Redox responses of Arabidopsis thaliana to the green peach aphid,Myzus persicae

The green peach aphid (Myzus persicae) is a phloem-feeding insect that causes economic damage on a wide array of crops. Using a luminol-based assay, a superoxide-responsive reporter gene (Zat12::luciferase), and a probe specific to hydrogen peroxide (HyPer), we demonstrated that this aphid induces accumulation of reactive oxygen species (ROS) in Arabidopsis thaliana. Similar to the apoplastic oxidative burst induced by pathogens, this response to aphids was rapid and transient, with two peaks occurring within 1 and 4 hr after infestation. Aphid infestation also induced an oxidative response in the cytosol and peroxisomes, as measured using a redox-sensitive variant of green fluorescent protein (roGFP2). This intracellular response began within minutes of infestation but persisted 20 hr or more after inoculation, and the response of the peroxisomes appeared stronger than the response in the cytosol. Our results suggest that the oxidative response to aphids involves both apoplastic and intracellular sources of ROS, including ROS generation in the peroxisomes, and these different sources of ROS may potentially differ in their impacts on host suitability for aphids.     

Characterization of a new densovirus infecting the green peach aphid Myzus persicae

A new icosahedral DNA virus was isolated from aphids (Myzus persicae) that showed abnormal growth and development. The purified virus particles have a diameter of 20 nm and contain a single-stranded DNA molecule of approximately 5.7 kb. The viral particles are composed of five structural proteins (92, 85, 68, 64, and 57 kDa). As the main biophysical properties of this virus are similar to those of the members of the genus Densovirus it was tentatively named Myzus persicae densovirus (MpDNV). A PCR-based detection method and a polyclonal antiserum raised against MpDNV allowed the detection of the virus in a single-infected aphid. MpDNV is immunologically related to Junonia coenia densovirus, but not to other members of the subfamily Densovirinae. Biological assays showed that MpDNV could be both transmitted transovarially and horizontally via honeydew and saliva. MpDNV was able to infect whiteflies but not other aphid species tested.     

Ecological genetics of host plant exploitation in the green peach aphid, Myzus persicae

The ecological consequences of genetic variability in host plant exploitation of Myzus persicae (Hemiptera, Aphididae) were studied in several agro-ecosystems, differing in crop plant heterogeneity. An analysis of aphid populations sampled from sugar beet, potatoes, and lettuce revealed changes in the frequency distribution of aphid clones according to their respective host plant adaptations. The spatial unit of differentiation was below an average field size of 3–5 hectares and a differentiation could be found in the centre of potato and sugar beet fields but not at the edge of the fields. On a temporal scale, the differentiation of populations is transitory even on a large-scale basis of highly specialized cropping areas. The ecological parameters of differentiation are discussed with special reference to agro-ecosystems and integrated pest management. Increasing the genetic heterogeneity of crop fields may help to reduce population outbreaks.

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Zusammenfassung Die ökologischen Konsequenzen genetischer Variabilität in der Wirtspflanzennutzung von Myzus persicae (Hemiptera, Aphididae) wurden in mehreren Agro-Ökosystemen untersucht, die sich in der Kulturpflanzenheterogenität unterscheiden. Eine Analyse von auf Rüben, Kartoffeln und Salat siedelnden Populationen zeigte eine genetische Differenzierung in Wirtspflanzen-angepaßte Feld-populationen. Die räumliche Einheit solcher Differenzierungen liegt unterhalb einer Feldgröße von 3–5 ha. Eine Differenzierung konnte hier in der Mitte der Felder aber nicht am Rand festgestellt werden. Aus zeitlicher Sicht ist die Differenzierung selbst in großräumigen, spezialisierten Anbaugebieten nur vorübergehend feststellbar. Die ökologischen Parameter der Differenzierung werden besonders in Hinsicht auf die integrierte Schädlingsbekämpfung in Agro-ökosystemen diskutiert. Eine Erhöhung der genetischen Heterogenität von Kulturpflanzenbeständen kann möglicherweise zu einer Verringerung von Blattlaus-Massenvermehrungen beitragen.

