Discovery shines light on crop yields

Glacier FarmMedia – Scientists have seen the light on photosynthesis research that is expected to greatly boost yields in food crops around the world.

Crops that are in full sunlight receive more energy than they can use. That extra energy can damage leaves.

Why it matters: Improving photosynthesis could result in higher yields.

Plants use a process called nonphotochemical quenching to dissipate that extra energy by converting it into heat, which is then harmlessly discharged.

When a leaf suddenly goes into the shade, it could use all that excess energy from the sunlight, but instead it continues to dissipate it as heat for many more minutes.

“If you add this up for (the) crop canopy over the course of the day, it’s quite a lot of lost photosynthesis,” said Steve Long, a professor of crop science and plant biology at the University of Illinois.

Long and his team identified the key enzymes and genes that code for the relaxation of the nonphotochemical quenching process.

“We identified two enzymes and one other protein involved in this process that we thought needed to be upregulated,” he said. “The plant has them natively growing. We wanted a lot more.”

They first worked with tobacco because it is easy to genetically transform and produces lots of seeds, so they were able to go to field trials quickly. Genes from the Arabidopsis plant were used to produce the desired proteins. The result was a 20 per cent increase in yields.

It took a few more years to repeat the process with soybeans because the transformation process is slower and it required more time to bulk up seed for field trials that took place in 2020 and 2021.

But the result was the same in five different field trials involving five independent transformation events, with an average 24.5 per cent increase in yield.

“These are small plot trials. We don’t know that we would get such a big increase in a farmer’s field,” said Long.

But achieving the same encouraging result with two very different crops should help resolve one big question in agriculture research circles.

“There has been a long debate with plant breeders about whether improving photosynthesis will ever get you more yield,” said Long. “This shows we think that it does.”

The research has garnered significant interest since landing on the August 2022 cover of Science, one of the most cited research journals in the world.

The plan is to do the same transformation with rice, corn and cowpeas. Fortunately, the photosynthesis process is similar in all crops.

“Unlike disease resistance, for example, if it works in one crop it probably works in others,” said Long.

– This article was originally published at The Western Producer.