Scientists at the John Innes Centre in Norwich have cracked a genetic mystery that could lead to healthier crop production worldwide. Professor Graham Moore and his team believe their breakthrough could have “big implications for agriculture.”
Wheat plants, like most crops, have a large and complex genome that is surprisingly stable but also extremely puzzling. For more than 50 years scientists have been trying to understand how wheat can handle six sets of chromosomes without losing fertility.
Prof Moore says his team’s breakthrough could help plant breeders who are trying to find ways to breed more valuable crops and produce more food for everyone. The discovery his team has made is how the Ph1 region of the wheat genome controls genetic exchange.
Ph1 is a part of the wheat genome that prevents incorrect chromosomes exchanging parts with each other. To be highly fertile and therefore high yielding, wheat must sort its chromosomes into the correct sets, without them incorrectly joining together and exchanging sections of their DNA.
Wild relatives of wheat carry very important traits that could make wheat resistance to pests, tolerant to heat or produce more flour, but they cannot be bred into wheat.
When breeding varieties of wheat, matching (homologous) chromosomes can associate and exchange if Ph1 is present, but the chromosomes of wild relatives do not. Following experiments conducted on developing wheat anthers the team has come up with an explanation of how the Ph1 region works. Their publication in Nature Communications outlines exactly how Ph1 promotes the pairing of homologous chromosomes at specific sites.
If breeders ‘switch-off’ the Ph1 region the chromosomes become heavily rearranged and the plants lose their fertility. What breeders need now, is a way to ‘turn off’ the function of the Ph1 region to allow rearrangement of wheat and wild relative genes and then easily ‘turn it on’ again to prevent the loss of fertility.
“The easier it is for plant breeders to cross wheat with wild relatives, the more likely we are to get the desirable characteristics from those relatives into modern wheat varieties,” said Prof Moore. “This discovery will help breeders, and other researchers along the road to our goal of food security.”