Insect feeding retards plant growth and decreases crop productivity. Plants respond to insect feeding at the molecular, cellular and physiological levels. The roles of the plant hormones jasmonic acid (JA), ethylene (ET) and salicylic acid (SA) in plant responses to insect feeding have been studied. However, these studies are focused on the plant responses to feeding by well-studied caterpillar type insects or aphid pests. In contrast, we have focused on a minute insect pest, the western flower thrips (Frankliniella occidentalis). Analyses of the responses of hormone-related mutants of Arabidopsis (i.e., JA-insensitive mutant coi1-1, ET-insensitive mutants ein2-1 and ein3-1, and SA-deficient mutant eds16-1) and transcriptome-based comparative analyses indicate the central role of JA in plant responses to thrips feeding. Our work clearly shows that JA signaling, but not JA/ET signaling, is involved in plant tolerance to thrips feeding. We intend to examine the utility and suitability of the Arabidopsis-thrips system in studies of plant responses to insect feeding.
Keywords: Arabidopsis thaliana; Frankliniella occidentalis; ethylene; insect feeding; jasmonate; western flower thrips.