TY - JOUR
T1 - Indolepyruvate pathway for indole-3-acetic acid biosynthesis in Bradyrhizobium elkanii
AU - Minamisawa, Kiwamu
AU - Ogawa, Ken Ichiro
AU - Fukuhara, Hideyuki
AU - Koga, Jinichiro
N1 - Funding Information:
This work was supported in part by a grant from the Ministry of Education, Science and Culture of Japan (no. 06660073). The authors gratefully acknowledge Drs. Y. Kogure and D. Miyagi (Takara Shuzo Co., Ltd.) for LC-MS-MS analysis, Drs. T. Asami and M. Kubota (Ibaraki University) for their continuing interest, and Mr. R. Rakwal (Ibaraki University) for his manuscript revision.
PY - 1996/6
Y1 - 1996/6
N2 - 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 Mg2+ 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.
AB - 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 Mg2+ 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.
KW - Bradyrhizobium elkanii
KW - Indole-3- acetaldehyde
KW - Indole-3-acetic acid (IAA)
KW - Indolepyruvate decarboxylase
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U2 - 10.1093/oxfordjournals.pcp.a028966
DO - 10.1093/oxfordjournals.pcp.a028966
M3 - Article
AN - SCOPUS:0029950334
SN - 0032-0781
VL - 37
SP - 449
EP - 453
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
IS - 4
ER -