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Sultana MS, Mazarei M, Millwood RJ, Liu W, Hewezi T, Stewart CN. Functional analysis of soybean cyst nematode-inducible synthetic promoters and their regulation by biotic and abiotic stimuli in transgenic soybean ( Glycine max). FRONTIERS IN PLANT SCIENCE 2022; 13:988048. [PMID: 36160998 PMCID: PMC9501883 DOI: 10.3389/fpls.2022.988048] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/18/2022] [Indexed: 06/16/2023]
Abstract
We previously identified cis-regulatory motifs in the soybean (Glycine max) genome during interaction between soybean and soybean cyst nematode (SCN), Heterodera glycines. The regulatory motifs were used to develop synthetic promoters, and their inducibility in response to SCN infection was shown in transgenic soybean hairy roots. Here, we studied the functionality of two SCN-inducible synthetic promoters; 4 × M1.1 (TAAAATAAAGTTCTTTAATT) and 4 × M2.3 (ATATAATTAAGT) each fused to the -46 CaMV35S core sequence in transgenic soybean. Histochemical GUS analyses of transgenic soybean plants containing the individual synthetic promoter::GUS construct revealed that under unstressed condition, no GUS activity is present in leaves and roots. While upon nematode infection, the synthetic promoters direct GUS expression to roots predominantly in the nematode feeding structures induced by the SCN and by the root-knot nematode (RKN), Meloidogyne incognita. There were no differences in GUS activity in leaves between nematode-infected and non-infected plants. Furthermore, we examined the specificity of the synthetic promoters in response to various biotic (insect: fall armyworm, Spodoptera frugiperda; and bacteria: Pseudomonas syringe pv. glycinea, P. syringe pv. tomato, and P. marginalis) stresses. Additionally, we examined the specificity to various abiotic (dehydration, salt, cold, wounding) as well as to the signal molecules salicylic acid (SA), methyl jasmonate (MeJA), and abscisic acid (ABA) in the transgenic plants. Our wide-range analyses provide insights into the potential applications of synthetic promoter engineering for conditional expression of transgenes leading to transgenic crop development for resistance improvement in plant.
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Affiliation(s)
- Mst Shamira Sultana
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, United States
- Center for Agricultural Synthetic Biology, University of Tennessee, Knoxville, TN, United States
| | - Mitra Mazarei
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, United States
- Center for Agricultural Synthetic Biology, University of Tennessee, Knoxville, TN, United States
| | - Reginald J. Millwood
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, United States
| | - Wusheng Liu
- Department of Horticultural Science, North Carolina State University, Raleigh, NC, United States
| | - Tarek Hewezi
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, United States
| | - C. Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, United States
- Center for Agricultural Synthetic Biology, University of Tennessee, Knoxville, TN, United States
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Zhang L, Zeng Q, Zhu Q, Tan Y, Guo X. Essential Roles of Cupredoxin Family Proteins in Soybean Cyst Nematode Resistance. PHYTOPATHOLOGY 2022; 112:1545-1558. [PMID: 35050680 DOI: 10.1094/phyto-09-21-0391-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Soybean cyst nematode (SCN, Heterodera glycines), one of the most devastating soybean pathogens, causes a significant yield loss in soybean production. One of the most effective ways to manage SCN is to grow resistant cultivars. Therefore, comparative study using resistant and susceptible soybean cultivars provides a powerful tool to identify new genes involved in soybean SCN resistance. In the present study, a transcriptome analysis was carried out using both the resistant (PI88788) and susceptible (Williams 82) soybean cultivars to characterize the responses to nematode infection. Various defense-related genes and different pathways involved in nematode resistance were recognized as being highly expressed in resistant cultivar. Promoter-GUS analysis was conducted to monitor the spatial expression pattern of the genes highly induced by nematode infection. Two nematode-inducible promoters for Glyma.05g147000 (encoding caffeoyl-CoA O-methyltransferase) and Glyma.06g036700 (encoding cupredoxin superfamily protein) were characterized, and the promoters could efficiently drive the expression of known nematode resistance genes (α-SNAPRhg1HC or GmSHMT) to affect soybean SCN resistance. Interestingly, expression of the cupredoxin family genes was upregulated not only by SCN, but also by jasmonic acid treatment. DNA sequence analysis identified that a conserved motif (GGTGCATG) with high similarity to SCNbox1 and GC-rich element is enriched in their promoter regions, suggesting its potential to serve as a nematode-responsive regulatory element. Overexpression of Glyma.06g036700 significantly enhanced soybean resistance to cyst nematode. Overall, our findings not only highlight the essential role of cupredoxin family genes in SCN resistance, but also offer potential functional tools to develop nematode resistance in crops.
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Affiliation(s)
- Lei Zhang
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Qian Zeng
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Qun Zhu
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yuanhua Tan
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Xiaoli Guo
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
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Baruah I, Baldodiya GM, Sahu J, Baruah G. Dissecting the Role of Promoters of Pathogen-sensitive Genes in Plant Defense. Curr Genomics 2020; 21:491-503. [PMID: 33214765 PMCID: PMC7604749 DOI: 10.2174/1389202921999200727213500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 06/15/2020] [Accepted: 06/30/2020] [Indexed: 11/22/2022] Open
Abstract
Plants inherently show resistance to pathogen attack but are susceptible to multiple bacteria, viruses, fungi, and phytoplasmas. Diseases as a result of such infection leads to the deterioration of crop yield. Several pathogen-sensitive gene activities, promoters of such genes, associated transcription factors, and promoter elements responsible for crosstalk between the defense signaling pathways are involved in plant resistance towards a pathogen. Still, only a handful of genes and their promoters related to plant resistance have been identified to date. Such pathogen-sensitive promoters are accountable for elevating the transcriptional activity of certain genes in response to infection. Also, a suitable promoter is a key to devising successful crop improvement strategies as it ensures the optimum expression of the required transgene. The study of the promoters also helps in mining more details about the transcription factors controlling their activities and helps to unveil the involvement of new genes in the pathogen response. Therefore, the only way out to formulate new solutions is by analyzing the molecular aspects of these promoters in detail. In this review, we provided an overview of the promoter motifs and cis-regulatory elements having specific roles in pathogen attack response. To elaborate on the importance and get a vivid picture of the pathogen-sensitive promoter sequences, the key motifs and promoter elements were analyzed with the help of PlantCare and interpreted with available literature. This review intends to provide useful information for reconstructing the gene networks underlying the resistance of plants against pathogens.
