1
|
Wang X, Guo Z, Dai D, Xie C, Zhao Z, Zheng J, Sun M, Peng D. High-resolution transcriptome datasets during embryogenesis of plant-parasitic nematodes. Sci Data 2024; 11:690. [PMID: 38926436 PMCID: PMC11208412 DOI: 10.1038/s41597-024-03542-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024] Open
Abstract
Understanding the transcriptional regulatory characteristics throughout the embryogenesis of plant-parasitic nematodes is crucial for elucidating their developmental processes' uniqueness. However, a challenge arises due to the lack of suitable technical methods for synchronizing the age of plant-parasitic nematodes embryo, it is difficult to collect detailed transcriptome data at each stage of embryonic development. Here, we recorded the 11 embryonic developmental time-points of endophytic nematode Meloidogyne incognita (isolated from Wuhan, China), Heterodera glycines (isolated from Wuhan, China), and Ditylenchus destructor (isolated from Jinan, China) species, and constructed transcriptome datasets of single embryos of these three species utilizing low-input smart-seq2 technology. The datasets encompassed 11 complete embryonic development stages, including Zygote, 2-cell, 4-cell, 8-cell, 24-44 cell, 64-78 cell, Comma, 1.5-fold, 2-fold, Moving, and L1, each stage generated four to five replicates, resulting in a total of 162 high-resolution transcriptome libraries. This high-resolution cross-species dataset serves as a crucial resource for comprehending the embryonic developmental properties of plant-parasitic nematodes and for identifying functional regulatory genes during embryogenesis.
Collapse
Affiliation(s)
- Xueyu Wang
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhiqing Guo
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dadong Dai
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Chuanshuai Xie
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ziwei Zhao
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jinshui Zheng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ming Sun
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Donghai Peng
- State Key Laboratory of Agricultural Microbiology, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
| |
Collapse
|
2
|
Churikova AK, Nekoval SN. Biological agents and their metabolites to control <i>Meloidogyne</i> spp. when growing vegetables (review). SOUTH OF RUSSIA: ECOLOGY, DEVELOPMENT 2022. [DOI: 10.18470/1992-1098-2022-3-175-186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Aim. Analysis of modern studies on the effectiveness of fungi and antagonist bacteria against Meloidogyne root‐knot nematodes on vegetable crops.Materials and Methods. Studies of Russian and foreign scientists on the use of biological agents and their metabolites to control Meloidogyne spp. when growing vegetables have been carefully analysed.Results. The harmfulness of gall nematodes on vegetable crops is described. Studies on the most pathogenic species of Meloidogyne, including those common in Russia, are summarised. Information is given regarding features of the relationship between the host plant and phytoparasites are highlighted. An analysis of the range of chemical and biological nematicides is presented. The problem of the lack of effective environmentally friendly products able to control root‐knot nematodes on vegetables, including the prospect of using biological agents, has been identified. The features of ongoing research on the study of the nematicidal activity of biological agents and their metabolites to control various stages of development of Meloidogyne species have been collected, analysed, systematised and described. The prospect of studying the mechanisms of action of microorganisms against root‐knot nematodes is substantiated in order to create new effective biological nematicides that allow the growth of high‐quality and healthy vegetable products.Conclusion. Gall nematodes (Meloidogyne spp.) remain a current pest of soil‐grown vegetables. Scientists are actively working on the study of nematophagous fungi and antagonist bacteria to create environmentally friendly biological nematicides. With proper use, biological agents and their metabolites can help protect plants from phytoparasites at the level of chemical nematicides and have an additional beneficial effect on the growth and development of vegetable crops.
