A research team at the University of Illinois has identified the gene that affects protein in soyabeans, Seedworld wrote.

The breakthrough followed a 30-year search for the specific gene, according to the 15 February report.

“Soyabeans are around 40% protein, and this gene increases that by about 2%. It doesn’t sound like a lot, but compared to any other seed-protein gene that’s been mapped for soyabean, it’s at least double,” Brian Diers, the Charles Adlai Ewing chair of Soybean Genetics and Breeding in the Department of Crop Sciences and co-author of the study was quoted as saying in The Plant Journal.

The study’s co-author Matt Hudson, Professor of Bioinformatics in Crop Sciences, said if the high protein form of the gene could be placed into commercially grown varieties, it would lead to a significant increase in protein for livestock and humans worldwide.

“Even a single percentage point increase in protein concentration would represent millions of tonnes of protein. That’s quite significant,” he added.

The 30-year search for the gene started in 1992, when Diers published the first seed protein map for soyabean, Seedworld wrote.

At that time, Diers had identified the region of the genome where the gene might be located, but it took many technological advances and the publication of two soyabean genomes to identify the specific gene: Glyma.20G85100, a gene without a known function but closely related to “clock and circadian timing” genes.

While originally mapping the gene to a section of a chromosome several million base pairs of DNA long, Diers said he slowly narrowed it down after testing generation after generation of plants carrying the gene within smaller genetic regions.

“We had to screen thousands and thousands of plants and then evaluate them with markers to see if we found an association,” Diers added.

The discovery of the gene was complicated by the fact that the link between the gene and its role in increasing protein content was not clear.

“We were hoping that when we finally found the gene, it was going to be involved in something obvious, for example, nitrogen fixation or nitrogen metabolism,” Diers said. “But it turns out it really isn’t what you would expect for a gene controlling a protein.”

Instead, the gene appeared to be part of the soyabean plant’s circadian machinery; the way the plant keeps track of time to maximise photosynthesis during the day, work out when to flower and set seed, and many other processes, he explained.

“It could be that the gene is involved in moving photosynthesis products into the seed or it could be some completely unrelated pathway… we really don’t know,” Hudson said.

“If we can understand the mechanism, that should give us some clues as to how we can increase protein without decreasing yield,” Diers added.