Antioxidant systems in insects

Felton, Gary W.; Summers, Clinton B.

doi:10.1002/arch.940290208

Cited by 504 publications

(349 citation statements)

References 41 publications

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“…The high levels of H 2 O 2 found to be present in nectar also correlates with the finding that peroxidase and catalase activity are abundant in the gut and malpighian tubules of insects (47)(48)(49)(50).…”

Section: Discussionsupporting

confidence: 73%

Tobacco Nectarin I

Carter

Thornburg

2000

Journal of Biological Chemistry

194

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Nectarin I, a protein that accumulates in the nectar of Nicotiana sp., was determined to contain superoxide dismutase activity by colorimetric and in-gel assays. This activity was found to be remarkably thermostable. did not restore superoxide dismutase activity. The quaternary structure of the reconstituted enzyme was examined, and only tetrameric and pentameric aggregates were enzymatically active. The reconstituted enzyme was also shown to generate H 2 O 2 . Putative nectarin I homologues were found in the nectars of several other plant species.

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Section: Discussionsupporting

confidence: 73%

Tobacco Nectarin I

Carter

Thornburg

2000

Journal of Biological Chemistry

194

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“…Insects utilize reactive oxygen species (ROS) as cytotoxic agents against pathogens, however ROS can cause oxidative stress to both the fungal pathogen and host, leading to DNA and protein damage [35]. The host’s cells can protect themselves against these fluctuations by producing enzymatic and non-enzymatic antioxidants [36,37]. Enhanced activity of esterases has been observed in the fat body and hemolymph of Leptinotarsa decemlineata and Locusta migratoria infected with M. anisopliae [38,39] These enzymes play an important role in host protection against pathogens, where increased activity of these enzymes results in the degradation of toxic molecules produced during EPF infection [39,40].…”

Section: Introductionmentioning

confidence: 99%

Highly specific host-pathogen interactions influence Metarhizium brunneum blastospore virulence against Culex quinquefasciatus larvae

et al. 2018

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Entomopathogenic fungi are potential biological control agents of mosquitoes. Our group observed that not all mosquitoes were equally susceptible to fungal infection and observed significant differences in virulence of different spore types. Conidiospores and blastospores were tested against Culex quinquefasciatus larvae. Blastospores are normally considered more virulent than conidia as they form germ tubes and penetrate the host integument more rapidly than conidia. However, when tested against Cx. quinquefasciatus, blastospores were less virulent than conidia. This host-fungus interaction was studied by optical, electron and atomic force microscopy (AFM). Furthermore, host immune responses and specific gene expression were investigated. Metarhizium brunneum (formerly M. anisopliae) ARSEF 4556 blastospores did not readily adhere to Culex larval integument and the main route of infection was through the gut. Adhesion forces between blastospores and Culex cuticle were significantly lower than for other insects. Larvae challenged with blastospores showed enhanced immune responses, with increased levels of phenoloxidase, glutathione-S-transferase, esterase, superoxide dismutase and lipid peroxidase activity. Interestingly, M. brunneum pathogenicity/stress-related genes were all down-regulated in blastospores exposed to Culex. Conversely, when conidia were exposed to Culex, the pathogenicity genes involved in adhesion or cuticle degradation were up-regulated. Delayed host mortality following blastospore infection of Culex was probably due to lower adhesion rates of blastospores to the cuticle and enhanced host immune responses deployed to counter infection. The results here show that subtle differences in host-pathogen interactions can be responsible for significant changes in virulence when comparing mosquito species, having important consequences for biological control strategies and the understanding of pathogenicity processes.

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“…ROS generated in the process of oxidative metabolism can cause oxidation of proteins, RNAs, DNAs and peroxidation of membrane lipids (Michiels et al 1994;Felton 1995;Felton and Summers 1995;Pardini 1995). The destructive reaction contributes to the processes of ageing, carcinogenesis and cell death.…”

Section: Introductionmentioning

confidence: 99%

Total antioxidant capacity of honeybee haemolymph in relation to age and exposure to pesticide, and comparison to antioxidant capacity of seminal plasma

et al. 2015

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-Oxidative stress is defined as a disturbance in the balance between the production of reactive oxygen species and antioxidant defences. We measured total antioxidant capacity (TAC) in honeybee haemolymph and seminal plasma and analysed TAC of haemolymph in relation to age and exposure to pesticide. TAC of haemolymph increased with age of bees (1.18 vs 1.97 mM of (±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) for 1-and 30-day-old bees, respectively, P ≤0.05). Exposure to imidacloprid (IMD) affected TAC of haemolymph of 1-day-old but not 30-day-old honeybees. TAC in haemolymph of 1-day-old bees was lower in treatments with the addition of 5 and 200 ppb IMD (1.57-1.46 mM of Trolox in treated bees compared with 2.37 mM of Trolox in controls; P ≤0.05). In conclusion, antioxidant protection of honeybees seems to be related to age and may be disturbed by exposure to IMD. Older bees with higher antioxidant protection seem to be less susceptible to IMD toxicity. The toxic effect of pesticide seems to be particularly dangerous in early life stages of honeybees.Apis mellifera / total antioxidant capacity / haemolymph / ageing / pesticide

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Antioxidant systems in insects

Cited by 504 publications

References 41 publications

Tobacco Nectarin I

Tobacco Nectarin I

Highly specific host-pathogen interactions influence Metarhizium brunneum blastospore virulence against Culex quinquefasciatus larvae

Total antioxidant capacity of honeybee haemolymph in relation to age and exposure to pesticide, and comparison to antioxidant capacity of seminal plasma

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