Kidney bean defense response induced by western flower thrips, Frankliniella occidentalis feeding and the attenuated effect of calcium ion chelator

Calcium ion (Ca2+) plays an important role in plant-insect interactions. Ethylene glycol-bis(2-aminoethylether)-N, N, N ', N '-tetraacetic acid (EGTA), a Ca2+ chelator, can abolish Ca2+ in plant cells following the disruption of plant physiological processes and the plant's defense responses against biotic stress. To clarify whether EGTA pretreatment plants have an inhibitory effect on insect feeding induction, we determined variations in kidney bean (Phaseolus vulgaris (L., Fabales: Fabaceae)) plant defense responses induced by western flower thrips (WFT) (Frankliniella occidentalis (Pergande)) feeding and the reversal effects of EGTA. The results showed that WFT feeding can significantly activate the expression level of the jasmonic acid (JA) pathway marker genes allene oxide synthase (AOS) and lipoxygenase (LOX) and salicylic acid (SA) pathway marker genes phenylalanine ammonia lyase (PAL) and beta-1,3 glucanase (PR-2), and induce the biosynthesis of JA and SA. However, pre-treatment with EGTA showed varying degrees of reversal effects on JA and SA content and related gene expression levels with WFT feeding. These results indicate that WFT feeding can induce the biosynthesis of JA and SA and the expression of related genes to enhance the defense responses in kidney beans plants, while pretreatment with EGTA can attenuate the WFT-induced defense responses.

Automated summary

Calcium ion (Ca2+) is important in plant-insect interactions. Ethylene glycol-bis(2-aminoethylether)-N, N, N ', N '-tetraacetic acid (EGTA) can abolish Ca2+ in plant cells, disrupting plant physiological processes and defense responses. This study investigates the effect of EGTA pretreatment on insect feeding induction and clarifies its reversal effects. The results show that Western flower thrips feeding activates the jasmonic acid (JA) and salicylic acid (SA) pathways in kidney beans, while EGTA pretreatment attenuates the induced defense responses.