Table 1. Summary of data indicating the broad ligand specificity of products of the Arabidopsis GLR gene family.

GLR gene	Assay system	Agonist(s)	Non-agonist(s)	Reference
AtGLR1.4	Xenopus oocytes/ patch clamp	Met, Trp, Phe, Leu, Tyr, Asn, Thr	Other proteinogenic amino acids	[9]
AtGLR1.4	Knockout mutant/ cotyledons/ membrane potential measurements	Met	L-Glu	[9]
AtGLR3.3	Knockout mutant/roots/ membrane potential measurements	GSH, L-Ala, Asn, Cys, L-Glu, Gly, L-Ser	Other proteinogenic amino acids, D-Glu, D-Ser, D-Ala, GABA, NMDA	[6]
AtGLR3.3/AtGLR3.4	Knockout mutants/ hypocotyls/ membrane potential measurements	L-Glu, L-Ala, Asn, Cys, Gly, L-Ser	Other proteinogenic amino acids	[7]
AtGLR3.4	HEK293 cells/ patch clamp	Asn, L-Ser, Gly	L-Glu, L-Ala, Cys, Phe	[10]

GABA, gamma-aminobutyric acid; GLR, glutamate-like receptor; GSH, glutathione (reduced); NMDA, N-methyl D-aspartate.