Plant Biology Colloquium | Characterizing Transcription Factor Activity within the Arabidopsis Gravity Response, April 21

The Environmental and Plant Biology Colloquium Series features Calvin Coffin  discussing “Characterizing Transcription Factor Activity within the Arabidopsis Gravity Responset” on Friday, April 21, at 11:50 am in Porter Hall, Room 104.

Coffin is a graduate student in Environmental & Plant Biology at Ohio University. Host: Calvin Coffin

Abstract : Gravity is among the most critical of environmental cues in shaping plant growth; however, its ubiquity on Earth limits available options in the study of the plant gravity response. NASA has circumvented this obstacle by hosting experiments in the microgravity environment of the International Space Station. The collection of gene expression data via RNAseq and microarray analyses of Arabidopsis seedlings grown in space has provided a wealth of data regarding how plants respond to this unique gravity condition. When intersected with similar expression data from terrestrial plants exposed to an alternate gravity stimulus - a new gravity vector - several novel components in the gravity signaling pathway have been implicated. Of particular interest in the analysis were transcription factors, for their role in regulating downstream expression patterns. Two transcription factors were identified at this basal level of the Arabidopsis gravity response: ERF104, which is upregulated on earth in response to a new gravity vector and downregulated in microgravity, and IQD21, which displays the inverse expression pattern. A third gene, CIB1, was shown to be upregulated in both scenarios. Phenotypic characterizations of mutant lines of each of these genes show significant gravity sensitivity in the root tip and/or shoot, confirming their gravitropic role. Human Influenza Hemagglutinin (HA) tagged fusion lines of each of these proteins have been generated and placed under the control of a constitutive promoter. These lines are enabling chromatin immunoprecipitation followed by sequencing (ChIP-Seq) to identify the binding sites of these three transcription factors in the Arabidopsis genome, and consequently to infer their downstream targets. Paired with qPCR analyses targeting the expression patterns of each protein in response to gravistimulation, this research will help to contextualize and clarify the gravity response pathway as well as shed light on the complex web of interconnected signaling events it entails.