Anoxic Accumulation of Amino Acids in Rice Coleoptiles

Effects of anoxia on the levels of free-amino acids were investigated in the coleoptiles of rice (Oryza sativa L.) seedlings. Rice coleoptiles are able to grow in extremely low oxygen condition. Anoxic stress increased the concentration of total free-amino acids in the coleoptiles. After 48 h, alanine (Ala) and γ-aminobutyric acid (Gaba) in anoxic coleoptiles were 2.7- and 10.6-fold greater than those in non-stressed coleoptiles, respectively. Ala and Gaba represented 40% of the amino acid pool in anoxic coleoptiles. These anoxic-induced amino acids may allow rice coleoptiles to make biochemical adjustment that enable them to cope with the stress condition.