A link between energy metabolism and plant host adaptation states in the two-spotted spider mite, Tetranychus urticae (Koch).

Energy metabolism is a highly conserved process that balances generation of cellular energy and maintenance of redox homeostasis. It consists of five interconnected pathways: glycolysis, tricarboxylic acid cycle, pentose phosphate, trans-sulfuration, and NAD+ biosynthesis pathways. Environmental stress rewires cellular energy metabolism.

Structural and functional studies reveal the molecular basis of substrate promiscuity of a glycosyltransferase originating from a major agricultural pest.

The two-spotted spider mite, Tetranychus urticae, is a major cosmopolitan pest that feeds on more than 1100 plant species. Its genome contains an unprecedentedly large number of genes involved in detoxifying and transporting xenobiotics, including 80 genes that code for UDP glycosyltransferases (UGTs). These enzymes were acquired via horizontal gene transfer from bacteria after loss in the Chelicerata lineage.

The Arabidopsis thioredoxin TRXh5regulates the S-nitrosylation pattern of the TIRK receptor being both proteins essential in the modulation of defences to Tetranychus urticae.

The interaction between plants and phytophagous arthropods encompasses a complex network of molecules, signals, and pathways to overcome defences generated by each interacting organism. Although most of the elements and modulators involved in this interplay are still unidentified, plant redox homeostasis and signalling are essential for the establishment of defence responses. Here, focusing on the response of Arabidopsis thaliana to the spider mite Tetranychus urticae, we demonstrate the involvement in plant defence of the thioredoxin TRXh5, a small redox protein whose expression is induced by mite infestation.

Host adaptation and specialization in Tetranychidae mites.

Composite generalist herbivores are comprised of host-adapted populations that retain the ability to shift hosts. The degree and overlap of mechanisms used by host-adapted generalist and specialist herbivores to overcome the same host plant defenses are largely unknown. Tetranychidae mites are exceptionally suited to address the relationship between host adaptation and specialization in herbivores as this group harbors closely related species with remarkably different host ranges-an extreme generalist the two-spotted spider mite (Tetranychus urticae Koch [Tu]) and the Solanaceous specialist Tetranychus evansi (Te).

Current status of structural studies of proteins originating from Arachnida.

Arthropods from class Arachnida constitute a large and diverse group with over 100,000 described species, and they are sources of many proteins that have a direct impact on human health. Despite the importance of Arachnida, few proteins originating from these organisms have been characterized in terms of their structure. Here we present a detailed analysis of Arachnida proteins that have their experimental structures determined and deposited to the Protein Data Bank (PDB).

Localized efficacy of environmental RNAi in Tetranychus urticae.

Environmental RNAi has been developed as a tool for reverse genetics studies and is an emerging pest control strategy. The ability of environmental RNAi to efficiently down-regulate the expression of endogenous gene targets assumes efficient uptake of dsRNA and its processing. In addition, its efficiency can be augmented by the systemic spread of RNAi signals.

Hydroxynitrile lyase defends Arabidopsis against Tetranychus urticae.

Plant-pest interactions involve multifaceted processes encompassing a complex crosstalk of pathways, molecules, and regulators aimed at overcoming defenses developed by each interacting organism. Among plant defensive compounds against phytophagous arthropods, cyanide-derived products are toxic molecules that directly target pest physiology. Here, we identified the Arabidopsis (Arabidopsis thaliana) gene encoding hydroxynitrile lyase (AtHNL, At5g10300) as one gene induced in response to spider mite (Tetranychus urticae) infestation.

β-Cyanoalanine synthase protects mites against Arabidopsis defenses.

Glucosinolates are antiherbivory chemical defense compounds in Arabidopsis (Arabidopsis thaliana). Specialist herbivores that feed on brassicaceous plants have evolved various mechanisms aimed at preventing the formation of toxic isothiocyanates. In contrast, generalist herbivores typically detoxify isothiocyanates through glutathione conjugation upon exposure.

Structural and functional characterization of β-cyanoalanine synthase from Tetranychus urticae.

Tetranychus urticae is a polyphagous spider mite that can feed on more than 1100 plant species including cyanogenic plants. The herbivore genome contains a horizontally acquired gene tetur10g01570 (TuCAS) that was previously shown to participate in cyanide detoxification. To understand the structure and determine the function of TuCAS in T.

Rapid specialization of counter defenses enables two-spotted spider mite to adapt to novel plant hosts.

Genetic adaptation, occurring over a long evolutionary time, enables host-specialized herbivores to develop novel resistance traits and to efficiently counteract the defenses of a narrow range of host plants. In contrast, physiological acclimation, leading to the suppression and/or detoxification of host defenses, is hypothesized to enable broad generalists to shift between plant hosts. However, the host adaptation mechanisms used by generalists composed of host-adapted populations are not known.

Delta class glutathione S-transferase (TuGSTd01) from the two-spotted spider mite Tetranychus urticae is inhibited by abamectin.

GSTs (Glutathione S-transferases) are known to catalyze the nucleophilic attack of the sulfhydryl group of reduced glutathione (GSH) on electrophilic centers of xenobiotic compounds, including insecticides and acaricides. Genome analyses of the polyphagous spider mite herbivore Tetranychus urticae (two-spotted spider mite) revealed the presence of a set of 32 genes that code for secreted proteins belonging to the GST family of enzymes. To better understand the role of these proteins in T.