     

Myzus persicae (green peach aphid) feeding on Arabidopsis induces the formation of a deterrent indole glucosinolate

Cruciferous plants produce a wide variety of glucosinolates as a protection against herbivores and pathogens. However, very little is known about the importance of individual glucosinolates in plant defense and the regulation of their production in response to herbivory. When Myzus persicae (green peach aphid) feeds on Arabidopsis aliphatic glucosinolates pass through the aphid gut intact, but indole glucosinolates are mostly degraded. Although aphid feeding causes an overall decrease in Arabidopsis glucosinolate content, the production of 4-methoxyindol-3-ylmethylglucosinolate is induced. This altered glucosinolate profile is not a systemic plant response, but is limited to the area in which aphids are feeding. Aphid feeding on detached leaves causes a similar change in the glucosinolate profile, demonstrating that glucosinolate transport is not required for the observed changes. Salicylate-mediated signaling has been implicated in other plant responses to aphid feeding. However, analysis of eds5, pad4, npr1 and NahG transgenic Arabidopsis, which are compromised in this pathway, demonstrated that aphid-induced changes in the indole glucosinolate profile were unaffected. The addition of purified indol-3-ylmethylglucosinolate to the petioles of cyp79B2 cyp79B3 mutant leaves, which do not produce indole glucosinolates, showed that this glucosinolate serves as a precursor for the aphid-induced synthesis of 4-methoxyindol-3-ylmethylglucosinolate. In artificial diets, 4-methoxyindol-3-ylmethylglucosinolate is a significantly greater aphid deterrent in the absence of myrosinase than its metabolic precursor indol-3-ylmethylglucosinolate. Together, these results demonstrate that, in response to aphid feeding, Arabidopsis plants convert one indole glucosinolate to another that provides a greater defensive benefit.     

Insect parasites of the green peach aphid,Myzus persicae Sulz., and their control potential

Zusammenfassung Von den ungef?hr 30 bekannten Hymenopterenarten, welche die Grüne Pfirsischblattlaus (Myzus persicae) parasitieren, sind 10 Arten relativ h?ufig und u. U. im Rahmen einer biologischen Bek?mpfung verwendbar. Die drei ArtenEphedrus persicae, Aphidius matricariae undDiaeretiella rapae zeichnen sich durch eine relative hohe Vermehrungsrate aus und verdienen besondere Aufmerksamkeit. Ein erfolgreicher Einsatz im Freiland in der gem?ssigten Klimazone ist durch das im Vergleich zuM. persicae h?here Temperaturoptimum der Schlupfwespen erschwert. Bessere Aussichten auf Erfolg bietet der Einsatz von Parasiten im Gew?chshaus und in Form von j?hrlich wiederholten Massenfreilassungen im Freiland.

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Contribution, International Biological Programme (UM), Subsection Biological Control, Project onMyzus persicae Sulzer.     

Effects of Lecanicillium longisporum infection on the behaviour of the green peach aphid Myzus persicae

The effects of the entomopathogenic fungus Lecanicillium longisporum (Zimmerman) Zare & Gams on three parameters of behaviour (feeding, reproduction and movement) of the green peach aphid Myzus persicae (Homoptera: Aphididae) were investigated in the laboratory. Visual analysis of video tapes established that honeydew excretion events of mycosed aphids gradually declined from 2 d post inoculation and reproduction rate was significantly reduced 2 d prior to death (which occurred on day 6); both parameters were stable in controls over the same period. A detailed comparison was made between mobility of aphids during infection with two isolates of L. longisporum, using image analysis of video recordings. Both isolates caused an increase in activity at the beginning of mycosis (during fungal germination and cuticle invasion) though the intensity and the duration of this behaviour varied with the isolate. The possibility that increased movement in early mycosis helps disseminate disease is discussed in the light of the observation that saprophytic surface growth occurs on living M. persicae as it does in at least some other Lecanicillium spp-insect interactions.     

