Bacterial but not fungal challenge up‐regulates the transcription of Coleoptericin genes in Tenebrio molitor

Abstract

Antimicrobial peptides (AMPs) are effector candidates that elicit humoral immunity in invertebrates. AMPs facilitate bacterial clearance by either physically disrupting the microbial membranes or the intracellular targets. In the Coleopteran pest, Tenebrio molitor, transcriptional regulation of AMPs has been studied in the context of innate immune signaling cascades and antimicrobial immunity. Here, we report the transcriptional response of three AMP genes, Coleoptericin A, B, and C (TmCole A, B and C) in T. molitor in response to bacterial (Escherichia coli, Staphylococcus aureus), and fungal (Candida albicans) challenges. These genes were expressed essentially in the gut and hemocytes followed by the integument tissue of the T. molitor larva. Further, these genes were highly expressed in the late-larval, pupal, and early adult stages. Furthermore, while all of these transcripts were highly upregulated in the fat body and Malpighian tubules after bacterial challenge, TmCole B and TmCole C were induced in the gut after E. coli challenge. Fungal stimulation was not required for the upregulation of the transcription of Coleoptericin genes in T. molitor.

TmSpz-like Plays a Fundamental Role in Response to E. coli but Not S. aureus or C. albican Infection in Tenebrio molitor via Regulation of Antimicrobial Peptide Production

“…The viability of E. coli -infected TmSpz-like knockdown T. molitor larvae may have decreased due to the downregulation of the AMP-encoding genes. These AMPs are reported to exert growth-inhibitory activity against E. coli [ 35 , 36 , 37 , 38 , 39 , 40 ]. Tm Tenecin3, an antifungal peptide, and Tm Thaumatin-like proteins are majorly induced in plant systems due to stress and other pathogenic insults [ 41 , 42 ].…”

Diverse Host Immune Responses of Different Geographical Populations of the Coconut Rhinoceros Beetle to Oryctes Rhinoceros Nudivirus (OrNV) Infection

“…4 and Tables S2 and S3), but this overexpression is profound in the recently established population of O. rhinoceros in the Solomon Islands (log 2 FC, >10). Previous studies showed upregulation of this protein in mealworm beetle ( Tenebrio molitor ) parasitized by Scleroderma guani ( 53 ) and after bacterial challenge ( 54 ). It has been shown that the expression and production of this AMP is dependent on the immune deficiency (Imd) pathway in the cereal weevil Sitophilus ( 55 ).…”

Tenebrio molitor Spätzle 1b Is Required to Confer Antibacterial Defense Against Gram-Negative Bacteria by Regulation of Antimicrobial Peptides

“…Expression patterns of 14 AMP genes including TmTenecin1, 2, 3 , and 4 ( TmTene1 , − 2 , − 3 , and − 4 ) ( Kim et al, 1998 ; Chae et al, 2012 ; Yang et al, 2017 ), TmDefensin and TmDefensin-like ( TmDef and TmDef-like ) ( Jang et al, 2020b ), TmColeoptericin-A and -B ( TmColeA and − B ) ( Zhu et al, 2014 ; Jang et al, 2020a ), TmAttacin-1a, −1b and -2 ( TmAtt1a , − 1b and − 2 ) ( Jo et al, 2018 ), TmCecropin-2 ( TmCec2 ) ( Ali Mohammadie Kojour et al, 2021 ), and TmThaumatin - like protein-1 and − 2 ( TmTLP1 and − 2 ) ( Noh and Jo, 2016 ; Kim et al, 2017 ), were examined by qRT-PCR with the AMP gene-specific primers ( Table 1 ). A relative quantitative PCR was performed as detailed above in an AMP-specific primer.…”