“Developing Griffithsia monilis as a model for the study and kinetic optimization of rubisco”
Rubisco, a vital but inefficient carbon-fixing enzyme, is the limiting factor in green plant growth. The rubisco found in red algae Griffithsia monilis exhibits superior kinetic properties to that of many plants, making it a potential target for genetic modification of green plants. Successful assembly of Griffithsia rubisco has not been observed in green plants, possibly due to unmet chaperone and assembly factor requirements. Studying the genome and proteome of the Griffithsia chloroplast could provide valuable insight into these assembly requirements. We sequenced the Griffthsia genome using Oxford Nanopore MinION technology and assembled organellar genomes from this data, as well as previously obtained Illumina data, using GetOrganelle and Flye. Genomes were corrected with Ratatosk and NextPolish and annotated with known and unknown genes. After bacterial contamination was discovered and confirmed in multiple liquid cultures of the algae, we tested several antibiotics in order to create an antibiotic cocktail to remove bacteria without harming the algae. In addition, we tested two different protocols for the isolation of chloroplasts, one using a sucrose gradient and another using a Percoll gradient for differential centrifugation, as well as testing what methods of lysing algal cells produced the most purified chloroplasts. In order to use Griffithsia to optimize photosynthesis in other plants, we have isolated its organellar genomes and determined protocols to purify its chloroplasts, allowing for the study of red algal rubisco assembly requirements.
Working in research full-time has helped me gain experience and confidence in the lab, as well as in my long-term goals. I assisted with multiple parts of a complex, ongoing project between the Li and Gunn labs, which allowed me to learn a variety of new lab and bioinformatic techniques. I worked with several different members of my lab and was able to learn from their individual interests and areas of expertise. This collaborative experience will be valuable as I continue to work with mentors and peers in my undergraduate and graduate education. In addition, I gained a new appreciation for and understanding of plant biology. I’m glad I was able to contribute to these meaningful projects, and I leave with many new questions about plant biology that I’d love the opportunity to study again someday.