scholarly journals Inhibition of acetyl-CoA carboxylase by spirotetramat causes lipid depletion and surface coat deficiency in nematodes

2018 ◽  
Author(s):  
Philipp Gutbrod ◽  
Katharina Gutbrod ◽  
Ralf Nauen ◽  
Abdelnaser Elashry ◽  
Shahid Siddique ◽  
...  
Keyword(s):  
De Novo ◽  
Foliar Application ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Surface Coat ◽  
Acetyl Coa Carboxylase ◽  
Systemic Insecticide ◽  
In Planta ◽  
Acetyl Coa ◽  
Plant Parasitic

AbstractPlant-parasitic nematodes pose a significant threat to agriculture causing annual yield losses worth more than 100 billion US$. Nematode control often involves the use of nematicides, but many of them including non-selective fumigants have been phased out, particularly due to ecotoxicological concerns. Thus new control strategies are urgently needed. Spirotetramat (SPT) is used as phloem-moble systemic insecticide targeting acetyl-CoA carboxylase (ACC) of pest insects and mites upon foliar application. Our studies revealed that SPT known to be activated in planta to SPT-enol acts as a developmental inhibitor of the free-living nematode Caenorhabditis elegans and the plant-parasitic nematode Heterodera schachtii. Exposure to SPT-enol leads to larval arrest and disruption of the life cycle. Furthermore, SPT-enol inhibits nematode ACC activity, affects storage lipids, fatty acid composition and disrupts surface coat synthesis. Silencing of H. schachtii ACC by RNAi induced similar phenotypes and thus mimics the effects of SPT-enol, supporting the conclusion that SPT-enol acts on nematodes by inhibiting ACC. Our studies demonstrated that the inhibition of de novo lipid biosynthesis by interfering with nematode ACC is a new nematicidal mode of action addressed by spirotetramat, a well-known systemic insecticide for sucking pest control.

scholarly journals Marasmius oreades agglutinin enhances resistance of Arabidopsis against plant-parasitic nematodes and a herbivorous insect

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Aboubakr Moradi ◽  
Tina Austerlitz ◽  
Paul Dahlin ◽  
Christelle AM Robert ◽  
Corina Maurer ◽  
...  
Keyword(s):  
Insecticidal Activity ◽  
Negative Impact ◽  
Crop Protection ◽  
Heterodera Schachtii ◽  
Relative Mass ◽  
Parasitic Nematodes ◽  
Herbivorous Insect ◽  
Plant Parasitic Nematodes ◽  
In Planta ◽  
Plant Parasitic

Abstract Background Plant-parasitic nematodes and herbivorous insects have a significant negative impact on global crop production. A successful approach to protect crops from these pests is the in planta expression of nematotoxic or entomotoxic proteins such as crystal proteins from Bacillus thuringiensis (Bt) or plant lectins. However, the efficacy of this approach is threatened by emergence of resistance in nematode and insect populations to these proteins. To solve this problem, novel nematotoxic and entomotoxic proteins are needed. During the last two decades, several cytoplasmic lectins from mushrooms with nematicidal and insecticidal activity have been characterized. In this study, we tested the potential of Marasmius oreades agglutinin (MOA) to furnish Arabidopsis plants with resistance towards three economically important crop pests: the two plant-parasitic nematodes Heterodera schachtii and Meloidogyne incognita and the herbivorous diamondback moth Plutella xylostella. Results The expression of MOA does not affect plant growth under axenic conditions which is an essential parameter in the engineering of genetically modified crops. The transgenic Arabidopsis lines showed nearly complete resistance to H. schachtii, in that the number of female and male nematodes per cm root was reduced by 86–91 % and 43–93 % compared to WT, respectively. M. incognita proved to be less susceptible to the MOA protein in that 18–25 % and 26–35 % less galls and nematode egg masses, respectively, were observed in the transgenic lines. Larvae of the herbivorous P. xylostella foraging on MOA-expression lines showed a lower relative mass gain (22–38 %) and survival rate (15–24 %) than those feeding on WT plants. Conclusions The results of our in planta experiments reveal a robust nematicidal and insecticidal activity of the fungal lectin MOA against important agricultural pests which may be exploited for crop protection.

scholarly journals Toward genetic modification of plant-parasitic nematodes: delivery of macromolecules to adults and expression of exogenous mRNA in second stage juveniles

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Olaf Kranse ◽  
Helen Beasley ◽  
Sally Adams ◽  
Andre Pires-daSilva ◽  
Christopher Bell ◽  
...  
Keyword(s):  
Food Security ◽  
Genetic Modification ◽  
The Body ◽  
Forward Genetics ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Cyst Nematodes ◽  
Plant Parasitic

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.

