Scientists at Cornell University and the U.K.’s Rothamsted Research report using genes from blue-green algae – called cyanobacteria – to create micro-compartments inside photosynthesizing plant cells, an important breakthrough for improving photosynthesis.
The study was published online in The Plant Journal.
All plants employ an enzyme called Rubisco to fix carbon dioxide during photosynthesis, where plants combine carbon dioxide, water and light to make oxygen and sucrose; the plant uses sucrose for energy and to build new plant tissues.
But Rubisco reacts with both carbon dioxide and oxygen in the air. When it reacts with oxygen, increasingly in warmer temperatures, the rate of photosynthesis decreases and it lowers yields.
Blue-green algae also photosynthesize, but they employ a mechanism to concentrate carbon dioxide in polyhedral micro-compartments around Rubisco, so Rubisco reacts with carbon dioxide and not oxygen, making photosynthesis more efficient.
Until now “nobody had been able to show you can make this micro-compartment in plants,” said Myat Lin, the paper’s first author and a postdoctoral fellow at Cornell.
Lin devised a way to insert the algal genes for making the outer layer – known as the shell – of the micro-compartments into model tobacco plants.
Now that the researchers have a method to insert these shells into chloroplasts – the organelles in plant cells where photosynthesis occurs – the next steps will be to incorporate Rubisco, other proteins and an enzyme that helps transport carbon dioxide into Rubisco with the micro-compartments.
The National Science Foundation and the Biotechnology and Biological Sciences Research Council in the U.K. funded the research.