A project team at the University of Illinois in the USA is researching how to genetically adapt plants to increase their yields by improving their ability to photosynthesise, according to a BBC report.
According to Prof Steve Long, the principal investigator and director of the Realizing Increased Photosynthetic Efficiency (Ripe) project, there have been few improvements to photosynthesis in current varieties of crops, such as soyabeans and wheat, in decades.
“We need to be able to increase productivity without increasing further demand, particularly in terms of water,” Prof Long was quoted as saying.
Although the efficiency of photosynthesis in crop plants was well below the levels that could be achieved in theory, was hard to influence due to the complex nature of the process, with more than 100 steps coded for by even more genes, giving millions of potential permutations, the BBC wrote.
Using powerful computers, Prof Long and his team built a digital twin of the photosynthesis process, which could tweak the process in millions of ways, the report said.
From these millions of options, the software could identify those that would make the biggest improvements.
“We then engineered these into crops, and if that results in an improvement in the glasshouse, then we take it to our experimental farm and test it in a real-world environment,” Prof Long said.
The research had already yielded promising results, the report said.
Changes to the mechanism of photosynthesis in soyabean plants had resulted in yield improvements of more than 20% in controlled environments, with field trials now underway.
One focus of the work involved tweaking the way plants responded to changes in light levels. The team had been working with three genes that coded for proteins of the xanthophyll cycle, the report said. This occurred as leaves moved from light to shade, preventing the plant from absorbing more light than it could use.
This process could take several minutes but Ripe’s gene changes meant the plants could adjust to changes in light levels more quickly.
Research work was also being conducted by other teams around the world. For example, Wild Bioscience, a spinout from Oxford University, was working to improve the proportion of each leaf that could photosynthesise, by increasing the expression of a gene found in wild plants, the report said. The process involved sophisticated computational biology.
“What we’re doing is trying to reverse engineer the naturally-occurring upgrades to photosynthesis that are out there in the wild, so we can copy them in crops,” co-founder Ross Hendron was quoted as saying.
Often, that gene was already present in the plant, and could be activated in different areas.
“We can look at wheat and find that gene is already in the wheat genome, it's just on in the wrong place,” Hendron said. “When we want to improve this particular process in this part of the plant, what we need to do is flick on a switch and turn that gene on in that location.”
The company is working on wheat, soyabean and maize, and has achieved increases of more than 20% in seed biomass, with field trials currently under evaluation, according to the report.
If all went to schedule, Hendron said crop plants could be available commercially by around 2030 or 2031.
However, some scientists were cautious about what could be achieved in terms of crops in the field, the report said.
According to Matthew Paul, principal research scientist at agricultural research institution Rothamsted Research, increasing leaves’ photosynthetic ability could simply result in smaller leaves, and high rates of photosynthesis could mean more water loss, meaning plants would need more irrigation.
“For any GM or gene editing approach to have widespread impact, it would need to be reproduced in varieties grown in different regions. Subtleties of expression control and interaction with genetic background of each variety will make this tricky,” he was quoted as saying.
However, Hendron said different techniques could be used in combination to boost yields.
