Deposition of Suberin in the Exodermis of the Tomato Root in Response to Abiotic Stress Conditions

Graduate #49
Discipline: Ecology Environmental and Earth Sciences
Subcategory: Plant Research
Session: 2
Room: Hoover

Bryshal Moore - Fort Valley State University
Co-Author(s): Alex Canto Pastor, University of California Davis, Davis, California; Sioban Brady, University of California Davis, Davis, California

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Plant roots are the contact point through which all communication and exchange with the soil occur, from absorption of water and minerals to biotic interactions. These different environmental conditions require the roots to adapt. For that purpose, different cell types within the root can act as additional layers of protection, such as the exodermis. The exodermis can deposit suberin, a hydrophobic polymer, in response to stressors in the soil. Suberin deposition is a complex process regulated by multiple transcription factors and biosynthetic proteins. However, the specific pathways that orchestrate this process in the tomato exodermis have not been characterized yet. In order to better elucidate how this process is controlled, we must first understand how suberin deposition is regulated under various stress conditions. In this work, we studied exodermal suberin content throughout the root developmental program in control conditions and in response to three different abiotic stressors: salt, sorbitol, and abscisic acid (ABA). After seven days of growth, roots were divided into four growing zones. The zones were sectioned and dyed with fluorol yellow 088, which adheres to the suberin polymer and produces a fluorescent signal. Images of the strained section were microscopically captured and the suberin content was measured. Results indicate that in the case of osmotic stressor (sorbitol) and hormonal stressor (ABA), the root began to deposit suberin earlier and in greater amounts, than when compared to normal growing conditions. In the case of saline, there was an earlier onset of suberin deposit but no increase in maximum suberin content. Ultimately, understanding how these processes are regulated and determining barrier-relevant genes will enable the breeding of cultivars with higher resistance to abiotic stresses.

Funder Acknowledgement(s): Special thanks to the Plant Agricultural Biology Graduate Admission Pathways Program at UC Davis, funded by the University of California HBCU initiative.

Faculty Advisor: Alex Canto Pastor, acantopastor@ucdavis.edu

Role: I performed all aspects of this research project.