Ricca’s factors as mobile proteinaceous effectors of electrical signaling

• DOI: 10.1016/j.cell.2023.02.006
• Publication Date: 2023-03-03T15:30:54Z
• Authors: Yong-Qiang Gao; Pedro Jimenez-San...; Satyam Tiwari; Stéphanie Stolz; Jing Wang; Gaëtan Glauser; Julia Santiago; Edward E. Farmer
• Keywords: Insecta; Glycoside Hydrolases; Arabidopsis Proteins; action-potentials; myrosinase; Glucosinolates; Arabidopsis; transporters; Article; defense; Animals; Animals; Glycoside Hydrolases/metabolism; Glucosinolates/metabolism; Arabidopsis/metabolism; Arabidopsis Proteins/metabolism; Insecta; glucosinolate; herbivore; insect; jasmonate; membrane potential; myrosinase; slow wave potential; wound; xylem; arabidopsis leaves; metabolites

Leaf-feeding insects trigger high-amplitude, defense-inducing electrical signals called slow wave potentials (SWPs). These are thought to be triggered by the long-distance transport of low molecular mass elicitors termed Ricca's factors. We sought mediators leaf-to-leaf signaling in Arabidopsis thaliana and identified them as β-THIOGLUCOSIDE GLUCOHYDROLASE 1 2 (TGG1 TGG2). SWP propagation from insect feeding sites was strongly attenuated tgg1 tgg2 mutants wound-response cytosolic Ca2+ increases were reduced these plants. Recombinant TGG1 fed into xylem elicited wild-type-like membrane depolarization transients. Moreover, TGGs catalyze deglucosidation glucosinolates. Metabolite profiling revealed rapid wound-induced breakdown aliphatic glucosinolates primary veins. Using vivo chemical trapping, we found evidence for roles short-lived aglycone intermediates generated glucosinolate hydrolysis depolarization. Our findings reveal a mechanism whereby organ-to-organ protein plays major role signaling.