Temperature-induced stress response in Lymantria dispar neurosecretory neurons

IntroductionAs a gradogenic polyphagous and invasive species, the gypsy moth (Lymantria dispar L.) encounters different environmental challenges. Considering that its host range is estimated at more than 500 plant species within 73 families (Liebhold et al., 1995), the gypsy moth is characterized by a variety of adaptations that ensure survival and reproduction in heterogeneous and stressful environments. Problems with gypsy moth overcrowding are not solved yet (Demir et al., 2009(Demir et al., , 2012. Plants from the genus Quercus are accepted as the most suitable food and the most susceptible to L. dispar population eruptions (Maksimović, 1987;Liebhold et al., 1995). In the Republic of Serbia, large areas of forest and orchards were attacked (171,914 ha) by gypsy moths in 2012 according to the State Enterprise for Forest Management of Serbia (http:// www.srbijasume.rs/). Other parts of Europe are also at risk of gypsy moth invasion and degradation of forest ecosystems. This pest insect is one of the most serious insect defoliators of North American forests and urban landscapes according to the US Forest Service (http:// www.fs.fed.us/). Gypsy moth defoliation results in loss of growth, mortality of oak species, and shifts in species composition in mixed-oak forests (McGraw et al., 1990). Young oak leaves contain low amounts of flavonoids in spring when L. dispar attacks them (Salminen et al., 2004). A high population density of gypsy moths induces changes in leaf chemistry during defoliation, i.e. flavonoid content increases, leading to suppression of the insect immune response, and their resistance to viruses is lowered (Martemyanov et al., 2012). One of the very rare species of plant that is an unsuitable host for gypsy moths is the locust tree, Robinia pseudoacacia (Barbosa and Krischik, 1987). A nonfamiliar host plant for L. dispar, R. pseudoacacia is a widespread species in its native habitat in southeastern North America. It was introduced to Europe in 1601 (Chapman, 1935). Today, it has spread throughout western, central, eastern, and southern Europe and has become a major invasive species with a significant impact on native plant communities. Despite the large number of polyphagous species of Lepidoptera and the long period after the introduction of R. pseudoacacia to Europe, so far only a few native lepidopteran species have adapted to it (Kulfan, 2012). The unfavorable effects of locust leaves on gypsy moth larvae can be attributed to the presence of phenolic defensive compounds (Barbosa Abstract: As a very invasive insect species, Lymantria dispar is adaptable and sensitive to a changing environment. In insects the neuroendocrine system first reacts to stress by production of prothoracicotropic neurohormones (PTTH) that control ecdysteroid synthesis (morphogenetic and stress hormones). In this article, we report changes in the L2' brain neurosecretory neurons that synthesize PTTH in L. dispar larvae after feeding on locust tree leaves (Robinia pseudoacacia), an unsuitable host plant. Groups of larvae...

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“…For further details, see our previous publications (Perić-Mataruga et al, 2001, 2006b; Ilijin et al, 2012a, 2012b, 2014.…”

Section: Histochemistry Preparation and Analysismentioning

confidence: 99%

Prothoracicotropic hormone-producing neurosecretory neurons and antioxidative defense in midgut of Lymantria dispar in trophic stress

Perić-Mataruga

Vlahović²,

Mrdaković³

2014

Turk J Biol

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“…PTTH is a neurohormone that could stimulate prothoracic glands to produce ecdysteroids and regulate insect metamorphosis [ 14 – 18 ]. Insect neurosecretory neurons that synthesize PTTH can receive many environmental stimuli through receptor systems, including cold, heat, photoperiod, injury, and plant allelic chemicals stimuli [ 35 – 37 ]. As UVB is a common environmental stimulus in nature, we wondered whether the UVB-induced changes in T .…”

Section: Discussionmentioning

confidence: 99%

UVB Radiation Delays Tribolium castaneum Metamorphosis by Influencing Ecdysteroid Metabolism

Sang

et al. 2016

PLoS ONE

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Ultraviolet B (UVB) radiation is an important environmental factor. It is generally known that UVB exhibits high genotoxicity due to causing DNA damage, potentially leading to skin carcinogenesis and aging in mammals. However, little is known about the effects of UVB on the development and metamorphosis of insects, which are the most abundant terrestrial animals. In the present study, we performed dose-response analyses of the effects UVB irradiation on Tribolium castaneum metamorphosis, assessed the function of the T. castaneum prothoracicotropic hormone gene (Trcptth), and analyzed ecdysteroid pathway gene expression profile and ecdysterone titers post-UVB irradiation. The results showed that UVB not only caused death of T. castaneum larvae, but also delayed larval-pupal metamorphosis and reduced the size and emergence rate of pupae. In addition, we verified the function of Trcptth, which is responsible for regulating metamorphosis. It was also found that the expression profiles of Trcptth as well as ecdysteroidogenesis and response genes were influenced by UVB radiation. Therefore, a disturbance pulse of ecdysteroid may be involved in delaying development under exposure to irradiation. To our knowledge, this is the first report indicating that UVB can influence the metamorphosis of insects. This study will contribute to a better understanding of the impact of UVB on signaling mechanisms in insect metamorphosis.

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“…It shows a tremendous capacity to feed on a wide range of trees and shrubs, totalling more than 500 plant species (Barbosa et al, 1971). Many secondary metabolites of host plants, in defense against Lymantria dispar L., may have strong prooxidative effects on midgut tissue and may provoke oxidative stress (Bi and Felton, 1995;Perić-Mataruga et al, 1997;Ilijin et al, 2014;. That is an imbalance between the production of free radicals and the ability of the body to counteract or detoxify their harmful effects through neutralization by antioxidants.…”

Section: Introductionmentioning

confidence: 99%

Ghrelin effects on midgut tissue antioxidative defense and glutathioneS-transferase activity in Lymantria dispar (Lepidoptera)

Perić-Mataruga¹,

Vlahović²,

Mrdaković³

et al. 2015

Turk J Biol

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The aim of the study was to examine changes in Cu-Zn superoxide dismutase (SOD), catalase (CAT), their gel electrophoresis profiles, glutathione reductase (GR) activity, amount of glutathione (GSH), and the activity of glutathione S-transferase (GST) -phase II biotransformation enzyme in the midgut tissue of gypsy moth (Lymantria dispar L. (Lepidoptera: Lymantriidae)) larvae after ghrelin treatment. Four subpicomolar injections of ghrelin (0.3 pmol) or physiological saline (control) were applied every 24 h. The SOD, CAT, GR, GST activity, and amount of GSH were higher in the ghrelin-treated group than in the control. Electrophoresis gel bands of SOD and CAT had higher area and density in the treated group. The effects of ghrelin on the antioxidative defense and GST activity in insects were detected for the first time. The results provided evidence for possible application of insects as simple model systems in future studies of the role of ghrelin in the antioxidative protection of complex organisms.

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Temperature-induced stress response in Lymantria dispar neurosecretory neurons

Cited by 7 publications

References 45 publications

Prothoracicotropic hormone-producing neurosecretory neurons and antioxidative defense in midgut of Lymantria dispar in trophic stress

Prothoracicotropic hormone-producing neurosecretory neurons and antioxidative defense in midgut of Lymantria dispar in trophic stress

UVB Radiation Delays Tribolium castaneum Metamorphosis by Influencing Ecdysteroid Metabolism

Ghrelin effects on midgut tissue antioxidative defense and glutathioneS-transferase activity in Lymantria dispar (Lepidoptera)

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