Looking at almost 1,300 of the ‘promoter’ regions that regulate the activity of genes in 95 different commercial, landrace and ancestral wheats, the team has shown that these promoter regions are remarkably similar when different wheat varieties are compared.
Research also revealed that these promoter regions have remained mostly unchanged meaning they are likely to be as important as the part of the gene coding for proteins.Also, when slight differences between individual varieties are seen, these could have significant impacts on plant traits.
Such traits include grain quality, nutrient use efficiency, disease resistance, and adaptation to climate change.Gold mine for plant breeders
According to first author Dr. Michael Hammond-Kosack, this new research provides a potential 'gold mine' for plant breeders and researchers looking to improve crops. He said: “Despite many decades of work to produce better and higher yielding varieties, on-farm wheat yield increases have stagnated in recent years.“Most molecular breeding efforts have focused on trying different sequence combinations, solely based on the protein coding parts of the genes directly responsible for traits.“What we have shown is that these regulatory regions could be just as important as targets for improvement.”
Findings from Rothamsted Research
The findings have already been made available to the plant breeding industry, with a great deal of interest in the results. Dr. Chris Burt, cereal genotyping manager at RAGT Seeds, said: “The ability to identify sequence variations that are known to be present in modern wheat varieties is very important to us as plant breeders. Importantly this work has identified naturally occurring variation in wheat that previously we were blind to.“Now we know about them, we can identify how these variations relate to key agronomic traits such as disease resistance."We can then track these variations using high-throughput molecular techniques, which provides us with an additional tool to select for improved characteristics in wheat.”
Second discovery
A second unexpected discovery was that promoter sequence variation found in some wheat landraces - traditional, locally-grown crop varieties - and in an ancestral einkorn wheat, could also be found in many commercial wheat varieties.These sequence variations are now immediately available for exploration in commercial wheat breeding.
Importantly, despite the promoters being highly conserved, the team did find some sequence differences across promoter regions, with many of those residing within binding sites for proteins that switch genes on or off. The limited sequence variation in the whole promoter regions means these small variations, that have now been discovered in various varieties, are likely to play a significant role in the plant’s biology.