Is the major alanine aminotransferase in roots that catalyzes the conversion of alanine to pyruvate (PubMed:17319845). Involved in the rapid conversion of alanine to pyruvate during recovery from low-oxygen stress (PubMed:17319845). 2-oxoglutarate + L-alanine = L-glutamate + pyruvate Photosynthesis; C4 acid pathway. Amino-acid degradation; L-alanine degradation via transaminase pathway; pyruvate from L-alanine: step 1/1. Homodimer. Mostly expressed in roots and shoots, mostly in vascular tissues, and, to a lower extent, in flowers and leaves. Rapidly induced upon low-oxygen stress in roots and shoots. The N-terminus is blocked. Strong overall decrease of alanine aminotransferase activity, especially in roots. Belongs to the class-I pyridoxal-phosphate-dependent aminotransferase family. Alanine aminotransferase subfamily. Truncated N-terminus.