Publications

bac libraries from wheat chromosome 7d: efficient tool for positional cloning of aphid resistance genes.	positional cloning in bread wheat is a tedious task due to its huge genome size and hexaploid character. bac libraries represent an essential tool for positional cloning. however, wheat bac libraries comprise more than million clones, which makes their screening very laborious. here, we present a targeted approach based on chromosome-specific bac libraries. such libraries were constructed from flow-sorted arms of wheat chromosome 7d. a library from the short arm (7ds) consisting of 49,152 clones ...	2011	21318113
comparisons of salivary proteins from five aphid (hemiptera: aphididae) species.	aphid (hemiptera: aphididae) saliva, when injected into host plants during feeding, causes physiological changes in hosts that facilitate aphid feeding and cause injury to plants. comparing salivary constituents among aphid species could help identify which salivary products are universally important for general aphid feeding processes, which products are involved with specific host associations, or which products elicit visible injury to hosts. we compared the salivary proteins from five aphid ...	2011	22182624
quantifying russian wheat aphid pest intensity across the great plains.	wheat, the most important cereal crop in the northern hemisphere, is at-risk for an approximate 10% reduction in worldwide production because of animal pests. the potential economic impact of cereal crop pests has resulted in substantial research efforts into the understanding of pest agroecosystems and development of pest management strategy. management strategy is informed frequently by models that describe the population dynamics of important crop pests and because of the economic impact of t ...	2012	23321099
cyclical parthenogenetic reproduction in the russian wheat aphid (hemiptera: aphididae) in the united states: sexual reproduction and its outcome on biotypic diversity.	in 1986, the russian wheat aphid, diuraphis noxia (kurdjumov) (hemiptera: aphididae), became an invasive species of united states. nearly 20 yr later, new biotypes appeared that were capable of overcoming most sources of resistance and became a renewed threat to wheat, triticum aestivum l., production. cyclical (cp) and obligate (op) parthenogenesis enables aphids to both adapt to changing environments and exploit host resources. we documented these forms of reproduction for russian wheat aphid ...	2012	22812148
barley tolerance of russian wheat aphid (hemiptera: aphididae) biotype 2 herbivory involves expression of defense response and developmental genes.	the russian wheat aphid, diuraphis noxia (kurdjumov), is an invasive insect pest that causes serious yield losses in bread wheat, triticum aestivum l., durum wheat, t. turgidum l and barley, hordeum vulgare l. successful management of d. noxia has been achieved through resistant varieties via plant antixenosis (aphid non-preference), antibiosis (reduced aphid growth or fecundity), tolerance (plant compensatory growth after aphid feeding), or a combination of each. previous phenotyping experiment ...	2012	22476464
antifeedant activity of fatty acid esters and phytosterols from echium wildpretii.	crude extracts and fractions from echium wildpretii h. pearson ex hook. f. subsp. wildpretii (boraginaceae) have been tested against insect species spodoptera littoralis, leptinotarsa decemlineata, and the aphids myzus persicae, diuraphis noxia, metopolophium dirhodum, rhopalosiphum maidis, and rhopalosiphum padi. the etoh extract and the lipid and steroidal fractions of e. wildpretii exhibited significant antifeedant activities against the aphids and l. decemlineata. two bioactive mixtures comp ...	2012	22422524
polymorphism and methylation of four genes expressed in salivary glands of russian wheat aphid (homoptera: aphididae).	dna methylation is a general epigenetic mechanism for plants, animals, and fungi to adapt to environmental variation. two biotypes of the russian wheat aphid (diuraphis noxia), biotype 1 and biotype 2, have different virulence to host plants. in this study, in addition to a high polymorphism, dna methylation at cytosines were observed in genomic fragments of four genes in biotype 1 and biotype 2, after the genomic dna was treated with sodium bisulfite. these genes presumably encode proteins and ...	2012	22420276