Collapse
Affiliation(s)
| | - S. N. Nekoval
- Federal Research Center of Biological Plant Protection
| |
Collapse
|
3
|
Wang L, Qin Y, Fan Z, Gao K, Zhan J, Xing R, Liu S, Li P. Novel Lead Compound Discovery from Aspergillus fumigatus 1T-2 against Meloidogyne incognita Based on a Chemical Ecology Study. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:4644-4657. [PMID: 35404052 DOI: 10.1021/acs.jafc.1c08147] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
To replace biohazardous nematicides, there is an ever-increasing need to identify natural product-based agents to contain root-knot nematodes (RKNs) in agriculture. In this chemical ecology study, an antagonistic fungus Aspergillus fumigatus 1T-2, which could cause the formation of withering of the gut and vacuole-like structures in the nematode body, was isolated based on the gradually increased antagonistic interactions between the soil fungi and RKNs. Based on these typical morphological characteristics, a potent nematode-antagonistic compound 2-furoic acid, which had a simple structure, was successfully identified from 1T-2 fermentation broth by liquid chromatography-mass spectrometry (LC-MS). 2-Furoic acid showed effective mortality activity in vitro, of which the LC50 value to Megalaima incognita at 24 h was 37.75 μg/mL. 2-Furoic acid had similar mortality activity to the positive control fosthiazate at 30 μg/mL. Continuous 2-furoic acid exposure had obvious negative influences on both nematode vitality and egg hatchability. Notably, significant variations were observed in nematodes and eggs with 2-furoic acid treatment, which might be induced by novel nematocidal mechanisms. Furthermore, the 1T-2 fermentation broth and 2-furoic acid had significant control efficacy on M. incognita under the greenhouse test-tube assay. Overall, these findings provide valuable insights into the use of 2-furoic acid with biocontrol potential as a preferable lead structure for the development of innovative nematicides.
Collapse
Affiliation(s)
- Linsong Wang
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
| | - Yukun Qin
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
| | - Zhaoqian Fan
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
| | - Kun Gao
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
| | - Jiang Zhan
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ronge Xing
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
| | - Song Liu
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
| | - Pengcheng Li
- CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), No. 1 Wenhai Road, Qingdao 266237, China
| |
Collapse
|
4
|
Ryss A, Petrov AA. Muscles of the male and female copulatory organs of Bursaphelenchus mucronatus and Chiloplacus sp. (Nematoda: Rhabditida). J Nematol 2022; 53:e2021-107. [PMID: 34993492 PMCID: PMC8727731 DOI: 10.21307/jofnem-2021-107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Indexed: 11/20/2022] Open
Abstract
Male and female copulatory organs figure prominently in nematode taxonomy, but the associated musculature remains insufficiently explored. The aim of this study was therefore to further our knowledge of the musculature of the vulva and male copulatory organs in nematodes by using phalloidin staining and confocal microscopy to examine two nematode species, Bursaphelenchus mucronatus and Chiloplacus sp. The musculature of the round vulva in Chiloplacus sp. comprises three pairs of radial vulval dilators and another pair of dilators of the anterior inner vulval plate. This arrangement is similar to that of the Rhabditida, but in Chiloplacus the anterior pair appears to have been transformed into the vulval plate muscles. The musculature of the slit-like vulva in B. mucronatus includes dilators of the vulval lips and external vulval flap, constrictors of the vulval slit and posterior transverse muscle bands. The opposing pairs of vulval dilators show quadrilateral symmetry as observed in the Rhabditida, but the constrictors running along the rim of the vulva have no counterparts in other species. The musculature of the male copulatory organ in Chiloplacus sp. comprises two pairs of spicule protractors and retractors and three pairs of gubernacular muscles. In B. mucronatus, as in the other Aphelenchoididae, the gubernaculum is absent and there is one pair of spicule protractors and two pairs of muscles inserted on the saddle (angular bend) of the spicules. The arrangement of the spicule saddle muscles resembles those of the gubernaculum, which may indicate that in this family the gubernaculum has become fused to the spicules. The literature review of muscles of nematode copulatory organs are given in a table for 15 muscle groups; it can be used for phylogenetic reconstruction and classification of the order Rhabditida.