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Affiliation(s)
| | | | - Jagajjit Sahu
- Address correspondence to these authors at the Department of Mycology & Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University (BHU), Varanasi-221005, Uttar Pradesh, India;, E-mail: ; Environment Division, Assam Science Technology & Environment Council, Bigyan Bhawan, Guwahati-781005, Assam, India; E-mail:
| | - Geetanjali Baruah
- Address correspondence to these authors at the Department of Mycology & Plant Pathology, Institute of Agricultural Sciences, Banaras Hindu University (BHU), Varanasi-221005, Uttar Pradesh, India;, E-mail: ; Environment Division, Assam Science Technology & Environment Council, Bigyan Bhawan, Guwahati-781005, Assam, India; E-mail:
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4
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Wang J, Yeckel G, Kandoth PK, Wasala L, Hussey RS, Davis EL, Baum TJ, Mitchum MG. Targeted suppression of soybean BAG6-induced cell death in yeast by soybean cyst nematode effectors. MOLECULAR PLANT PATHOLOGY 2020; 21:1227-1239. [PMID: 32686295 PMCID: PMC7411569 DOI: 10.1111/mpp.12970] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 05/29/2023]
Abstract
While numerous effectors that suppress plant immunity have been identified from bacteria, fungi, and oomycete pathogens, relatively little is known for nematode effectors. Several dozen effectors have been reported from the soybean cyst nematode (SCN). Previous studies suggest that a hypersensitive response-like programmed cell death is triggered at nematode feeding sites in soybean during an incompatible interaction. However, virulent SCN populations overcome this incompatibility using unknown mechanisms. A soybean BAG6 (Bcl-2 associated anthanogene 6) gene previously reported by us to be highly up-regulated in degenerating feeding sites induced by SCN in a resistant soybean line was attenuated in response to a virulent SCN population. We show that GmBAG6-1 induces cell death in yeast like its Arabidopsis homolog AtBAG6 and also in soybean. This led us to hypothesize that virulent SCN may target GmBAG6-1 as part of their strategy to overcome soybean defence responses during infection. Thus, we used a yeast viability assay to screen SCN effector candidates for their ability to specifically suppress GmBAG6-1-induced cell death. We identified several effectors that strongly suppressed cell death mediated by GmBAG6-1. Two effectors identified as suppressors showed direct interaction with GmBAG6-1 in yeast, suggesting that one mechanism of cell death suppression may occur through an interaction with this host protein.
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Affiliation(s)
- Jianying Wang
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
| | - Greg Yeckel
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Present address:
Corteva AgriscienceJohnstonIAUSA
| | - Pramod K. Kandoth
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Present address:
National Agri‐food Biotechnology InstituteMohaliIndia
| | - Lakmini Wasala
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Present address:
Department of Veterinary PathobiologyUniversity of MissouriColumbiaMOUSA
| | | | - Eric L. Davis
- Department of Entomology and Plant PathologyNorth Carolina State UniversityRaleighNCUSA
| | - Thomas J. Baum
- Department of Plant Pathology and MicrobiologyIowa State UniversityAmesIAUSA
| | - Melissa G. Mitchum
- Division of Plant Sciences and Bond Life Sciences CenterUniversity of MissouriColumbiaMOUSA
- Department of Plant Pathology and Institute of Plant Breeding, Genetics, and GenomicsUniversity of GeorgiaAthensGAUSA
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Verma A, Lee C, Morriss S, Odu F, Kenning C, Rizzo N, Spollen WG, Lin M, McRae AG, Givan SA, Hewezi T, Hussey R, Davis EL, Baum TJ, Mitchum MG. The novel cyst nematode effector protein 30D08 targets host nuclear functions to alter gene expression in feeding sites. THE NEW PHYTOLOGIST 2018; 219:697-713. [PMID: 29726613 DOI: 10.1111/nph.15179] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 03/15/2018] [Indexed: 05/29/2023]
Abstract
Cyst nematodes deliver effector proteins into host cells to manipulate cellular processes and establish a metabolically hyperactive feeding site. The novel 30D08 effector protein is produced in the dorsal gland of parasitic juveniles, but its function has remained unknown. We demonstrate that expression of 30D08 contributes to nematode parasitism, the protein is packaged into secretory granules and it is targeted to the plant nucleus where it interacts with SMU2 (homolog of suppressor of mec-8 and unc-52 2), an auxiliary spliceosomal protein. We show that SMU2 is expressed in feeding sites and an smu2 mutant is less susceptible to nematode infection. In Arabidopsis expressing 30D08 under the SMU2 promoter, several genes were found to be alternatively spliced and the most abundant functional classes represented among differentially expressed genes were involved in RNA processing, transcription and binding, as well as in development, and hormone and secondary metabolism, representing key cellular processes known to be important for feeding site formation. In conclusion, we demonstrated that the 30D08 effector is secreted from the nematode and targeted to the plant nucleus where its interaction with a host auxiliary spliceosomal protein may alter the pre-mRNA splicing and expression of a subset of genes important for feeding site formation.
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Affiliation(s)
- Anju Verma
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Chris Lee
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Stephanie Morriss
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Fiona Odu
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Charlotte Kenning
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | | | - William G Spollen
- Informatics Research Core Facility, University of Missouri, Columbia, MO, 65211, USA
| | - Marriam Lin
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Amanda G McRae
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
| | - Scott A Givan
- Informatics Research Core Facility, University of Missouri, Columbia, MO, 65211, USA
| | - Tarek Hewezi
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Richard Hussey
- Department of Plant Pathology, University of Georgia, Athens, GA, 30602, USA
| | - Eric L Davis
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, 27695, USA
| | - Thomas J Baum
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
| | - Melissa G Mitchum
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO, 65211, USA
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Ali MA, Anjam MS, Nawaz MA, Lam HM, Chung G. Signal Transduction in Plant⁻Nematode Interactions. Int J Mol Sci 2018; 19:ijms19061648. [PMID: 29865232 PMCID: PMC6032140 DOI: 10.3390/ijms19061648] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 05/26/2018] [Accepted: 05/29/2018] [Indexed: 12/26/2022] Open
Abstract
To successfully invade and infect their host plants, plant parasitic nematodes (PPNs) need to evolve molecular mechanisms to overcome the defense responses from the plants. Nematode-associated molecular patterns (NAMPs), including ascarosides and certain proteins, while instrumental in enabling the infection, can be perceived by the host plants, which then initiate a signaling cascade leading to the induction of basal defense responses. To combat host resistance, some nematodes can inject effectors into the cells of susceptible hosts to reprogram the basal resistance signaling and also modulate the hosts’ gene expression patterns to facilitate the establishment of nematode feeding sites (NFSs). In this review, we summarized all the known signaling pathways involved in plant–nematode interactions. Specifically, we placed particular focus on the effector proteins from PPNs that mimic the signaling of the defense responses in host plants. Furthermore, we gave an updated overview of the regulation by PPNs of different host defense pathways such as salicylic acid (SA)/jasmonic acid (JA), auxin, and cytokinin and reactive oxygen species (ROS) signaling to facilitate their parasitic successes in plants. This review will enhance the understanding of the molecular signaling pathways involved in both compatible and incompatible plant–nematode interactions.
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Affiliation(s)
- Muhammad Amjad Ali
- Department of Plant Pathology, University of Agriculture, Faisalabad 38040, Pakistan.
- Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad 38040, Pakistan.
| | - Muhammad Shahzad Anjam
- Institute of Molecular Biology & Biotechnology, Bahauddin Zakariya University, Multan 66000, Pakistan.
| | | | - Hon-Ming Lam
- School of Life Sciences and Centre for Soybean Research of the Partner State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
| | - Gyuhwa Chung
- Department of Biotechnology, Chonnam National University, Yeosu 59626, Korea.
