Nematode management through genome editing.

2021 ◽  
pp. 408-413
Author(s):  
Shahid Siddique ◽  
Sebastian Eves-van den Akker

Abstract Plant parasitic nematodes are among the most destructive plant pathogens, causing an estimated US$78 billion yield losses globally. Although approximately 3000 species of plant parasitic nematodes have been described, most of the damage is caused by a small group of root-infecting sedentary endoparasitic nematodes that include root-knot nematodes (Meloidogyne spp.) and cyst nematodes (Heterodera spp.). Given that previous literature amply reviews the breadth of biotechnological methods for the control of plant parasitic nematodes, this chapter will briefly touch on long-standing biotechnological methods but focus on recent progress in, and long-term promise of, the use of CRISPR technology for introducing targeted modifications into host genomes with the goal of enhancing resistance against plant parasitic nematodes. It is predicted that expanding reverse genetic approaches beyond RNA interference, using low-cost, technically simple and efficient transformation (transient or stable) will be the single most important advance in the field in some years.

2007 ◽  
Vol 8 (5) ◽  
pp. 701-711 ◽  
Author(s):  
CATHERINE J. LILLEY ◽  
MANJULA BAKHETIA ◽  
WAYNE L. CHARLTON ◽  
PETER E. URWIN

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.


2002 ◽  
Vol 15 (8) ◽  
pp. 747-752 ◽  
Author(s):  
P. E. Urwin ◽  
Catherine J. Lilley ◽  
Howard J. Atkinson

RNA interference is of value in determining gene function in many organisms. Plant parasitic nematodes are refractory to microinjection as a means of introducing RNA and do not show any oral uptake until they are within plants. We have used octopamine to stimulate uptake by prepara-sitic second stage juveniles of two cyst nematodes, Heterodera glycines and Globodera pallida. This new technique was used to facilitate uptake of double stranded RNA (dsRNA) together with fluoroscein isothiocyanate as a visual marker. Targeting cysteine proteinases did not reduce the number of parasites but caused a shift from the normal female/male ratio of 3:1 to 1:1 by 14 days postinfection (dpi). Exposure of H. glycines to dsRNA corresponding to a newly characterized protein with homology to C-type lectins did not affect sexual fate, but 41% fewer parasites were recovered from the plants. As expected, treatment with dsRNA corresponding to the major sperm protein (MSP) had no effect on either parasite development or sexual fate over 14 days. Northern analysis showed lower transcript abundance for the two targeted mRNAs that occur in J2, plus a later inhibition for MSP transcripts when males developed sperm at 15 dpi. These findings establish a procedure for RNAi of plant parasitic nematodes.


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.


Nematology ◽  
2007 ◽  
Vol 9 (4) ◽  
pp. 451-458 ◽  
Author(s):  
Julia Hofmann ◽  
Florian Grundler

AbstractSedentary cyst and root-knot nematodes withdraw large amounts of solutes from feeding structures induced in host roots. The feeding structures are specialised cells with a high metabolic activity and a tremendous capacity in translocation of nutrients. The required nutrients are provided by the plant transport systems – water and inorganic solutes from the xylem, assimilates such as sugars and amino acids from the phloem. Here we discuss the available data on the mechanisms by which nutrients are translocated into the nematode feeding sites. The interaction between Heterodera schachtii and Arabidopsis thaliana serves as a model system for cyst nematodes. In this case sufficient data are available to propose a conclusive concept for the mechanisms of nutrient flow: basically, in the early stages of nematode development syncytia are symplasmically isolated, so that transport proteins are responsible for the nutrient supply. Later, connections to the phloem via plasmodesmata are established, so that developing females are well supplied with assimilates. The interactions of root-knot nematodes with their hosts share a number of similarities but the data currently available are not sufficient to draw similar conclusions. As nutrient supply and functionality of feeding structures are the basis of biotrophic parasitism of sedentary nematodes, it is tempting to unravel the mechanisms by which both plant and nematodes influence each other via nutrient fluxes.


