Convergent Evolution of Algal CO2-fixing Organelles
Published:23 May2024 Source:University of Tsukuba
Plants and algae fix carbon through photosynthesis, which converts CO2 to organic carbon. This biological process is catalyzed by the Rubisco enzyme, the most abundant protein on Earth. In many algae, Rubisco is densely packed into a microcompartment called the pyrenoid, which plays an important role in the CO2 accumulation in aquatic environments. Notably, approximately one-third of global carbon fixation is estimated to occur within algal pyrenoids. Apart from Rubisco, the primary component of pyrenoids, the pyrenoid-associated proteins in most algae remain unclarified.
In this study, pyrenoid-associated proteins in a marine chlorarachniophyte alga were identified through a proteomic approach. Interestingly, various pyrenoid-associated proteins have been reported among the algae studied to date, suggesting that CO2-fixing organelles evolved independently in each algal group.
This is an example of convergent evolution at the molecular level. Genetic engineering of plants using algal genes is underway to increase the photosynthetic performance. The pyrenoid-associated proteins reported herein are a potential basis for improving crop productivity in the future.