Higher yields and better breeding of wheat – which accounts for some 20 percent of the earth’s population calorie intake -- are promised in the wake of researchers recently unlocking the genome of the crop. The discoveries by teams of scientists in England, Germany the United States could also provide guideposts to dealing with diseases like UG99 and mitigate alarming claims about coming climate change-caused food catastrophes.
For more on the wheat genome, see here.
One of the research teams involved is at New York’s Cold Spring Harbor Laboratory. To meet the challenge, according to a statement from the lab, “they used ‘next-generation’ sequencing techniques, in which the DNA is broken up randomly into numerous small segments and assembled into longer sequence reads by identifying the overlapping ends. The sequence ‘reads’ generated for bread wheat were then compared to those from the known sequences of a diverse range of grasses, including rice and barley.”
“We wanted to know whether we could use next-(generation) sequencing on large complex genomes in what was almost a worst-case scenario for challenging the technology,” said Richard McCombie, who headed the lab’s wheat genome work. “We wanted to do it using an agriculturally important crop.”
McCombie recently spoke to Farm Press about the lab and how the findings could be used. Among his comments:
On the lab...
“The lab has been around for over 100 years and is a bit unusual in that we really focus on genomics.
“The lab, as a whole, has always had a strong tradition of plant genetics – as well as human genetics in cancer. (Nobel Laureate) Barbara McClintock did her maize research here.
“We were actively engaged in the first plant genome to be sequenced. That was a small weed genome sequenced in the 1990s as part of an international consortium. The weed was about one-sixteenth the size of wheat genome. We were also involved in the rice and corn genomes.”
Note:The first plant genome done was a member of the mustard species – generally termed a ‘weed.’ It’s used by plant scientists to study various things, although it has no agricultural value.
“Our biggest area of research is actually the genetics underlying major psychiatric illnesses.
“To some extent I think it’s fair to say our forte is focusing on how to apply the technology to challenging problems, whether a big genome or a complex genetic problem in humans.”
Was UG99 a driver behind the research?
“No, it really wasn’t driven from a particular agricultural problem. It was driven from the standpoint that having this basic information would help breeders with any problem they approach. It will provide them with more detailed markers within the genome to help them evaluate sensitivity – or resistance in the case of rust.
“So, the reasons for getting into the research were broader.
“I’m a chemistry and computational guy – not a breeder. But, in general, when people do crosses they’ll identify strains that are more or less resistant. Being able to more precisely understand the mechanisms of that in terms of what genes are involved and where they are.
“One of the things the study did is provide a good, although not perfect, view of the wheat genome. It’s certainly the best view we have so far.
“That will help identify the genes contributing to resistance. It will also provide around 100,000 markers for more precise mapping locations within the genome when crosses are made. That way breeders can tell which component genome is present in each of the crosses.”
Did the sheer size of the genome surprise you?
“We actually knew that going in.
“To be candid, I was surprised it worked as well as it did. I knew it was a tremendous challenge and we’d get a pretty good, valuable view of the total gene content. The work done by the computational people, particularly in Germany, really gave a much better view of the genome.