Wheat gene expression is differentially affected by a virulent Russian wheat aphid biotype.

An improved understanding of the complex interactions between plants and aphids is emerging. Recognition of aphid feeding in plant tissues involves production of several defense response signaling pathways and downstream production of defense and detoxification compounds. Feeding by Russian wheat aphid, Diuraphis noxia (Kurdjumov), a serious pest of cereal crops worldwide, induces foliar deformity and chlorophyll loss during compatible wheat-D.

Aphid feeding activates expression of a transcriptome of oxylipin-based defense signals in wheat involved in resistance to herbivory.

Damage by the Russian wheat aphid (RWA), Diuraphis noxia, significantly reduces wheat and barley yields worldwide. In compatible interactions, virulent RWA populations flourish and susceptible plants suffer extensive leaf chlorophyll loss. In incompatible interactions, RWA reproduction and population growth are significantly reduced and RWA-related chlorophyll loss in resistant plants is minor.

Identification and characterization of eleven glutathione S-transferase genes from the aquatic midge Chironomus tentans (Diptera: Chironomidae).

Eleven cDNAs encoding glutathione S-transferases (GSTs) were sequenced and characterized in Chironomus tentans, an ecologically important aquatic midge. Phylogenetic analysis revealed seven GSTs in three different cytosolic classes including 4 in sigma (CtGSTs1, CtGSTs2, CtGSTs3, CtGSTs4), 2 in delta (CtGSTd1, CtGSTd2), and 1 in omega (CtGSTo1). The remaining four GSTs (CtGSTu1, CtGSTu2, CtGSTu3, CtGSTu4) were unclassified due to their low relatedness to currently known classes of insect GSTs.

Feeding behavior of Russian wheat aphid (Hemiptera: Aphididae) biotype 2 in response to wheat genotypes exhibiting antibiosis and tolerance resistance.

In this study, wheat, Triticum aestivum L. (em Thell), genotypes containing the Dnx, Dn7, Dn6, and Dn4 genes for resistance to the Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), along with Dn0, a susceptible control, were assessed to determine the categories of D. noxia biotype 2 (RWA2) resistance in each genotype and RWA2 feeding behaviors on Dnx and Dn0 plants by using the electronic penetration graph technique.

Resistance to Russian wheat aphid biotype 2 in CIMMYT synthetic hexaploid wheat lines.

The Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Hemiptera: Aphididae), devastates wheat and barley production on all continents except Australia. Although D. noxia-resistant cultivars exist, virulent D.

Gene expression profiling reveals decreased expression of two hemoglobin genes associated with increased consumption of oxygen in Chironomus tentans exposed to atrazine: a possible mechanism for adapting to oxygen deficiency.

Atrazine is an extensively used triazine herbicide in agricultural and residential areas and has been routinely detected in many surface and ground waters. This study reveals various up- and down-regulated genes associated with hypoxic stress in atrazine-treated fourth-instar Chironomus tentans larvae (midges) by using restriction fragment differential display-PCR. Two down-regulated hemoglobin cDNAs were isolated from the midges.

Comparative studies on effects of three chitin synthesis inhibitors on common malaria mosquito (Diptera: Culicidae).

Toxicities of three chitin synthesis inhibitors (diflubenzuron, nikkomycin Z and polyoxin D) were evaluated using second instars of the common malaria mosquito, Anopheles quadrimaculatus Say (Diptera: Culicidae). Neither nikkomycin Z nor polyoxin D at 50 microg/liter caused significant larval mortality, although they reduced the body weight of the survivors by 20.5 and 33.

Categories and inheritance of resistance to Russian wheat aphid (Homoptera: Aphididae) biotype 2 in a selection from wheat cereal introduction 2401.

The Russian wheat aphid, Diuraphis noxia (Kurdjumov) (Homoptera: Aphididae), is one of the most devastating insect pests of wheat (Triticum spp.) and barley (Hordeum spp.) in the world.

Molecular basis of plant gene expression during aphid invasion: wheat Pto- and Pti-like sequences are involved in interactions between wheat and Russian wheat aphid (Homoptera: Aphididae).

The Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae), is a major pest of bread wheat, Triticum aestivum L. (em Thell), in most wheat-growing areas worldwide. Aphid-resistant cultivars are used to combat this pest, but very little is known about the molecular basis of resistance.

Identification of Russian wheat aphid (Homoptera: Aphididae) populations virulent to the Dn4 resistance gene.

The Russian wheat aphid, Diuraphis noxia (Mordvilko), is a serious worldwide pest of wheat and barley. Russian wheat aphid populations from Hungary, Russia, and Syria have previously been identified as virulent to D. noxia (Dn) 4, the gene in all Russian wheat aphid-resistant cultivars produced in Colorado.

Resistance to greenbug (Heteroptera: Aphididae) biotype I in Aegilops tauschii synthetic wheats.

The greenbug, Schizaphis graminum (Rondani), is a major pest of wheat in North America, reducing U.S. wheat production by 60 to 100 million dollars each year.