The genome and lifestage-specific transcriptomes of a plant-parasitic nematode and its host reveal susceptibility genes involved in trans-kingdom synthesis of vitamin B5

2021 ◽  
Author(s):  
Shahid Siddique ◽  
Zoran S. Radakovic ◽  
Clarissa Hiltl ◽  
Clement Pellegrin ◽  
Thomas J. Baum ◽  
...  
Keyword(s):  
Metabolic Pathways ◽  
Crop Production ◽  
Susceptibility Genes ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Cyst Nematodes ◽  
Novel Approach ◽  
Vitamin B5 ◽  
Dual Analysis ◽  
Plant Parasitic

AbstractPlant-parasitic nematodes are a major, and in some cases a dominant, threat to crop production in all agricultural systems. The relative scarcity of classical resistance genes highlights a pressing need to identify new ways to develop nematode-resistant germplasm. Here, we sequence and assemble a high-quality genome of the model cyst nematode Heterodera schachtii to provide a platform for the first system-wide dual analysis of host and parasite gene expression over time, covering all major stages of the interaction. This novel approach enabled the analysis of the hologenome of the infection site, to identify metabolic pathways that were incomplete in the parasite but complemented by the host. Using a combination of bioinformatic, genetic, and biochemical approaches, we show that the highly atypical completion of vitamin B5 biosynthesis by the parasitic animal, putatively enabled by a horizontal gene transfer from a bacterium, is critically important for parasitism. Knockout of either the plant-encoded or the now nematode-encoded steps in the pathway blocks parasitism. Our experiments establish a reference for cyst nematodes, use this platform to further our fundamental understanding of the evolution of plant-parasitism by nematodes, and show that understanding congruent differential expression of metabolic pathways represents a new way to find nematode susceptibility genes, and thereby, targets for future genome editing-mediated generation of nematode-resistant crops.

scholarly journals Acetyl-CoA Carboxylase 2−/− Mutant Mice are Protected against Fatty Liver under High-fat, High-carbohydrate Dietary and de Novo Lipogenic Conditions

2012 ◽  
Vol 287 (15) ◽  
pp. 12578-12588 ◽  
Author(s):  
Lutfi Abu-Elheiga ◽  
Hongmei Wu ◽  
Ziwei Gu ◽  
Rubin Bressler ◽  
Salih J. Wakil
Keyword(s):  
Fatty Liver ◽  
De Novo ◽  
Mutant Mice ◽  
Acetyl Coa Carboxylase ◽  
Wild Type ◽  
High Fat ◽  
Acetyl Coa ◽  
High Carbohydrate ◽  
Ppar Γ ◽  
Hepatic Fat

Hepatic fat accumulation resulting from increased de novo fatty acid synthesis leads to hepatic steatosis and hepatic insulin resistance. We have shown previously that acetyl-CoA carboxylase 2 (Acc2−/−) mutant mice, when fed a high-fat (HF) or high-fat, high-carbohydrate (HFHC) diet, are protected against diet-induced obesity and maintained whole body and hepatic insulin sensitivity. To determine the effect of an ACC2 deletion on hepatic fat metabolism, we studied the regulation of the enzymes involved in the lipogenic pathway under Western HFHC dietary and de novo lipogenic conditions. After completing the HFHC regimen, Acc2−/− mutant mice were found to have lower body weight, smaller epididymal fat pads, lower blood levels of nonesterified fatty acids and triglycerides, and higher hepatic cholesterol than wild-type mice. Significant up-regulation of lipogenic enzymes and an elevation in hepatic peroxisome proliferator-activated receptor-γ (PPAR-γ) protein were found in Acc2−/− mutant mice under de novo lipogenic conditions. The increase in lipogenic enzyme levels was accompanied by up-regulation of the transcription factors, sterol regulatory element-binding proteins 1 and 2, and carbohydrate response element-binding protein. In contrast, hepatic levels of the PPAR-γ and PPAR-α proteins were significantly lower in the Acc2−/− mutant mice fed an HFHC diet. When compared with wild-type mice fed the same diet, Acc2−/− mutant mice exhibited a similar level of AKT but with a significant increase in pAKT. Hence, deleting ACC2 ameliorates the metabolic syndrome and protects against fatty liver despite increased de novo lipogenesis and dietary conditions known to induce obesity and diabetes.

