Resistance genes against plant-parasitic nematodes: a durable control strategy?

Nematology ◽  
2015 ◽  
Vol 17 (3) ◽  
pp. 249-263 ◽  
Author(s):  
Laura J. Davies ◽  
Axel A. Elling

Plant-parasitic nematodes are a major pest of all agricultural systems, causing extensive economic losses. Natural resistance (R) genes offer an alternative to chemical control and have been shown effectively to limit nematode damage to crops in the field. Whilst a number of resistant cultivars have conferred resistance against root-knot and cyst nematodes for many decades, an increasing number of reports of resistance-breaking nematode pathotypes are beginning to emerge. The forces affecting the emergence of virulent nematodes are complex, multifactorial and involve both the host and parasite of the plant-nematode interaction. This review provides an overview of the root-knot and cyst nematodeRgenes characterised to date, in addition to examining the evolutionary forces influencing nematode populations and the emergence of virulence. Finally, potential strategies to improveRgene durability in the field are outlined, and areas that would benefit from further research efforts are highlighted.

Author(s):  
Wim Wesemael

Abstract This chapter provides information on the methods for initial screening to determine the resistance or susceptibility of plants, cultivars or breeding lines to plant parasitic nematodes. Specific protocols for screening and further resistance breeding on several plant-nematode combinations are described and practical guidelines for screening of Musa germplasm and several screening procedures for cyst nematodes are presented.


2019 ◽  
Vol 109 (12) ◽  
pp. 1988-1996 ◽  
Author(s):  
Isgouhi Kaloshian ◽  
Marcella Teixeira

Plant infections by plant-parasitic nematodes (PPNs) continue to be one of the major limitations in agricultural systems. Root-knot nematodes (RKNs), belonging to the genus Meloidogyne, are one of the most important groups of PPNs worldwide. Their wide host range combined with ubiquitous presence, continues to provide challenges for their control and breeding for resistance. Although resistance to RKNs has been identified, incorporation of these resistances into crops and durability of the resistance remains challenging. In addition, progress in cloning of RKN resistance genes has been dismal. Recent identification of pattern-triggered immunity in roots against nematodes, an ascaroside as a nematode-associated molecular pattern (NAMP) and the discovery of a NAMP plant receptor, provide tools and opportunities to develop durable host resistance against nematodes including RKNs.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Olaf Kranse ◽  
Helen Beasley ◽  
Sally Adams ◽  
Andre Pires-daSilva ◽  
Christopher Bell ◽  
...  

Abstract Plant-parasitic nematodes are a continuing threat to food security, causing an estimated 100 billion USD in crop losses each year. The most problematic are the obligate sedentary endoparasites (primarily root knot nematodes and cyst nematodes). Progress in understanding their biology is held back by a lack of tools for functional genetics: forward genetics is largely restricted to studies of natural variation in populations and reverse genetics is entirely reliant on RNA interference. There is an expectation that the development of functional genetic tools would accelerate the progress of research on plant-parasitic nematodes, and hence the development of novel control solutions. Here, we develop some of the foundational biology required to deliver a functional genetic tool kit in plant-parasitic nematodes. We characterize the gonads of male Heterodera schachtii and Meloidogyne hapla in the context of spermatogenesis. We test and optimize various methods for the delivery, expression, and/or detection of exogenous nucleic acids in plant-parasitic nematodes. We demonstrate that delivery of macromolecules to cyst and root knot nematode male germlines is difficult, but possible. Similarly, we demonstrate the delivery of oligonucleotides to root knot nematode gametes. Finally, we develop a transient expression system in plant-parasitic nematodes by demonstrating the delivery and expression of exogenous mRNA encoding various reporter genes throughout the body of H. schachtii juveniles using lipofectamine-based transfection. We anticipate these developments to be independently useful, will expedite the development of genetic modification tools for plant-parasitic nematodes, and ultimately catalyze research on a group of nematodes that threaten global food security.


2016 ◽  
Vol 283 (1835) ◽  
pp. 20160942 ◽  
Author(s):  
Jinshui Zheng ◽  
Donghai Peng ◽  
Ling Chen ◽  
Hualin Liu ◽  
Feng Chen ◽  
...  

Plant-parasitic nematodes were found in 4 of the 12 clades of phylum Nematoda. These nematodes in different clades may have originated independently from their free-living fungivorous ancestors. However, the exact evolutionary process of these parasites is unclear. Here, we sequenced the genome sequence of a migratory plant nematode, Ditylenchus destructor . We performed comparative genomics among the free-living nematode, Caenorhabditis elegans and all the plant nematodes with genome sequences available. We found that, compared with C. elegans , the core developmental control processes underwent heavy reduction, though most signal transduction pathways were conserved. We also found D. destructor contained more homologies of the key genes in the above processes than the other plant nematodes. We suggest that Ditylenchus spp. may be an intermediate evolutionary history stage from free-living nematodes that feed on fungi to obligate plant-parasitic nematodes. Based on the facts that D. destructor can feed on fungi and has a relatively short life cycle, and that it has similar features to both C. elegans and sedentary plant-parasitic nematodes from clade 12, we propose it as a new model to study the biology, biocontrol of plant nematodes and the interaction between nematodes and plants.


