Screening and Identification of Salivary Proteins in Frankliniella occidentalis Triggered by Jasmonic Acid-Mediated Defense of Kidney Bean Plants

Frankliniella occidentalis has caused serious damage to horticultural plants and vegetables. However, the role of its salivary proteins remains unclear. Transcriptome sequencing identified 510 differentially expressed genes in F. occidentalis fed on jasmonic acid (JA)-treated versus water-treated kidney bean plants, primarily involved in carbohydrate metabolism and secondary metabolite pathways. The genes Fomyr6, Foαglu1, Fosp3, and Fotryp1 were highly expressed in the salivary glands and during voracious feeding stages. Silencing these genes resulted in significant reductions in survival, fecundity, and feeding capacity. Feeding by F. occidentalis enhanced defensive enzyme activities of plants, especially when Fomyr6 and Foαglu1 were silenced, and promoted the production of secondary substances such as lignin, tannins, and flavonoids. Additionally, both JA and salicylic acid levels were activated. Furthermore, nearly all these responses were more pronounced in JA-treated kidney bean plants. These findings lay the groundwork for further research into the functions and molecular mechanisms of salivary proteins in F. occidentalis.