Genes from blue-green algae could offer a way to boost plant efficiency and ultimately increase crop yields in an effort to keep pace with the growing global food demand.
Scientists used the genes from blue-green algae—called cyanobacteria—to create micro-compartments inside plant cells, an important breakthrough for improving photosynthesis.
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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 it reacts with carbon dioxide and not oxygen, making photosynthesis more efficient.
Chloroplast shells
Until now “nobody had been able to show you can make this micro-compartment in plants,” says first author Myat Lin, a postdoctoral fellow in the lab of Maureen Hanson, professor of plant molecular biology at Cornell University and senior coauthor of the study published in the Plant Journal.
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, Hanson says.
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 UK funded the research.
Source: Cornell University
