PhD Proposal Exam – Anna Van Weringh (Provart lab)

PhD Proposal Exam

Wednesday April 27^th, 2:10 pm – Earth Sciences Centre, Rm. ESC3087

Anna van Weringh (Provart lab)

“Characterization of Drought Responsive Transcriptional Programs in Guard Cells“

Abstract

During drought, guard cells (GCs) are signaled to close stomatal pores to reduce water loss, necessary for survival during prolonged dry periods. As the site of gas exchange for photosynthesis, stomatal aperture is also a key determinant of plant productivity and water use efficiency. Thus, GCs are a topic of great study for crop improvement. My PhD research aims to tackle the gene regulatory programs induced within the GCs of Arabidopsis thaliana during drought by profiling the dynamic transcriptomic and epigenomic changes in GCs over the course of a drought, using RNA-seq and ATAC-seq respectively. The INTACT (Isolation of Nuclei Tagged in Cell-Types) system expressed under a GC-specific promoter will be used to sample nuclei from GCs during a time course during mild, moderate and severe drought. To identify the drought responsive transcription factors driving these changes, a YIH approach will be taken to determine which transcription factors (TF) can bind the promoters of differentially expressed genes. Y1H experiments provide TF-DNA interactions outside of the native context, yet chromatin accessibility shapes which target genes of a TF are activated at a given moment. Therefore, the network of Y1H connections will be filtered by chromatin accessibility and genes expressed at each time point. The functional contribution of TFs to GC behaviour during drought will be assessed by generating Arabidopsis plants with GC-specific knock-down or overexpression of identified TFs, and regulatory models will be tested by examining gene expression patterns in these mutants.