Poster abstracts
Poster number 55 submitted by Qurat Ashraf
Assessing START-Dependent Regulation of PHABULOSA Targets in Arabidopsis thaliana
Ashraf Qurat (The Ohio State University)
Abstract:
The primary locus of control in plant development is the regulation of gene expression by transcription factors (TFs). Thus, TFs that can directly integrate intrinsic/extrinsic signals into their transcriptional activity are likely to be particularly important for development. Class III Homeodomain-Leucine Zipper (HD-ZIPIII) TFs are an ancient, highly conserved family of plant-specific proteins. Interestingly, HD-ZIPIII TFs possess a putative lipid-binding domain, termed the START domain, presenting them as one such class of important developmental regulators. In support of this, HD-ZIPIII proteins regulate fundamental processes such as embryogenesis, abaxial-adaxial patterning, lateral organ initiation, and meristem formation. Preliminary data using PHABULOSA (PHB) as a representative HD-ZIPIII in Arabidopsis thaliana suggest that the START domain is required for the developmental function of PHB. The START domain affects multiple facets of PHB function, including DNA-binding competence, dimerization, and transcriptional potency. However, the role of START domain in the regulation of PHB targets is unknown. I hypothesize that the START domain affects the regulation of PHB targets at the level of target selection, transcriptional output, and/or chromatin remodeling. In this proposal, I aim to uncover the contribution of the START domain to the regulation of PHB targets using genome-wide approaches on transgenic PHB- and PHB-Delta-expressing Arabidopsis seedlings. Together, these experiments will reveal START-dependent direct targets of PHB, and uncover additional mechanisms by which the START domain regulates the activity of HD-ZIPIII proteins.
Keywords: Gene Regulation and Development, START Domain, Arabidopsis thaliana HD-ZIPIII protein PHABULOSA