Date of Award
Doctor of Philosophy (PhD)
The plant hormone auxin is remarkable in its capacity to seemingly regulate all plant growth and developmental processes. Because of this, plants have evolved numerous mechanisms to allow for specific responses to auxin dependent on tissue type and developmental stage. Despite the importance of this specificity, we understand very little with respect to the molecular mechanisms underlying it. In this work, we examine two mechanisms used by plants to modulate auxin response across different tissues. First, we describe our finding that auxin interactions with another plant hormone, abscisic acid, is used as a mechanism to regulate auxin responsiveness in the root and the hypocotyl. Second, we describe studies seeking to better understand the role that different protein regions of the auxin-responsive transcription factor AUXIN RESPONSE FACTOR (ARF) 19 have in regulating its nucleocytoplasmic partitioning, which is a mechanism previously established to regulate auxin sensitivity across the root. The studies on ARF19 are largely focused on the role that the intrinsically disordered region (IDR) has in the formation of large cytoplasmic assemblies (condensates). Finally, we describe two novel computational tools that will aid in thestudy of IDRs in the future. The first tool, metapredict, is a machine learning based protein disorder predictor. The second tool, GOOSE, enables the rational design of amino acid sequences for IDRs or IDR variants with user-specified sequence parameters. Both tools will aid in further elucidating which aspects of the ARF19 IDR are important for its function. Together, this work advances our understanding of the molecular mechanisms underlying auxin response specificity across different tissues and provides new tools to aid the study of some of these mechanisms including nucleocytoplasmic partitioning of ARF19.
Chair and Committee
Alex S. Holehouse
Lucia C. Strader
Emenecker, Ryan Joseph, "Advances in the Understanding of Auxin Signaling Through Indirect Mechanisms" (2020). Arts & Sciences Electronic Theses and Dissertations. 2583.
Available for download on Saturday, December 16, 2023