Indole-3-acetic acid production via the indole-3-pyruvate pathway by plant growth promoter Rhizobium tropici CIAT 899 is strongly inhibited by ammonium.

Autor: Imada EL; Laboratório de Genética de Microrganismos, Departamento de Biologia Geral, Universidade Estadual de Londrina, PR-445, Km 380, Campus Universitário, PO Box 6001, CP 86.051-970, Londrina, PR, Brazil. Electronic address: eddie.imada@gmail.com., Rolla Dos Santos AAP; Laboratório de Biotecnologia do Solo, Embrapa Soja, PO Box 231, CP 86.001-970, Londrina, PR, Brazil. Electronic address: amandaaapr@gmail.com., Oliveira ALM; Departamento de Bioquímica e Biotecnologia, Universidade Estadual de Londrina, PR-445, Km 380, Campus Universitário, PO Box 6001, CP 86.051-970, Londrina, PR, Brazil. Electronic address: almoliva@uel.br., Hungria M; Laboratório de Biotecnologia do Solo, Embrapa Soja, PO Box 231, CP 86.001-970, Londrina, PR, Brazil. Electronic address: mariangela.hungria@embrapa.br., Rodrigues EP; Laboratório de Genética de Microrganismos, Departamento de Biologia Geral, Universidade Estadual de Londrina, PR-445, Km 380, Campus Universitário, PO Box 6001, CP 86.051-970, Londrina, PR, Brazil. Electronic address: elisete@uel.br.
Jazyk: angličtina
Zdroj: Research in microbiology [Res Microbiol] 2017 Apr; Vol. 168 (3), pp. 283-292. Date of Electronic Publication: 2016 Nov 11.
DOI: 10.1016/j.resmic.2016.10.010
Abstrakt: Like many rhizobia, Rhizobium tropici produces indole-3-acetic acid (IAA), an important signal molecule required for root hair infection in rhizobia-legume symbioses. However, the IAA biosynthesis pathway and its regulation by R. tropici are still poorly understood. In this study, IAA synthesis and the effects of mineral N in IAA production by R. tropici CIAT 899 were verified by ultraperformance liquid chromatography-mass spectrometry (UPLC-MS). Furthermore, expression of genes related to IAA biosynthesis and metabolism were evaluated by RT-qPCR. Results indicated that IAA production by CIAT 899 was 12 times lower in the presence of [Formula: see text] . Moreover, it was found that indole-3-pyruvate (IPyA) is the major IAA biosynthesis intermediate. Genes y4wE, lao and iorA were identified by analysis of R. tropici genome in silico and were upregulated by tryptophan, indicating a possible role of these genes in IAA biosynthesis by CIAT 899. In conclusion, we show that IPyA is the major pathway for IAA biosynthesis in CIAT 899 and that its production is strongly inhibited by [Formula: see text] . Although present results arose from in vitro experiments, they provide new insight into the role of nitrogen in early events related to legume nodulation.
(Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.)
Databáze: MEDLINE
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