scholarly journals Exploitation of FTA Cartridges for the Sampling, Long-Term Storage, and DNA-Based Analyses of Plant-Parasitic Nematodes

2014 ◽  
Vol 104 (3) ◽  
pp. 306-312 ◽  
Author(s):  
Martin Marek ◽  
Miloslav Zouhar ◽  
Ondřej Douda ◽  
Marie Maňasová ◽  
Pavel Ryšánek
Keyword(s):  
Solid Phase ◽  
Complex Structure ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Plant Tissues ◽  
Single Individual ◽  
Plant Parasitic Nematodes ◽  
Important Species ◽  
Plant Parasitic

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).

Mutualistic endophytic fungi and in-planta suppressiveness to plant parasitic nematodes

2008 ◽  
Vol 46 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Richard A. Sikora ◽  
Luis Pocasangre ◽  
Alexandra zum Felde ◽  
Bjoern Niere ◽  
Tam T. Vu ◽  
...  
Keyword(s):  
Endophytic Fungi ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
In Planta ◽  
Plant Parasitic

Fatty-acid biosynthesis and acetyl-coa carboxylase as a target of diclofop, fenoxaprop and other aryloxy-phenoxy-propionic acid herbicides

1988 ◽  
Vol 43 (1-2) ◽  
pp. 47-54 ◽  
Author(s):  
Klaus Kobek ◽  
Manfred Focke ◽  
K. Lichtenthaler Botanisches
Keyword(s):  
Fatty Acid ◽  
Propionic Acid ◽  
Fatty Acid Biosynthesis ◽  
De Novo ◽  
Free Acid ◽  
Acetate Incorporation ◽  
Acetyl Coa Carboxylase ◽  
Acid Biosynthesis ◽  
Acetyl Coa ◽  
Acid Herbicides

The effect of the herbicides and aryloxy-phenoxy-propionic acid derivatives diclofop, fenoxaprop, fluazifop and haloxyfop and their ethyl, methyl or butyl esters on the de novo fatty-acid biosynthesis of isolated chloroplasts was investigated with intact chloroplasts isolated from sensitive grasses (Poaceae) and tolerant dicotyledonous plants (Pisum, Spinacia). The 4 herbicides (free-acid form) block the de novo fatty-acid biosynthesis ([2-14C]acetate incorporation into the total fatty-acid fraction) of the sensitive Avena chloroplasts in a dose-dependent manner. The I50- values (a 50% inhibition of the [14C]acetate incorporation) lie in the range of 10-7 to 2 x 10-6 ᴍ. The ethyl or methyl esters (diclofop, fenoxaprop, haloxyfop) and butyl ester (fluazifop) do not affect the de novo fatty-acid biosynthesis of isolated chloroplasts or only at a very high concentration of ca. 10-4 ᴍ. In contrast, the de novo fatty-acid biosynthesis of the tolerant dicotyledonous species (pea, spinach) is not affected by the 4 aryloxy-phenoxy-propionic acid herbicides. In an enzyme preparation isolated from chloroplasts of the herbicide-sensitive barley plants the de novo fatty-acid biosynthesis from [14C]acetate and [14C]acetyl-CoA is blocked by all 4 herbicides (free acids), whereas that of [14C]malonate and [14C]malonyl-CoA is not affected. This strongly suggests that the target of all 4 herbicides (free-acid form) is the acetyl-CoA carboxylase within the chloroplasts. The applied ester derivatives, in turn, which are ineffective in the isolated chloroplast test system, have equally little or no effect on the activity of the acetyl-CoA carboxylase. It is assumed that the acetyl-CoA carboxylase of the tolerant dicot plants investigated is modified in such a way that the 4 herbicides cannot bind to and affect the target

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