Exogenous Gamma-aminobutyric Acid Coordinates Active Oxygen and Amino Acid Homeostasis to Enhance Heat Tolerance in Wheat Seedlings

Heat stress has detrimental impacts on wheat growth and yield formation. Conferring heat tolerance through applying plant growth regulators is a feasible strategy to reduce loss. Gamma aminobutyric acid (GABA) is a four-carbon non-proteinogenic amino acid existing in organisms and accumulates in response to stress. In this study, spring wheat Liaochun17 and winter wheat Jingdu 40 were used to investigate the function of exogenous GABA on the heat tolerance of wheat seedlings. Data displayed that GABA treatment not only reduced the production of reactive active oxygen (ROS), but also improved the scavenging capacity of diphenyl picryl phenyl hydrazine active oxygen under heat stress, thus alleviating the accumulation of malondialdehyde and the damage of cell membrane. In addition, analysis of protein and amino acids revealed that GABA effectively promoted the accumulation of soluble protein and coordinated amino acid homeostasis. Summarily, our current findings revealed that GABA strengthened the resistance of wheat seedling to heat stress by maintaining the metabolism balance of ROS and amino acids.