The glutamate receptors AtGLR1.2 and AtGLR1.3 increase cold tolerance by regulating jasmonate signaling in Arabidopsis thaliana

Abstract

Plant glutamate-like receptors (GLRs), which are homologs of mammalian ionotropic glutamate receptors (iGluRs), are thought to be involved in plant growth, development, and environmental stress responses. In this study, we demonstrated that two members of Arabidopsis glutamate-like receptors, AtGLR1.2 and AtGLR1.3, play positive roles in the plant response to cold stress. Genetic and biochemical experiments revealed that exogenous jasmonate could attenuate the cold sensitivity of glr1.2 and glr1.3 mutants, and the overexpression of GLR1.2 or GLR1.3 enhanced cold tolerance by increasing endogenous jasmonate levels under cold stress. In addition, the expression of genes in the CBF/DREB1 signaling pathway was decreased in the glr1.2 and glr1.3 mutants, but was promoted in GLR1.2-OE and GLR1.3-OE transgenic plants compared with the wild-type during cold treatment. Further investigation revealed that AtGLR1.2 and AtGLR1.3 independently drove similar functions without directly interacting. Together, our findings suggest that AtGLR1.2 and 1.3 positively enhance cold tolerance in Arabidopsis by activating endogenous jasmonate accumulation and subsequently promoting the downstream CBF/DREB1 cold response pathway during cold stress.