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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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Ali MA, Azeem F, Li H, Bohlmann H. Smart Parasitic Nematodes Use Multifaceted Strategies to Parasitize Plants. FRONTIERS IN PLANT SCIENCE 2017; 8:1699. [PMID: 29046680 PMCID: PMC5632807 DOI: 10.3389/fpls.2017.01699] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/15/2017] [Indexed: 05/03/2023]
Abstract
Nematodes are omnipresent in nature including many species which are parasitic to plants and cause enormous economic losses in various crops. During the process of parasitism, sedentary phytonematodes use their stylet to secrete effector proteins into the plant cells to induce the development of specialized feeding structures. These effectors are used by the nematodes to develop compatible interactions with plants, partly by mimicking the expression of host genes. Intensive research is going on to investigate the molecular function of these effector proteins in the plants. In this review, we have summarized which physiological and molecular changes occur when endoparasitic nematodes invade the plant roots and how they develop a successful interaction with plants using the effector proteins. We have also mentioned the host genes which are induced by the nematodes for a compatible interaction. Additionally, we discuss how nematodes modulate the reactive oxygen species (ROS) and RNA silencing pathways in addition to post-translational modifications in their own favor for successful parasitism in plants.
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Affiliation(s)
- Muhammad A. Ali
- Department of Plant Pathology, University of Agriculture Faisalabad, Faisalabad, Pakistan
- Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture Faisalabad, Faisalabad, Pakistan
- *Correspondence: Muhammad A. Ali ;
| | - Farrukh Azeem
- Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan
| | - Hongjie Li
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Holger Bohlmann
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Vienna, Austria
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Li R, Rashotte AM, Singh NK, Lawrence KS, Weaver DB, Locy RD. Transcriptome Analysis of Cotton (Gossypium hirsutum L.) Genotypes That Are Susceptible, Resistant, and Hypersensitive to Reniform Nematode (Rotylenchulus reniformis). PLoS One 2015; 10:e0143261. [PMID: 26571375 PMCID: PMC4646469 DOI: 10.1371/journal.pone.0143261] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 11/02/2015] [Indexed: 11/18/2022] Open
Abstract
Reniform nematode is a semi-endoparasitic nematode species causing significant yield loss in numerous crops, including cotton (Gossypium hirsutum L.). An RNA-sequencing analysis was conducted to measure transcript abundance in reniform nematode susceptible (DP90 & SG747), resistant (BARBREN-713), and hypersensitive (LONREN-1) genotypes of cotton (Gossypium hirsutum L.) with and without reniform nematode infestation. Over 90 million trimmed high quality reads were assembled into 84,711 and 80, 353 transcripts using the G. arboreum and the G. raimondii genomes as references. Many transcripts were significantly differentially expressed between the three different genotypes both prior to and during nematode pathogenesis, including transcripts corresponding to the gene ontology categories of cell wall, hormone metabolism and signaling, redox reactions, secondary metabolism, transcriptional regulation, stress responses, and signaling. Further analysis revealed that a number of these differentially expressed transcripts mapped to the G. raimondii and/or the G. arboreum genomes within 1 megabase of quantitative trait loci that had previously been linked to reniform nematode resistance. Several resistance genes encoding proteins known to be strongly linked to pathogen perception and resistance, including LRR-like and NBS-LRR domain-containing proteins, were among the differentially expressed transcripts mapping near these quantitative trait loci. Further investigation is required to confirm a role for these transcripts in reniform nematode susceptibility, hypersensitivity, and/or resistance. This study presents the first systemic investigation of reniform nematode resistance-associated genes using different genotypes of cotton. The candidate reniform nematode resistance-associated genes identified in this study can serve as the basis for further functional analysis and aid in further development of reniform a nematode resistant cotton germplasm.
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Affiliation(s)
- Ruijuan Li
- Department of Biological Sciences, Auburn University, Auburn, Alabama, United States of America
| | - Aaron M. Rashotte
- Department of Biological Sciences, Auburn University, Auburn, Alabama, United States of America
| | - Narendra K. Singh
- Department of Biological Sciences, Auburn University, Auburn, Alabama, United States of America
| | - Kathy S. Lawrence
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America
| | - David B. Weaver
- Department of Crop, Soil and Environmental Sciences, Auburn University, Auburn, Alabama, United States of America
| | - Robert D. Locy
- Department of Biological Sciences, Auburn University, Auburn, Alabama, United States of America
- * E-mail:
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Ng JLP, Perrine-Walker F, Wasson AP, Mathesius U. The Control of Auxin Transport in Parasitic and Symbiotic Root-Microbe Interactions. PLANTS (BASEL, SWITZERLAND) 2015; 4:606-43. [PMID: 27135343 PMCID: PMC4844411 DOI: 10.3390/plants4030606] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 08/12/2015] [Accepted: 08/18/2015] [Indexed: 01/13/2023]
Abstract
Most field-grown plants are surrounded by microbes, especially from the soil. Some of these, including bacteria, fungi and nematodes, specifically manipulate the growth and development of their plant hosts, primarily for the formation of structures housing the microbes in roots. These developmental processes require the correct localization of the phytohormone auxin, which is involved in the control of cell division, cell enlargement, organ development and defense, and is thus a likely target for microbes that infect and invade plants. Some microbes have the ability to directly synthesize auxin. Others produce specific signals that indirectly alter the accumulation of auxin in the plant by altering auxin transport. This review highlights root-microbe interactions in which auxin transport is known to be targeted by symbionts and parasites to manipulate the development of their host root system. We include case studies for parasitic root-nematode interactions, mycorrhizal symbioses as well as nitrogen fixing symbioses in actinorhizal and legume hosts. The mechanisms to achieve auxin transport control that have been studied in model organisms include the induction of plant flavonoids that indirectly alter auxin transport and the direct targeting of auxin transporters by nematode effectors. In most cases, detailed mechanisms of auxin transport control remain unknown.
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Affiliation(s)
- Jason Liang Pin Ng
- Division of Plant Science, Research School of Biology, Australian National University, Linnaeus Way, Building 134, Canberra ACT 2601, Australia.
| | | | | | - Ulrike Mathesius
- Division of Plant Science, Research School of Biology, Australian National University, Linnaeus Way, Building 134, Canberra ACT 2601, Australia.
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Dąbrowska-Bronk J, Czarny M, Wiśniewska A, Fudali S, Baranowski Ł, Sobczak M, Święcicka M, Matuszkiewicz M, Brzyżek G, Wroblewski T, Dobosz R, Bartoszewski G, Filipecki M. Suppression of NGB and NAB/ERabp1 in tomato modifies root responses to potato cyst nematode infestation. MOLECULAR PLANT PATHOLOGY 2015; 16:334-48. [PMID: 25131407 PMCID: PMC6638365 DOI: 10.1111/mpp.12183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Plant-parasitic nematodes cause significant damage to major crops throughout the world. The small number of genes conferring natural plant resistance and the limitations of chemical control require the development of new protective strategies. RNA interference or the inducible over-expression of nematicidal genes provides an environment-friendly approach to this problem. Candidate genes include NGB, which encodes a small GTP-binding protein, and NAB/ERabp1, which encodes an auxin-binding protein, which were identified as being up-regulated in tomato roots in a transcriptome screen of potato cyst nematode (Globodera rostochiensis) feeding sites. Real-time reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization confirmed the localized up-regulation of these genes in syncytia and surrounding cells following nematode infection. Gene-silencing constructs were introduced into tomato, resulting in a 20%-98% decrease in transcription levels. Nematode infection tests conducted on transgenic plants showed 57%-82% reduction in the number of G. rostochiensis females in vitro and 30%-46% reduction in pot trials. Transmission electron microscopy revealed a deterioration of cytoplasm, and degraded mitochondria and plastids, in syncytia induced in plants with reduced NAB/ERabp1 expression. Cytoplasm in syncytia induced in plants with low NGB expression was strongly electron translucent and contained very few ribosomes; however, mitochondria and plastids remained intact. Functional impairments in syncytial cytoplasm of silenced plants may result from NGB's role in ribosome biogenesis; this was confirmed by localization of yellow fluorescent protein (YFP)-labelled NGB protein in nucleoli and co-repression of NGB in plants with reduced NAB/ERabp1 expression. These results demonstrate that NGB and NAB/ERabp1 play important roles in the development of nematode-induced syncytia.
