Alternative mechanism for the evaluation of indole-3-acetic acid (IAA) production by Azospirillum brasilense strains and its effects on the germination and growth of maize seedling...

Authors
Masciarelli, Oscar Alberto; Urbani, Lucia; Reinoso, Herminda Elmira; Luna, Virginia
Publication Year
2013
Language
English
Format
article
Status
Published version
Description
We evaluated the production of indole-3-acetic acid (IAA) by Azospirillum brasilense strains in vitro (cell culture supernatants) and in vivo (stems and roots of maize seedlings) to clarify the role of this phytohormone as a signaling and effector molecule in the symbiotic interaction between maize and A. brasilense. The three strains all showed IAA production when cultured in NFb medium supplemented with 100 μg/ml L-tryptophan. The level of IAA production was 41.5 μg/ml for Yu62, 12.9 μg/ml for Az39, and 0.15 μg/ml for ipdC-. The release of IAA into culture medium by the bacteria appeared to be the main activator of the early growth promotion observed in the inoculated maize seedlings. The application of supernatants with different IAA contents caused significant differences in the seedling growth. This observation provides the basis for novel technological tools for effective quality control procedures on inoculants. The approach described can be incorporated into different inoculation methods, including line sowing, downspout, and foliar techniques, and increase the sustainability of symbiotic plant-bacteria systems.
Fil: Masciarelli, Oscar Alberto. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Fil: Urbani, Lucia. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; Argentina
Fil: Reinoso, Herminda Elmira. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; Argentina
Fil: Luna, Virginia. Universidad Nacional de Rio Cuarto. Facultad de Ciencias Exactas Fisicoquimicas y Naturales; Argentina
Subject
A. brasilense
Plant growth-promoting activity
Indole 3-acetic acid
Inoculation
Maize roots
Ética relacionada con Biotecnología Agrícola
Biotecnología Agropecuaria
CIENCIAS AGRÍCOLAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/23003