Effect of the antimicrobial peptide indolicidin on the green peach aphid Myzus persicae (Sulzer)

Abstract:  The green-peach aphid, Myzus persicae (Sulzer) (Hem., Aphididae), is a major agricultural pest of a wide range of host plants, causing damage by feeding and indirectly by transmitting viruses. In this study we tested the effect of the antimicrobial peptide indolicidin on M. persicae survival and on its essential bacterial endosymbionts. Artificial diet bioassays showed a significant dose-dependent lethal response of indolicidin on M. persicae survival (LD₅₀ of 209 ± 60  μ g/ml). Histological analysis of indolicidin-treated aphids revealed a lower number of distorted mycetocytes, whereas control aphids showed abundant number of rounded and filled mycetocytes. These results suggest that aphid survival could be affected via reduction of its endosymbionts. Thus, aphid control based on antimicrobial substances against endosymbionts could be a promising strategy that needs to be further explored.     

A functional genomics approach identifies candidate effectors from the aphid species Myzus persicae (green peach aphid)

Aphids are amongst the most devastating sap-feeding insects of plants. Like most plant parasites, aphids require intimate associations with their host plants to gain access to nutrients. Aphid feeding induces responses such as clogging of phloem sieve elements and callose formation, which are suppressed by unknown molecules, probably proteins, in aphid saliva. Therefore, it is likely that aphids, like plant pathogens, deliver proteins (effectors) inside their hosts to modulate host cell processes, suppress plant defenses, and promote infestation. We exploited publicly available aphid salivary gland expressed sequence tags (ESTs) to apply a functional genomics approach for identification of candidate effectors from Myzus persicae (green peach aphid), based on common features of plant pathogen effectors. A total of 48 effector candidates were identified, cloned, and subjected to transient overexpression in Nicotiana benthamiana to assay for elicitation of a phenotype, suppression of the Pathogen-Associated Molecular Pattern (PAMP)-mediated oxidative burst, and effects on aphid reproductive performance. We identified one candidate effector, Mp10, which specifically induced chlorosis and local cell death in N. benthamiana and conferred avirulence to recombinant Potato virus X (PVX) expressing Mp10, PVX-Mp10, in N. tabacum, indicating that this protein may trigger plant defenses. The ubiquitin-ligase associated protein SGT1 was required for the Mp10-mediated chlorosis response in N. benthamiana. Mp10 also suppressed the oxidative burst induced by flg22, but not by chitin. Aphid fecundity assays revealed that in planta overexpression of Mp10 and Mp42 reduced aphid fecundity, whereas another effector candidate, MpC002, enhanced aphid fecundity. Thus, these results suggest that, although Mp10 suppresses flg22-triggered immunity, it triggers a defense response, resulting in an overall decrease in aphid performance in the fecundity assays. Overall, we identified aphid salivary proteins that share features with plant pathogen effectors and therefore may function as aphid effectors by perturbing host cellular processes.     

Myzus persicae (green peach aphid) salivary components induce defence responses in Arabidopsis thaliana

Myzus persicae (green peach aphid) feeding on Arabidopsis thaliana induces a defence response, quantified as reduced aphid progeny production, in infested leaves but not in other parts of the plant. Similarly, infiltration of aphid saliva into Arabidopsis leaves causes only a local increase in aphid resistance. Further characterization of the defence-eliciting salivary components indicates that Arabidopsis recognizes a proteinaceous elicitor with a size between 3 and 10 kD. Genetic analysis using well-characterized Arabidopsis mutants shows that saliva-induced resistance against M. persicae is independent of the known defence signalling pathways involving salicylic acid, jasmonate and ethylene. Among 78 Arabidopsis genes that were induced by aphid saliva infiltration, 52 had been identified previously as aphid-induced, but few are responsive to the well-known plant defence signalling molecules salicylic acid and jasmonate. Quantitative PCR analyses confirm expression of saliva-induced genes. In particular, expression of a set of O -methyltransferases, which may be involved in the synthesis of aphid-repellent glucosinolates, was significantly up-regulated by both M. persicae feeding and treatment with aphid saliva. However, this did not correlate with increased production of 4-methoxyindol-3-ylmethylglucosinolate, suggesting that aphid salivary components trigger an Arabidopsis defence response that is independent of this aphid-deterrent glucosinolate.     