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Affiliation(s)
- Joanna Dąbrowska-Bronk
- Department of Plant Genetics, Breeding and Biotechnology, Warsaw University of Life Sciences (SGGW), Nowoursynowska 159, 02-787, Warsaw, Poland
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Chen S, Lang P, Chronis D, Zhang S, De Jong WS, Mitchum MG, Wang X. In planta processing and glycosylation of a nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-like effector and its interaction with a host CLAVATA2-like receptor to promote parasitism. PLANT PHYSIOLOGY 2015; 167:262-72. [PMID: 25416475 PMCID: PMC4281011 DOI: 10.1104/pp.114.251637] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants.
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Affiliation(s)
- Shiyan Chen
- Department of Plant Pathology and Plant-Microbe Biology (S.C., P.L., X.W.), Proteomics and Mass Spectrometry Facility, Institute of Biotechnology and Life Science Technologies (S.Z.), and Department of Plant Breeding and Genetics (W.S.D.J.), Cornell University, Ithaca, New York 14853;Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture, Agricultural Research Service, Ithaca, New York 14853 (D.C., X.W.); andDivision of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211 (M.G.M.)
| | - Ping Lang
- Department of Plant Pathology and Plant-Microbe Biology (S.C., P.L., X.W.), Proteomics and Mass Spectrometry Facility, Institute of Biotechnology and Life Science Technologies (S.Z.), and Department of Plant Breeding and Genetics (W.S.D.J.), Cornell University, Ithaca, New York 14853;Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture, Agricultural Research Service, Ithaca, New York 14853 (D.C., X.W.); andDivision of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211 (M.G.M.)
| | - Demosthenis Chronis
- Department of Plant Pathology and Plant-Microbe Biology (S.C., P.L., X.W.), Proteomics and Mass Spectrometry Facility, Institute of Biotechnology and Life Science Technologies (S.Z.), and Department of Plant Breeding and Genetics (W.S.D.J.), Cornell University, Ithaca, New York 14853;Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture, Agricultural Research Service, Ithaca, New York 14853 (D.C., X.W.); andDivision of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211 (M.G.M.)
| | - Sheng Zhang
- Department of Plant Pathology and Plant-Microbe Biology (S.C., P.L., X.W.), Proteomics and Mass Spectrometry Facility, Institute of Biotechnology and Life Science Technologies (S.Z.), and Department of Plant Breeding and Genetics (W.S.D.J.), Cornell University, Ithaca, New York 14853;Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture, Agricultural Research Service, Ithaca, New York 14853 (D.C., X.W.); andDivision of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211 (M.G.M.)
| | - Walter S De Jong
- Department of Plant Pathology and Plant-Microbe Biology (S.C., P.L., X.W.), Proteomics and Mass Spectrometry Facility, Institute of Biotechnology and Life Science Technologies (S.Z.), and Department of Plant Breeding and Genetics (W.S.D.J.), Cornell University, Ithaca, New York 14853;Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture, Agricultural Research Service, Ithaca, New York 14853 (D.C., X.W.); andDivision of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211 (M.G.M.)
| | - Melissa G Mitchum
- Department of Plant Pathology and Plant-Microbe Biology (S.C., P.L., X.W.), Proteomics and Mass Spectrometry Facility, Institute of Biotechnology and Life Science Technologies (S.Z.), and Department of Plant Breeding and Genetics (W.S.D.J.), Cornell University, Ithaca, New York 14853;Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture, Agricultural Research Service, Ithaca, New York 14853 (D.C., X.W.); andDivision of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211 (M.G.M.)
| | - Xiaohong Wang
- Department of Plant Pathology and Plant-Microbe Biology (S.C., P.L., X.W.), Proteomics and Mass Spectrometry Facility, Institute of Biotechnology and Life Science Technologies (S.Z.), and Department of Plant Breeding and Genetics (W.S.D.J.), Cornell University, Ithaca, New York 14853;Robert W. Holley Center for Agriculture and Health, United States Department of Agriculture, Agricultural Research Service, Ithaca, New York 14853 (D.C., X.W.); andDivision of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211 (M.G.M.)
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13
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Li R, Rashotte AM, Singh NK, Weaver DB, Lawrence KS, Locy RD. Integrated signaling networks in plant responses to sedentary endoparasitic nematodes: a perspective. PLANT CELL REPORTS 2015; 34:5-22. [PMID: 25208657 DOI: 10.1007/s00299-014-1676-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 08/13/2014] [Accepted: 08/18/2014] [Indexed: 05/24/2023]
Abstract
Sedentary plant endoparasitic nematodes can cause detrimental yield losses in crop plants making the study of detailed cellular, molecular, and whole plant responses to them a subject of importance. In response to invading nematodes and nematode-secreted effectors, plant susceptibility/resistance is mainly determined by the coordination of different signaling pathways including specific plant resistance genes or proteins, plant hormone synthesis and signaling pathways, as well as reactive oxygen signals that are generated in response to nematode attack. Crosstalk between various nematode resistance-related elements can be seen as an integrated signaling network regulated by transcription factors and small RNAs at the transcriptional, posttranscriptional, and/or translational levels. Ultimately, the outcome of this highly controlled signaling network determines the host plant susceptibility/resistance to nematodes.
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Affiliation(s)
- Ruijuan Li
- Department of Biological Sciences, Auburn University, 101 Rouse Life Science Building, Auburn, AL, 36849, USA
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14
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Woo MO, Beard H, MacDonald MH, Brewer EP, Youssef RM, Kim H, Matthews BF. Manipulation of two α-endo-β-1,4-glucanase genes, AtCel6 and GmCel7, reduces susceptibility to Heterodera glycines in soybean roots. MOLECULAR PLANT PATHOLOGY 2014; 15:927-39. [PMID: 24844661 PMCID: PMC6638630 DOI: 10.1111/mpp.12157] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Plant endo-β-1,4-glucanases (EGases) include cell wall-modifying enzymes that are involved in nematode-induced growth of syncytia (feeding structures) in nematode-infected roots. EGases in the α- and β-subfamilies contain signal peptides and are secreted, whereas those in the γ-subfamily have a membrane-anchoring domain and are not secreted. The Arabidopsis α-EGase At1g48930, designated as AtCel6, is known to be down-regulated by beet cyst nematode (Heterodera schachtii) in Arabidopsis roots, whereas another α-EGase, AtCel2, is up-regulated. Here, we report that the ectopic expression of AtCel6 in soybean roots reduces susceptibility to both soybean cyst nematode (SCN; Heterodera glycines) and root knot nematode (Meloidogyne incognita). Suppression of GmCel7, the soybean homologue of AtCel2, in soybean roots also reduces the susceptibility to SCN. In contrast, in studies on two γ-EGases, both ectopic expression of AtKOR2 in soybean roots and suppression of the soybean homologue of AtKOR3 had no significant effect on SCN parasitism. Our results suggest that secreted α-EGases are likely to be more useful than membrane-bound γ-EGases in the development of an SCN-resistant soybean through gene manipulation. Furthermore, this study provides evidence that Arabidopsis shares molecular events of cyst nematode parasitism with soybean, and confirms the suitability of the Arabidopsis-H. schachtii interaction as a model for the soybean-H. glycines pathosystem.
