| the invasion route for an insect pest species: the tobacco aphid in the new world. | biological invasions are rapid evolutionary events in which populations are usually subject to a founder event during introduction followed by rapid adaptation to the new environment. molecular tools and bayesian approaches have shown their utility in exploring different evolutionary scenarios regarding the invasion routes of introduced species. we examined the situation for the tobacco aphid, myzus persicae nicotianae, a recently introduced aphid species in chile. using seven microsatellite loc ... | 2010 | 20958814 |
| transgenic tobacco expressing zephyranthes grandiflora agglutinin confers enhanced resistance to aphids. | plant lectins have been reported as transgenic resistance factors against a variety of insect pests. herein, homologous analysis demonstrated that zephyranthes grandiflora agglutinin (zga) exhibited high similarity with other monocot mannose-binding lectins (mbls). phylogenetic analysis revealed that it had taxonomical relationships with insecticidal mbls. subsequently, a plasmid expression vector pbi121 containing zga gene (pbizga) was constructed using the zga sequence, under the control of ca ... | 2009 | 19067248 |
| carbohydrate-binding activity of the type-2 ribosome-inactivating protein sna-i from elderberry (sambucus nigra) is a determining factor for its insecticidal activity. | in recent years, different classes of proteins have been reported to promote toxic effects when ingested. type-2 ribosome-inactivating proteins (rips) are a group of chimeric proteins built up of an a-chain with rna n-glycosidase activity and a b-chain with lectin activity. these proteins are thought to play a role in plant protection. sambucus nigra agglutinin i (sna-i) is a type-2 rip, isolated from the bark of elderberry (s. nigra l.). this study demonstrated the insecticidal potency of sna-i ... | 2008 | 18951590 |
| expression of sambucus nigra agglutinin (sna-i') from elderberry bark in transgenic tobacco plants results in enhanced resistance to different insect species. | tobacco plants (nicotiana tabacum cv samsun nn) have been transformed with the gene encoding the type-2 ribosome-inactivating protein (rip) sna-i' from elderberry (sambucus nigra) under the control of the cauliflower mosaic virus 35s promoter. previous research confirmed that these plants synthesize, correctly process and assemble a fully active rip. variability in protein expression was observed within the transgenic lines. the effects of the type-2 rip sna-i' delivered through a leaf feeding a ... | 2009 | 18720022 |
| expression of garlic leaf lectin under the control of the phloem-specific promoter asus1 from arabidopsis thaliana protects tobacco plants against the tobacco aphid (myzus nicotianae). | to check for correlation between the insecticidal properties and the specificity of lectins, a comparative study was made of the insecticidal activities of two garlic lectins with different biological activities. | 2007 | 17912690 |
| impact of early-season thrips management on reducing the risks of spotted wilt virus and suppressing aphid populations in flue-cured tobacco. | the influence of tray drench (td) treatments, with and without foliar applications of the plant activator acibenzolar-s-methyl (actigard), was examined in replicated field plots in 2000--2002. td treatments of actigard, imidacloprid (admire), and these two products combined had little effect on seasonal mean thrips populations; however, thrips densities were lower in the admire-treated plots at 4 and 5 wk after transplanting. actigard and admire td treatments significantly reduced the seasonal i ... | 2005 | 15765674 |
| an analysis of plant-aphid interactions by different microarray hybridization strategies. | aphids have long been considered 'stealthy' herbivores that subvert a plant's induced defenses and manipulate its source-sink signaling, but these hypotheses are largely untested at a transcriptional level. we analysed gene expression in native tobacco plants (nicotiana attenuata) infested with myzus nicotianae aphids, without resorting to the use of clip-cages, with a cdna microarray containing 240 defense-related n. attenuata genes. using a hybridization scheme ('ratio analysis' and 'state ana ... | 2004 | 15367131 |
| structure-function relationships affecting the insecticidal and miticidal activity of sugar esters. | synthetic sugar esters are a relatively new class of insecticidal compounds that are produced by reacting sugars with fatty acids. the objective of this research was to determine how systematic alterations in sugar or fatty acid components of sugar ester compounds influenced their insecticidal properties. sucrose octanoate, sorbitol octanoate, sorbitol decanoate, sorbitol caproate, xylitol octanoate, xylitol decanoate and xylitol dodecanoate were synthesized and evaluated against a range of arth ... | 2003 | 12852599 |
| influence of substrate type and temperature on the developmental morphology of pandora neoaphidis (zygomycetes: entomophthorales), a pathogen of the tobacco aphid (homoptera: aphididae). | developmental morphology of pandora neoaphidis was observed on the surfaces of the tobacco aphid, myzus nicotianae, tobacco leaves (nicotiana tabacum), and glass coverslips at 13 and 20 degrees c for 12 and 24 h postinoculation. pandora neoaphidis responded similarly on the two living substrates, but differed on the inert coverslips. the proportions of ellipsoid conidia (primary and secondary) were similar on all substrates. higher proportions of appressoria and lower proportions of round second ... | 1998 | 9709010 |
