Date of Award
5-31-2026
Document Type
Campus Access Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Biology
Abstract
The plant hormone auxin governs a great many aspects of plant growth and development, in part by regulating gene expression via the Aux/IAA, Auxin Response Factor and TOPLESS families of transcription factors. The enormous number of possible combinations of these proteins acting together at specific points in development and differentiation is thought to underlie the ability of a single hormone to exert control over such a diversity of growth processes; however, for many such, the participating members are not yet specifically known. This work focused on the function of the Arabidopsis Aux/IAA gene IAA3/SHY2 in several developmental processes. A gain-of-function mutant allele, shy2-2, is pleiotropic, affecting lateral root formation, the size and morphology of rosette leaves, hypocotyl elongation and cotyledon expansion in the dark, and root hair density. In lateral root development, our results lend support to possible roles for IAA3/SHY2 in the initiation and patterning/differentiation phases, as well as in auxin transport and distribution. It is unclear whether IAA3/SHY2 is involved in the priming phase. The study also sought to identify other players in the transcriptional regulatory network in which IAA/SHY2 participates. Genetic analysis indicates that none of the contributions to phenotype of IAA3/SHY2 that were examined require specific interaction with any individual member of the TOPLESS gene family.
Recommended Citation
Stark, James, "Arabidopsis IAA3/SHY2 in Plant Development, and Its Interactions With TOPLESS Family Genes" (2026). Graduate Doctoral Dissertations. 1166.
https://scholarworks.umb.edu/doctoral_dissertations/1166