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Volume 11 Number 4 December 2025

The Role of Glutamate Receptor AtGLR3.7 and Mutants in Arabidopsis thaliana Growth


Authors: Ibrahim Njimona ; Matthias Weiland ; Felipe Yamashita ; Stefano Mancuso ; František Baluška
Pages: 24-35
DOI: doi.org/10.32861/jbr.114.24.35
Abstract
Glutamate receptor-like genes (GLRs) in Arabidopsis thaliana have been implicated in various physiological processes, yet the specific role of AtGLR3.7 remains poorly understood. In this study, we investigated the impact of altered AtGLR3.7 expression on plant development by analysing three overexpression lines and one knockout line, all in a Col-0 background. The overexpression lines were selected to represent a gradient of AtGLR3.7 expression levels. Phenotypic analyses revealed that AtGLR3.7 positively regulates seed size, root length and aerial tissue expansion in a dose-dependent manner. Overexpression lines exhibited enlarged seeds and accelerated rosette and stem growth, while the knockout line showed reduced development in all traits. Root architecture remained largely unchanged across genotypes, except for a reduced primary root length in the knockout, which led to a higher lateral root density. Exposure to exogenous L-glutamate revealed that overexpression of AtGLR3.7 increases plant sensitivity to glutamate-induced root growth inhibition, whereas the knockout line displayed an unexpected stimulation of root growth under high glutamate concentrations. Interestingly, 250 µM L-glutamate was sufficient to restore normal root growth in both mutant backgrounds, suggesting a critical balance between AtGLR3.7 expression and glutamate availability. These findings support a model in which AtGLR3.7 modulates root meristem activity through glutamate signaling, potentially by influencing auxin dynamics at the root tip. Our results highlight AtGLR3.7 as a key modulator of plant growth and glutamate responsiveness and provide new insights into the functional specificity of GLRs in Arabidopsis development.