- Feb 27, 2018
Date & Location: February 27, 2018, at 12p; Room 168 Plant Biology Building
Subject: Control of isoprene emission from plants by substrate supply and isoprene synthase
Abstract: Plants emit over 600 teragrams of isoprene per year - more than any other hydrocarbon from all sources. However the physiological control and purpose of this emission is not fully understood. Understanding the control of emission is important not only for understanding atmospheric chemistry and plant stress tolerance, but for engineering synthetic systems for industrial terpenoid production.
The chloroplastic MEP pathway gives rise to isoprene via isoprene synthase, which is an enzyme unique to plants. Isoprene flux requires light, is highly dependent on temperature, and is inhibited by high CO2 in a similar pattern as triose phosphate utilization limitation. These dependencies are jointly controlled by the activity of the enzyme by temperature and the MEP pathway's ATP and reducing equivalent requirements. Increasing availability of isoprene's percursor, dimethylallyldiphosphate, increases isoprene production from transgenic systems. Engineering the enzyme itself to improve activity is also possible. In my work, I have studied the temperature and CO2 dependence of isoprene and the MEP metabolites. In collaboration with the lab of Cheryl Kerfeld we have created a modified isoprene synthase with improved characteristics.
Alexandra Lantz is a graduate student in the lab of Thomas Sharkey.