Generation of Aluminum Tolerant Roots Through Bypassing a DNA Damage Checkpoint.

Paul Larsen, Associate Professor, University of California, Riverside

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Launch presentation

About the speaker

Paul B. Larsen is currently an Associate Professor of Biochemistry at the University of California-Riverside in the USA. His research program focuses on two distinct topics in plant biology, including the response of roots to abiotic stress, in particular Al toxicity, and the mechanism by which plants sense the hormone ethylene, which is critical for control of such phenomena as fruit ripening and leaf senescence. Current work in his laboratory focuses on determining whether the results seen for AtATR in Arabidopsis can be used for modification of crops to improve global agriculture in acid soil regions.

Abstract

Al toxicity severely limits global agriculture in acid soil regions, which comprise upwards of 50% of the world’s arable land. Plants have evolved mechanisms by which they cope with Al in their environment, although little is known about the biochemical basis for these mechanisms. This is especially true for Al tolerance, which results from an increased capability to tolerate internalized Al. Recent work from our laboratory has shown that Al-dependent root growth inhibition primarily results from the response of roots to Al toxicity rather than the damage itself. By generation of Al tolerant Arabidopsis thaliana mutants, it was found that substantial gains in root growth in the presence of toxic levels of Al can be made by reducing or eliminating the function of a protein, AtATR, that is responsible for assessing DNA integrity. From this work, it appears that Al dependent root growth inhibition results in large part from AtATR-mediated terminal differentiation of the cells of the root quiescent center, with atr loss-of-function mutants incapable of detecting and/or responding to Al toxicity, which subsequently results in maintenance of the quiescent center and root growth even in the presence of high levels of Al.

Launch presentation