The expression of proteins involved in digestion and detoxification are regulated in Helicoverpa armigera to cope up with chlorpyrifos insecticide

Abstract

Helicoverpa armigera is a key pest in many vital crops, which is mainly controlled by chemical strategies. To manage this pest is becoming challenging due to its ability and evolution of resistance against insecticides. Further, its subsequent spread on nonhost plant is remarkable in recent times. Hence, decoding resistance mechanism against phytochemicals and synthetic insecticides is a major challenge. The present work describes that the digestion, defense and immunity related enzymes are associated with chlorpyrifos resistance in H. armigera. Proteomic analysis of H. armigera gut tissue upon feeding on chlorpyrifos containing diet (CH) and artificial diet (AD) using nano-liquid chromatography-mass spectrometry identified upregulated 23-proteins in CH fed larvae. Database searches combined with gene ontology analysis revealed that the identified gut proteins engrossed in digestion, proteins crucial for immunity, adaptive responses to stress, and detoxification. Biochemical and quantitative real-time polymerase chain reaction analysis of candidate proteins indicated that insects were struggling to get nutrients and energy in presence of CH, while at the same time endeavoring to metabolize chlorpyrifos. Moreover, we proposed a potential processing pathway of chlorpyrifos in H. armigera gut by examining the metabolites using gas chromatography-mass spectrometry. H. armigera exhibit a range of intriguing behavioral, morphological adaptations and resistance to insecticides by regulating expression of proteins involved in digestion and detoxification mechanisms to cope up with chlorpyrifos. In these contexts, as gut is a rich repository of biological information; profound analysis of gut tissues can give clues of detoxification and resistance mechanism in insects.

Identification of a novel cytochrome P450 CYP321B1 gene from tobacco cutworm (Spodoptera litura) and RNA interference to evaluate its role in commonly used insecticides

“…PBO is an insecticide synergist known to inhibit the activity of cytochrome P450 enzymes (Willoughby et al, 2007). Previous studies have suggested that resistance against chlorpyrifos, β-cypermethrin and methomyl in S. litura and Helicoverpa armigera is monooxygenase-mediated (Sasabe et al, 2004;Bues et al, 2005;Ahmad et al, 2007;Ahmad et al, 2009;Rehan & Freed, 2014;Dawkar et al, 2015). The toxicity of chlorpyrifos, β-cypermethrin and methomyl against S. litura increased 3.25-, 5.73-and 3.12-fold, respectively, when applied with PBO, as compared with chlorpyrifos, β-cypermethrin and methomyl alone (Table 1).…”

Insecticide resistance and nutrition interactively shape life-history parameters in German cockroaches

“…For example, diets that support good body condition typically also support higher immune response and survival upon pathogen exposure 18 23 , and animals in good body condition would similarly be expected to better resist and detoxify secondary metabolites and insecticides. Although it is well known that nutrient availability may play an important role in the ability of insects to handle and detoxify xenobiotics 24 25 26 27 , the interactive effects of nutritional condition and insecticide resistance on life-history outcomes have, to our knowledge, not been investigated.…”

Esterase activity in homogenates of Helicoverpa armigera (Hubner) (Lepidoptera: noctuidae) exposed to different insecticides and the behavioral effect

“…Bacillus thuringiensis and chlorpyrifos showed higher LC 50 and LC 95 values than those recommended by the manufacturer, as well as increased alpha and beta esterase activity. The high the alpha and beta esterase activity observed in H. armigera population indicates a higher metabolic rate, which may mean some level of resistance, a likely consequence of a long period of exposure to organophosphate, pyrethroids and cry toxin, for example (ODHIAMBO et al, 2010;DAWKAR et al, 2016). These enzymes are able to metabolize the insecticides, due to the high expression of the genes that codify them.…”