Collapse
Affiliation(s)
- Alexander Ryss
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya Naberezhnaya 1, St Petersburg, 199034, Russia
| | - Anatoly A Petrov
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya Naberezhnaya 1, St Petersburg, 199034, Russia
| |
Collapse
|
5
|
Delattre M, Goehring NW. The first steps in the life of a worm: Themes and variations in asymmetric division in C. elegans and other nematodes. Curr Top Dev Biol 2021; 144:269-308. [PMID: 33992156 DOI: 10.1016/bs.ctdb.2020.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Starting with Boveri in the 1870s, microscopic investigation of early embryogenesis in a broad swath of nematode species revealed the central role of asymmetric cell division in embryonic axis specification, blastomere positioning, and cell fate specification. Notably, across the class Chromadorea, a conserved theme emerges-asymmetry is first established in the zygote and specifies its asymmetric division, giving rise to an anterior somatic daughter cell and a posterior germline daughter cell. Beginning in the 1980s, the emergence of Caenorhabditis elegans as a model organism saw the advent of genetic tools that enabled rapid progress in our understanding of the molecular mechanisms underlying asymmetric division, in many cases defining key paradigms that turn out to regulate asymmetric division in a wide range of systems. Yet, the consequence of this focus on C. elegans came at the expense of exploring the extant diversity of developmental variation exhibited across nematode species. Given the resurgent interest in evolutionary studies facilitated in part by new tools, here we revisit the diversity in this asymmetric first division, juxtaposing molecular insight into mechanisms of symmetry-breaking, spindle positioning and fate specification, with a consideration of plasticity and variability within and between species. In the process, we hope to highlight questions of evolutionary forces and molecular variation that may have shaped the extant diversity of developmental mechanisms observed across Nematoda.
Collapse
Affiliation(s)
- Marie Delattre
- Laboratory of Biology and Modeling of the Cell, Ecole Normale Supérieure de Lyon, CNRS, Inserm, UCBL, Lyon, France.
| | | |
Collapse
|
6
|
Forghani F, Hajihassani A. Recent Advances in the Development of Environmentally Benign Treatments to Control Root-Knot Nematodes. FRONTIERS IN PLANT SCIENCE 2020; 11:1125. [PMID: 32793271 PMCID: PMC7387703 DOI: 10.3389/fpls.2020.01125] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 07/08/2020] [Indexed: 05/17/2023]
Abstract
Root-knot nematodes (RKNs), Meloidogyne spp., are sedentary endoparasites that negatively affect almost every crop in the world. Current management practices are not enough to completely control RKN. Application of certain chemicals is also being further limited in recent years. It is therefore crucial to develop additional control strategies through the application of environmentally benign methods. There has been much research performed around the world on the topic, leading to useful outcomes and interesting findings capable of improving farmers' income. It is important to have dependable resources gathering the data produced to facilitate future research. This review discusses recent findings on the application of environmentally benign treatments to control RKN between 2015 and April 2020. A variety of biological control strategies, natural compounds, soil amendments and other emerging strategies have been included, among which, many showed promising results in RKN control in vitro and/or in vivo. Development of these methods continues to be an area of active research, and new information on their efficacy will continuously become available. We have discussed some of the control mechanisms involved and suggestions were given on maximizing the outcome of the future efforts.
Collapse
|
7
|
Ewe CK, Torres Cleuren YN, Rothman JH. Evolution and Developmental System Drift in the Endoderm Gene Regulatory Network of Caenorhabditis and Other Nematodes. Front Cell Dev Biol 2020; 8:170. [PMID: 32258041 PMCID: PMC7093329 DOI: 10.3389/fcell.2020.00170] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 03/02/2020] [Indexed: 01/17/2023] Open
Abstract
Developmental gene regulatory networks (GRNs) underpin metazoan embryogenesis and have undergone substantial modification to generate the tremendous variety of animal forms present on Earth today. The nematode Caenorhabditis elegans has been a central model for advancing many important discoveries in fundamental mechanistic biology and, more recently, has provided a strong base from which to explore the evolutionary diversification of GRN architecture and developmental processes in other species. In this short review, we will focus on evolutionary diversification of the GRN for the most ancient of the embryonic germ layers, the endoderm. Early embryogenesis diverges considerably across the phylum Nematoda. Notably, while some species deploy regulative development, more derived species, such as C. elegans, exhibit largely mosaic modes of embryogenesis. Despite the relatively similar morphology of the nematode gut across species, widespread variation has been observed in the signaling inputs that initiate the endoderm GRN, an exemplar of developmental system drift (DSD). We will explore how genetic variation in the endoderm GRN helps to drive DSD at both inter- and intraspecies levels, thereby resulting in a robust developmental system. Comparative studies using divergent nematodes promise to unveil the genetic mechanisms controlling developmental plasticity and provide a paradigm for the principles governing evolutionary modification of an embryonic GRN.