russian wheat aphids (diuraphis noxia) in china: native range expansion or recent introduction?	in this study, we explore the population genetics of the russian wheat aphid (rwa) (diuraphis noxia), one of the world's most invasive agricultural pests, in north-western china. we have analysed the data of 10 microsatellite loci and mitochondrial sequences from 27 populations sampled over 2 years in china. the results confirm that the rwas are holocyclic in china with high genetic diversity indicating widespread sexual reproduction. distinct differences in microsatellite genetic diversity and ...	2012	22417053
proteomic analysis of secreted saliva from russian wheat aphid (diuraphis noxia kurd.) biotypes that differ in virulence to wheat.	diuraphis noxia, russian wheat aphid (rwa), biotypes are classified by their differential virulence to wheat varieties containing resistance genes. rwa salivary proteins, unlike those of most aphid species, cause foliar damage and physiological alterations in plants. a comparative proteomic analysis of secreted saliva from four differentially virulent rwa biotypes identified thirty-four individual proteins. the five major proteins were glucose dehydrogenase, lipophorin, chitinase, civ16.8g1-like ...	2012	22348819
host associations of diuraphis noxia (homoptera: aphididae) biotypes in south africa.	the incidence and host associations of russian wheat aphid were investigated in the wheat-growing areas of south africa from 2009 to 2011. most russian wheat aphid samples were collected on dryland wheat, while few samples were collected on irrigation wheat. volunteer wheat and rescue grass were the preferred alternative host plants to cultivated wheat for all three biotypes. no rwasa1 samples were collected from oats, but rwasa2 seemed to be able to survive successfully on oats, with 12.26% of ...	2013	24498762
response of russian wheat aphid resistance in wheat and barley to four diuraphis (hemiptera: aphididae) species.	three diuraphis species, diuraphis frequens (walker), diuraphis mexicana (mcvicar baker), and diuraphis tritici (gillette), were known to exist in the united states before the 1986 appearance of the russian wheat aphid, diuraphis noxia kurdjumov. the russian wheat aphid soon became a significant pest of wheat although other endemic diuraphis species were known to infest wheat. wheat and barley entries resistant and susceptible to russian wheat aphid biotype 2 were evaluated against all four diur ...	2013	23786097
effects of planting date and barley variety on russian wheat aphid (hemiptera: aphididae) populations in colorado, kansas, and nebraska.	the russian wheat aphid, diuraphis noxia (kurdjumov) (hemiptera: aphididae), is an important pest in the western great plains of the united states, where it causes hundreds of millions of dollars of losses to barley and wheat production through reduced yields. experiments to evaluate the effect of early planting and resistance in barley (hordeum vulgare l.) on d. noxia were conducted at fort collins, co; tribune, ks; and sidney, ne, in 2007, 2008, and 2009. treatments included two planting dates ...	2014	26309288
variation between ethiopian and north american barley varieties (hordeum vulgare) in response to russian wheat aphid (diuraphis noxia) populations.	the russian wheat aphid, diuraphis noxia (mordvilko) (hemiptera: aphididae), causes severe damage to barley, hordeum vulgare l. (poales: poaceae), in the highlands of ethiopia. little information is available on the control of this pest in ethiopia. an experiment aimed at evaluating the resistance of barley varieties from the usa to d. noxia populations and determining biotypic variation between ethiopian and north american d. noxia populations was conducted. the d. noxia-resistant barley variet ...	2014	25373187
near-isogenic lines of triticum aestivum with distinct modes of resistance exhibit dissimilar transcriptional regulation during diuraphis noxia feeding.	russian wheat aphid (diuraphis noxia, kurdjumov) feeding on susceptible triticum aestivum l. leads to leaf rolling, chlorosis and plant death - symptoms not present in resistant lines. although the effects of several d. noxia (dn) resistance genes are known, none have been isolated or characterized. wheat varieties expressing different dn genes exhibit distinct modes of d. noxia resistance, such as antibiosis (dn1), tolerance (dn2), and antixenosis (dn5). however, the mechanism whereby feeding a ...	2014	25361582
