Ricca's factors as mobile proteinaceous effectors of electrical signaling

Cell. 2023 Mar 30;186(7):1337-1351.e20. doi: 10.1016/j.cell.2023.02.006. Epub 2023 Mar 3.


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

Keywords: glucosinolate; herbivore; insect; jasmonate; membrane potential; myrosinase; slow wave potential; wound; xylem.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arabidopsis Proteins* / metabolism
  • Arabidopsis* / metabolism
  • Glucosinolates / metabolism
  • Glycoside Hydrolases / metabolism
  • Insecta


  • Glycoside Hydrolases
  • Glucosinolates
  • Arabidopsis Proteins
  • TGG1 protein, Arabidopsis
  • TGG2 protein, Arabidopsis