Transcription Analysis of the Stress and Immune Response Genes to Temperature Stress in Ostrinia furnacalis

Abstract

Ostrinia furnacalis is one of the most important pests on maize. O. furnacalis larvae are frequently exposed to the temperature challenges such as high temperature in summer and cold temperature in winter in the natural environment. High and low temperature stress, like any abiotic stress, impairs the physiology and development of insects. Up to now, there is limited information about gene regulation and signaling pathways related to the high and cold stress response in O. furnacalis. High-throughput sequencing of transcriptome provides a new approach for detecting stress and immune response genes under high and low temperature stresses in O. furnacalis. In the present study, O. furnacalis larvae were treated with the temperature at 8 and 40°C, and the responses of O. furnacalis larvae to the temperature stress were investigated through RNA-sequencing and further confirmation. The results showed that immune responses were up-regulated in larvae by the cold stress at 8°C while some stress response genes, such as HSP family, GST-2, Bax inhibitor and P450, were significantly increased at 40°C. Furthermore, quantitative real time polymerase chain reaction were performed to quantify the expression levels of immune related genes, such as PGRP-LB, antimicrobial peptides, lysozyme, serine protease and stress response genes such as small HSPs and HSP90, and the expression levels of these genes were similar to the RNA-seq results. In addition, the iron storage protein Ferritin was found to be involved in the response to temperature stress, and the changes of total iron concentration in the hemolymph were, in general, consistent with the expression levels of Ferritin. Taken together, our results suggested that the stress response genes were involved in the defense against the heat stress at 40°C, and the immune responses triggered by cold stress might provide protection for larvae from cold stress at 8°C. More interestingly, our results showed that during the responses to temperature stress, the total iron concentration in hemolymph regulated by Ferritin increased, which might help O. furnacalis in surviving the low and high temperature stress.

Odorant-Binding Proteins Contribute to the Defense of the Red Flour Beetle, Tribolium castaneum, Against Essential Oil of Artemisia vulgaris

“…However, the precise functions of OBP genes in the insect fat body, Malpighian tubule, and hemolymph is unknown. Coincidentally, these tissues are involved in metabolic detoxification in insects ( Beyenbach et al, 2010 ; Chen K. et al, 2019 ; Li et al, 2019 ). Therefore, we speculate that TcOBPC11 in T. castaneum could play an important role in the degradation of exogenous substances.…”

Interplay between Fungal Infection and Bacterial Associates in the Wax Moth Galleria mellonella under Different Temperature Conditions

“…It was previously shown that a short exposure of G. mellonella to low temperatures led to an increase in AMP expression in response to B. thuringiensis infection [ 28 ]. Similar exposure led to enhanced AMP expression in Ostrinia furnacalis in the absence of infection [ 29 ]. Elevated antibacterial responses were also observed under prolonged cooling.…”

“…Insect antibacterial responses are also dependent on environmental temperatures [ 25 , 26 , 27 ] and elevated temperature often promotes bacterial infection [ 16 , 17 ]. There are examples of increased antibacterial responses in insects under short-term or prolonged exposure to low temperatures [ 16 , 26 , 28 , 29 ]. Importantly, in a state of cold diapause, cellular immunity continues to work [ 30 ] and changes in microbiome composition, immune response and susceptibility to fungal and bacterial infections may also occur [ 27 , 31 ].…”

“…In fact, the level of AMP gene expression clearly responds to changes in the microbial community during fungal infections [ 3 ]. Moreover, AMP gene expression is dependent on temperature [ 23 , 29 ].…”

Expression analysis of genes related to cold tolerance in Dendroctonus valens

“…Recent studies of cold tolerance in insects have focused on the determination of the supercooling point, survival in low-temperature conditions, the cold tolerance index, and the influence of cold acclimation on insect biology. Transcriptome techniques, such as gene chip technology, expressed sequence tags, serial analysis of gene expression, and RNA sequencing, have been used to identify highly expressed cold-related genes in insects ( Barth et al, 2018 ; Chen et al, 2019 ; Enriquez & Colinet, 2019 ). To screen cold-tolerant genes, a variety of tools for studying differential gene expression are available, including cDNA library screening, suppression subtractive hybridization, and microarray screening ( Parker et al, 2018 ; Martinson et al, 2019 ; Wang et al, 2019 ).…”