Original paper
Abiotic stress as an immunity catalyst: heat-driven miR-34-5p enhances resistance to CpGV in codling moths via RNAi pathway activation
Li, Zaiyuan; Li, Xiaojiang; Fu, Lianhai; Lu, Yin; Qiao, Xi; Zhang, Bin; Wan, Fanghao; Liu, Bo; Qian, Wanqiang
Entomologia Generalis Volume 45 Number 6 (2025), p. 1617 - 1628
published: Dec 4, 2025
published online: Oct 23, 2025
manuscript accepted: Jul 31, 2025
final revised version received: Jun 26, 2025
manuscript revision requested: Apr 18, 2025
manuscript received: Mar 28, 2025
Open Access (paper may be downloaded free of charge)
Abstract
Temperature fluctuations can significantly influence the immune responses of ectothermic arthropods, including insects. Over the past 50 years, global warming has accelerated, coinciding with the development of significant resistance by the Cydia pomonella to a commercially used baculovirus insecticide (CpGV). However, the contribution of rising temperatures to the evolution of CpGV resistance remains unclear. This study explores the regulatory effects of high temperature on CpGV resistance in codling moths. Short-term exposure to elevated temperatures activated antiviral defenses in larvae, improving their survival against CpGV infection. The RNAi pathway, a crucial antiviral mechanism in insects, was found to play a pivotal role in this process. Genome analysis identified six key Dicer and AGO genes involved in the biogenesis and function of small RNAs (miRNAs, siRNAs, and piRNAs). Under high-temperature stress, the expression of Dicer and AGO genes were significantly upregulated. Functional analyses revealed that silencing specific genes, such as CmDcr-1, CmDcr-2, and CmAgo3, reduced larval survival under high-temperature and CpGV infection. Interestingly, the small RNA miR-34-5p was upregulated following short-term high-temperature exposure and was shown to suppress CpGV replication. Overexpression and silencing experiments confirmed its regulatory role, with CmDcr-1 identified as an upstream regulator of miR-34-5p. This study provides novel insights into the role of abiotic stress as an enhancer of immune defenses, highlighting the complex interactions between environmental stressors and insect immune responses. These findings offer potential strategies to mitigate environmental resistance and optimize biocontrol approaches in pest management.
Keywords
Cydia pomonella
•
environmental adaptability mechanism •
high temperature •
RNAi pathway •
antiviral immunity •
thermal stress adaptation •
global warming •
thermotolerance