KINETIC ANALYSIS OF AUXIN-INDUCED TRANSCRIPTION FACTOR NETWORKS CONTROLLING LATERAL ROOT DEVELOPMENT IN ARABIDOPSIS THALIANA

Auxin is a phytohormone that regulates lateral root development through complex transcriptional networks. An 8-timepoint microarray of roots treated with indole-3-acetic acid (IAA), the major form of auxin, was utilized to identify the transcriptome wide kinetics of auxin response. This microarray allowed identification of novel auxin responsive genes beyond those found in four other auxin microarray datasets. This dataset contains 88 transcription factors whose transcripts change with varied kinetics. Clustering of these transcription factors revealed sequential activation of expression, with MYB93, MYB6 and ARF4 identified as possible downstream transcription factors from ARF19. Quantitative RT-PCR and T-DNA mutant phenotype analysis support their regulation by ARF19 and roles in lateral root development. Using literature and in silico relationships between all transcription factors, 12 transcription factors were identified from this network to model computationally with fuzzy logic and continuous Bayesian modeling techniques. The resultant transcription factor network was tested through qRT-PCR in the arf19-1 background and T-DNA mutant phenotype analysis. MIF1 and NF-YB2 are mis-expressed in the arf19-1 background. As bhlh122 and nf-yb2 shared phenotypic responses and ARF19 regulated synthesis, this suggests that bHLH122 and NF-YB2 function downstream of ARF19 to control lateral root development.

Grantor dc:publisher

Wake Forest University

Year dc:date.issued

2013

Author dc:creator

• Lundy, Stacey Reavis

• Auxin

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/10339/39026

OAI identifier oai:identifier

oai:wakespace.lib.wfu.edu:10339/39026