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Query: UMLS:C0851341 (infestation)
 10,121 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nasal myiasis is the infestation of the nasal cavities by larvae (maggots) of Diptera flies. Several species of flies deposit their ova in the nose and the larvae feed on the host's tissues. We present a case of nasal myiasis by larvae of Oestrus ovis--Sheep Nasal Bot Fly. The larvae of Oestrus ovis are well known parasites in the nasal cavities and paranasal sinuses of sheep and goat. In Britain very rarely larvae may be deposited in the eye, nostrils or outer ear of man, usually husbandry workers. Reputedly, the larvae never survive beyond the first stage with acute catarrhal symptoms lasting only a few days. This is the first reported case in the UK of an urban-dwelling patient infected by mature, third instar larvae of O. ovis. His nasal infestation resolved after endoscopic removal of the live maggots.
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PMID:Vile bodies: an endoscopic approach to nasal myiasis. 786 Oct 88

Between May and September, 1996, seedlings of Pinus halepensis were placed at a site adjacent to an automated air pollution monitoring station within the urban area of Florence. Additional 'control' plants were placed in chambers ventilated with charcoal/Purafil(R)-filtered air. All trees were well watered throughout the whole experimental period. During the exposure period, ambient levels of sulphur dioxide were very low, whilst the accumulated hourly exposure to ozone above 40 ppb (i.e. AOT40) exceeded 20000 ppb h(-1) - peak hourly ozone concentrations rising to levels above 100 ppb. Trees exposed to ambient levels of air pollution exhibited typical symptoms of ozone damage (chlorotic mottle) on previous year needles toward the end of the summer. Similar symptoms were not observed on equivalent trees exposed to filtered-air, nor were visible symptoms accompanied by insect or pest infestation. Anatomical and ultrastructural observations made on symptomatic needles revealed degeneration in mesophyll cells bordering sub-stomatal cavities and alterations in chloroplast ultrastructure (fat accumulation, starch and tannin pattern modifications). These observations are consistent with the known effects of air pollutants (namely ozone) recorded in the literature. Findings are discussed in relation to the impacts of ozone on P. halepensis in the Mediterranean region.
Environ Exp Bot 2000 Aug 01
PMID:Impacts of urban levels of ozone on Pinus halepensis foliage. 1092 30

The role of the host in the nitrogen nutrition of Striga hermonthica (Del.) Benth. (Scrophulariaceae) parasitic on Sorghum bicolor cv. SH4 Arval has been investigated using (15)N-nitrate as the tracer. It is shown that, when nitrate is absorbed only by the roots of the host plant, a rapid transfer of nitrogen to the parasite can be detected. The xylem sap of S. hermonthica contained approximately equal amounts of nitrate and amino acids, mostly glutamine and asparagine. Infection altered the free amino acid profile of the host tissues, leading notably to a large increase in asparagine and a decrease in glutamine. The haustoria of S. hermonthica, although rich in nitrate, showed a low concentration of free amino acids, particularly lacking in asparagine and glutamine. The roots of S. hermonthica, in contrast, were rich in both asparagine and glutamine while, in the shoots, asparagine constituted 80% of the total FAA pool. Asparagine was also found to be the primary (15)N-enriched amino acid in the shoots of S. hermonthica while, interestingly, it was glutamate that was most strongly enriched in the roots. It is concluded that nitrogen nutrition in S. hermonthica is based on a supply of both nitrate and amino acids from the host. This implies a non-specific transfer in the transpiration stream. Nitrate reduction probably occurs mainly in the leaves of the parasite. Assimilation also occurs in S. hermonthica and excess nitrogen is stored as the non-toxic nitrogen-rich compound, asparagine. This specific trait of nitrogen metabolism of the parasite is discussed in relation to the effect of nitrogen fertilization on reducing infestation.
J Exp Bot 2003 Feb
PMID:Characterization of nitrogen relationships between Sorghum bicolor and the root-hemiparasitic angiosperm Striga hermonthica (Del.) Benth. using K15 NO3 as isotopic tracer. 1255 22

