Data_Sheet_2_Transcription Analysis of the Stress and Immune Response Genes to Temperature Stress in Ostrinia furnacalis.pdf

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.

Ostrinia furnacalis 被视为玉米作物上最为重要的害虫之一。该物种的幼虫在自然环境中所经历的温度挑战尤为频繁，如夏季的高温及冬季的低温。此类高温与低温的胁迫，如同其他非生物胁迫一般，会对昆虫的生理机能与生长发育造成损害。截至目前，关于 O. furnacalis 在高温与低温胁迫下的基因调控及其信号通路的相关信息仍然有限。转录组的高通量测序技术为检测 O. furnacalis 在高温与低温胁迫下的应激与免疫反应基因提供了一种新的途径。在本研究中，通过对 O. furnacalis 幼虫进行 8°C 和 40°C 的温度处理，并通过 RNA 测序技术及其后续验证，我们探究了幼虫对温度胁迫的反应。研究结果揭示，在 8°C 的低温胁迫下，幼虫的免疫反应被上调，而在 40°C 时，一些应激反应基因如 HSP 家族、GST-2、Bax 抑制剂和 P450 的表达水平显著增加。此外，通过定量实时聚合酶链反应（qRT-PCR）技术对与免疫相关的基因，例如 PGRP-LB、抗菌肽、溶菌酶、丝氨酸蛋白酶以及与应激反应相关的基因如小 HSPs 和 HSP90 的表达水平进行了量化，其结果与 RNA-seq 数据相符。此外，发现铁储存蛋白 Ferritin 参与了对温度胁迫的反应，且其总铁浓度在血淋巴中的变化总体上与 Ferritin 的表达水平相一致。综合上述结果，我们的研究指出，应激反应基因参与了 40°C 高温胁迫的防御，而由低温胁迫引发的免疫反应可能为幼虫在 8°C 低温下的生存提供了保护。更有趣的是，我们的研究还表明，在应对温度胁迫的过程中，由 Ferritin 调节的血淋巴中铁的总浓度增加，这或许有助于 O. furnacalis 应对低温与高温的胁迫。