2021 ◽  
Vol 4 (2) ◽  
pp. 327-338
Author(s):  
Honey Raj Mandal ◽  
Shambhu Katel ◽  
Sudeep Subedi ◽  
Jiban Shrestha

Plant Parasitic Nematodes are small worm like transparent, bilateral symmetry, pseudocoelomate, multicellular, free living or parasitic microorganism which are predatory, aquatic, terrestrial, entopathogenic, ectoparasite, endoparasite, semi-endoparasite or sedentary. They cause substantial problems to major crops throughout the world, including vegetables, fruits, and grain crops. The root knot and cyst nematodes are economically important pests in numerous crops. Crop damage from nematodes is not readily apparent in most cases, and it often remains hidden by the many other factors limiting plant growth. In the past, the control of the nematodes has been based on the synthetic nematicides, the number of which has been drastically restricted in the EU because of their environmental side effects and subsequent restriction in European Union (EU) rules and regulations. Many other methods like cultural control, biological control, use of biotechnological tools and methods, use of resistant cultivars are tested and proven successful in controlling different species of nematodes all over the world. Alternatively, combinations of the different methods are proven to be highly effective both economically and environmentally.


Plant Disease ◽  
2021 ◽  
Author(s):  
İmren Mustafa ◽  
Göksel Özer ◽  
Timothy Paulitz ◽  
Alexei Morgounov ◽  
Abdelfattah A. Dababat

Kazakhstan is one of the biggest wheat producers, however, its wheat production is far below the average international wheat production standard due to biotic and abiotic stressors. Plant-parasitic nematodes are devastating for cereal production systems worldwide. A comprehensive survey was conducted in 2019 to identify plant-parasitic nematodes associated with wheat in different locations of central, eastern, and south-eastern Kazakhstan. The results revealed 33 root-lesion and 27 cyst nematode populations from the 77 localities sampled. These two genera occurred in separate or in mixed populations. The root-lesion populations were identified as Pratylenchus neglectus and P. thornei while all cyst nematodes were identified as Heterodera filipjevi. The identification of nematodes was firstly performed based on morphological and morphometric features and confirmed by BLAST and phylogenetic analyses based on the internal transcribed spacer and the D2-D3 expansion located in the 28S gene of ribosomal DNA for CCN and RLN populations, respectively. Pratylenchus neglectus and P. thornei populations from Kazakhstan showed a high similarity with the American, European, and Asian populations. Heterodera filipjevi populations formed a well-supported cluster with the corresponding populations from different countries and showed a slightly intraspecific polymorphism. Kazakhstan populations of H. filipjevi may have multiple introductions in Kazakhstan due to the divergence among them. The results of this study are of great importance for breeding programs and will enable awareness to extension advisors to develop measures to control these nematodes in cereal cropping areas in Kazakhstan.


Parasitology ◽  
1996 ◽  
Vol 113 (6) ◽  
pp. 589-597 ◽  
Author(s):  
R. H. C. Curtis

SUMMARYSecretions of plant-parasitic nematodes which are released into plant tissue may play critical roles in plant-nematode interactions. The identification and characterization of these molecules are of fundamental importance and may help to facilitate the development of novel strategies to interfere with nematode infection of plants and thereby decrease nematode-induced damage to crops. An antibody-based approach was used to isolate molecules present on the nematode surface and in nematode secretions. Monoclonal antibodies (MAbs) were produced to secretions and to whole Heterodera avenue 2nd-stage juveniles; several of these MAbs recognized molecules present in nematode secretions produced in vitro. Three of these molecules have been partly characterized in H. avenae, Globodera rostochiensis, G. pallida and Meloidogyne incognita. A MAb reacting with the surfaces of these nematodes recognized antigens of different molecular weight in each of the species tested. This difference in antigenicity might be related to specific functions in these nematodes. Preliminary results show that this antibody also localized the antigen in root cells surrounding the feeding site induced by M. incognita in Arabidopsis thaliana.


1999 ◽  
Vol 73 (1) ◽  
pp. 67-71 ◽  
Author(s):  
P. Mendoza de Gives ◽  
K.G. Davies ◽  
M. Morgan ◽  
J.M. Behnke

Populations of Pasteuria penetrans isolated from root-knot nematodes (Meloidogyne spp.) and cyst nematodes (Heterodera spp.) were tested for their ability to adhere to a limited selection of sheathed and exsheathed animal parasitic nematodes, free living nematodes, including Caenorhabditis elegans wild type and several srf mutants, and plant parasitic nematodes. The attachment of spores of Pasteuria was restricted and no spores were observed adhering to any of the animal parasitic nematodes either with or without their sheath or to any of the free living nematodes including C. elegans and the srf mutants. All spore attachment was restricted to plant parasitic nematodes; however, spores isolated from cyst nematodes showed the ability to adhere to other genera of plant parasitic nematodes which was not the case with spores isolated from root-knot nematodes. The results are discussed in relationship to cuticular heterogeneity.


EDIS ◽  
2018 ◽  
Vol 2018 (1) ◽  
Author(s):  
Gilma X. Castillo ◽  
Monica Ozores-Hampton ◽  
Pablo A. Navia Gine

Plant-parasitic nematodes pose a problem in agricultural systems by feeding on crops, therefore affecting their yield. Fluensulfone is a chemical that can be applied using various methods to manage the impact of plant-parasitic nematodes on crop production. This 6-page document discusses the characteristics and use of fluensulfone as a tool for nematode management practices. Written by Gilma X. Castillo, Monica Ozores-Hampton, and Pablo A. Navia Gine and published by the UF/IFAS Department of Horticultural Sciences, January 2018. http://edis.ifas.ufl.edu/hs1313


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