Hormone response of Lycium barbarum to gall mite Aceria pallida and effects of exogenous salicylic acid on the infestation and development of gall mite

To investigate the hormone responses of Lycium barbarum to Aceria pallida infestation and the effects of exogenous salicylic acid on the infestation and development of gall mite, four phytohormones (salicylic acid (SA), jasmonic acid (JA), Auxin, and abscisic acid (ABA)) of L. barbarum leaves infested with A. pallida were determined by LC-MS/MS. Moreover, the effects of exogenous SA on the growth of gall and mite population were investigated. The results showed that contents of SA and JA in leaves infested with A. pallida were significantly higher (4.0 and 13.0 folds, respectively) than that in control, but that of Auxin and ABA did not change. The growth of gall was inhibited significantly by exogenous SA, with the inhibition increasing with the prolongation of treatment time. Meanwhile, mite population in galls treated with SA was significantly lower than that in control. Our results suggested that A. pallida could induce SA and JA resistance of L. barbarum, and that the exogenous SA could inhibit the growth of gall and mite population. Exogenous SA could be potentially used in A. pallida prevention.