Plants are equipped with a range of defence mechanisms against herbivorous insects. In cruciferous species, jasmonic acid, salicylic acid, and ethylene along with glucosinolates and their hydrolysis products play important roles in plant protection and plant-insect communication. In turn, a number of herbivores have adapted to plants that contain glucosinolates. As a result of adaptation to their host plants, specialized insects may elicit different plant-inducible responses than generalists. Oligonucleotide microarrays and qRT-PCR analysis were used to characterize transcriptional profiles of Arabidopsis thaliana plants in response to infestation with a generalist aphid, Myzus persicae, or a cruciferous plant specialist, Brevicoryne brassicae. To find possible differences and similarities in molecular responses between plants differing in predominant glucosinolate hydrolysis products, three ecotypes of A. thaliana were chosen: Wassilewskija (Ws), Cape Verde Islands (Cvi), and Landsberg erecta (Ler), which, respectively, produce mainly isothiocyanates, epithionitriles, and nitriles. In all three ecotypes, general stress-responsive genes, genes belonging to octadecanoid and indole glucosinolate synthesis pathways were induced upon both generalist and specialist attack. By contrast, transcription of myrosinases, enzymes hydrolysing glucosinolates, was suppressed. The induction of the jasmonic acid synthesis pathway was strongest in Cvi, while the up-regulation of the indole glucosinolate synthesis pathway was highest in Ler, suggesting a slightly different defence strategy in these two ecotypes. Specialist and generalist infestations caused statistically significant differential regulation of 60 genes in Ws and 21 in Cvi. Among these were jasmonic acid and tryptophan synthesis pathway enzymes, and pathogenesis related protein (PR1). Insect no-choice experiments revealed lowered fitness of B. brassicae on Ler and Cvi in comparison to Ws, but no ecotype-dependent change in fecundity of M. persicae. Targeted studies employing constructs of GUS reporter gene under the control of promoters from CYP79B2 and CYP79B3 genes showed insect-specific induction of the indole glucosinolates synthesis pathway.
J Exp Bot 2007
PMID:Transcriptional responses of Arabidopsis thaliana ecotypes with different glucosinolate profiles after attack by polyphagous Myzus persicae and oligophagous Brevicoryne brassicae. 1754 20

Monitoring transcriptional reorganization triggered in response to a particular stress is an essential first step for the functional analysis of genes involved in the process. To characterize Cicer arietinum L. defence responses against Helicoverpa armigera feeding, transcript patterns elicited by both herbivore and mechanical wounding were profiled and compared, and the application of defence regulators was assessed. A combination of approaches was employed to develop transcript profiles, including suppression subtractive hybridization (SSH), macroarray, northern blot, and cluster analysis. Of the 63 unique genes isolated, 29 genes expressed differentially when Helicoverpa feeding and wounding responses were compared. Comparative macroarray analyses revealed that most of the Helicoverpa-induced transcripts were methyl jasmonate (MeJA) and ethylene (ET) regulated. The effects of mild insect infestation and the exogenous application of signalling compounds on larval feeding behaviour were also monitored. Bioassays were performed to measure dispersal percentage and growth of larvae on elicited plants. Larvae released on elicited plants had decreased larval performance, demonstrating the central role of induced plant defence against herbivory. Similarly, wounding and exogenous application of MeJA and ET also affected larval growth and feeding behaviour. Our results demonstrated that Helicoverpa attack up-regulated large transcriptional changes and induced chickpea defence responses. Therefore, the results of this study advance the understanding of non-model plant-insect interactions on a broader scale.
J Exp Bot 2008
PMID:Differential transcript accumulation in Cicer arietinum L. in response to a chewing insect Helicoverpa armigera and defence regulators correlate with reduced insect performance. 1854 10

Plant defensive strategies bring into play blends of compounds dependent on the type of attacker and coming from different synthesis pathways. Interest in the field is mainly focused on volatile organic compounds (VOCs) and jasmonic acid (JA). By contrast, little is known about the oxidized polyunsaturated fatty acids (PUFAs), such as PUFA-hydroperoxides, PUFA-hydroxides, or PUFA-ketones. PUFA-hydroperoxides and their derivatives might be involved in stress response and show antimicrobial activities. Hydroperoxides are also precursors of JA and some volatile compounds. In this paper, the differential biochemical response of a plant against insects with distinct feeding behaviours is characterized not only in terms of VOC signature and JA profile but also in terms of their precursors synthesized through the lipoxygenase (LOX)-pathway at the early stage of the plant response. For this purpose, two leading pests of potato with distinct feeding behaviours were used: the Colorado Potato Beetle (Leptinotarsa decemlineata Say), a chewing herbivore, and the Green Peach Aphid (Myzus persicae Sulzer), a piercing-sucking insect. The volatile signatures identified clearly differ in function with the feeding behaviour of the attacker and the aphid, which causes the smaller damages, triggers the emission of a higher number of volatiles. In addition, 9-LOX products, which are usually associated with defence against pathogens, were exclusively activated by aphid attack. Furthermore, a correlation between volatiles and JA accumulation and the evolution of their precursors was determined. Finally, the role of the insect itself on the plant response after insect infestation was highlighted.
J Exp Bot 2009
PMID:Attacks by a piercing-sucking insect (Myzus persicae Sultzer) or a chewing insect (Leptinotarsa decemlineata Say) on potato plants (Solanum tuberosum L.) induce differential changes in volatile compound release and oxylipin synthesis. 1922 Nov 42

