Date of Award

January 2016

Degree Type


Degree Name

Master of Science (MS)


Botany and Plant Pathology

First Advisor

Anjali Iyer-Pascuzzi

Committee Member 1

Peter B Goldsbrough

Committee Member 2

Mary A Webb


Bacterial wilt is a devastating plant disease that can cause upwards of 90% crop loss. The soil-borne bacterium Ralstonia solanacearum, is the causal agent of bacterial wilt, and infects over 200 plant species, including tomatoes. Roots are fundamental to resistance in tomato, as grafting resistant rootstocks to susceptible scions results in resistant plants. Despite the devastation it causes, there are no known resistance genes in crops to R. solanacearum, and crop defense mechanisms are unknown. Here, we investigated the role of root anatomy and root architecture in tomato resistance to R. solanacearum. We find that bacteria colonize root tissue types of resistant and susceptible plants differently, and that vascular treachery elements are generally larger in resistant plants. Further, we find that the production of lateral roots may contribute to mechanisms of resistance. Our data suggest that differences in root anatomy and architecture are part of plant defense mechanisms to R. solanacearum.