桃蚜自然种群初级和次级共生菌的分子鉴定

蚜虫不仅带有专性初级内共生菌,还常常带有不同类群的兼性次级共生菌。本研究采用真细菌16S rDNA的通用引物,从桃蚜Myzus persicae (Sulzer)烟草种群体内扩增出1.5 kb的共迁移目的条带,然后将其克隆,并在阳性克隆筛选时进行了RFLP分析。当采用EcoRⅠ进行单酶切分析时,目的片段被切割成～650 bp和～850 bp两个小片段;当采用EcoRⅠ和HindⅢ进行双酶切分析时,该蚜群共生菌酶切谱带被分成2组,其中1组(GroupⅠ)只具有一个EcoRⅠ酶切位点,而另1组(Group Ⅱ)不仅具有一个EcoRⅠ酶切位点,还具有一个HindⅢ酶切位点,而且GroupⅠ为优势共生菌群。在此基础上分别对2组共生菌的16S rDNA全序列（～1.5 kb）进行了测定,结果表明：GroupⅠ属于泛菌属Pantoea,与成团泛菌Pantoea agglomerans亲缘关系最近（同源性达99.70%）,而Group Ⅱ属于蚜虫的专性内共生菌,即Buchnera aphidicola（同源性达99.50%）。这是在蚜虫体内存在泛菌次级共生菌的首次报道。     

Ultrastructure of antennal sensilla of the peach aphid Myzus persicae Sulzer, 1776

The antennal sensilla of alate Myzus persicae were mapped using transmission electron microscopy and the ultrastructure of sensilla trichoidea, coeloconica, and placoidea are described. Trichoid sensilla, located on the tip of the antennae, are innervated by 2–4 neurons, with some outer dendrites reaching the distal end of the hair. Coeloconic sensilla in primary rhinaria are of two morphological types, both equipped with two dendrites. Dendrites of Type II coeloconic sensilla are enveloped in the dendrite sheath, containing the sensillum lymph. In sensilla coeloconica of Type I, instead, dendrites are enclosed by an electron opaque solid cuticle, with no space left for the sensillum lymph. The ultrastructure of big placoid sensillum reveals the presence of three groups of neurons, with 2–3 dendrites in each neuron group, while both small placoid sensilla are equipped with a single group of neurons, consisting of three dendrites. Both large and small placoid sensilla bear multiple pores on the outer cuticle. The function of these sensilla is also discussed. J. Morphol. 276:219–227, 2015. © 2014 Wiley Periodicals, Inc.     

Probing behavior of aposymbiotic green peach aphid (Myzus persicae) on susceptible Solanum tuberosum and resistant Solanum stoloniferum plants

The green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae) is one of the potato important pests; it is the most efficient vector of potato viruses. Myzus persicae harbors the endosymbiotic bacteria Buchnera aphidicola which supplements their diet. There is increasing evidence that B. aphidicola is involved in plant–aphid interactions and we previously demonstrated that B. aphidicola disruption (aposymbiosis) affected the probing behavior of M. persicae on radish plants, delaying host plant acceptance. In this work, we evaluated the effect of aposymbiosis on the probing behavior of M. persicae on 2 Solanum species with different compatibility with M. persicae, Solanum tuberosum (susceptible) and Solanum stoloniferum (resistant) with the electrical penetration graph technique (EPG). To disrupt B. aphidicola, rifampicin was administered to aphids through artificial diets. Aposymbiotic aphids, on both plant species, showed increased pathway activities, mechanical problems with the stylets, and delayed salivation in the phloem. The extended time in derailed stylet mechanics affected the occurrence of most other probing activities; it delayed the time to the first phloem phase and prevented ingestion from the phloem. The effect of aposymbiosis was more evident in the compatible interaction of M. persicae–S. tuberosum, than in the incompatible interaction with S. stoloniferum, which generated the M. persicae–S. tuberosum interaction to become incompatible. These results confirm that B. aphidicola is involved in the plant–aphid interaction in relation to plant acceptance, presumably through a role in stylets penetration in the plant.     

