PS PhD Exit Seminar - Analysing cyanobacterial bicarbonate transporters in heterologous systems: linking structure to function

Abstract: The efficient photosynthetic capability of marine phytoplankton is key to their significant contribution to global primary production. The main factor contributing to this is their CO₂-concentrating mechanisms (CCM). The primary component of the CCM of cyanobacteria is a microcompartment where the primary CO₂-fixing enzyme, Rubisco, is located and CO₂ is concentrated here, often with the assistance of inorganic (Ci) transporters.

Ci transporters have recently become a key focus of research as part of improving photosynthetic efficiency in crops, to circumvent the looming food shortages as population increases. Their inclusion on the plant chloroplast envelope has been modelled to boost Ci supply to Rubisco and thus improve photosynthesis.

Here, I focus my research on characterising undescribed bicarbonate (HCO₃^-) transporters, and to expand our repertoire of options to install in to different crop plants. I show that we can identify and characterise new HCO₃^- transporters from cyanobacterial and microalgal species in a heterologous system. I will describe the use of a specialised E. coli mutant strain that I used to screen for functional HCO₃^- transporters. This E. coli has the capability to evolve/mutate putative HCO₃^- transporter genes to generate novel membrane proteins to show functional HCO₃^- transport in E. coli. I will also describe attempts to assess how these proteins affect photosynthetic measurements when expressed in planta.

Biography: After I completed my undergraduate studies I spent a short amount of time in animal pharmaceuticals. Then after moving to Canberra I transitioned into the molecular biology field. My molecular biology career includes over 20 years as a technical officer, the majority of that time in the Price lab. I continue to act as a technical officer in a small capacity while I undertake my PhD as part of the Price and Byrt labs.