Date of Award

Spring 2024

Degree Type

Thesis

Department

Biological Sciences

Director of Thesis

Dr. Beth Krizek

Second Reader

Dr. Johannes Stratmann

Abstract

Arabidopsis thaliana is a model organism that is used in laboratories across the world for the study of cellular and molecular processes in plants. GROWTH-REGULATING FACTOR 2 (GRF2) is a transcription factor that promotes leaf growth in Arabidopsis. It is a member of a family of transcription factors that is conserved across all land plants. Previous studies have characterized GRF2 expression in leaves, but GRF2 expression in floral organs has not been studied as extensively. GRF2 acts redundantly with other members of the GRF transcription factor family during floral development. grf1/2/3/5 quadruple mutants show malformed gynoecia, severe fusions between floral organs, and a reduction in the number of stamens and petals. These defects are much more severe than in grf1/3/5 triple mutants, indicating an important role for GRF2 in flower development. Here, we created a pGRF2:GUS transcriptional reporter to visualize the transcriptional activity of the GRF2 gene in Arabidopsis flowers. Inflorescences from transformed plants were embedded in wax and sectioned via microtome. Tissues that express the GUS enzyme under the transcriptional control of the GRF2promoter are stained blue, allowing us to visualize the transcriptional activity of GRF2. We found that GRF2 is expressed in the inflorescence meristem and broadly in young flowers. The staining is somewhat variable with dark spots of GUS staining visible in some tissue sections. Further work is needed to elucidate the regulatory networks responsible for controlling GRF2 expression in inflorescences. In particular, additional translational reporters are being made to investigate whether GRF2 expression is regulated by MIR396 in flowers, as it is in leaves. This study provides valuable insights into the expression of GRF2 in Arabidopsis.

First Page

1

Last Page

32

Rights

© 2024, Sophia S. Henry

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