Azadirachtin-A from Azadirachta indica Impacts Multiple Biological Targets in Cotton Bollworm Helicoverpa armigera

Abstract

Azadirachtin-A (AzaA) from the Indian neem tree ( Azadirachta indica ) has insecticidal properties; however, its molecular mechanism remains elusive. The “targeted and nontargeted proteomic profiling”, metabolomics, matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) imaging, gene expression, and in silico analysis provided clues about its action on Helicoverpa armigera . Fourth instar H. armigera larvae fed on AzaA-based diet (AzaD) suffered from significant mortality, growth retardation, reduced larval mass, complications in molting, and prolonged development. Furthermore, death of AzaD-fed larvae was observed with various phenotypes like bursting, blackening, and half-molting. Liquid chromatography–mass spectrometry (LC–MS) data showed limited catabolic processing of ingested AzaA and dramatic alternations of primary metabolism in H. armigera . MALDI-TOF imaging indicated the presence of AzaA in midgut of H. armigera . In the gut, out of 79 proteins identified, 34 were upregulated, which were related to digestion, immunity, energy production, and apoptosis mechanism. On the other hand, 45 proteins were downregulated, including those from carbohydrate metabolism, lipid metabolism, and energy transfer. In the hemolymph, 21 upregulated proteins were reported to be involved in immunity, RNA processing, and mRNA-directed protein synthesis, while 7 downregulated proteins were implicated in energy transfer, hydrolysis, lipid metabolism, defense mechanisms, and amino acid storage-related functions. Subsequently, six target proteins were identified using labeled AzaA that interacted with whole insect proteins. In silico analysis suggests that AzaA could be efficiently accommodated in the hydrophobic pocket of juvenile hormone esterase and showed strong interaction with active site residues, indicating plausible targets of AzaA in H. armigera . Quantitative polymerase chain reaction analysis suggested differential gene expression patterns and partly corroborated the proteomic results. Overall, data suggest that AzaA generally targets more than one protein in H. armigera and hence could be a potent biopesticide.

Azadirachtin-Based Insecticide: Overview, Risk Assessments, and Future Directions

“…However, azadirachtin is still considered as one of the best alternatives to conventional insecticides in IPMprograms and considered as one of the most promising plant compounds for pest control organic agriculture (Tomé et al, 2013;Bezzar-Bendjazia et al, 2017). Despite the progress on the physiological and biological activities and agricultural application of azadirachtin, its exact mechanism of action, especially, at the molecular level is not yet fully understood (Lai et al, 2014;Dawkar et al, 2019).…”

The toxicity of neem (Azadirachta indica), citronella (Cymbopogon nardus), castor (Ricinus communis), and clove (Syzygium aromaticum) oil against Spodoptera frugiferda

“…Larva serangga uji yang bertahan hidup menunjukkan indikasi pertumbuhan terhambat, bobot tubuh yang lebih rendah, waktu perkembangan yang lebih lama yang sejalan dengan percobaan sebelumnya (uji penapisan). Beberapa hasil penelitian melaporkan bahwa senyawa aktif dari dari biji A. indica memiliki aktivitas sebagai penghambat pertumbuhan, gangguan perkembangan, memperlama waktu perkembangan dan penghambat makan (Senthil-Nathan,2013;Dawkar et al, 2019;Bezzar-Bendjazia et al, 2016). Mordue & Blackwell (1993) dan Koul (1996) mengemukakan bahwa senyawa aktif azadirakhtin yang terkadung dalam minyak mimba mengakibatkan hambatan pelepasan protorasikotropik hormon (PTTH) dari kelenjar korpora kardiaca dan menghambat pelepasan ekdison dari brain ring glands complex (BRC's) sehingga mengakibatkan gangguan perkembangan pada serangga uji.…”

Current Advances in Mass Spectrometry Imaging for Insect Physiology and Metabolism

“…Azadirachta indica is an economical tree that can be used to distract a biopesticide component, azadirachtin-A. It was only presented in the midgut of Helicoverpa armigera after application [61].…”