The Glutamate Receptor-Like Protein GLR3.7 Interacts With 14-3-3ω and Participates in Salt Stress Response in Arabidopsis thaliana

Abstract

Ionotropic glutamate receptors (iGluRs) are ligand-gated cation channels that mediate fast excitatory neurotransmission in the mammalian central nervous system. In the model plant Arabidopsis thaliana, a family of 20 glutamate receptor-like proteins (GLRs) shares similarities to animal iGluRs in sequence and predicted secondary structure. However, the function of GLRs in plants is little known. In the present study, a serine site (Ser-860) of AtGLR3.7 phosphorylated by a calcium-dependent protein kinase (CDPK) was identified and confirmed by an in vitro kinase assay. Using a bimolecular fluorescence complementation and quartz crystal microbalance analyses, the physical interaction between AtGLR3.7 and the 14-3-3ω protein was confirmed. The mutation of Ser-860 to alanine abolished this interaction, indicating that Ser-860 is the 14-3-3ω binding site of AtGLR3.7. Compared with wild type, seed germination of the glr3.7-2 mutant was more sensitive to salt stress. However, the primary root growth of GLR3.7-S860A overexpression lines was less sensitive to salt stress than that of the wild-type line. In addition, the increase of cytosolic calcium ion concentration by salt stress was significantly lower in the glr3.7-2 mutant line than in the wild-type line. Moreover, association of 14-3-3 proteins to microsomal fractions was less in GLR3.7-S860A overexpression lines than in GLR3.7 overexpression line under 150 mM NaCl salt stress condition. Overall, our results indicated that GLR3.7 is involved in salt stress response in A. thaliana by affecting calcium signaling.

Signaling Role of Glutamate in Plants

“…Similarly, in Arabidopsis, besides AtGLR3.4, AtGLR3.7 also is involved in the regulation of seed germination under NaCl stress (Cheng et al, 2016). Recently, Wang et al (2019) also found that AtGLR3.7 interaction with 14-3-3 proteins participated in salt stress response in Arabidopsis by affecting calcium signaling pathways. The data imply that Ca 2+ influx mediated by AtGLRs (mainly AtGLR3.4 and AtGLR3.7) regulates seed germination under salt stress.…”

Genome- and Transcriptome-Wide Identification of C3Hs in Common Bean (Phaseolus vulgaris L.) and Structural and Expression-Based Analyses of Their Functions During the Sprout Stage Under Salt-Stress Conditions

“…The differences in the expression levels of PvC3H s in R were more significant than those in N, suggesting that PvC3H s participate in the enrichment of the pathway and traits. The pathways for inhibitor activities, binding, and ion channel inhibitor, which were enriched in the GO analysis have been reported in previous studies on salt tolerance in plants, such as A. thaliana ( Li et al, 2014 ; Kim et al, 2019 ; Wang et al, 2019 ), rice ( Mansuri et al, 2019 ), cotton ( Mu et al, 2019 ), poplar ( Gaudet et al, 2011 ), and alfalfa ( Lai et al, 2014 ). The spliceosome pathway has anti-stress effects in A. thaliana ( Feng et al, 2015 ; Narasimha et al, 2018 ), O. sativa ( Ashwini et al, 2018 ), and Cannabis sativa ( Liu et al, 2016 ).…”

Changes in the Flower and Leaf Proteome of Common Buckwheat (Fagopyrum esculentum Moench) under High Temperature

“…This protein is a component of the glutamate receptor-like channel (GLR). GLRs play a role in calcium signaling during the response to environmental stresses [ 46 ]. Two proteins up-regulated by heat stress in wilted flowers were involved in carbohydrate metabolism: cytosolic phosphoglycerate kinase (PGK) and chloroplastic fructose-bisphosphate aldolase (FBA).…”