High impact information on AAO1

• The last step of ABA biosynthesis involves oxidation of abscisic aldehyde, and aldehyde oxidase (EC ) is thought to catalyze this reaction [1].
• We have reported the occurrence of three isoforms of aldehyde oxidase, AOalpha, AObeta and AOgamma, in Arabidopsis thaliana seedlings, but none oxidized abscisic aldehyde [2].
• Higher activity of an aldehyde oxidase in the auxin-overproducing superroot1 mutant of Arabidopsis thaliana [3].
• One of them (AO1) had a higher substrate preference for indole-3-aldehyde [3].
• However, considering the enzymatic characters of AAO1 and AAO4, their involvement in ABA biosynthesis in wild-type seeds may be negligible [4].

Biological context of AAO1

• The two corresponding full-length cDNAs (atAO-1 and atAO-2; 4,484 and 4,228 bp long, respectively) were cloned by screening the Arabidopsis cDNA library followed by rapid amplification of cDNA end-PCR [5].
• From the amino acid sequences and molecular masses of the derivative peptides, it was revealed that the 150- and 145-kDa polypeptides were the products of atAO-1 and atAO-2, respectively [6].

Associations of AAO1 with chemical compounds

• An aldehyde oxidase is the last step in abscisic acid (ABA) biosynthesis [7].
• Three different cDNA clones encoding putative aldehyde oxidases (AtAO1, 2, 3) were isolated [7].

Other interactions of AAO1

• We have concluded that AAO3 is the AAO that plays a major role in ABA biosynthesis in Arabidopsis seeds as well as in leaves [4].

References