Arthropod-associated plant effectors

Definition

Molecules secreted by herbivorous arthropods—primarily through saliva or regurgitant—that actively modulate host-plant physiology, immunity, or metabolism to the arthropod's advantage. These effectors may suppress jasmonic acid or salicylic acid defense signaling, alter nutrient allocation, or manipulate plant secondary metabolism, thereby facilitating feeding and colonization. The term parallels 'pathogen-associated effectors' in phytopathology but encompasses the broader range of arthropod secretions that function as molecular interfaces between insect or mite and plant.

Etymology

From Greek arthron (joint) + podos (foot); Latin effector (producer of a result), in the plant-pathology sense of a molecule that effects change in host cells.

Example

The salivary protein C002 from the green peach aphid Myzus persicae acts as an arthropod-associated plant effector: when the gene is silenced, aphids experience reduced phloem ingestion because the plant's sieve-tube occlusion response is no longer suppressed.

Synonyms

• herbivore effectors
• insect effectors

Related Terms

• effector-triggered immunity
• herbivore-associated molecular patterns
• salivary sheath
• stylet probing
• jasmonic acid pathway
• gall induction
• mite effectors

Usage Notes

Distinguish from damage-associated molecular patterns (DAMPs), which are plant-derived signals released by mechanical injury rather than arthropod-secreted molecules. The term is sometimes used interchangeably with 'herbivore effectors' in literature focused on insects, though 'arthropod-associated' explicitly includes mites and other chelicerate herbivores. Effector function is typically validated by heterologous expression in plants or by RNAi knockdown in the arthropod, followed by feeding-assay or transcriptomic readouts.