Key disease-resistant gene spotted in wheat

A team of researchers have identified Yr15, a broad-spectrum disease-resistant gene derived from wild emmer wheat, the ancestor of durum (pasta) wheat, and analysed it.

Identification of the Yr15 gene facilitates the invention of a durable solution for controlling yellow rust, a major threat to food security for millions of people, believes the international group of researchers led by Natural Resources Institute Finland (Luke), the Institute of Biotechnology at the University of Helsinki, and the University of Haifa.

Yellow rust is a devastating fungal disease threatening much of global wheat production. The problem has been increasing with climate change, said a press release issued by Luke.

Wheat is the most cultivated food crop globally, but more than five million tons of wheat harvest valued at around one billion USD are estimated to be lost annually to yellow rust, affecting food security and affordability for millions of people.

The international collaborative study involving about 30 researchers at 14 institutions in eight countries unlocks interesting opportunities for breeding more disease-resistant wheat varieties.

“Aaron Aaronsohn discovered wild wheat in 1906, and believed it would hold the key to breeding disease- and stress-resistant crops. With the work on Yr15, Aaronsohn’s vision is bearing fruit,” said Prof Alan Schulman of Luke.

“Crop’s wild relatives, like wild emmer wheat, are a great reservoir of useful genes and need conservation. Combined with a genome sequence – which became available this year – rapid advances in breeding are now possible,” said Schulman.

Although new disease-resistant genes are frequently discovered from various sources, fungi rapidly evolve to overcome them, rendering the majority of the world wheat production susceptible to epidemics. However, Yr15 has been found to be remarkably stable over several decades.

“We now understand why Yr15 is so robust – its structure is highly unusual for a disease-resistance gene. The project showed, though, that related genes are present in many plants, opening the door to widespread use,” Schulman added.

The results of the study ‘Cloning of the wheat Yr15 resistance gene’ sheds light on the plant tandem kinase-pseudokinase family have been published in the September 2018 issue of Nature Communications.