CMCB Life Sciences Seminar: Prof. Yusuke Matsuda, Kwansei Gakuin University, Japan

Host: Nils Kröger (B CUBE)

Title: "Photosynthesis of diatoms in seawater – mechanisms based on the unique chloroplast structure"

Abstract: The pyrenoid is a unique chloroplast structure in aquatic autotrophs and diatom has one with thylakoid membrane traversing the axis of the pyrenoid (Pyrenoid penetrating thylakoid: PPT). PPT is the CO2 evolving machinery (CEM) which is critical to provide an ample flux of CO2 to condensed CO2-fixing enzyme, Rubisco in the pyrenoid. CEM also requires transporter(s) to provide HCO3- into the PPT lumen, luminal theta CA to dehydrate HCO3-, and structurization of the pyrenoid with the right form of the PPT at the core. Our recent study succeeded to genome edit these critical requisite factors and the resulting state of photosynthesis of the transformants clearly showed that diatom photosynthesis can be categorized into least three phases. These data provide numerous insights into the diatom photosynthesis in the oceans that is responsible for 20% of the global primary production.