Identification of indole glucosinolate breakdown products with antifeedant effects on Myzus persicae (green peach aphid)

The cleavage of glucosinolates by myrosinase to produce toxic breakdown products is a characteristic insect defense of cruciferous plants. Although green peach aphids ( Myzus persicae ) are able to avoid most contact with myrosinase when feeding from the phloem of Arabidopsis thaliana , indole glucosinolates are nevertheless degraded during passage through the insects. A defensive role for indole glucosinolates is suggested by the observation that atr1D mutant plants, which overproduce indole glucosinolates, are more resistant to M. persicae , whereas cyp79B2 cyp79B3 double mutants, which lack indole glucosinolates, succumb to M. persicae more rapidly. Indole glucosinolate breakdown products, including conjugates formed with ascorbate, glutathione and amino acids, are elevated in the honeydew of M. persicae feeding from atr1D mutant plants, but are absent when the aphids are feeding on cyp79B2 cyp79B3 double mutants. M. persicae feeding from wild-type plants and myrosinase-deficient tgg1 tgg2 double mutants excrete a similar profile of indole glucosinolate-derived metabolites, indicating that the breakdown is independent of these foliar myrosinases. Artificial diet experiments show that the reaction of indole-3-carbinol, a breakdown product of indol-3-ylmethylglucosinolate, with ascorbate, glutathione and cysteine produces diindolylmethylcysteines and other conjugates that have antifeedant effects on M. persicae . Therefore, the post-ingestive breakdown of indole glucosinolates provides a defense against herbivores such as aphids that can avoid glucosinolate activation by plant myrosinases.     

不同黄板和二混合色板对烟蚜的引诱作用

【目的】探究黄色及其配色对烟蚜Myzuspersicae行为的影响,有助于烟蚜绿色防控技术的优化。为田间黄板诱蚜的应用技术研发提供理论指导。【方法】利用电脑软件设置8种不同RGB黄色以及不同颜色的双色图卡,测定烟蚜对色板的趋性反应。【结果】RGB数值为215∶255∶6的3号黄色对烟蚜的引诱作用显著高于其他黄色,其对烟蚜的平均引诱量为8.5头/块。在3号黄色的基础上配置另一种颜色,发现在面积比2∶1的比例下,相对于3号色板只有3-黑色板降低了诱虫量。在1∶1的比例下,3号黄色比所有双色板对烟蚜的引诱作用都强,说明增加配色的比例会降低黄板的引诱力。在1∶1的比例下不同双色板的引诱力也存在着显著差异,双色之间存在着互作现象,这表明不同配色会影响色板对蚜虫的引诱作用。【结论】3号黄色色板对烟蚜的引诱效果最好。     

Olfactory response by the aphidophagous gall midge, Aphidoletes aphidimyza to honeydew from green peach aphid, Myzus persicae

Female adults of the aphidopagous gall midge, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae), showed an olfactory response to honeydew excreted by the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) under laboratory conditions. The response was only elicited by treatments with honeydew, whereas aphids, aphids with pepper plants or leaves, and pepper plants or leaves were not attractive to the midges. Dose‐dependent responses were observed from whole honeydew, honeydew volatiles extracted in pentane, and honeydew volatiles captured on Porapak Q®. When honeydew was eluted with three sequential pentane washes, a positive response was only observed from the midges for the first wash. Female midges laid more eggs on pepper plants infested with higher densities of M. persicae. The olfactory response of midges to honeydew is discussed with respect to prey location.     

Egg production by the coccinellid Hippodamia convergens fed on two morphs of the green peach aphid, Myzus persicae

Adults of the lady beetle Hippodamia convergens Guérin-Méneville requiring aphids for egg production, were fed suboptimal amounts of apteriform virginoparous larvae or alatiform gynoparous larvae of the green peach aphid, Myzus persicae (Sulz.), and artificial diet ad lib. The beetles initiated oviposition sooner and deposited significantly more eggs when supplied with the same weight of apterous virginoparous morph. The possible nutritional, hormonal, and ecological implications of the findings are discussed.

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Zusammenfassung Die Eiproduktion des Marienkäfers Hippodamia convergens, welcher hierzu Blattläuse als Nahrung benötigt, wurde bei Fütterung mit zwei verschiedenen Morphen der Blattlaus Myzus persicae untersucht. Der Verzehr derselben Menge flügelloser Virginoparen führte im Vergleich zu geflügelten Gynoparen zu früherer und signifikant erhöhter Eiabgabe. Der hormonale und ernährungsphysiologische Hintergrund und die ökologische Bedeutung dieser Ergebnisse werden diskutiert.

