The Glutamate Receptor Plays a Role in Defense against Botrytis cinerea through Electrical Signaling in Tomato

Abstract

Plant glutamate-like receptor genes (GLRs) are homologous to mammalian ionotropic glutamate receptors genes (iGluRs). Although GLRs have been implicated in plant defenses to biotic stress, the relationship between GLR-mediated plant immunity against fungal pathogens and electrical signals remains poorly understood. Here, we found that pretreatment with a GLR inhibitor, 6,7-dinitriquinoxaline-2,3-dione (DNQX), increased the susceptibility of tomato plants to the necrotrophic fungal pathogen Botrytis cinerea. Assessment of the glr3.3, glr3.5 and glr3.3/glr3.5 double-mutants upon B. cinerea infection showed that tomato GLR3.3 and GLR3.5 are essential for plant immunity against B. cinerea, wherein GLR3.3 plays the main role. Analysis of the membrane potential changes induced by glutamate (Glu) or glycine (Gly) revealed that amplitude was significantly reduced by knocking out GLR3.3 in tomato. While treatment with Glu or Gly significantly increased immunity against B. cinerea in wild-type plants, this effect was significantly attenuated in glr3.3 mutants. Thus, our data demonstrate that GLR3.3- and GLR3.5-mediated plant immunity against B. cinerea is associated with electrical signals in tomato plants.

Genetic loci associated with Fusarium wilt resistance in tomato (Solanum lycopersicum L.) discovered by genome‐wide association study

“…Moreover, the glutamate receptor‐like 2.5 ( Solyc06g063210, SLGLR2_5 ) gene was responsible for FW resistance in tomatoes. Similar to the report of Feng et al (2021), it stated that the AtGLR3.3 gene in Arabidopsis thaliana enhanced the resistance to Pseudomanas syringae pv. tomato DC3000 and Hyaloperonospora arabidopsidis .…”

Herbivore‐induced Ca2+ signals trigger a jasmonate burst by activating ERF16‐mediated expression in tomato

“…Herbivory‐induced electrical signals, Ca 2+ signals and JA biosynthesis were all attenuated in glr3.3/3.5 mutants (Figs 1a–d, S1). These results are in agreement with our early findings showing that GLR3.3 and GLR3.5 play crucial roles in JA‐mediated tomato defense against nematodes, and also in immunity against Botrytis cinerea and cold responses (Li et al ., 2019; G. Wang et al ., 2019; Feng et al ., 2021). Therefore, GLR3.3 and GLR3.5 participate in a wide range of JA‐mediated defense strategies against biotic and abiotic stresses in tomato.…”

Wound-Induced Systemic Responses and Their Coordination by Electrical Signals

“…Membrane depolarization promotes full activity of the GLRs in distal tissues in response to wounding. Synergistic propagation of Ca 2+ waves and SWPs efficiently induces systemic wound responses for plant survival ( Fromm and Lautner, 2007 ; Feng et al, 2021 ).…”