Armet is an effector protein mediating aphid-plant interactions

Area of Science:

• Plant-insect interactions
• Molecular biology
• Entomology

Background:

• Aphid saliva contains proteins that help insects feed and suppress plant defenses.
• Armet is a known bifunctional protein in mammals, but its role in insects was unknown.

Purpose of the Study:

• To investigate the role of Armet in the pea aphid (Acyrthosiphon pisum).
• To determine if Armet functions as an effector protein in aphid saliva and influences aphid-plant interactions.

Main Methods:

• Detected Armet in aphid saliva and plant phloem sap using biochemical assays.
• Quantified Armet transcript levels in salivary glands under different feeding conditions.
• Used RNA interference (RNAi) to reduce Armet transcript levels and assessed aphid feeding behavior with electrical penetration graph (EPG) technology.
• Inoculated tobacco leaves with pea aphid Armet protein and analyzed transcriptional changes.

Main Results:

• Armet was found in pea aphid saliva and fava bean phloem sap.
• Armet transcript levels increased in salivary glands when aphids fed on plants compared to an artificial diet.
• RNAi-mediated knockdown of Armet impaired aphid feeding behavior and reduced lifespan.
• Inoculation with Armet induced pathogen-responsive genes in tobacco plants.

Conclusions:

• Armet functions as an effector protein in pea aphid saliva.
• Armet plays a crucial role in mediating aphid feeding behavior and plant interactions.
• Armet contributes to aphid survival and potentially influences plant defense responses.