@Article{phyton.2020.07835, AUTHOR = {Aarón Giovanni Munguía-Rodríguez, José López-Bucio, Gerardo Rangel Sánchez, León Francisco Ruiz-Herrera, Yazmín Carreón-Abud, Miguel Martínez-Trujillo}, TITLE = {Chromium Differentially Affects Hydrogen Peroxide Distribution in Primary and Adventitious Roots of Arabidopsis thaliana L.}, JOURNAL = {Phyton-International Journal of Experimental Botany}, VOLUME = {89}, YEAR = {2020}, NUMBER = {1}, PAGES = {35--43}, URL = {http://www.techscience.com/phyton/v89n1/38397}, ISSN = {1851-5657}, 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 (KCrO4) 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 KCrO4 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.}, DOI = {10.32604/phyton.2020.07835} }