Riptortus pedestris effector induces autophagy through interaction with ATG8, enhancing insect feeding.

Area of Science:

• Plant-insect interactions
• Molecular plant-pathology
• Cellular biology

Background:

• Autophagy is a conserved eukaryotic degradation pathway.
• Plant pathogens manipulate host autophagy for infection.
• Herbivore modulation of host autophagy remains largely unknown.

Purpose of the Study:

• To investigate if herbivores, specifically Riptortus pedestris, modulate host plant autophagy to facilitate feeding.
• To identify and characterize the role of salivary protein RP246 in this process.

Main Methods:

• Gene silencing of RP246 in soybean plants.
• Assessing insect feeding behavior, honeydew excretion, and body weight.
• Investigating the interaction between RP246 and autophagy proteins (ATG8) using molecular techniques.
• Utilizing autophagy inhibitors (3-methyladenine) to evaluate the role of autophagy in feeding.

Main Results:

• RP246 protein is delivered into soybean plants during R. pedestris infestation.
• Silencing RP246 significantly reduced insect feeding, honeydew excretion, and body weight.
• RP246 interacts with ATG8 proteins via its AIM2 motif, promoting autophagosome formation.
• Autophagy inhibition significantly reduced R. pedestris feeding on soybean.

Conclusions:

• RP246 acts as a virulent effector, activating plant autophagy to enhance R. pedestris feeding.
• This study reveals a novel mechanism where herbivores hijack plant autophagy machinery for infestation.