Good news: Bioengineered photosynthesis hack promises to dramatically increase yields in a variety of crops

Norman Borlaug is widely credited for saving a billion people from starvation. This comes from his development of high-yield, disease-resistant wheat varieties, which play a real role in the over-abundance of food we currently produce. It remains the fact that, despite hunger still being a big problem in the world, we produce enough food to feed billions more people than are currently alive. Nobody starves because we can’t feed them – they starve because their miserable deaths are more profitable than their lives. That said, I fully expect climate change to cause ever-increasing difficulties for the conventional farming practices on which we rely. This means that even if we do manage to build a society that values life, we may be hard-pressed to grow enough food to keep people alive on a rapidly warming planet. No matter what the future holds, Borlaug’s work will continue saving lives in to the future. It now appears that there may be another similar advance in another staple crop – soybeans:

Photosynthesis, the natural process all plants use to convert sunlight into energy and yield, is a surprisingly inefficient 100+ step process that RIPE researchers have been working to improve for more than a decade. In this first-of-its-kind work, recently published in Science, the group improved the VPZ construct within the soybean plant to improve photosynthesis and then conducted field trials to see if yield would be improved as a result.

The VPZ construct contains three genes that code for proteins of the xanthophyll cycle, which is a pigment cycle that helps in the photoprotection of the plants. Once in full sunlight, this cycle is activated in the leaves to protect them from damage, allowing leaves to dissipate the excess energy. However, when the leaves are shaded (by other leaves, clouds, or the sun moving in the sky) this photoprotection needs to switch off so the leaves can continue the photosynthesis process with a reserve of sunlight. It takes several minutes for the plant to switch off the protective mechanism, costing plants valuable time that could have been used for photosynthesis.

The overexpression of the three genes from the VPZ construct accelerates the process, so every time a leaf transitions from light to shade the photoprotection switches off faster. Leaves gain extra minutes of photosynthesis which, when added up throughout the entire growing season, increases the total photosynthetic rate. This research has shown that despite achieving a more than 20% increase in yield, seed quality was not impacted.

“Despite higher yield, seed protein content was unchanged. This suggests some of the extra energy gained from improved photosynthesis was likely diverted to the nitrogen-fixing bacteria in the plant’s nodules,” said RIPE Director Stephen Long (CABBI/BSD/GEGC), Ikenberry Endowed University Chair of Crop Sciences and Plant Biology.

This is very, very, very good news. As a species, we currently get about 17% of our protein from the oceans, and that is devastating oceanic ecosystems. While many of us really need to decrease our protein intake, the fact remains that we need to stop commercial fishing. That means that we’re going to need alternate sources of protein – doubly so because we really ought to get rid of most animal agriculture (though we need to keep some for those with dietary restrictions, and we need to guarantee access to good food, so the decrease in animal agriculture doesn’t suddenly make it astronomically expensive to exist if you require meat to survive). As with most innovations, this one by itself isn’t going to solve all our problems. That said, this could solve a lot of problems, and make it much easier to feed people despite the decline in good farming conditions around the world.

What’s more, this innovation is not limited to soybeans – it seems like it could be used for a wide variety of crops:

The researchers first tested their idea in tobacco plants because of the ease of transforming the crop’s genetics and the amount of seeds that can be produced from a single plant. These factors allow researchers to go from genetic transformation to a field trial within months. Once the concept was proven in tobacco, they moved into the more complicated task of putting the genetics into a food crop, soybeans.

“Having now shown very substantial yield increases in both tobacco and soybean, two very different crops, suggests this has universal applicability,” said Long. “Our study shows that realizing yield improvements is strongly affected by the environment. It is critical to determine the repeatability of this result across environments and further improvements to ensure the environmental stability of the gain.”

Additional field tests of these transgenic soybean plants are being conducted this year, with results expected in early 2023.

“The major impact of this work is to open the roads for showing that we can bioengineer photosynthesis and improve yields to increase food production in major crops,” said De Souza. “It is the beginning of the confirmation that the ideas ingrained by the RIPE project are a successful means to improve yield in major food crops.”

The RIPE project and its sponsors are committed to ensuring Global Access and making the project’s technologies available to the farmers who need them the most.

“This has been a road of more than a quarter century for me personally,” said Long. “Starting first with a theoretical analysis of theoretical efficiency of crop photosynthesis, simulation of the complete process by high-performance computation, followed by application of optimization routines that indicated several bottlenecks in the process in our crops. Funding support over the past ten years has now allowed us to engineer alleviation of some of these indicated bottlenecks and test the products at field scale. After years of trial and tribulation, it is wonderfully rewarding to see such a spectacular result for the team.”

Combined with changes in farming practices, an increase in indoor farming, and increased reliance on things like microalgae and edible bacteria, this could save billions of lives, if we can build a society that sees that as a thing worth doing.

If you like the content of this blog, please share it around. If you like the blog and you have the means, please consider joining my lovely patrons in paying for the work that goes into it. Due to my immigration status, I’m currently prohibited from conventional wage labor, so for the next couple years at least this is going to be my only source of income. You can sign up for as little as $1 per month (though more is obviously welcome), to help us make ends meet – every little bit counts!

Leave a Reply

Your email address will not be published. Required fields are marked *