Young investigator Martin Jonikas has broad ambitions: to transform our fundamental understanding of photosynthetic organisms by developing game-changing tools. In the long run, his lab aims to increase photosynthetic efficiency of crops, which could improve food production around the world.
When photosynthesis first evolved, the atmosphere contained much more carbon dioxide and much less oxygen than it does today. As a result, the photosynthetic machinery of many organisms may not be completely optimized for today’s environment.
The protein responsible for fixing carbon dioxide—called Rubisco—worked very well in the Earth’s early atmosphere. As photosynthetic organisms spread around the world, they absorbed carbon dioxide and released oxygen at such a rate that atmospheric levels of oxygen rose and levels of carbon dioxide fell dramatically. The decreased carbon dioxide concentrations revealed a critical flaw in Rubisco. Under the low concentrations of carbon present in today’s atmosphere, Rubisco functions extremely slowly and often mistakenly fixes oxygen instead of carbon dioxide, resulting in the loss of previously fixed carbon. However, Rubisco is such a central component of photosynthetic metabolism that it cannot be removed or replaced, in spite of its inefficiency.
Jonikas and his colleagues are studying a special mechanism by which the unicellular green alga Chlamydomonas reinhardtii is able to increase the concentration of carbon dioxide in proximity to Rubisco, thus dramatically improving its performance and improving the overall efficiency of photosynthesis.
To identify components of this mechanism in Chlamydomonas, Jonikas and team are developing tools to enable high-throughput genetic analysis. By adapting a next-generation sequencing technology from bacteria, the team has increased the pace at which mutated genes in Chlamydomonas can be identified by more than 1,000-fold.
Beyond identifying algal genes that could increase crop yields, the tools they develop in algae will enable the functional characterization of many genes that are found in plants much more rapidly than is currently possible with multi-cellular plant models.
Jonikas received his B.S. in aerospace engineering from MIT and his Ph. D. in molecular biology and genetics from UC San Francisco, where he developed cutting edge tools to characterize genes in yeast. He joined Carnegie in 2010. For more information, see: https://dpb.carnegiescience.edu/labs/jonikas-lab