1186/s12870-015-0654-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 10/23/2015] [Indexed: 05/19/2023]
Abstract
BACKGROUND Biochar is a solid coproduct of biomass pyrolysis, and soil amended with biochar has been shown to enhance the productivity of various crops and induce systemic plant resistance to fungal pathogens. The aim of this study was to explore the ability of wood biochar to induce resistance to the root-knot nematode (RKN) Meloidogyne graminicola in rice (Oryza sativa cv. Nipponbare) and examine its histochemical and molecular impact on plant defense mechanisms. RESULTS A 1.2 % concentration of biochar added to the potting medium of rice was found to be the most effective at reducing nematode development in rice roots, whereas direct toxic effects of biochar exudates on nematode viability, infectivity or development were not observed. The increased plant resistance was associated with biochar-primed H2O2 accumulation as well as with the transcriptional enhancement of genes involved in the ethylene (ET) signaling pathway. The increased susceptibility of the Ein2b-RNAi line, which is deficient in ET signaling, further confirmed that biochar-induced priming acts at least partly through ET signaling. CONCLUSION These results suggest that biochar amendments protect rice plants challenged by nematodes. This priming effect partially depends on the ET signaling pathway and enhanced H2O2 accumulation.
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Affiliation(s)
- Wen-kun Huang
- Department of Molecular Biotechnology, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, Beijing, P. R. China.
| | - Hong-li Ji
- Department of Molecular Biotechnology, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
- Institute of Plant Protection, Sichuan Academy of Agricultural Sciences, Jingjusi Road 20, 610066, Chengdu, P. R. China.
| | - Godelieve Gheysen
- Department of Molecular Biotechnology, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
| | - Jane Debode
- Plant Sciences Unit - Plant Protection, Institute for Agricultural and Fisheries Research (ILVO), Burg. van Gansberghelaan 96, 9820, Merelbeke, Belgium.
| | - Tina Kyndt
- Department of Molecular Biotechnology, Ghent University, Coupure Links 653, B-9000, Ghent, Belgium.
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