Effects of Abscisic Acid, Brassinosteroids, and Jasmonic Acid on Sepal Initiation

Consistency and reproducibility of organ size and shape against the strain of environmental factors provides an organism robustness, which is critical to proper organogenesis. Robustness is important to all organisms, as developmental defects are often detrimental to an organism’s health and/or function. In agricultural crops, a lack of robustness can lead to misshapen and unappealing merchandise that consumers will not purchase. In plants, an important model organ for robustness is the Arabidopsis thaliana sepal, a small leaf-like floral organ outside the petal with a function to protect the developing floret. The development related myb-like1 (drmy1) mutant influences robustness of floral development, disrupting the sepal’s function to protect the flower by increasing variability in sepal surface area and count. Hormones such as auxin and cytokinin are known to affect sepal primordium initiation and are well understood, but there is little literature on the effect of other hormones. Using various biosynthesis and signaling mutants and chemical treatments both enhancing and disrupting abscisic acid, brassinosteroid, and jasmonic acid signaling in drmy1 mutants, I was able to draw preliminary conclusions to what hormone treatments are involved in the drmy1 regulatory pathway, leading to robust organ development. The purpose of this study is to develop a detailed model describing how drmy1 and various plant hormones lead to organogenesis.

The Roeder lab has given me the opportunity to become involved in research unavailable to a small liberal arts university. I have a better understanding of graduate school and the joy of engaging in my own research. I have rediscovered my love of learning and working with hormones and found new interests in developmental biology. Skills I have accumulated throughout this project such as dissections, transformations, mutant crossing, and confocal imaging are only just the beginning of my professional career, as I foresee more Arabidopsis in my future. The skill of developing and communicating research will be carried and honed for the rest of my life. Being in a cohort of such talented peoples brings at first a sense of misplacement, but then a greater sense of inclusion and understanding of personal alikeness. Meeting peers of various backgrounds and knowledge of science was one of the most rewarding experiences here.