Aphis gossypii Glover causes direct and indirect damage to Cucumis melo L. crops. To decrease the harmful effects of this pest, one of the most economically and environmentally acceptable options is to use genetically resistant melon varieties. To date, several sources of resistance carrying the Vat gene are used in melon breeding programmes that aim to prevent A. gossypii colonization and the subsequent aphid virus transmission. The results suggest that the resistance conferred by this gene is associated with a microscopic hypersensitive response specific against A. gossypii. Soon after aphid infestation, phenol synthesis, deposits of callose and lignin in the cell walls, damage to the plasmalemma, and a micro-oxidative burst were detected in genotypes carrying the Vat gene. According to electrical penetration graph experiments, this response seems to occur after aphid stylets puncture the plant cells and not during intercellular stylet penetration. This type of plant tissue reaction was not detected in melon plants infested with Bemisia tabaci Gennadius nor Myzus persicae Sulzer.
J Exp Bot 2009
PMID:Hypersensitive response to Aphis gossypii Glover in melon genotypes carrying the Vat gene. 1947 89

Despite evidence that both pollinators and nonpollinator agents of selection can shape the evolution of floral characters, there have been few attempts to compare the strengths and directions of selection from pollinators and other agents in the same study system. In this investigation of Leucanthemum vulgare, a self-incompatible composite known for its conspicuous white rays, I obtained data from a ray removal experiment in the field and from a segregating F(2) population in an experimental garden to assess the role of pollinator and nonpollinator selection as stabilizing factors on floral evolution in this species. Removal of all rays reduced the pollination success of heads by 31-35%, but did not significantly affect the level of infestation by larvae of the fly Tephritis neesii. Data from F(2) plants indicated a potential for indirect selection on ray morphology, mediated through links between ray morphology and measures of vegetative size and plant vigor. The results of this study show that individuals of the normal, rayed phenotype have a clear selective advantage, in terms of both pollinator attraction and general plant vigor. Thus, there were no conflicting selection pressures between the pollinators and the other selective agents considered in this study.
Am J Bot 2008 Sep
PMID:Pollinator and nonpollinator selection on ray morphology in Leucanthemum vulgare (oxeye daisy, Asteraceae). 2163 27

Antagonists can play a role in sexual system evolution if tolerance or resistance is sex-dependent. Our understanding of this role will be enhanced by consideration of the effects of antagonists on other plant-animal interactions. This study determined whether the sex morphs of a gynodioecious Fragaria virginiana differ in their susceptibility and response to damage by spittlebugs and whether damage altered pollinator attraction traits or interactions with other antagonists. Tolerance, but not resistance, to spittlebugs differed between the sexes. Generally, spittlebugs were more damaging to hermaphrodites than females, a finding in accord with the hypothesis that the pollen-bearing morph is less tolerant of source-damage than the pollen-sterile morph when damage is incurred during flowering. In both sex morphs, spittlebugs reduced inflorescence height, increased petal size, but did not affect the number of open flowers per day, suggesting that the net effect of damage may be to increase pollinator attraction. Spittlebug infestation modified interactions with other antagonists in a sex-dependent manner: spittlebugs reduced attack by bud-clipping weevils in hermaphrodites but increased infection by leaf fungi in females. The complex interactions between plant sex, antagonists, and pollinator attraction documented here emphasize the importance of considering sex-differential multi-species interactions in plant sexual evolution.
Am J Bot 2005 Oct
PMID:Sexes show differential tolerance to spittlebug damage and consequences of damage for multi-species interactions. 2164 88

Salivary secretions of neonate Hessian fly larvae initiate a two-way exchange of molecules with their wheat host. Changes in properties of the leaf surface allow larval effectors to enter the plant where they trigger plant processes leading to resistance and delivery of defence molecules, or susceptibility and delivery of nutrients. To increase understanding of the host plant's response, the timing and characteristics of the induced epidermal permeability were investigated. Resistant plant permeability was transient and limited in area, persisting just long enough to deliver defence molecules before gene expression and permeability reverted to pre-infestation levels. The abundance of transcripts for GDSL-motif lipase/hydrolase, thought to contribute to cuticle reorganization and increased permeability, followed the same temporal profile as permeability in resistant plants. In contrast, susceptible plants continued to increase in permeability over time until the entire crown of the plant became a nutrient sink. Permeability increased with higher infestation levels in susceptible but not in resistant plants. The ramifications of induced plant permeability on Hessian fly populations are discussed.
J Exp Bot 2011 Aug
PMID:Induced epidermal permeability modulates resistance and susceptibility of wheat seedlings to herbivory by Hessian fly larvae. 2165 64


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