     

Comparative analysis of Solanum stoloniferum responses to probing by the green peach aphid Myzus persicae and the potato aphid Macrosiphum euphorbiae

Abstract Plants protect themselves against aphid attacks by species‐specific defense mechanisms. Previously, we have shown that Solanum stoloniferum Schlechtd has resistance factors to Myzus persicae Sulzer (Homoptera: Aphididae) at the epidermal/mesophyll level that are not effective against Macrosiphum euphorbiae Thomas (Homoptera: Aphididae). Here, we compare the nymphal mortality, the pre‐reproductive development time, and the probing behavior of M. persicae and M. euphorbiae on S. stoloniferum and Solanum tuberosum L. Furthermore, we analyze the changes in gene expression in S. stoloniferum 96 hours post infestation by either aphid species. Although the M. euphorbiae probing behavior shows that aphids encounter more probing constrains on phloem activities–longer probing and salivation time– on S. stoloniferum than on S. tuberosum, the aphids succeeded in reaching a sustained ingestion of phloem sap on both plants. Probing by M. persicae on S. stoloniferum plants resulted in limited feeding only. Survival of M. euphorbiae and M. persicae was affected on young leaves, but not on senescent leaves of S. stoloniferum. Infestation by M. euphorbiae changed the expression of more genes than M. persicae did. At the systemic level both aphids elicited a weak response. Infestation of S. stoloniferum plants with a large number of M. persicae induced morphological changes in the leaves, leading to the development of pustules that were caused by disrupted vascular parenchyma and surrounding tissue. In contrast, an infestation by M. euphorbiae had no morphological effects. Both plant species can be regarded as good host for M. euphorbiae, whereas only S. tuberosum is a good host for M. persicae and S. stoloniferum is not. Infestation of S. stoloniferum by M. persicae or M. euphorbiae changed the expression of a set of plant genes specific for each of the aphids as well as a set of common genes.     

Effects of dietary amino acids on the production of sexual morph by the green peach aphid,Myzus persicae

In order to complete a holocycle of the green peach aphid, Myzus persicae, on a synthetic diet, the effects of dietary amino acid contents on development of sexuals were investigated. For this purpose, the aphids were reared on holidic diets for two to three generations at 20°C under a scotophase of 15 h per diem. Under these conditions, the production of males by the aphids on a synthetic diet was very much poorer than those reared on radish seedling. On reducing the amino acid concentration of the diet, the proportion of males produced was comparable to that produced by aphids fed on radish seedlings. The obtained males were smaller and survived longer than those reared on radish seedling. Under the long night photoperiod and on the synthetic diet with reduced amino acids, gynoparae and then oviparae were also obtained. The oviparae were mated with the males grown on the synthetic diet, and laid eggs. The eggs, however, did not turn dark in color, and perished. © 1995 Wiley-Liss, Inc.     

Two different farnesyl diphosphate synthase genes exist in the genome of the green peach aphid, Myzus persicae.

Farnesyl diphosphate synthase (FPS; EC 2.5.1.1, 2.5.1.10) catalyzes biosynthesis of farnesyl diphosphate, which is important to insects as the precursor of juvenile hormone and the substrate for (E)-beta-farnesene synthase. Here, two FPS cDNAs were isolated from the green peach aphid, Myzus persicae (EU334430 and EU334431). Their shared identity within the coding region is approximately 82%. The deduced amino acid sequences of the two M. persicae FPS cDNAs have the highly conserved motifs characteristic of most known FPSs. Phylogenetic analyses showed that they are closely related to other insect FPSs. Homology modeling of structures suggested a very good fit between the three-dimensional structures of the two putative M. persicae FPSs (designated as MpFPS1 and MpFPS2) and the avian FPS crystal structure. The corresponding genomic DNA sequences were subsequently determined (EU429295 and EU429296). Sequence comparisons revealed a different splicing pattern between the two MpFPS genes. Furthermore, the two MpFPS genes exhibited a seemingly very primitive gene-splicing pattern at 5' ends but a gene-splicing style similar to mammalian FPS genes at 3' ends. These data, combined with results of Southern blotting, suggest that M. persicae contains two different FPS genes. This is the first report that two different FPS genes exist in a hemipteran insect.