EDIS ◽  
2007 ◽  
Vol 2007 (19) ◽  
Author(s):  
R. Krueger ◽  
K. E. Dover ◽  
Robert McSorley ◽  
K. H. Wang

ENY-056, an 8-page fact sheet by R. Krueger, K. E. Dover, R. McSorley, and K. -H. Wang, introduces homeowners to the problem of root-knot nematodes, the use of marigolds as an allelopathic cover crop for nematode suppression. It describes the mode of action, planting tips, considerations, and frequently asked questions. Includes references and tables showing susceptibility of marigold varieties to root-knot and plant-parasitic nematodes in Florida. Published by the UF Department of Entomology and Nematology, August 2007. ENY-056/NG045: Marigolds (Tagetes spp.) for Nematode Management (ufl.edu)


Parasitology ◽  
2012 ◽  
Vol 140 (4) ◽  
pp. 445-454 ◽  
Author(s):  
JUAN E. PALOMARES-RIUS ◽  
JOHN T. JONES ◽  
PETER J. COCK ◽  
PABLO CASTILLO ◽  
VIVIAN C. BLOK

SUMMARYThe potato cyst nematodes (PCN) Globodera pallida and G. rostochiensis are major pests of potatoes. The G. pallida (and G. rostochiensis) life cycle includes both diapause and quiescent stages. Nematodes in dormancy (diapause or quiescent) are adapted for long-term survival and are more resistant to nematicides. This study analysed the mechanisms underlying diapause and quiescence. The effects of several compounds (8Br-cGMP, oxotremorine and atropine) on the activation of hatching were studied. The measurements of some morphometric parameters in diapaused and quiescent eggs after exposure to PRD revealed differences in dorsal gland length, subventral gland length and dorsal gland nucleolus. In addition, the expression of 2 effectors (IVg9 and cellulase) was not induced in diapaused eggs in water or PRD, while expression was slightly induced in quiescent eggs. Finally, we performed a comparative study to identify orthologues of C. elegans diapause related genes in plant-parasitic nematodes (G. pallida, Meloidogyne incognita, M. hapla and Bursaphelenchus xylophilus). This analysis suggested that it was not possible to identify G. pallida orthologues of the majority of C. elegans genes involved in the control of dauer formation. All these data suggest that G. pallida may use different mechanisms to C. elegans in regulating the survival stage.


2014 ◽  
Vol 104 (3) ◽  
pp. 306-312 ◽  
Author(s):  
Martin Marek ◽  
Miloslav Zouhar ◽  
Ondřej Douda ◽  
Marie Maňasová ◽  
Pavel Ryšánek

The use of DNA-based analyses in molecular plant nematology research has dramatically increased over recent decades. Therefore, the development and adaptation of simple, robust, and cost-effective DNA purification procedures are required to address these contemporary challenges. The solid-phase-based approach developed by Flinders Technology Associates (FTA) has been shown to be a powerful technology for the preparation of DNA from different biological materials, including blood, saliva, plant tissues, and various human and plant microbial pathogens. In this work, we demonstrate, for the first time, that this FTA-based technology is a valuable, low-cost, and time-saving approach for the sampling, long-term archiving, and molecular analysis of plant-parasitic nematodes. Despite the complex structure and anatomical organization of the multicellular bodies of nematodes, we report the successful and reliable DNA-based analysis of nematode high-copy and low-copy genes using the FTA technology. This was achieved by applying nematodes to the FTA cards either in the form of a suspension of individuals, as intact or pestle-crushed nematodes, or by the direct mechanical printing of nematode-infested plant tissues. We further demonstrate that the FTA method is also suitable for the so-called “one-nematode-assay”, in which the target DNA is typically analyzed from a single individual nematode. More surprisingly, a time-course experiment showed that nematode DNA can be detected specifically in the FTA-captured samples many years after initial sampling occurs. Collectively, our data clearly demonstrate the applicability and the robustness of this FTA-based approach for molecular research and diagnostics concerning phytonematodes; this research includes economically important species such as the stem nematode (Ditylenchus dipsaci), the sugar beet nematode (Heterodera schachtii), and the Northern root-knot nematode (Meloidogyne hapla).


Sign in / Sign up

Export Citation Format

Share Document