examining the competitive advantage of diuraphis noxia (hemiptera: aphididae) biotype 2 over biotype 1.	the russian wheat aphid, diuraphis noxia (kurdjumov) is a serious pest of small grains, such as wheat and barley. high population growth rates and a broad gramineae host range have allowed this aphid to successfully establish and become pestiferous across much of north america since its invasion in the mid-1980s. resistant wheat cultivars were developed and provided control ofd. noxia until 2003, when a new biotype (designated rwa2, as contrasted with the original biotype's designation, rwa1) em ...	2014	25195438
characterization of eight russian wheat aphid (hemiptera: aphididae) biotypes using two-category resistant-susceptible plant responses.	eight biotypes of the russian wheat aphid, diuraphis noxia (kurdjumov), have been discovered in the united states since 2003. biotypes are identified by the distinct feeding damage responses they produce on wheat carrying different russian wheat aphid resistance genes, namely, from dn1 to dn9. each russian wheat aphid biotype has been named using plant damage criteria and virulence categories that have varied between studies. the study was initiated to compare the plant damage caused by all the ...	2014	25026693
hypervirulent diuraphis noxia (hemiptera: aphididae) biotype sam avoids triggering defenses in its host (triticum aestivum) (poales: poaceae) during feeding.	in the molecular arms race between aphids and plants, both organisms rely on adaptive strategies to outcompete their evolutionary rival. in the current study, we investigated the difference in elicited defense responses of wheat (triticum aestivum l.) near-isogenic lines with different dn resistance genes, upon feeding by an avirulent and hypervirulent diuraphis noxia kurdjumov biotype. after measuring the activity of a suite of enzymes associated with plant defense, it became apparent that the ...	2014	24874154
selection of reference genes for expression analysis in diuraphis noxia (hemiptera: aphididae) fed on resistant and susceptible wheat plants.	the russian wheat aphid (rwa), diuraphis noxia kurdjumov, is a major global pest of wheat and barley production that causes enormous economic damage. few studies have been conducted to explore and decipher the molecular basis of rwa strategies to evade plant defense mechanisms. gene expression studies of rwa in response to wheat genotypes carrying different rwa resistance genes have been initiated in our group; however, a secure and accurate understanding of rwa gene expression is dependent on i ...	2014	24862828
evaluation of tetraploid switchgrass (poales: poaceae) populations for host suitability and differential resistance to four cereal aphids.	switchgrass, panicum virgatum l., is being developed as a bioenergy feedstock. the potential for large-scale production has encouraged its evaluation as a host for important grass pests. eight no-choice studies were performed for two developmental stages of two switchgrass cultivars ('kanlow' and'summer') and two experimental strains, k x s, and s x k produced by reciprocal mating of these cultivars followed by selection for high yield. plants were evaluated for host suitability and damage diffe ...	2014	24665729
a multi-genome analysis approach enables tracking of the invasion of a single russian wheat aphid (diuraphis noxia) clone throughout the new world.	this study investigated the population genetics, demographic history and pathway of invasion of the russian wheat aphid (rwa) from its native range in central asia, the middle east and europe to south africa and the americas. we screened microsatellite markers, mitochondrial dna and endosymbiont genes in 504 rwa clones from nineteen populations worldwide. following pathway analyses of microsatellite and endosymbiont data, we postulate that turkey and syria were the most likely sources of invasio ...	2014	24617944
salivary proteins of plant-feeding hemipteroids - implication in phytophagy.	many hemipteroids are major pests and vectors of microbial pathogens, infecting crops. saliva of the hemipteroids is critical in enabling them to be voracious feeders on plants, including the economically important ones. a plethora of hemipteroid salivary enzymes is known to inflict stress in plants, either by degrading the plant tissue or by affecting their normal metabolism. hemipteroids utilize one of the following three strategies of feeding behaviour: salivary sheath feeding, osmotic-pump f ...	2014	24280006