Environmental RNA interference in two-spotted spider mite, Tetranychus urticae, reveals dsRNA processing requirements for efficient RNAi response.

Comprehensive understanding of pleiotropic roles of RNAi machinery highlighted the conserved chromosomal functions of RNA interference. The consequences of the evolutionary variation in the core RNAi pathway genes are mostly unknown, but may lead to the species-specific functions associated with gene silencing. The two-spotted spider mite, Tetranychus urticae, is a major polyphagous chelicerate pest capable of feeding on over 1100 plant species and developing resistance to pesticides used for its control.

The silk of gorse spider mite Tetranychus lintearius represents a novel natural source of nanoparticles and biomaterials.

Spider mites constitute an assemblage of well-known pests in agriculture, but are less known for their ability to spin silk of nanoscale diameters and high Young's moduli. Here, we characterize silk of the gorse spider mite Tetranychus lintearius, which produces copious amounts of silk with nano-dimensions. We determined biophysical characteristics of the silk fibres and manufactured nanoparticles and biofilm derived from native silk.

Resistance to pyridaben in Canadian greenhouse populations of two-spotted spider mites, Tetranychus urticae (Koch).

Two-spotted spider mite (TSSM) Tetranychus urticae (Koch) is an important agricultural pest that causes considerable yield losses to over 150 field and greenhouse crops. Mitochondrial electron transport inhibitors (METI) acaricides are commonly used to control mite species in commercial Canadian greenhouses. Development of resistance to METIs in TSSM populations have been reported worldwide, but not until recently in Canada.

A Leaf-Mimicking Method for Oral Delivery of Bioactive Substances Into Sucking Arthropod Herbivores.

Spider mites (Acari: Tetranychidae) are pests of a wide range of agricultural crops, vegetables, and ornamental plants. Their ability to rapidly develop resistance to synthetic pesticides has prompted the development of new strategies for their control. Evaluation of synthetic pesticides and bio-pesticides-and more recently the identification of RNA interference (RNAi) target genes-requires an ability to deliver test compounds efficiently.

Plant Defenses Against Pests Driven by a Bidirectional Promoter.

The plant defense responses to pests results in the synchronized change of a complex network of interconnected genes and signaling pathways. An essential part of this process is mediated by the binding of transcription factors to the specific responsive -elements within in the promoters of phytophagous-responsive genes. In this work, it is reported the identification and characterization of a bidirectional promoter that simultaneously co-regulate two divergent genes, and , upon arthropod feeding.

An Arabidopsis TIR-Lectin Two-Domain Protein Confers Defense Properties against .

Plant immunity depends on fast and specific transcriptional reprogramming triggered by the perception of biotic stresses. Numerous studies have been conducted to better understand the response of plants to the generalist herbivore two-spotted spider mite (). However, how plants perceive mites and how this perception is translated into changes in gene expression are largely unknown.

Structural and functional characterization of an intradiol ring-cleavage dioxygenase from the polyphagous spider mite herbivore Tetranychus urticae Koch.

Genome analyses of the polyphagous spider mite herbivore Tetranychus urticae (two-spotted spider mite) revealed the presence of a set of 17 genes that code for secreted proteins belonging to the "intradiol dioxygenase-like" subgroup. Phylogenetic analyses indicate that this novel enzyme family has been acquired by horizontal gene transfer. In order to better understand the role of these proteins in T.

The Digestive System of the Two-Spotted Spider Mite, Koch, in the Context of the Mite-Plant Interaction.

The two-spotted spider mite (TSSM), Koch (Acari: Tetranychidae), is one of the most polyphagous herbivores, feeding on more than 1,100 plant species. Its wide host range suggests that TSSM has an extraordinary ability to modulate its digestive and xenobiotic physiology. The analysis of the TSSM genome revealed the expansion of gene families that encode proteins involved in digestion and detoxification, many of which were associated with mite responses to host shifts.

Arabidopsis response to the spider mite Tetranychus urticae depends on the regulation of reactive oxygen species homeostasis.

Reactive oxygen species (ROS) are molecules that play a prominent role in plant response to numerous stresses, including plant interactions with herbivores. Previous findings indicate that Arabidopsis plants showed an increase in HO accumulation after Tetranychus urticae infestation. Despite its importance, no information has been reported on the relationships between ROS-metabolizing systems and the spider mite-triggered plant-induced responses.

Correction: Protocols for the delivery of small molecules to the two-spotted spider mite, Tetranychus urticae.

[This corrects the article DOI: 10.1371/journal.pone.

RNAi-based reverse genetics in the chelicerate model Tetranychus urticae: A comparative analysis of five methods for gene silencing.

RNA interference (RNAi) can be used for the protection against agricultural pests through the silencing of genes required for pest fitness. To assess the potential of RNAi approaches in the two-spotted spider mite, Tetranychus urticae, we compared 5 methods for the delivery of double-stranded RNA (dsRNA). These methods include mite feeding on either (i) leaves floating on a dsRNA solution, (ii) dsRNA-expressing plants, (iii) artificial diet supplemented with dsRNA, or (iv) dsRNA-coated leaves, and (v) mite soaking in a dsRNA solution.