Australian and British scientists say they have found a way to speed up photosynthesis in some plants, potentially boosting production of crops such as maize and sorghum.

By increasing the production of Rieske FeS, a protein that controls the rate in which electrons flow, they were able to relieve a bottleneck in the process by which the plants transform sunlight into food.

In trials, photosynthesis increased by up to 10%.

“The Rieske FeS protein belongs to a complex which is like a hose through which electrons flow, so the energy can be used by the carbon engine of the plant,” says lead author Maria Ermakova, from Australia’s ARC Centre of Excellence for Translational Photosynthesis (CoETP),

“By overexpressing this protein, we have discovered how to release the pressure of the hose, so more electrons can flow…”

The findings are published in the journal Communications Biology. The Australian researchers worked with colleagues for the University of Essex in the UK, who are part of the international Realising Increased Photosynthetic Efficiency (RIPE) project.{%recommended 9099%}

The researchers say that to date efforts to improve photosynthesis have focused on crops that use C3 photosynthesis, such as wheat and rice, despite the fact that equally important crops, such as maize and sorghum use C4 photosynthesis. [The names relate to whether a three- or four-carbon compound is produced initially.]

The Rieske protein is particularly important in environments with high radiance, where C4 plants grow.

“These results demonstrate that changing the rate of electron transport enhances photosynthesis in the C4 model species, Setaria viridis, a close relative of maize and sorghum,” says co-author Susanne von Caemmerer, from CoETP.

“It is an important proof of concept that helps us enormously to understand more about how C4 photosynthesis works.”

The aim now is “to transform this into sorghum and test the effect it has on biomass in a food crop”.

“In the last 30 years, we have learnt a lot about how C4 plants work by making them worse – by breaking them as part of the process of discovery,” adds Robert Furbank, also from CoETP. “However, this is the first example in which we have actually improved the plants”

“Our next steps are to assemble the whole protein FeS complex, which has many other components.”