Microalgae inspire faster growing plants

During photosynthesis in plants, carbon from atmospheric carbon dioxide is “fixed” and converted into sugars.

Rubisco, the key enzyme for carbon-fixation in plants with complex structures, is also involved in photorespiration—a process that partially reverses carbon-fixation and hampers plant growth. Microalgae are more efficient than plants at carbon-fixation, because they compartmentalise Rubisco in very small volumes—in liquid droplets called pyrenoids—that help to concentrate carbon dioxide gas at the enzyme’s active site.

To mimic the more economical strategy of microalgal carbon-fixation, a research team led by Assoc Prof Oliver Mueller-Cajar of NTU’s School of Biological Sciences engineered liquid droplets by combining purified Rubisco enzymes with a specific linker protein. The researchers succeeded when they used algal Rubisco enzyme, but not when they used plant-derived Rubisco enzyme.

Their findings represent a big step towards engineering crop plants that are more efficient at photosynthesis, and a small step towards feeding the world’s burgeoning population.

The study “The phase separation underlying the pyrenoid-based microalgal Rubisco supercharger” was published in Nature Communications (2018), DOI: 10.1038/s41467-018-07624-w.

A video showing the formation of a liquid non-membranous compartment through the combination of microalgal Rubisco and linker protein (made visible through inclusion of linker protein fused with green fluorescent protein) can be accessed here: 41467_2018_7624_MOESM4_ESM.

The article appeared first in NTU’s research & innovation magazine Pushing Frontiers (issue #15, June 2019).