Possible amino acid signaling in higher plants

Abstract

Amino acids, an essential component that constitutes proteins in vivo, are also known to play as a signaling molecule that regulates various physiological functions in the living organism.　Ionotropic glutamate receptors （iGluRs） are ligand-gated channels that specifically transmit amino acid signals in the central nervous system.　Surprisingly, homologs of iGluRs, known as glutamate receptor-like channels （GLRs）, were also found in higher plant genomes.　However, their physiological roles or molecular functions are still obscure.　Here, I review the latest research of plant GLRs and discuss their roles in plant signaling including environmental adaptation and cell-to-cell communications.