Collapse
Affiliation(s)
- Chee Kiang Ewe
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
| | | | - Joel H. Rothman
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA, United States
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
| |
Collapse
|
8
|
Rajasekharan SK, Kim S, Kim JC, Lee J. Nematicidal activity of 5-iodoindole against root-knot nematodes. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2020; 163:76-83. [PMID: 31973872 DOI: 10.1016/j.pestbp.2019.10.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/04/2019] [Accepted: 10/29/2019] [Indexed: 06/10/2023]
Abstract
Multi-drug resistance in nematodes is a serious problem as lately several resistant phenotypes have emerged following the intermittent usage of synthetic nematicides. Contemporary research continues to focus on developing and/or repurposing small molecule inhibitors that are eco-friendly. Here, we describe the repurposing of the indole derivative, 5-iodoindole, as a nematicide for the root-knot nematode, Meloidogyne incognita. 5-Iodoindole effectively killed juveniles and freshly hatched juveniles by inducing multiple vacuole formation. Notably, at higher dosage (50 μg/mL), 5-iodoindole induced rapid juvenile death within 6 h. Microscopic analysis confirmed that the rapid death was due to the generation of reactive oxygen species (ROS). Computational docking attributed this ROS production to the antagonistic effect of 5-iodoindole on glutathione S-transferase (GST), which is known to play a critical role in the suppression of ROS in nematode models. Furthermore, 5-iodoindole also effectively reduced the gall formations and eggs masses of M. incognita on Solanum lycopersicum roots in pot experiments, and importantly it did not harm the physiological properties of the plant. Overall, the study provides valuable insights on the use of 5-iodoindole as an alternate measure to control root-knot nematodes. Overall, our findings suggest the efficacy of 5-iodoindole should be studied under field conditions.
Collapse
Affiliation(s)
| | - Seulbi Kim
- Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jin-Cheol Kim
- Department of Agricultural Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Republic of Korea.
| | - Jintae Lee
- School of Chemical Engineering, Yeungnam University, Gyeongsan 38541, Republic of Korea.
| |
Collapse
|
9
|
Haag ES, Fitch DHA, Delattre M. From "the Worm" to "the Worms" and Back Again: The Evolutionary Developmental Biology of Nematodes. Genetics 2018; 210:397-433. [PMID: 30287515 PMCID: PMC6216592 DOI: 10.1534/genetics.118.300243] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 08/03/2018] [Indexed: 12/13/2022] Open
Abstract
Since the earliest days of research on nematodes, scientists have noted the developmental and morphological variation that exists within and between species. As various cellular and developmental processes were revealed through intense focus on Caenorhabditis elegans, these comparative studies have expanded. Within the genus Caenorhabditis, they include characterization of intraspecific polymorphisms and comparisons of distinct species, all generally amenable to the same laboratory culture methods and supported by robust genomic and experimental tools. The C. elegans paradigm has also motivated studies with more distantly related nematodes and animals. Combined with improved phylogenies, this work has led to important insights about the evolution of nematode development. First, while many aspects of C. elegans development are representative of Caenorhabditis, and of terrestrial nematodes more generally, others vary in ways both obvious and cryptic. Second, the system has revealed several clear examples of developmental flexibility in achieving a particular trait. This includes developmental system drift, in which the developmental control of homologous traits has diverged in different lineages, and cases of convergent evolution. Overall, the wealth of information and experimental techniques developed in C. elegans is being leveraged to make nematodes a powerful system for evolutionary cellular and developmental biology.
