Expression patterns and antifungal function study of KaSPI in Mythimna separata.

Area of Science:

• Insect molecular biology
• Biochemistry
• Pest management

Background:

• Kazal-type serine protease inhibitors (KaSPI) are crucial for insect physiology.
• Understanding KaSPI function in Mythimna separata is vital for pest control.

Purpose of the Study:

• To investigate the role of MsKaSPI in Mythimna separata development and immune response.
• To analyze the impact of MsKaSPI on protease activity and fungal infection.

Main Methods:

• Transcriptome analysis and gene cloning of MsKaSPI.
• Spatial and temporal gene expression analysis.
• RNA interference (RNAi) to silence MsKaSPI expression.
• Enzyme activity assays and mortality assessment after Beauveria bassiana infection.

Main Results:

• MsKaSPI expression is regulated by development, 20-hydroxyecdysone, and Beauveria bassiana infection.
• MsKaSPI inhibits serine protease, trypsin, and chymotrypsin activity.
• MsKaSPI silencing leads to prolonged development, reduced weight, decreased fecundity, and increased mortality upon fungal infection.

Conclusions:

• MsKaSPI plays a dual role in regulating insect growth and immunity.
• MsKaSPI influences M. separata development by modulating protease activity.
• MsKaSPI is involved in the insect's defense against pathogenic fungi.