Abstract: 【Aim】 This study aims to investigate the molecular mechanisms of systemic defense of kidney bean (Phaseolus vulgaris) plants fed by the western flower thrips, Frankliniella occidentalis， which is a kind of insect with rasping-sucking mouthparts. 【Methods】 Real-time quantitative PCR was used to detect the expression levels of lipoxygenase gene (LOX)， phenylalanine ammonialyase gene (PAL) and β-1， 3-glucanase gene (PR-2)， which are involved in jasmonic acid and salicylic acid signal transduction pathways， in leaves at different parts (upper， middle and lower parts) of kidney bean plant at different time (24， 48， 72 and 96 h) after feeding steadily by western flower thrips for 2 h. 【Results】 The expression levels of LOX， PAL and PR-2 in the damaged middle leaves， the healthy upper and lower leaves of kidney bean plant were all significantly induced by western flower thrips， but changed more rapidly in the damaged middle leaves. The expression modes of genes changed with time. The relative expression level of LOX in the damaged middle leaves was significantly higher than that of the control (non-inoculated leaves)， and increased with the time extension， which was 209.54-fold as high as that of the control at 96 h. The expression level of LOX increased first and then decreased and finally rose again in the healthy upper and lower leaves. The expression level of PAL reached the maximum in both damaged middle leaves and healthy upper leaves at 48 h after infestation of western flower thrips， which were 52.70- and 41.20-fold as high as that of the control， respectively. However， its expression level reached the peak at 72 h in the healthy lower leaves， which was 47.06-fold as high as that of the control. The expression level of PR-2 reached the maximum at 48 h after infestation of western flower thrips in the healthy upper leaves， at 96 h in both damaged middle leaves and healthy lower leaves.  PR-2 was barely expressed in the healthy lower leaves at 24 h after infestation of western flower thrips. 【Conclusion】 Western flower thrip infestation could induce the expression of defensive genes LOX， PAL and PR-2 involved in jasmonic acid and salicylic acid signal transduction pathways and result in systemic resistance in leaves at different parts of kidney bean.

Key words: Frankliniella occidentalis, systemic defense, jasmonic acid pathway, salicylic acid pathway, defense genes