Collapse
Affiliation(s)
- Eric S Haag
- Department of Biology, University of Maryland, College Park, Maryland 20742
| | | | - Marie Delattre
- Laboratoire de Biologie Moléculaire de la Cellule, CNRS, INSERM, Ecole Normale Supérieure de Lyon, 69007, France
| |
Collapse
|
10
|
Host-mediated RNAi of a Notch-like receptor gene in Meloidogyne incognita induces nematode resistance. Parasitology 2018; 145:1896-1906. [PMID: 29692277 DOI: 10.1017/s0031182018000641] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
GLP-1 (abnormal germline proliferation) is a Notch-like receptor protein that plays an essential role in pharyngeal development. In this study, an orthologue of Caenorhabditis elegans glp-1 was identified in Meloidogyne incognita. A computational analysis revealed that the orthologue contained almost all the domains present in the C. elegans gene: specifically, the LIN-12/Notch repeat, the ankyrin repeat, a transmembrane domain and different ligand-binding motifs were present in orthologue, but the epidermal growth factor-like motif was not observed. An expression analysis showed differential expression of glp-1 throughout the life cycle of M. incognita, with relatively higher expression in the egg stage. To evaluate the silencing efficacy of Mi-glp-1, transgenic Arabidopsis plants carrying double-stranded RNA constructs of glp-1 were generated, and infection of these plants with M. incognita resulted in a 47-50% reduction in the numbers of galls, females and egg masses. Females obtained from the transgenic RNAi lines exhibited 40-60% reductions in the transcript levels of the targeted glp-1 gene compared with females isolated from the control plants. Second-generation juveniles (J2s), which were descendants of the infected females from the transgenic lines, showed aberrant phenotypes. These J2s exhibited a significant decrease in the overall distance from the stylet to the metacorpus region, and this effect was accompanied by disruption around the metacorporeal bulb of the pharynx. The present study suggests a role for this gene in organ (pharynx) development during embryogenesis in M. incognita and its potential use as a target in the management of nematode infestations in plants.
Collapse
|
11
|
Thapa S, Patel JA, Reuter-Carlson U, Schroeder NE. Embryogenesis in the parasitic nematode Heterodera glycines is independent of host-derived hatching stimulation. BMC DEVELOPMENTAL BIOLOGY 2017; 17:2. [PMID: 28077087 PMCID: PMC5225516 DOI: 10.1186/s12861-016-0144-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/21/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND Many parasites regulate their development to synchronize their life cycle with a compatible host. The parasitic nematode Heterodera glycines displays incomplete host-mediated hatching behavior wherein some H. glycines individuals hatch only in the presence of a host-derived cue while others hatch in water alone. Furthermore, H. glycines shows variable hatching behavior based on oviposition location. The mechanisms regulating this hatching variability are unknown. In this study, we established a detailed timeline of the H. glycines pre-hatch development from early embryogenesis to the pre-hatched J2. These descriptive data were then used to test hypotheses regarding the effect of host stimulus and oviposition location on pre-hatch development. RESULTS We found that H. glycines develops from a single-cell egg to a fully formed J2 in approximately 172 hours. The stylet-based mouthpart, which is used to pierce the eggshell during hatching, is not completely formed until late in pre-hatch J2 development and is preceded by the formation of stylet protractor muscles. We also found that the primary motor nervous system of H. glycines did not complete development until late in pre-hatch J2 development. These data suggest possible structural requirements for H. glycines hatching. As expected, exposure of H. glycines eggs to host-derived cues increased the percentage of nematodes that hatched. However, exposure to hatching cues did not affect pre-hatch development. Similarly, we found no obvious differences in the pre-hatch developmental timeline between eggs laid in an egg sac or retained within the mother. CONCLUSIONS The pattern of early embryonic development in H. glycines was very similar to that recently described in the related parasitic nematode Meloidogyne incognita. However, the speed of H. glycines pre-hatch development was approximately three times faster than reported for M. incognita. Our results suggest that hatching stimulants do not affect embryogenesis itself but only influence the hatching decision once J2 development is complete. Similarly, the oviposition location does not alter the rate of embryogenesis. These results provide insight into the primary survival mechanism for this important parasite.
Collapse
Affiliation(s)
- Sita Thapa
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Ave, Urbana, 61801 IL USA
| | - Jayna A. Patel
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Ave, Urbana, 61801 IL USA
| | - Ursula Reuter-Carlson
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Ave, Urbana, 61801 IL USA
| | - Nathan E. Schroeder
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, 1102 S. Goodwin Ave, Urbana, 61801 IL USA
| |
Collapse
|