the mitochondrial genome of the russian wheat aphid diuraphis noxia: large repetitive sequences between trne and trnf in aphids.	to characterize aphid mitochondrial genome (mitogenome) features, we sequenced the complete mitogenome of the russian wheat aphid, diuraphis noxia. the 15,784-bp mitogenome with a high a+t content (84.76%) and strong c skew (-0.26) was arranged in the same gene order as that of the ancestral insect. unlike typical insect mitogenomes, d. noxia possessed a large tandem repeat region (644 bp) located between trne and trnf. sequencing partial mitogenome of the cotton aphid (aphis gossypii) further c ...	2014	24095774
virus-induced gene silencing suggests (1,3;1,4)-β-glucanase is a susceptibility factor in the compatible russian wheat aphid-wheat interaction.	the russian wheat aphid (rwa), diuraphis noxia (kurdjumov), is a significant insect pest of wheat (triticum aestivum l.) and has a major economic impact worldwide, especially on winter wheat in the western united states. the continuing emergence of new rwa biotypes virulent to existing resistance genes reinforces the need for more durable resistance. studies have indicated that resistance in previously susceptible plants can be produced by knock-down of susceptibility genes or other genes involv ...	2014	24964057
erwinia iniecta sp. nov., isolated from russian wheat aphid (diuraphis noxia).	short, gram-negative-staining, rod-shaped bacteria were isolated from crushed bodies of russian wheat aphid [diuraphis noxia (kurdjumov)] and artificial diets after russian wheat aphid feeding. based on multilocus sequence analysis involving the 16s rrna, atpd, infb, gyrb and rpob genes, these bacterial isolates constitute a novel clade in the genus erwinia, and were most closely related to erwinia toletana. representative distinct strains within this clade were used for comparisons with related ...	2015	26198254
the genome of diuraphis noxia, a global aphid pest of small grains.	the russian wheat aphid, diuraphis noxia kurdjumov, is one of the most important pests of small grains throughout the temperate regions of the world. this phytotoxic aphid causes severe systemic damage symptoms in wheat, barley, and other small grains as a direct result of the salivary proteins it injects into the plant while feeding.	2015	26044338
change in biotypic diversity of russian wheat aphid (hemiptera: aphididae) populations in the united states.	a key component of russian wheat aphid, diuraphis noxia (kurdjumov), management has been through planting resistant wheat cultivars. a new biotype, rwa2, appeared in 2003 which caused widespread damage to wheat cultivars containing the dn4 gene. biotypic diversity in russian wheat aphid populations has not been addressed since 2005 when rwa2 dominated the biotype complex. our objectives were to determine the biotypic diversity in the central great plains and colorado plateau at regional (2010, 2 ...	2015	26470192
electrical penetration graph recording of russian wheat aphid (hemiptera: aphididae) feeding on aphid-resistant wheat and barley.	biotypes of russian wheat aphid, diuraphis noxia (kurdjumov), have nullified d. noxia-resistant wheat. in this study, feeding of north american d. noxia was measured in aphids fed resistant and susceptible wheat and barley using electrical penetration graph (epg) recordings. interactions between barley genotypes and d. noxia biotypes were significant. epg recordings of biotype 1 aphids fed on d. noxia-resistant ibrwagp4-7 barley plants displayed significantly more non-phloem (pathway) phase move ...	2015	26453736
validating spatiotemporal predictions of an important pest of small grains.	arthropod pests are typically managed using tactics applied uniformly to the whole field. precision pest management applies tactics under the assumption that within-field pest pressure differences exist. this approach allows for more precise and judicious use of scouting resources and management tactics. for example, a portion of a field delineated as attractive to pests may be selected to receive extra monitoring attention. likely because of the high variability in pest dynamics, little attenti ...	2015	24648393
