Indolepyruvate Pathway for Indole-3-Acetic Acid Biosynthesis in Bradyrhizobium elkanii

概要

論文の詳細を見る
Indole-3-acetaldehyde (IAAld) was detected in the culture supernatant of Bradyrhizobium elkanii. Deuterium-labelled L-tryptophan (Trp) was incorporated into IAAld and indole-3-acetic acid (IAA), suggesting that B. elkanii produces IAA via IAAld from Trp. In B. elkanii cell suspension, indole-3-pyruvic acid (IPyA) was converted to IAAld, and exogenously added IAAld was rapidly converted to IAA. Furthermore, the activity of indolepyruvate decarboxylase (IPDC), which catalyzes the decarboxylation of IPyA to produce IAAld and is a key enzyme for IPyA pathway, was detected in B. elkanii cell-free extract. The IPDC activity depended on Mg^<2+> and thiamine pyrophosphate, cofactors of decarboxylation. This mounting evidence strongly suggests that IAA synthesis occurs via IPyA pathway (Trp→IpyA→IAAld→IAA) in B. elkanii.
日本植物生理学会の論文