Open Access

ARTICLE

Participation of Auxin Transport in the Early Response of the Arabidopsis Root System to Inoculation with Azospirillum brasilense

by Elizabeth Carrillo-Flores¹, Jonanci Arreola-Rivera¹, Denní Mariana Pazos-Solís², Moisés Bocanegra-Mondragón², Grisel Fierro-Romero³, Ma. Elena Mellado-Rojas¹, Elda Beltrán-Peña^1,*

1 Laboratorio de Transducción de Señales, Edificio B3, Instituto de Investigaciones Químico-Biológicas de la Universidad Michoacana de San Nicolás de Hidalgo, Ciudad Universitaria, Morelia, 58030, México
2 Tecnológico de Monterrey, School of Engineering and Sciences, Campus Querétaro, San Pablo, Querétaro, 76130, México
3 School of the Environment, Florida A&M University, Tallahassee, 32307, USA

* Corresponding Author: Elda Beltrán-Peña. Email:

(This article belongs to the Special Issue: Integrating Agronomy and Plant Physiology for Improving Crop Production)

Phyton-International Journal of Experimental Botany 2022, 91(11), 2383-2401. https://doi.org/10.32604/phyton.2022.021507

Received 18 January 2022; Accepted 09 April 2022; Issue published 12 July 2022

Abstract

The potential of Plant Growth Promoting Rhizobacteria (PGPR) has been demonstrated in the case of plant inoculation with bacteria of the genus Azospirillum which improves yield. A. brasilense produces a wide variety of molecules, including the natural auxin indole-3-acetic acid (IAA), as well as other phytoregulators. However, several studies have suggested that auxin induces changes in plant development during their interaction with the bacteria. The effects of A. brasilense Sp245 on the development of Arabidopsis thaliana root were investigated to help explain the molecular basis of the interaction. The results obtained showed a decrease in primary root length from the first day and remained so throughout the exposure, accompanied by a stimulation of initiation and maturation of lateral root primordia and an increase of lateral roots. An enhanced auxin response was evident in the vascular tissue and lateral root meristems of inoculated plants. However, after five days of bacterization, the response disappeared in the primary root meristems. The role of polar auxin transport (PAT) in auxins relocation involved the PGP1, AXR4-1, and BEN2 proteins, which apparently mediated A. brasilense-induced root branching of Arabidopsis seedlings.

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