| the peach-potato aphid myzus persicae and the tobacco aphid myzus nicotianae have the same esterase-based mechanisms of insecticide resistance. | biochemical and molecular studies have established that in the peach-potato aphid, myzus persicae, insecticide resistance is conferred by amplification of genes encoding the insecticide-detoxifying esterases e4 or fe4. here we report that two insecticide-resistant clones of the closely related tobacco aphid myzus nicotianae have elevated esterases indistinguishable from e4 and fe4 and amplified esterase dna sequences, and flanking regions, with identical restriction maps to the m. persicae genes ... | 1994 | 7894746 |
| systemin in solanum nigrum. the tomato-homologous polypeptide does not mediate direct defense responses. | we extend ryan's seminal work on the 18-amino acid polypeptide systemin in tomato's (solanum lycopersicum) systemic wound response to the closely related solanaceous species solanum nigrum. we compared wild-type plants to plants transformed with an inverted repeat prosystemin construct (irsys) to silence the expression of the endogenous s. nigrum prosystemin gene. in wild-type plants elicited with wounding + oral secretions from manduca sexta larvae, trypsin-proteinase inhibitors (tpis) accumula ... | 2006 | 17071641 |
| a novel combination of a new umbravirus, a new satellite rna and potato leafroll virus causes tobacco bushy top disease in ethiopia. | etiological studies of a recently emerged bushy top disease of tobacco in ethiopia indicated that a ~4.5-kb dsrna from infected plants represents an umbravirus, whereas a smaller band (~0.5 kb) is that of a new satellite rna. potato leafroll virus was also consistently associated with the disease. the three agents, whose experimental host ranges are restricted to members of the family solanaceae, always occurred together in field samples and are transmitted together by the aphid myzus persicae n ... | 2014 | 25119677 |
| characterization and distribution analysis of a densovirus infecting myzus persicae nicotianae (hemiptera: aphididae). | densoviruses (dvs) are a group of viruses that contain a linear single-stranded dna genome between 4–6 kb in length. herein, we report a dv with a 5,480-nt genome, isolated from tobacco aphid (myzus persicae nicotianae blackman), named mpndv. unlike the genome of m. persicae densovirus (mpdv), which possesses five open reading frames (orfs), the genome of mpndv contains four putative orfs—the nonstructural protein 1 (ns1) and ns2 from mpndv are 98- and 52-amino acids longer than those of mpdv, r ... | 2016 | 26791818 |
| reduced abundance of the cyp6cy3-targeting let-7 and mir-100 mirnas accounts for host adaptation of myzus persicae nicotianae. | nicotine is one of the most abundant and toxic secondary plant metabolites in nature and is defined by high toxicity to plant-feeding insects. studies suggest that increased expression of cytochrome p450 (cyp6cy3) and the homologous cyp6cy4 genes in myzus persicae nicotianae is correlated with tolerance to nicotine. indeed, through expression analyses of the cyp6cy3 and cyp6cy4 genes of different m. persicae subspecies, we determined that the mrna levels of these two genes were much higher in m. ... | 2016 | 27318250 |
| genetic variability of myzus persicae nicotianae densovirus based on partial ns and vp gene sequences. | we previously described a novel densovirus [myzus persicae nicotianae densovirus (mpndv)] infecting m. persicae nicotianae (hemiptera: aphididae) with 34% prevalence. this single-stranded dna virus has a 5480-nucleotide ambisense genome and belongs to the densovirinae subfamily within the family parvoviridae. in the present study, we estimated the genetic diversity of mpndv using partial nonstructural protein (ns) and capsid protein (vp) gene sequences from 10 locations in china. first, we ident ... | 2016 | 27886347 |
| insecticide resistance status of myzus persicae in greece: long-term surveys and new diagnostics for resistance mechanisms. | myzus persicae nicotianae is an important pest in greece, controlled mainly by neonicotinoids. monitoring of the aphid populations for resistance mechanisms is essential for effective control. | 2016 | 25960200 |
| gene amplification and microsatellite polymorphism underlie a recent insect host shift. | host plant shifts of herbivorous insects may be a first step toward sympatric speciation and can create new pests of agriculturally important crops; however, the molecular mechanisms that mediate this process are poorly understood. certain races of the polyphagous aphid myzus persicae have recently adapted to feed on tobacco (myzus persicae nicotianae) and show a reduced sensitivity to the plant alkaloid nicotine and cross-resistance to neonicotinoids a class of synthetic insecticides widely use ... | 2013 | 24218582 |
| population genetic structure of myzus persicae nicotianae (hemiptera: aphididae) in china by microsatellite analysis. | the tobacco aphid, myzus persicae nicotianae (hemiptera: aphididae), is an important agricultural pest that feeds on host plants and transmits plant viruses in china. to effectively control this pest, we investigated the genetic variation and genetic structure of 54 populations of tobacco aphids collected in china, using five microsatellite loci. an average of 7 alleles with effective number ranging from 1.5 to 6.6 was detected using these five loci, and the average polymorphic information conte ... | 2015 | 26681063 |
| long-term phenological trends, species accumulation rates, aphid traits and climate: five decades of change in migrating aphids. | aphids represent a significant challenge to food production. the rothamsted insect survey (ris) runs a network of 12·2-m suction-traps throughout the year to collect migrating aphids. in 2014, the ris celebrated its 50th anniversary. this paper marks that achievement with an extensive spatiotemporal analysis and the provision of the first british annotated checklist of aphids since 1964. our main aim was to elucidate mechanisms that advance aphid phenology under climate change and explain these ... | 2015 | 25123260 |