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Affiliation(s)
- Mi-Ok Woo
- Soybean Genomics and Improvement Laboratory, USDA-ARS, Beltsville, MD, 20705, USA
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15
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Cabrera J, Díaz-Manzano FE, Sanchez M, Rosso MN, Melillo T, Goh T, Fukaki H, Cabello S, Hofmann J, Fenoll C, Escobar C. A role for LATERAL ORGAN BOUNDARIES-DOMAIN 16 during the interaction Arabidopsis-Meloidogyne spp. provides a molecular link between lateral root and root-knot nematode feeding site development. THE NEW PHYTOLOGIST 2014; 203:632-645. [PMID: 24803293 DOI: 10.1111/nph.12826] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/21/2014] [Indexed: 05/08/2023]
Abstract
Plant endoparasitic nematodes induce the formation of their feeding cells by injecting effectors from the esophageal glands into root cells. Although vascular cylinder cells seem to be involved in the formation of root-knot nematode (RKN) feeding structures, molecular evidence is scarce. We address the role during gall development of LATERAL ORGAN BOUNDARIES-DOMAIN 16 (LBD16), a key component of the auxin pathway leading to the divisions in the xylem pole pericycle (XPP) for lateral root (LR) formation. Arabidopsis T-DNA tagged J0192 and J0121 XPP marker lines, LBD16 and DR5::GUS promoter lines, and isolated J0192 protoplasts were assayed for nematode-dependent gene expression. Infection tests in LBD16 knock-out lines were used for functional analysis. J0192 and J0121 lines were activated in early developing galls and giant cells (GCs), resembling the pattern of the G2/M-transition specific ProC yc B 1;1 :CycB1;1(NT)-GUS line. LBD16 was regulated by auxins in galls as in LRs, and induced by RKN secretions. LBD16 loss of function mutants and a transgenic line with defective XPP cells showed a significantly reduced infection rate. The results show that genes expressed in the dividing XPP, particularly LBD16, are important for gall formation, as they are for LR development.
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Affiliation(s)
- Javier Cabrera
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Av. Carlos III s/n, E-45071, Toledo, Spain
| | - Fernando E Díaz-Manzano
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Av. Carlos III s/n, E-45071, Toledo, Spain
| | - María Sanchez
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Av. Carlos III s/n, E-45071, Toledo, Spain
| | - Marie-Noëlle Rosso
- INRA, Aix-Marseille Université, UMR 1163, Biotechnologie des Champignons Filamenteux, F-13009, Marseille, France
| | - Teresa Melillo
- Istituto per la Protezione de lle Piante, CNR, 70126, Bari, Italy
| | - Tatsuaki Goh
- Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Kobe, 657-8501, Japan
| | - Hidehiro Fukaki
- Department of Biology, Graduate School of Science, Kobe University, 1-1 Rokkodai, Kobe, 657-8501, Japan
| | - Susana Cabello
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Applied Life Sciences, Konrad Lorenz Str. 24, Tulln a. d. Donau, A-3430, Austria
| | - Julia Hofmann
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Applied Life Sciences, Konrad Lorenz Str. 24, Tulln a. d. Donau, A-3430, Austria
| | - Carmen Fenoll
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Av. Carlos III s/n, E-45071, Toledo, Spain
| | - Carolina Escobar
- Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla-La Mancha, Av. Carlos III s/n, E-45071, Toledo, Spain
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16
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Replogle A, Wang J, Paolillo V, Smeda J, Kinoshita A, Durbak A, Tax FE, Wang X, Sawa S, Mitchum MG. Synergistic interaction of CLAVATA1, CLAVATA2, and RECEPTOR-LIKE PROTEIN KINASE 2 in cyst nematode parasitism of Arabidopsis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:87-96. [PMID: 22835273 DOI: 10.1094/mpmi-05-12-0118-fi] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plant-parasitic cyst nematodes secrete CLAVATA3 (CLV3)/ENDOSPERM SURROUNDING REGION (CLE)-like effector proteins. These proteins act as ligand mimics of plant CLE peptides and are required for successful nematode infection. Previously, we showed that the CLV2/CORYNE (CRN) heterodimer receptor complex is required for nematode CLE signaling. However, there was only a partial reduction in nematode infection when this signaling was disrupted, indicating that there might be additional nematode CLE receptors. In this study, we demonstrate that CLV1 and RECEPTOR-LIKE PROTEIN KINASE 2/TOADSTOOL2 (RPK2), two additional receptors that can transmit the CLV3 signal independent of CLV2/CRN for shoot apical meristem maintenance, also play a role in nematode CLE perception. Localization studies showed that both receptors are expressed in nematode-induced syncytia. Infection assays with clv1 and rpk2 single mutants revealed a decrease in both nematode infection and syncytium size. Significantly, further reduction in nematode infection was observed when rpk2 was combined with clv1 and clv2 mutants. Taken together, our results indicate that parallel signaling pathways involving CLV1, CLV2, and RPK2 are important for nematode parasitism.
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17
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Wiśniewska A, Dąbrowska-Bronk J, Szafrański K, Fudali S, Święcicka M, Czarny M, Wilkowska A, Morgiewicz K, Matusiak J, Sobczak M, Filipecki M. Analysis of tomato gene promoters activated in syncytia induced in tomato and potato hairy roots by Globodera rostochiensis. Transgenic Res 2012; 22:557-69. [PMID: 23129482 PMCID: PMC3653032 DOI: 10.1007/s11248-012-9665-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 10/05/2012] [Indexed: 11/29/2022]
Abstract
The potato cyst nematode (Globodera rostochiensis) induces feeding sites (syncytia) in tomato and potato roots. In a previous study, 135 tomato genes up-regulated during G. rostochiensis migration and syncytium development were identified. Five genes (CYP97A29, DFR, FLS, NIK and PMEI) were chosen for further study to examine their roles in plant-nematode interactions. The promoters of these genes were isolated and potential cis regulatory elements in their sequences were characterized using bioinformatics tools. Promoter fusions with the β-glucuronidase gene were constructed and introduced into tomato and potato genomes via transformation with Agrobacterium rhizogenes to produce hairy roots. The analysed promoters displayed different activity patterns in nematode-infected and uninfected transgenic hairy roots.
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Affiliation(s)
- A Wiśniewska
- Department of Plant Physiology, Faculty of Agriculture and Biology, Warsaw University of Life Sciences (SGGW), Nowoursynowska 159, 02-776 Warsaw, Poland.
