Changes in immune responses of Helicoverpa armigera Hübner followed by feeding on Knotgrass, Polygonum persicaria agglutinin

Abstract

There is no study implying the effect of plant lectins on insect immune elements in both challenged and nonchallenged conditions with entomopathogenic agents. Lectins may bind to immune receptors on the surface of insect hemocytes, thus inducing or even disabling common immune functions including hemocyte counts, nodulation/encapsulation, phenoloxidase activity, and synthesis of antimicrobial peptides. In the present study, effect of Polygonum persicaria L. agglutinin (PPA) on immune responses of Helicoverpa armigera Hübner was investigated by feeding artificial diet treated to the larvae. Subsequently hemocyte count and expression of some immune-related genes were considered for analyses. The two groups of larvae including control and PPA-treated (1%) were divided into four subgroups of intact, Tween-80 injected, latex-bead injected and Beauveria bassiana-injected. Except for intact larvae, the highest numbers of total and differential hemocyte counts were recorded 12 hr postinjection, however, the PPA-fed larvae showed a significantly lower hemocyte counts compared to control.The number of nodules in PPA-fed larvae was significantly lower than control, but the injected larvae of both control and PPA showed the highest nodulation 24 hr postinjection.Although the highest activity of phenoloxidase was observed 12 and 24 hr postinjection but its activity significantly decreased in PPA-fed larvae compared to control. Gene expression of antimicrobial peptides including attacin, Arch. Insect Biochem. Physiol. 2019;101:e21543.wileyonlinelibrary.com/journal/arch

Responses of continuous cadmium exposure on some biological and physiological performance of cotton bollworm Helicoverpa armigera

“…This reduction in blood cell numbers may be attributed to cellular lysis (Lu et al, 2011). The decreased number of total cells under cadmium excess is an indication of lack of metallothionein production (Roesijadi et al, 1997; J. Yang et al, 2011) or could be related to a disturbance in hemopoietic organs that are the source of haemocyte production (Rahimi et al, 2019). H. Wu et al (2022) found that Cd stress significantly reduced the number of haemocytes in a model organism, L. dispar larvae.…”

Changes in immune responses, gene expression, and life table parameters of Helicoverpa armigera Hübner fed on a diet containing the saponin of tea plant, Camellia sinensis

“…The insect's innate immune system embraces the cellular and humoral responses in which cell‐mediated immunity is performed particularly by hemocytes (Takov et al, 2020) through phagocytosis, nodulation, encapsulation, and melanization of invaders (Dubovskiy et al, 2016). Although the effects of tea seed saponin on insect immune responses have not been studied, there are some pieces of evidence suggesting that plant extracts such as azadirachtin (Azambuja et al, 1991), Artemisia annua L. (Asterales: Asteraceae) extracts (Zibaee & Bandani, 2010), and Polygonum persicaria lectins (Rahimi et al, 2019) negatively affect insect immune responses. Furthermore, De Geyter et al (2012) confirmed that saponins exert cytotoxic effects through fast and stringent permeation of insect cell membrane.…”

Methanolic Extract of Winter Cherry Causes Morpho-Histological and Immunological Ailments in Mulberry Pyralid Glyphodes pyloalis

“…Insects defend themselves by two methods against foreign bodies, a general method (i.e., cuticle and chemicals involve in defending insects) and the second one involving cellular and humeral responses ( Beckage, 2011 ; Dubovskiy et al, 2016 ; Rahimi et al, 2019 ). The plant products are capable of indulging in both of them and thus weakening the insects and make them susceptible to various diseases and parasites ( Veyrat et al, 2016 ; Gasmi et al, 2019 ).…”