Open Access

ARTICLE

Chromium Differentially Affects Hydrogen Peroxide Distribution in Primary and Adventitious Roots of Arabidopsis thaliana L.

Aarón Giovanni Munguía-Rodríguez^1,2, José López-Bucio¹, Gerardo Rangel Sánchez^1,2, León Francisco Ruiz-Herrera¹, Yazmín Carreón-Abud², Miguel Martínez-Trujillo^2,*

1 Instituto de Investigaciones Químico-Biológicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio B3, Ciudad Universitaria, C. P, 58030, Morelia, Michoacán, México
2 Facultad de Biología, Universidad Michoacana de San Nicolás de Hidalgo. Edificio R, Ciudad Universitaria, C. P, 58030 Morelia, Michoacán, México

* Corresponding Author: Miguel Martínez-Trujillo. Email:

Phyton-International Journal of Experimental Botany 2020, 89(1), 35-43. https://doi.org/10.32604/phyton.2020.07835

Received 02 July 2019; Accepted 16 October 2019; Issue published 01 March 2020

Abstract

The post-embryonic growth of the Arabidopsis thaliana root system can be modified by different types of stress, such as sublethal concentrations of metals, which may induce the production of reactive oxygen species (ROS). In this study, the effects of different concentrations of potassium chromate (K_₂CrO₄) on the distribution and relative quantity of hydrogen peroxide (H₂O₂) were determined in primary and adventitious roots in A. thaliana HyPer line seedlings. This line has a biosensor that specifically reports H₂O₂ levels within tissues as fluorescence. Primary root growth was inhibited at 100 μM Cr (VI); in contrast, adventitious root formation was induced over the main root growth axis. These structures proliferated from 100-160 μM Cr (VI), and much higher concentrations (180-200 μM) of K_₂CrO₄ were required to affect their growth. The H₂O₂ distributions were observed in the columella and lateral root cap of primary roots of plants grown in medium lacking dichromate, but following the development of toxicity symptoms, H₂O₂ changed its distribution to the meristem and differentiation zones. Conversely, adventitious roots had comparable H₂O₂ distribution patterns in untreated plants and those exposed to Cr (VI) supplementation. Thus, differential H₂O₂ distribution correlates with the resistance of adventitious roots, but not primary roots, to dichromate and underlies cell reorganization at the apex to support growth.

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Keywords

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