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18
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Mitchum MG, Wang X, Wang J, Davis EL. Role of nematode peptides and other small molecules in plant parasitism. ANNUAL REVIEW OF PHYTOPATHOLOGY 2012; 50:175-95. [PMID: 22578179 DOI: 10.1146/annurev-phyto-081211-173008] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Molecular, genetic, and biochemical studies are demonstrating an increasingly important role of peptide signaling in nematode parasitism of plants. To date, the majority of nematode-secreted peptides identified share similarity with plant CLAVATA3/ESR (CLE) peptides, but bioinformatics analyses of nematode genomes have revealed sequences homologous to other classes of plant peptide hormones that may be utilized by these pests. Extracellular host receptors for secreted nematode peptides are beginning to be identified and their roles in parasitism elucidated. Here, we outline recent advances from studies of biologically active nematode-secreted peptides that function as molecular mimics of endogenous plant peptides to promote parasitism. Several strategies are being used to exploit this information to provide new targets for engineering nematode resistance.
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Affiliation(s)
- Melissa G Mitchum
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211, USA
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19
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Tucker ML, Murphy CA, Yang R. Gene expression profiling and shared promoter motif for cell wall-modifying proteins expressed in soybean cyst nematode-infected roots. PLANT PHYSIOLOGY 2011; 156:319-29. [PMID: 21430185 PMCID: PMC3091069 DOI: 10.1104/pp.110.170357] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Accepted: 03/21/2011] [Indexed: 05/29/2023]
Abstract
We hypothesized that soybean cyst nematode (SCN; Heterodera glycines) co-opts part or all of one or more innate developmental process in soybean (Glycine max) to establish its feeding structure, syncytium, in soybean roots. The syncytium is formed within the vascular bundle by partial degradation of cell walls and membranes between adjacent parenchyma cells. A mature syncytium incorporates as many as 200 cells into one large multinucleated cell. Gene expression patterns for several cell wall-modifying proteins were compared in multiple tissues undergoing major shifts in cell wall integrity. These included SCN-colonized roots, root tips where vascular differentiation occurs, flooded roots (aerenchyma), adventitious rooting in hypocotyls, and leaf abscission zones. A search in the 5' upstream promoters of these genes identified a motif (SCNbox1: WGCATGTG) common to several genes that were up-regulated in several different tissues. The polygalacturonase 11 promoters (GmPG11a/b) include the SCNbox1 motif. The expression pattern for GmPG11a was examined further in transgenic soybean containing a PG11a promoter fused to a β-glucuronidase (GUS) reporter gene. GUS expression was highest in cells undergoing radial expansion in the stele and/or cell wall dissolution. GUS staining was not observed in cortical cells where a lateral root tip or a growing nematode emerged through the root cortex.
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Affiliation(s)
- Mark L Tucker
- Soybean Genomics and Improvement Lab, Agricultural Research Service, United States Department of Agriculture, Beltsville Agricultural Research Center, Beltsville, Maryland 20705, USA.
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20
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Kandoth PK, Ithal N, Recknor J, Maier T, Nettleton D, Baum TJ, Mitchum MG. The Soybean Rhg1 locus for resistance to the soybean cyst nematode Heterodera glycines regulates the expression of a large number of stress- and defense-related genes in degenerating feeding cells. PLANT PHYSIOLOGY 2011; 155:1960-75. [PMID: 21335526 PMCID: PMC3091121 DOI: 10.1104/pp.110.167536] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 02/14/2011] [Indexed: 05/19/2023]
Abstract
To gain new insights into the mechanism of soybean (Glycine max) resistance to the soybean cyst nematode (Heterodera glycines), we compared gene expression profiles of developing syncytia in soybean near-isogenic lines differing at Rhg1 (for resistance to Heterodera glycines), a major quantitative trait locus for resistance, by coupling laser capture microdissection with microarray analysis. Gene expression profiling revealed that 1,447 genes were differentially expressed between the two lines. Of these, 241 (16.8%) were stress- and defense-related genes. Several stress-related genes were up-regulated in the resistant line, including those encoding homologs of enzymes that lead to increased levels of reactive oxygen species and proteins associated with the unfolded protein response. These results indicate that syncytia induced in the resistant line are undergoing severe oxidative stress and imbalanced endoplasmic reticulum homeostasis, both of which likely contribute to the resistance reaction. Defense-related genes up-regulated within syncytia of the resistant line included those predominantly involved in apoptotic cell death, the plant hypersensitive response, and salicylic acid-mediated defense signaling; many of these genes were either partially suppressed or not induced to the same level by a virulent soybean cyst nematode population for successful nematode reproduction and development on the resistant line. Our study demonstrates that a network of molecular events take place during Rhg1-mediated resistance, leading to a highly complex defense response against a root pathogen.
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Affiliation(s)
| | | | | | | | | | | | - Melissa G. Mitchum
- Division of Plant Sciences, Interdisciplinary Plant Group, and Bond Life Sciences Center, University of Missouri, Columbia, Missouri 65211 (P.K.K., N.I., M.G.M.); Department of Statistics (J.R., D.N.) and Department of Plant Pathology (T.M., T.J.B.), Iowa State University, Ames, Iowa 50011
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21
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Replogle A, Wang J, Bleckmann A, Hussey RS, Baum TJ, Sawa S, Davis EL, Wang X, Simon R, Mitchum MG. Nematode CLE signaling in Arabidopsis requires CLAVATA2 and CORYNE. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 65:430-40. [PMID: 21265896 DOI: 10.1111/j.1365-313x.2010.04433.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Plant-parasitic cyst nematodes secrete CLAVATA3 (CLV3)/ESR (CLE)-like effector proteins. These proteins have been shown to act as ligand mimics of plant CLE peptides and are required for successful nematode infection; however, the receptors for nematode CLE-like peptides have not been identified. Here we demonstrate that CLV2 and CORYNE (CRN), members of the receptor kinase family, are required for nematode CLE signaling. Exogenous peptide assays and overexpression of nematode CLEs in Arabidopsis demonstrated that CLV2 and CRN are required for perception of nematode CLEs. In addition, promoter-reporter assays showed that both receptors are expressed in nematode-induced syncytia. Lastly, infection assays with receptor mutants revealed a decrease in both nematode infection and syncytium size. Taken together, our results indicate that perception of nematode CLEs by CLV2 and CRN is not only required for successful nematode infection but is also involved in the formation and/or maintenance of nematode-induced syncytia.
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Affiliation(s)
- Amy Replogle
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
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22
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Lee C, Chronis D, Kenning C, Peret B, Hewezi T, Davis EL, Baum TJ, Hussey R, Bennett M, Mitchum MG. The novel cyst nematode effector protein 19C07 interacts with the Arabidopsis auxin influx transporter LAX3 to control feeding site development. PLANT PHYSIOLOGY 2011; 155:866-80. [PMID: 21156858 PMCID: PMC3032472 DOI: 10.1104/pp.110.167197] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 12/08/2010] [Indexed: 05/18/2023]
Abstract
Plant-parasitic cyst nematodes penetrate plant roots and transform cells near the vasculature into specialized feeding sites called syncytia. Syncytia form by incorporating neighboring cells into a single fused cell by cell wall dissolution. This process is initiated via injection of esophageal gland cell effector proteins from the nematode stylet into the host cell. Once inside the cell, these proteins may interact with host proteins that regulate the phytohormone auxin, as cellular concentrations of auxin increase in developing syncytia. Soybean cyst nematode (Heterodera glycines) Hg19C07 is a novel effector protein expressed specifically in the dorsal gland cell during nematode parasitism. Here, we describe its ortholog in the beet cyst nematode (Heterodera schachtii), Hs19C07. We demonstrate that Hs19C07 interacts with the Arabidopsis (Arabidopsis thaliana) auxin influx transporter LAX3. LAX3 is expressed in cells overlying lateral root primordia, providing auxin signaling that triggers the expression of cell wall-modifying enzymes, allowing lateral roots to emerge. We found that LAX3 and polygalacturonase, a LAX3-induced cell wall-modifying enzyme, are expressed in the developing syncytium and in cells to be incorporated into the syncytium. We observed no decrease in H. schachtii infectivity in aux1 and lax3 single mutants. However, a decrease was observed in both the aux1lax3 double mutant and the aux1lax1lax2lax3 quadruple mutant. In addition, ectopic expression of 19C07 was found to speed up lateral root emergence. We propose that Hs19C07 most likely increases LAX3-mediated auxin influx and may provide a mechanism for cyst nematodes to modulate auxin flow into root cells, stimulating cell wall hydrolysis for syncytium development.
