title: New roles for the GLUTAMATE RECEPTOR-LIKE 3.3, 3.5, and 3.6 genes as on/off switches of wound-induced systemic electrical signals.
abstract: Wounding induces systemic potentials in Arabidopsis thaliana that can be abolished by concomitant suppression of the GLUTAMATE RECEPTOR-LIKE GLR3.3 and GLR3.6 genes. However, the roles of specific GLR channels to these potentials remain unclear. Here I applied the Electrical Penetration Graph (EPG) to study the contribution of three GLR channels to wound-induced, systemically propagated electrical potentials in Arabidopsis thaliana. In contrast to recordings made with conventional rigs for whole-plant electrophysiology, the EPG allows for the unambiguous distinction of the phloem-propagated action potential (AP) from the electrical activity outside of the phloem. The data reported here suggest that: (a) the transmission of wound-induced, phloem-propagated AP to neighbor leaves, requires expression of GLR3.3 or GLR3.6, whereas GLR3.5 prevents its transmission to non-neighbor leaves; (b) the generation of wound-induced electrical signals outside the phloem network depends on GLR3.6 expression; and (c) wound-induced systemic potentials initiated in the shoot are transmitted to the root in the adult plant, which suggests a role for these electrical signals in coordinating the plant defenses in the shoot and in the root. Here, I propose a model for wound-induced systemic electrical signals at the molecular, cellular and anatomical level. In this model, GLR3.3 and GLR3.6 function as on switches for the propagation of wound-induced potentials beyond the wounded leaf, while GLR3.5 functions as an off switch that prevents the propagation of wound-induced electrical potentials to distal, non-neighbor leaves.
authors.affiliation: a Ronin Institute , Montclair NJ , USA.
authors.forename: Vicenta
authors.initials: V
authors.lastname: Salvador-Recatalà
mesh_terms: D000200:Action Potentials; D017360:Arabidopsis / Q000235:genetics* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D004566:Electrodes; D055724:Electrophysiological Phenomena; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D052585:Phloem / Q000502:physiology; D018515:Plant Leaves / Q000502:physiology; D017470:Receptors, Glutamate / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C516468:GLR3.3 protein, Arabidopsis; D017470:Receptors, Glutamate; C000601589:glutamate receptor 3.5, Arabidopsis
keywords: Action potential; aphid; arabidopsis; electrical penetration graph; glutamate receptor-like channel; phloem; root; wounding