School of Biotechnology, Gautam Buddha University, Greater Noida. India.
GABA play dual role in plants. In response to stress, H+ and Ca2+ concentrations have been changed. It activates glutamate decarboxylase (GAD). GAD catalyzed the decarboxylation of glutamate to GABA or inhibition of GABA transaminase (GABA-T). In plant GADs contains calmodulin-binding domains (CaM-BDs), having 22 to 25 additional amino acids at the C-terminal end, helps in CaM binding in the presence of Ca2+. TaALMT1 gene (formerly named ALMT1) in plants regulated aluminum-activated malate transporter (ALMT) channel of GABA under stress condition (similar to mammalian anionic channels-GABAA receptors). It alters the electrical potential across membranes. ALMTs under lie a variety of processes, including metal toxicity avoidance, mineral nutrition, ion homeostasis, turgor regulation, fruit quality, and guard cell function.
Key words: Gamma-aminobutyric acid (GABA), glutamate decarboxylase (GAD), aluminum-activated malate transporter (ALMT), stress