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23
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Wang J, Lee C, Replogle A, Joshi S, Korkin D, Hussey R, Baum TJ, Davis EL, Wang X, Mitchum MG. Dual roles for the variable domain in protein trafficking and host-specific recognition of Heterodera glycines CLE effector proteins. THE NEW PHYTOLOGIST 2010; 187:1003-1017. [PMID: 20497349 DOI: 10.1111/j.1469-8137.2010.03300.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
*Soybean cyst nematodes (Heterodera glycines) produce secreted effector proteins that function as peptide mimics of plant CLAVATA3/ESR (CLE)-like peptides probably involved in the developmental reprogramming of root cells to form specialized feeding cells called syncytia. *The site of action and mechanism of delivery of CLE effectors to host plant cells by the nematode, however, have not been established. In this study, immunologic, genetic and biochemical approaches were used to reveal the localization and site of action of H. glycines-secreted CLE proteins in planta. *We present evidence indicating that the nematode CLE propeptides are delivered to the cytoplasm of syncytial cells, but ultimately function in the apoplast, consistent with their proposed role as ligand mimics of plant CLE peptides. We determined that the nematode 12-amino-acid CLE motif peptide is not sufficient for biological activity in vivo, pointing to an important role for sequences upstream of the CLE motif in function. *Genetic and biochemical analysis confirmed the requirement of the variable domain in planta for host-specific recognition and revealed a novel role in trafficking cytoplasmically delivered CLEs to the apoplast in order to function as ligand mimics.
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Affiliation(s)
- Jianying Wang
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Chris Lee
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Amy Replogle
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Sneha Joshi
- Informatics Institute, Department of Computer Science and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Dmitry Korkin
- Informatics Institute, Department of Computer Science and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Richard Hussey
- Department of Plant Pathology, University of Georgia, Athens, GA 30602, USA
| | - Thomas J Baum
- Department of Plant Pathology, Iowa State University, Ames, IA 50011, USA
| | - Eric L Davis
- Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
| | - Xiaohong Wang
- USDA-ARS, Robert W. Holley Center for Agriculture and Health and Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA
| | - Melissa G Mitchum
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
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Patel N, Hamamouch N, Li C, Hewezi T, Hussey RS, Baum TJ, Mitchum MG, Davis EL. A nematode effector protein similar to annexins in host plants. JOURNAL OF EXPERIMENTAL BOTANY 2010; 61:235-48. [PMID: 19887499 PMCID: PMC2791119 DOI: 10.1093/jxb/erp293] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 09/08/2009] [Accepted: 09/09/2009] [Indexed: 05/18/2023]
Abstract
Nematode parasitism genes encode secreted effector proteins that play a role in host infection. A homologue of the expressed Hg4F01 gene of the root-parasitic soybean cyst nematode, Heterodera glycines, encoding an annexin-like effector, was isolated in the related Heterodera schachtii to facilitate use of Arabidopsis thaliana as a model host. Hs4F01 and its protein product were exclusively expressed within the dorsal oesophageal gland secretory cell in the parasitic stages of H. schachtii. Hs4F01 had a 41% predicted amino acid sequence identity to the nex-1 annexin of C. elegans and 33% identity to annexin-1 (annAt1) of Arabidopsis, it contained four conserved domains typical of the annexin family of calcium and phospholipid binding proteins, and it had a predicted signal peptide for secretion that was present in nematode annexins of only Heterodera spp. Constitutive expression of Hs4F01 in wild-type Arabidopsis promoted hyper-susceptibility to H. schachtii infection. Complementation of an AnnAt1 mutant by constitutive expression of Hs4F01 reverted mutant sensitivity to 75 mM NaCl, suggesting a similar function of the Hs4F01 annexin-like effector in the stress response by plant cells. Yeast two-hybrid assays confirmed a specific interaction between Hs4F01 and an Arabidopsis oxidoreductase member of the 2OG-Fe(II) oxygenase family, a type of plant enzyme demonstrated to promote susceptibility to oomycete pathogens. RNA interference assays that expressed double-stranded RNA complementary to Hs4F01 in transgenic Arabidopsis specifically decreased parasitic nematode Hs4F01 transcript levels and significantly reduced nematode infection levels. The combined data suggest that nematode secretion of an Hs4F01 annexin-like effector into host root cells may mimic plant annexin function during the parasitic interaction.
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Affiliation(s)
- Nrupali Patel
- Department of Plant Pathology, North Carolina State University, Raleigh, NC 27607, USA
| | - Noureddine Hamamouch
- Department of Plant Pathology, North Carolina State University, Raleigh, NC 27607, USA
| | - Chunying Li
- Department of Plant Pathology, North Carolina State University, Raleigh, NC 27607, USA
| | - Tarek Hewezi
- Department of Plant Pathology, Iowa State University, Ames, IA 50011, USA
| | - Richard S. Hussey
- Department of Plant Pathology, University of Georgia, Athens, GA 30602, USA
| | - Thomas J. Baum
- Department of Plant Pathology, Iowa State University, Ames, IA 50011, USA
| | - Melissa G. Mitchum
- Division of Plant Sciences and Bond Life Sciences Center, University of Missouri, Columbia 65211, USA
| | - Eric L. Davis
- Department of Plant Pathology, North Carolina State University, Raleigh, NC 27607, USA
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25
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Cloning and Expression of Calcium-Dependent Protein Kinase (CDPK) Gene Family in Common Tobacco (Nicotiana tabacum). ACTA ACUST UNITED AC 2009. [DOI: 10.1016/s1671-2927(08)60358-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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26
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Lu SW, Chen S, Wang J, Yu H, Chronis D, Mitchum MG, Wang X. Structural and functional diversity of CLAVATA3/ESR (CLE)-like genes from the potato cyst nematode Globodera rostochiensis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2009; 22:1128-42. [PMID: 19656047 DOI: 10.1094/mpmi-22-9-1128] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Plant CLAVATA3/ESR-related (CLE) peptides have diverse roles in plant growth and development. Here, we report the isolation and functional characterization of five new CLE genes from the potato cyst nematode Globodera rostochiensis. Unlike typical plant CLE peptides that contain a single CLE motif, four of the five Gr-CLE genes encode CLE proteins with multiple CLE motifs. These Gr-CLE genes were found to be specifically expressed within the dorsal esophageal gland cell of nematode parasitic stages, suggesting a role for their encoded proteins in plant parasitism. Overexpression phenotypes of Gr-CLE genes in Arabidopsis mimicked those of plant CLE genes, and Gr-CLE proteins could rescue the Arabidopsis clv3-2 mutant phenotype when expressed within meristems. A short root phenotype was observed when synthetic GrCLE peptides were exogenously applied to roots of Arabidopsis or potato similar to the overexpression of Gr-CLE genes in Arabidopsis and potato hairy roots. These results reveal that G. rostochiensis CLE proteins with either single or multiple CLE motifs function similarly to plant CLE proteins and that CLE signaling components are conserved in both Arabidopsis and potato roots. Furthermore, our results provide evidence to suggest that the evolution of multiple CLE motifs may be an important mechanism for generating functional diversity in nematode CLE proteins to facilitate parasitism.
