Comparative Analysis of Adelphocoris suturalis Jakovlev (Hemiptera: Miridae) Immune Responses to Fungal and Bacterial Pathogens

Abstract

The wide-spread culture of transgenic Bt cotton resisting the infamous cotton bollworms has reduced the adoption of broad-spectrum insecticides to a large extent. Consequently, the non-targeted insect Adelphocoris suturalis Jakovlev has become a major cotton pest in China. Entomopathogenic microbes show promising results for controlling this pest in the future, but A. suturalis innate immune responses to these pathogens are poorly understood. Here, we used the entomopathogenic fungus Beauveria bassiana and the Gram-negative pathogenic bacteria Enterobactor cloacae to infect A. suturalis nymphs, followed by high throughput RNA-seq to analyze the immune transcriptomes of A. suturalis in response to the two pathogens. A total of 150 immunity-related genes were identified, including pattern recognition receptors, extracellular signal modulators, signal pathways (Toll, IMD, JNK, and JAK/STAT), and response effectors. Further quantitative real-time PCR analysis demonstrated that B. bassiana and E. cloacae were recognized by different receptors (GNBP and PGRP, respectively); activated Toll pathway and IMD pathway respectively; and both induced expression of the effector gene Defensin. However, melanization is suppressed in B. bassiana-infected nymphs. Collectively, this study provides a transcriptomic snapshot of the A. suturalis immune system, and at the genetic level, gains multifaceted insights of the immune response to fungal and Gram-negative bacterial pathogens. Ultimately this work pioneers the study of molecular mechanisms underlying immune interactions between A. suturalis and its pathogens and assists in the development of novel mitigation strategies to control this pest.

Gut Bacterial Diversity in Different Life Cycle Stages of Adelphocoris suturalis (Hemiptera: Miridae)

“…Previous studies have reported that some symbiotic bacteria help insect hosts form new feeding habits, thus expanding food sources and enhancing the adaptability of insects to the environment ( Lu et al, 2001 ; Douglas, 2009 ), which may also increase the difficulty of A.suturalis control. There are currently few studies examining the symbiotic bacteria of A. suturalis , making the number and species of the symbiotic bacteria in A. suturalis uncertain ( Luo et al, 2021 ; Ma et al, 2021 ). Therefore, it is necessary to investigate the distribution of symbiotic bacteria at different stages of A. suturalis , which will provide a framework for exploring the function of symbiotic bacteria and pest control in A. suturalis .…”

Identification of 35 C-Type Lectins in the Oriental Armyworm, Mythimna separata (Walker)

“…In the Japanese pine sawyer beetle, Monochamus alternatus infected with the entomopathogenic fungus Metarhizium anisopliae, several differentially expressed unigenes were CTLs [51]. Twelve CTL genes were identified in Adelphocoris suturalis (Hemiptera: Miridae) immune responsive genes against fungal and bacterial pathogens [52]. Fourteen CTLs were identified in immunity-related genes in Ostrinia furnacalis against entomopathogenic fungi [53].…”

Odorant binding protein 18 increases the pathogen resistance of the imported willow leaf beetle, Plagiodera versicolora

“…Three time points were selected to collected samples, first day, time to reach 10% and 50% mortality. Time to reach 10% and 50% mortality were the time point that the mortality rates of larvae were nearly 10% and 50% ( Ma et al., 2021 ). Considering the dynamics of pathogenicity and lethality in P. aeruginosa , the infected group was sampled at day 1, day 2 (time to reach 10% mortality), day 5 (time to reach 50% mortality) after infection and the H 2 O treatment group was sampled at the same time points as controls.…”