Sex-Specific Thermal Adaptation in Riptortus pedestris: Integrating Logistic Thresholds and Transcriptomic Responses

Area of Science:

• Entomology
• Molecular Biology
• Climate Change Adaptation

Background:

• The bean bug (Riptortus pedestris) is a significant Asian soybean pest facing climate change impacts.
• Existing data indicate higher heat tolerance in female bean bugs compared to males, suggesting sex-specific physiological responses.

Purpose of the Study:

• To investigate the molecular mechanisms underlying sex-specific thermal tolerance in Riptortus pedestris.
• To identify heat shock protein (HSP) gene expression patterns under varying temperature conditions.

Main Methods:

• Transcriptome sequencing of male and female bean bugs exposed to control (24°C), sublethal (40°C), and lethal (44°C) temperatures.
• Identification and phylogenetic analysis of heat shock protein (HSP) genes and heat shock factors (HSFs).

Main Results:

• A total of 71 HSP genes were identified across six subfamilies, showing both constitutive expression and strong induction at high temperatures.
• Sexually dimorphic expression of HSPs was observed: females upregulated reproductive-protective HSPs, while males induced specific HSPs potentially for signaling.
• Phylogenetic analysis confirmed the conservation of these HSPs within Hemiptera.

Conclusions:

• Heat shock proteins play a dual role in basal proteostasis and thermal stress defense in Riptortus pedestris.
• Sex-specific HSP induction highlights distinct molecular strategies for thermal adaptation in male and female bean bugs.
• Identified HSPs represent potential targets for novel pest management strategies, including RNAi and HSP inhibitors.