Barkan, AliceLjungdahl, Sonja2020-02-272020-02-27https://hdl.handle.net/1794/25213Light, while necessary for plants, can cause photo-oxidative damage. Adaptations to fluctuating light conditions optimize photosynthetic yield and minimize light-induced damage. Light-regulated synthesis of the chloroplast gene psbA and its protein product D1 is at the core of these responses. Shifting light intensity regulates D1 synthesis at the level of translation. This thesis investigates specific proteins we hypothesized mediate the effects of light on D1 synthesis. Our experiments on TPJ1, a maize mutant lacking one of these proteins, showed that TPJ1 does not influence psbA translation. Instead, our results show it is required for the translation of the chloroplast psbJ mRNA. In addition, I elucidated the biochemical interactions between two known psbA translational activators, OHP2 and HCF244, by identifying a short segment of OHP2 that is sufficient for its interaction with HCF244. This thesis includes published, co-authored material.en-USAll Rights Reserved.chloroplast translationppr proteinsribosome profilingElectronic Thesis or Dissertation