Abstract

The peroxisome is a vital organelle conserved through the entire eukaryotic lineage. In all examined species, peroxisomes are responsible for such essential processes as fatty acid beta-oxidation and metabolism of reactive oxygen species (ROS). In plants, peroxisomes have taken on additional specialized roles, such as production of some plant hormones and vitamins. In this work, I have uncovered novel factors regulating peroxisome number in model species Arabidopsis thaliana, and novel mechanisms governing how peroxisomes respond to salt stress. I discovered a role for Arabidopsis MAP KINASE17 (MPK17) as a negative regulator of peroxisome division that acts in the salt-stress response pathway of peroxisome division. Additionally, I uncovered a novel role for the known peroxisome division factor PEROXISOME AND MITOCHONDRIAL DIVISION FACTOR 1 (PMD1) as another regulator of salt-induced peroxisome division and as the first known plant peroxisome division factor to bind to actin. A forward genetics approach was undertaken to attempt to isolate peroxisome-deficient mutants in the genetically tractable crop species Solanum lycopersicum, screening mutagenized tomato seeds on the auxin precursor indole-3-butyric acid (IBA). Although no peroxisome mutants were isolated by this method, several mutants impaired in various other aspects of auxin homeostasis were isolated and used to make new discoveries regarding the contributions of IBA to vegetative and reproductive tomato development.

Committee Chair

Lucia C. Strader

Committee Members

Joseph Jez, Elizabeth Haswell, Bethany Zolman, Arpita Bose,

Comments

Permanent URL: https://doi.org/10.7936/K75H7FPZ

Degree

Doctor of Philosophy (PhD)

Author's Department

Biology & Biomedical Sciences (Plant & Microbial Biosciences)

Author's School

Graduate School of Arts and Sciences

Document Type

Dissertation

Date of Award

Winter 12-15-2017

Language

English (en)

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