Semester of Graduation

May 2023


Master of Biological Science (MBioSci)



Document Type



Photosynthesis serves as the primary process for plants to synthesize ATP and sugar molecules, however, this reaction requires many cofactors such as heme, plastoquinone, and iron-sulfur clusters to assist in energy gathering and electron transfer steps. Many of these require trace metals, such as iron, to cross across the chloroplast membranes and be incorporated into proteins and other organic molecules to form useable cofactors. The light-independent reactions of photosynthesis are also inefficient, with up to 25% of the photosynthetic energy wasted to metabolize the toxic waste product glycolate. The cellular logistics of both photorespiration and iron transport have been studied, but the transport proteins responsible for moving the reactions and products in and out of the chloroplast are not fully characterized. Although significant transporters such as permease in chloroplast 1 (PIC1), responsible for transporting iron, and plastidic glycolate glycerate transporter (PLGG1), responsible for transporting glycerate and glycolate in the chloroplast are well studied, other auxiliary transporters may still play a role in transporting molecules in and out of the chloroplast. This thesis attempts to understand the role of a poorly understood transporter, mitoferrin-like transporter (MFL1), in Arabidopsis thaliana within the chloroplast using three approaches: bioinformatics to predict its likely function; Golden Gate cloning to construct plasmids into both wild type A. thaliana and MFL1 deficient A. thaliana to observe the physiological effect under high, ambient, and low CO2 conditions; and expressing the gene mfl1 into Saccharomyces cerevisiae to determine its growth rate in conditions lacking iron and conditions lacking fermentable sugars. Experimental results suggest that MFL1 may play a role in transporting the molecule S-adenosyl methionine into the chloroplast. This study may provide insight into vi discovering more transport proteins responsible for shuttling molecules in and out of the chloroplast to maintain the complex machinery for photosynthesis.



Committee Chair

Naohiro Kato