Cereal host interactions with Russian wheat aphid: A review

Abstract

A lack of understanding the interaction between the Russian wheat aphid (RWA) and its host plant is a limitation in developing effective strategies for controlling the aphid. It is generally assumed that the interaction between aphid and plant is similar to that between plant and pathogen; that is, an elicitor from the insect is recognized by a protein from the host plant and a cascade of signal transduction events follows. However, evidence suggests that RWA feeding is eliciting both the SA- and JA/ethylene-dependent signaling pathways by mimicking aspects of both pathogen and herbivorous insect attacks. Results further suggest that phenotypic symptoms after RWA feeding are under regulation via two independent reactions, namely an immediate response (i.e., leaf rolling) and a downstream event (i.e., chlorosis). These defense responses enable a resistant host plant to defend itself and overcome the stress response, while their susceptible counterparts die. The processes involved in the onset of the defense response are discussed, and mechanisms enabling resistant plants to overcome the stress associated with the feeding process are presented as a working model for RWA-cereal host interaction. Knowledge of genes involved in wheat's defense responses against the RWA and an understanding of their functions may provide additional strategies for developing broad-spectrum resistance in plants.