Date of Defense

Spring 4-22-1998


Biological Sciences

First Advisor

Alexander Enyedi, Biological Sciences

Second Advisor

David Karowe, Biological Sciences


Plants have the ability to develop resistance to a wide range of pathogens following exposure to a single bacterium, fungus, or virus. This resistance occurs in all tissues, not only those that were previously infected. This mechanisms is termed systemic acquired resistance (SAR). The phenolic compound salicylic acid (SA) has been linked to SAR in tobacco, arabidopsis, and cucumber plants. Oxidative stress also causes SA production, which leads to SAR. An engineered tobacco plant (nahG) that does not have the ability to accumulate SA has been used as a research tool in investigations concerning SA activity. Rose Bengal (RB), a dye which causes singlet oxygen atoms to form in the leaf mesophyll, was applied to nahG and wild type tobacco plants. Ethylene diurea (EDU), an antioxidant, was sprayed on prior to RB applications in some treatments. SA production was measured at 24 hour time points for 3 days. SA was shown to reach a peak at 24 hours in wild type plants treated with RB. This peak was deferred and decreased in wild type plants treated with EDU and RB both, suggesting that oxidative stress produces an SA response.

Access Setting

Honors Thesis-Open Access

Included in

Plant Biology Commons