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Affiliation(s)
- Shun-Wen Lu
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY, USA
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27
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Wubben MJ, Callahan FE, Triplett BA, Jenkins JN. Phenotypic and molecular evaluation of cotton hairy roots as a model system for studying nematode resistance. PLANT CELL REPORTS 2009; 28:1399-1409. [PMID: 19578854 DOI: 10.1007/s00299-009-0739-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 06/17/2009] [Accepted: 06/21/2009] [Indexed: 05/28/2023]
Abstract
Agrobacterium rhizogenes-induced cotton (Gossypium hirsutum L.) hairy roots were evaluated as a model system for studying molecular cotton-nematode interactions. Hairy root cultures were developed from the root-knot nematode (RKN) (Meloidogyne incognita [Kofoid and White] Chitwood, race 3)-resistant breeding line M315 and from the reniform nematode (RN) (Rotylenchulus reniformis Linford & Oliveira)-resistant accession GB713 (G. barbadense L.) and compared to a nematode-susceptible culture derived from the obsolete cultivar DPL90. M315, GB713, and DPL90 hairy roots differed significantly in their appearance and growth potential; however, these differences were not correlated with transcript levels of the A. rhizogenes T-DNA genes rolB and aux2 which help regulate hairy root initiation and proliferation. DPL90 hairy roots were found to support both RKN and RN reproduction in tissue culture, whereas M315 and GB713 hairy roots were resistant to RKN and RN, respectively. M315 hairy roots showed constitutive up-regulation of the defense gene MIC3 (Meloidogyne Induced Cotton3) compared to M315 whole-plant roots and DPL90 hairy roots. Our data show the potential use of cotton hairy roots in maintaining monoxenic RKN and RN cultures and suggest hairy roots may be useful in evaluating the effect of manipulated host gene expression on nematode resistance in cotton.
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Affiliation(s)
- Martin J Wubben
- Crop Science Research Laboratory, USDA/ARS, Mississippi State, MS 39762, USA.
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28
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Wasson AP, Ramsay K, Jones MGK, Mathesius U. Differing requirements for flavonoids during the formation of lateral roots, nodules and root knot nematode galls in Medicago truncatula. THE NEW PHYTOLOGIST 2009; 183:167-179. [PMID: 19402878 DOI: 10.1111/j.1469-8137.2009.02850.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
* In this study, we tested whether the organogenesis of symbiotic root nodules, lateral roots and root galls induced by parasitic root knot nematodes (Meloidogyne javanica) was regulated by the presence of flavonoids in the roots of Medicago truncatula. Flavonoids accumulate in all three types of root organ, and have been hypothesized previously to be required for secondary root organogenesis because of their potential role as auxin transport regulators. * Using RNA interference to silence the flavonoid biosynthetic pathway in M. truncatula, we generated transformed flavonoid-deficient hairy roots which were used to study flavonoid accumulation, cell division and organogenesis of nodules, lateral roots and root galls. * Flavonoid-deficient roots did not form nodules, as demonstrated previously, but showed altered root growth in response to rhizobia. By contrast, flavonoid-deficient roots showed no difference in the number of lateral roots and root galls. Galls on flavonoid-deficient roots formed normal giant cells, but were shorter, and were characterized by reduced numbers of dividing pericycle cells. * We rejected the hypothesis that flavonoids are required as general regulators of the organogenesis of secondary root organs, but flavonoids appear to be necessary for nodulation. Possible reasons for this difference in the requirement for flavonoids are discussed.
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Affiliation(s)
- Anton P Wasson
- Australian Research Council Centre of Excellence for Integrative Legume Research, Department of Biochemistry and Molecular Biology, School of Biology, Australian National University, Canberra ACT 0200, Australia
| | - Kerry Ramsay
- School of Biological Sciences and Biotechnology, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
| | - Michael G K Jones
- School of Biological Sciences and Biotechnology, Murdoch University, South Street, Murdoch, Western Australia 6150, Australia
| | - Ulrike Mathesius
- Australian Research Council Centre of Excellence for Integrative Legume Research, Department of Biochemistry and Molecular Biology, School of Biology, Australian National University, Canberra ACT 0200, Australia
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Molecular Insights in the Susceptible Plant Response to Nematode Infection. CELL BIOLOGY OF PLANT NEMATODE PARASITISM 2008. [DOI: 10.1007/978-3-540-85215-5_3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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30
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Molecular Insights in the Susceptible Plant Response to Nematode Infection. PLANT CELL MONOGRAPHS 2008. [DOI: 10.1007/7089_2008_35] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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31
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Wieczorek K, Hofmann J, Blöchl A, Szakasits D, Bohlmann H, Grundler FMW. Arabidopsis endo-1,4-beta-glucanases are involved in the formation of root syncytia induced by Heterodera schachtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 53:336-51. [PMID: 18069944 DOI: 10.1111/j.1365-313x.2007.03340.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Cyst nematodes induce root syncytia with specific features such as hypertrophy, increased metabolic activity and fusion with adjacent cells. Cell walls of the syncytia undergo massive changes such as thickening, local dissolution and formation of ingrowths. Cell wall degrading and modifying proteins are apparently involved in syncytium formation but detailed knowledge of this is still limited. Therefore, we studied the regulation and function of the entire Arabidopsis endo-1,4-beta-glucanase gene family in syncytia induced by Heterodera schachtii. Endo-1,4-beta-glucanases hydrolyze the 1,4-beta-glucosidic linkages between glucose residues. Using semi-quantitative and quantitative approaches we identified seven genes that are upregulated in syncytia. Two of these genes, coding for secreted AtCel2 and membrane-bound KOR3, are shoot-specific but show high expression in syncytia at different developmental stages. In silico analysis of the promoter regions of both genes compared with other genes with modified regulation in nematode feeding sites did not reveal specific cis-acting elements that could be related to specific transcription in syncytia. However, motifs responsive to sugar and different plant hormones were identified. Accordingly, treatments with sucrose, gibberellic acid and NAA induced upregulation of AtCel2, whereas ABA triggered downregulation of both AtCel2 and KOR3 in roots. As AtCel2 is related to degradation of the cell wall matrix, we analysed the hemicellulose content in syncytia. The measured values resembled the expression pattern of AtCel2. A distinctly reduced number of females developed in cel2 and kor3 T-DNA mutants, and we therefore conclude that endo-1,4-beta-glucanases play an important role in the formation and function of syncytia.
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Affiliation(s)
- Krzysztof Wieczorek
- Institute of Plant Protection, Department of Applied Plant Sciences and Plant Biotechnology, University of Natural Resources and Applied Life Sciences, A-1190 Vienna, Austria
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