Date of Award
Microbiology, Molecular Biology and Biochemistry
Daniel J. Ballhorn
Plant defenses -- Analysis, Botanical chemistry, Organic compounds -- Synthesis
The optimal defense theory describes an ideal distribution of chemical defense patterns in plants. Chemical defenses are finite, and should be allocated based upon the vulnerability and value of a given tissue. In this study, we quantified hydrogen cyanide production (defense parameter) and protein content (nutritive parameter) in photosynthetic and reproductive organs of experimental plant Phaseolus lunatus L.. Feeding trials using a generalist herbivore were also conducted to determine insect preference, and compare against defense and nutritional values obtained. Our findings show that young leaves have highest concentrations of hydrogen cyanide, and are thus best defended, and reproductive organs and mature tissues are least defended. Tissues most consumed (by weight) were young and mature flowers. These findings indicate that the optimal defense theory does not represent the chemical defense patterns shown in Phaseolus lunatus.
Stady, Lauren M., "A Test of the Optimal Defense Theory: Cyanogenesis in Phaseolus lunatus L." (2014). University Honors Theses. Paper 106.