phi-class glutathione-s-transferase is involved in dn1-mediated resistance.	wheat dn genes afford resistance to the economically important pest, diuraphis noxia (kurdjumov, russian wheat aphid, rwa) and have been the topic of transcriptomic and proteomic studies aimed at unraveling the pathways involved in resistance. the antibiotic resistance conveyed by dn1 is characterized by a hypersensitive response (hr) followed by systemic acquired resistance (sar). although many candidate genes differentially expressed during the dn1-mediated resistance response have been identi ...	2015	25243379
chromosomal genomics facilitates fine mapping of a russian wheat aphid resistance gene.	making use of wheat chromosomal resources, we developed 11 gene-associated markers for the region of interest, which allowed reducing gene interval and spanning it by four bac clones. positional gene cloning and targeted marker development in bread wheat are hampered by high complexity and polyploidy of its nuclear genome. aiming to clone a russian wheat aphid resistance gene dn2401 located on wheat chromosome arm 7ds, we have developed a strategy overcoming problems due to polyploidy and enabli ...	2015	25862680
reproduction and population dynamics as biotypic markers of russian wheat aphid diuraphis noxia (kurdjumov).	russian wheat aphid diuraphis noxia (kurdjumov) is widely established in wheat-growing countries where it causes significant economic losses. the development and use of russian wheat aphid (rwa)-resistant wheat varieties has been constrained by the variation in resident rwa populations and the evolution of virulent biotypes. an experiment was set up at the kenya agricultural and livestock research organization (kalro), njoro, to characterize rwa populations based on phenotypic characteristics of ...	2016	27049398
virulent diuraphis noxia aphids over-express calcium signaling proteins to overcome defenses of aphid-resistant wheat plants.	the russian wheat aphid, diuraphis noxia, an invasive phytotoxic pest of wheat, triticum aestivum, and barley, hordeum vulgare, causes huge economic losses in africa, south america, and north america. most acceptable and ecologically beneficial aphid management strategies include selection and breeding of d. noxia-resistant varieties, and numerous d. noxia resistance genes have been identified in t. aestivum and h. vulgare. north american d. noxia biotype 1 is avirulent to t. aestivum varieties ...	2016	26815857
changes in the russian wheat aphid (hemiptera: aphididae) biotype complex in south africa.	russian wheat aphid diuraphis noxia (kurdjumov) has spread from its native area in central asia to all the major wheat-producing countries in the world to become an international wheat pest. because the russian wheat aphid is a serious threat to the wheat industry in south africa, it is important to investigate the key factors involved in the distribution of russian wheat aphid biotypes and in the changes of the russian wheat aphid biotype complex in south africa. there are currently four known ...	2016	26803815
diversity, frequency and geographic distribution of facultative bacterial endosymbionts in introduced aphid pests.	facultative bacterial endosymbionts in insects have been under intense study during the last years. endosymbionts can modify the insect's phenotype, conferring adaptive advantages under environmental stress. this seems particularly relevant for a group of worldwide agricultural aphid pests, because endosymbionts modify key fitness related traits, including host plant use, protection against natural enemies and heat tolerance. aimed to understand the role of facultative endosymbionts on the succe ...	2016	26773849
whole genome sequence of the soybean aphid, aphis glycines.	aphids are emerging as model organisms for both basic and applied research. of the 5,000 estimated species, only three aphids have published whole genome sequences: the pea aphid acyrthosiphon pisum, the russian wheat aphid, diuraphis noxia, and the green peach aphid, myzus persicae. we present the whole genome sequence of a fourth aphid, the soybean aphid (aphis glycines), which is an extreme specialist and an important invasive pest of soybean (glycine max). the availability of genomic resourc ...	2017	28119199
