Three stress-responsive peptides modulate immunity and development in the fall armyworm Spodoptera frugiperda

Area of Science:

• Insect molecular biology
• Pest management
• Immune signaling

Background:

• Insect stress-responsive peptides (SRPs) are crucial for development and immunity.
• Their specific roles in the invasive pest Spodoptera frugiperda are not well understood.

Purpose of the Study:

• To identify and characterize SRP genes in Spodoptera frugiperda.
• To investigate the function of these SRPs in development, immunity, and stress responses.
• To explore their potential as targets for pest management.

Main Methods:

• Gene identification and characterization (RT-qPCR).
• Functional assays including peptide injection and RNA interference (RNAi).
• Transcriptomic profiling and signaling pathway analysis (NF-κB, JAK-STAT, IP3-mediated Ca2+ release).

Main Results:

• Three SRP genes (SfSRP1-3) were identified and found to be induced by pathogens and environmental stressors.
• Peptide injection affected larval growth, development, and cell behavior.
• SfSRP3 significantly boosted immune gene expression and its RNAi reduced larval survival after infection.
• SfSRP3 signaling involves IP3-mediated Ca2+ release, upregulating immune effectors like SfIML-1.

Conclusions:

• SfSRP1-3 act as integrators of developmental and immune signaling in Spodoptera frugiperda.
• These peptides represent promising novel targets for developing effective pest management strategies against this invasive species.