PS PhD Exit Seminar: Pathways to engineer plant Rubisco


Abstract: In plants, Rubisco is responsible for the assimilation of CO2 during photosynthesis. Often characterized as a slow and confused catalyst, much attention has been paid to improve (or circumvent) these perceived kinetic shortcomings to increase assimilation. Methods to improve Rubisco either exploit variation already found in nature or engineer the enzyme to have new catalytic properties. In this talk, I will detail some of the progress we have made towards engineering a ‘better’ plant Rubisco through these two methods. From nature, we surveyed the kinetics among high-temperature adapted plants containing the CAM carbon concentrating mechanism. In the lab, we adapted the traditional Rubisco-dependent E. coli (RDE) selection system to work with plant Rubisco and conducted various directed evolution studies. These include evolving a chaperonin complex with the ability to produce maize Rubisco in E. coli, trying to create a selection system that increases Rubisco specificity, and selecting nine putative mutations that influence both kinetics and solubility for tobacco Rubisco.

Biography: My first exposure to research was with Caroline Gross at the University of New England in Armidale where I worked on the pollination ecology of pioneer shrubs. After finishing a Bsc(Hons), I was employed as a research assistant for Bronwyn Barkla at Southern Cross Plant Sciences looking at endopolyploidy changes in a facultative halophyte. With the intent of improving plant Rubisco, I found the Whitney lab and commenced a PhD here at ANU in 2017.