profiling diuraphis noxia (hemiptera: aphididae) transcript expression of the biotypes sa1 and sam feeding on various triticum aestivum varieties.	the intimate relationship between an aphid and its host is mediated by the composition of the secreted saliva. in the present study, aphid heads were sampled and transcript profiling conducted after aphids were fed on their preference host and transferred to a variety of preference and nonpreference hosts. it was found that the virulent diuraphis noxia (kurdjumov) (hemiptera: aphididae) biotype sam was able to selectively up-regulate more transcripts when confronted with feeding on a variety of ...	2017	28334389
more virulent offspring result from hybridization of invasive aphid species, diuraphis noxia (hemiptera: aphididae), with diuraphis tritici endemic to the united states.		2017	28199674
isolation of early-responsive microrna from diuraphis noxia (hemiptera: aphididae)-resistant wheat.	the russian wheat aphid (diuraphis noxia kurdjumov) is an economically important pest of small grains in many countries. the past decades have seen the deployment of resistance-carrying wheat (triticum aestivum l.) cultivars to control d. noxia. however, the emergence of resistance-breaking biotypes is negating this strategy. the role that noncoding rna (ncrna) molecules play in the wheat-d. noxia interaction has not been studied to date. this study aimed to isolate differentially regulated micr ...	2017	28407081
genome of russian wheat aphid an economically important cereal aphid.	although the hemipterans (aphididae) are comprised of roughly 50,000 extant insect species, only four have sequenced genomes that are publically available, namely acyrthosiphon pisum (pea aphid), rhodnius prolixus (kissing bug), myzus persicae (green peach aphid) and diuraphis noxia (russian wheat aphid). as a significant proportion of agricultural pests are phloem feeding aphids, it is crucial for sustained global food security that a greater understanding of the genomic and molecular functioni ...	2017	29299110
diversity and evolution of mariner-like elements in aphid genomes.	although transposons have been identified in almost all organisms, genome-wide information on mariner elements in aphididae remains unknown. genomes of acyrthosiphon pisum, diuraphis noxia and myzus persicae belonging to the macrosiphini tribe, actually available in databases, have been investigated.	2017	28662628
survival and feeding rates of four aphid species (hemiptera: aphididae) on various sucrose concentrations in diets.	different concentrations of sucrose were used to investigate how survival and feeding was affected in four species of aphids (hemiptera: aphididae). seven sucrose concentrations were evaluated in feeding chambers fitted with parafilm membranes and infested with nymphs of aphis glycines matsumura, diuraphis noxia kurdjumov, myzus persicae sulzer, or schizaphis graminum rondani at 25 °c and a photoperiod of 14:10 (l:d) h. survival on each diet was recorded 1, 3, 5, 7, 9, and 11 d. diet volumes (μl ...	2017	28637212
rapid cold hardening capacity and its impact on performance of russian wheat aphid (hemiptera: aphididae).	the russian wheat aphid, diuraphis noxia (kurdjumov), is one of the most important pests of wheat and barley in most wheat-producing countries. rapid cold hardiness (rch) is a capacity of insects to develop, within hours, protection against subfreezing temperatures that plays an important role in aphid survival in response to sudden decreases in air temperature. in this research, we investigated the duration and rate of cooling on the induction of rch of d. noxia and the costs of rch on aphid de ...	2017	28541434
a large-scale field study of bacterial communities in cereal aphid populations across morocco.	insects are frequently associated with bacteria that can have significant ecological and evolutionary impacts on their hosts. to date, few studies have examined the influence of environmental factors to microbiome composition of aphids. the current work assessed the diversity of bacterial communities of five cereal aphid species (sitobion avenae, rhopalosiphum padi, r. maidis, sipha maydis and diuraphis noxia) collected across morocco and covering a wide range of environmental conditions. we aim ...	2018	29346623
retraction: virulent diuraphis noxia aphids over-express calcium signaling proteins to overcome defenses of aphid-resistant wheat plants.		2018	29346432