Honors Theses and Capstones

Date of Award

Summer 2012

Project Type

Senior Honors Thesis

College or School



Biological Sciences

Program or Major


Degree Name

Bachelor of Science

First Advisor

Dennis Mathews


The processes of cell division and differentiation are critical to the development of any multicellular organism. During the formation of plant roots these processes take place at a region of the root tip called the meristem. Cytokinin and auxin are two plant growth hormones that influence this process. Although these two growth hormones are both necessary they also appear in many ways to have an antagonistic relationship. As meristematic root cells undergo differentiation they cease dividing. It has been proposed that the size of the root meristem and thus the overall rate of root growth are determined by the balance between the rate of cell division, determined by auxin, and the rate of cell differentiation, determined by cytokinin. One of the ways cytokinin may have an antagonistic influence on auxin regulation is by limiting auxin transport. Directed auxin transport from one part of a plant to another is controlled by a family of auxin efflux proteins called PIN proteins. To date, studies reported in the literate are inconsistent as to whether and how cytokinin influences PIN protein production at the transcriptional and/or translational level. This study was undertaken to explore the effect of cytokinin signaling on PIN gene expression using real-time quantitative PCR.