Threonine aldolase involved in threonine degradation to glycine. May play a role in the removal of L-allo-threonine. L-threonine = acetaldehyde + glycine L-allo-threonine = acetaldehyde + glycine Amino-acid degradation; L-threonine degradation via aldolase pathway; acetaldehyde and glycine from L-threonine: step 1/1. A number of isoforms are produced. According to EST sequences. Expressed in roots, leaf vasculature and flowers. Lethal albino phenotype when homozygous. Belongs to the threonine aldolase family.