Degree Type

Honors Capstone Project

Date of Submission

Spring 5-1-2010

Capstone Advisor

Ramesh Raina

Honors Reader

Michael Cosgrove

Capstone Major


Capstone College

Arts and Science

Audio/Visual Component


Capstone Prize Winner


Won Capstone Funding


Honors Categories

Sciences and Engineering

Subject Categories

Biochemistry | Biochemistry, Biophysics, and Structural Biology


The study of plant genetics and the molecular mechanisms regulating plant-pathogen interactions is an intensely studied area of research in molecular genetics. Gaining an understanding of the defense mechanisms of plants has proven highly useful in the construction of transgenic plants for increased crop yield. The focus of my research was on the defense mechanisms of Arabidopsis thaliana, a plant in the mustard family. Several features of Arabidopsis make it an excellent model plant for molecular genetic studies. A few of these include a short life cycle (approximately 8 weeks), a completely sequenced genome, high fecundity, and the availability of a large mutant pool. My research more specifically focused on the shl3 (suppressor of the hrl1 3) mutant and its suppression of the hrl1 (hypersensitive response-like lesions 1) mutant phenotype. Previous work in the lab has demonstrated that hrl1 mutant plants up-regulate multiple pathogen defense pathways, resulting in constitutive expression of defense genes and much higher resistance to several pathogens than wild-type plants. Additionally, hrl1 plants are much smaller in size than wild-type plants and display leaf lesions similar to those on plants undergoing the hypersensitive response. To identify additional components of the defense pathway regulated by hrl1, insertional mutagenesis was carried out in hrl1 plants to identify suppressors of the hrl1-associated phenotype. In this screen a mutant, shl3, was identified to cause a near-complete reversion of the hrl1-associated phenotypes. My research involved investigating the molecular mechanisms involved in regulating this suppression and the role of shl3 in regulating pathogen defense. In addition, I determined the effects of this insertion on the genes flanking the shl3 insertion and the relationship of shl3 to expression levels of other defense-related genes of Arabidopsis. These studies should help to gain a better understanding of the role of shl3 in the defense pathways in Arabidopsis.

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Included in

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