Degree Type

Thesis

Date of Award

2008

Degree Name

Master of Science

Department

Theses & dissertations (Interdisciplinary)

Major

Molecular, Cellular, and Developmental Biology

First Advisor

Yanhai Yin

Second Advisor

Jo Anne Powell-Coffman

Third Advisor

Kristen Johansen

Abstract

Brassinosteroids (BRs), the plant steroid hormones, play an important role in mediating plant responses to developmental and environmental cues. BRs signal through a membrane receptor BRI1 and a GSK3 kinase BIN2 to control the activity of BES1/BZR1 family transcription factors. To understand how BES1 regulates gene expression, I looked into both trans-acting protein factors and cis-acting DNA elements that affect BES1 functions, by yeast genetic screen and chromatin immunoprecipitation coupled with DNA microarray (ChIP-chip), respectively. We identified 1609 BES1 direct target genes and discovered conserved DNA motifs in BES1 binding regions. We also showed that BES1 target genes were largely devoid of H3K27me3. In contrast, 35% of BES1 target genes were associated with H3K9me3 and two putative H3K9me3 demethylases, ELF6 and REF6, were recruited to target gene promoters by interacting with BES1, loss-of-function of which caused BR-related phenotypes. Therefore, we provided significant insights into mechanisms of BES1-regulated gene expression.

DOI

https://doi.org/10.31274/rtd-180813-3117

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Xiaofei Yu

Language

en

Proquest ID

AAI1453062

OCLC Number

251522918

ISBN

9780549540984

File Format

application/pdf

File Size

72 pages

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