Algal Mechanisms

The Algal Mechanisms Objective was part of RIPE 1 and 2, 2012-2022.

Over 85 percent of plant species are called C3 because the enzyme Rubisco converts the carbon dioxide into a carbohydrate made up of three carbon atoms. Rubisco is an inefficient enzyme because it cannot distinguish between carbon dioxide and oxygen molecules. Around 35 percent of the time, Rubisco binds with oxygen instead of carbon dioxide, resulting in wasted energy and reduced photosynthesis. Cyanobacteria (blue-green algae) have overcome this limitation of Rubisco by evolving mini-organelles, called carboxysomes, to house Rubisco. Bicarbonate pumps surround Rubisco with high concentration of carbon dioxide so that oxygen cannot Rubisco.

Models suggest that re-engineering the active bicarbonate pumps and carboxysome structures could greatly improve photosynthetic efficiency in crops. Many proteins are required to form carboxysomes and active pumps, making this is a particularly high-risk strategy, but one that could pay maximum dividends. However, our team from The Australian National University has already had success building carboxysome-like structures in a crop plant; learn more about their work in the video below. 


Laurie Leonelli Headshot
Justin McGrath
Petri dishes in a refrigerator with green leaf samples in them.

Reduced plant growth found in double mutants by RIPE researchers

RIPE researchers from Louisiana State University experimented with removing two proteins vital to photosynthesis from a plant to see how it would affect crop growth. Their findings were published in Frontiers in Molecular Biosciences.

Hacking photosynthesis

We Can Grow 60% More Food By Hacking Photosynthesis

Hacking photosynthesis could grow up to 60% more food, on the same land we use today, according to an international team of researchers.

By: Amanda Winkler || Freethink 

Path in the countryside with trees and paddy fields, of blond color with cut rice on the left, and still green on the right, during the harvest of October 2017 in Don Det, Si Phan Don, Laos.

The Golden Revolution

With the famed Green Revolution running out of puff, scientists are working on a new Golden Revolution that will deliver a step-change in agricultural output.

By: Ben Long || Rural Business

The predicted molecular structure of the mutant form of BCT1 the researchers evolved for function in plants. Each color represents a subunit of the four-component pumping system. The mutant form has fused the blue-colored subunits and enabled the pump to work without the need to switch it 'on’. Figure generated by Loraine Rourke, ANU.

Scientists Engineer CO2-Boosting Protein to Supercharge Plant Photosynthesis

RIPE scientists have introduced a specialized protein complex into the chloroplasts of plants to deliver more carbon dioxide to the enzyme responsible for carbon fixation during photosynthesis. Their work was recently published in the Journal of Experimental Botany.

Soybean leaves in circles around a light.

RIPE researchers put plant protein mechanism into bacteria to help move forward 50 years of effort

ANU researchers have added components of plant chloroplasts to bacteria. This feat, 50 years in the making, allows them to analyze the proteins in greater detail in order to improve Rubisco, and eventually photosynthesis!

PNAS_Rubisco Proton

Rubisco proton production can enhance CO2 acquisition

Recently published in PNAS, RIPE members at ANU are gaining insight into possibly building Rubisco compartments in crops to increase yield productivity.