KAUST-led study unveils a genomic resource that could revolutionize modern wheat breeding by drawing on the genetic diversity of Tausch’s goatgrass. This international collaboration holds promise for improving wheat varieties, providing enhanced disease resistance and stress tolerance in the face of global agricultural challenges.
A groundbreaking study led by King Abdullah University of Science and Technology (KAUST) researchers has unlocked the genetic secrets of Tausch’s goatgrass (Aegilops tauschii), a wild ancestor of modern bread wheat. This discovery promises to accelerate gene discovery and enhance wheat breeding efforts, potentially transforming global food security.
Modern bread wheat (Triticum aestivum) owes its versatility to the hybridization of three wild grass species, among which Aegilops tauschii is pivotal. This wild relative contributes the D genome, a treasure trove of genetic traits that can bolster disease resistance and stress tolerance in wheat.
KAUST researchers Brande Wulff and Simon Krattinger have spearheaded numerous projects focused on cloning genes from wheat and its wild relatives. Now, with the involvement of doctoral researchers Emile Cavalet-Giorsa and Andrea Gonzalez-Munoz, as well as postdoc Naveenkumar Athiyannan, they’ve created an extensive genomic resource for Aegilops tauschii.
Their project, in collaboration with the Open Wild Wheat Consortium (OWWC) — an international alliance of research groups from 15 countries — has identified 493 genetically distinct accessions from an initial pool of 900. These samples represent key traits like disease resistance and stress tolerance, contributing to the diversity essential for robust wheat breeding programs.
“Many of the accessions we selected have disease resistance genes or agronomic traits of interest, such as stress tolerance,” Gonzalez-Munoz said in a news release, emphasizing the project’s importance.
Employing these collections, the Wulff lab has compiled 46 high-quality genome assemblies of Aegilops tauschii. This meticulous work has paved the way for significant gene discovery. Gonzalez-Munoz and Athiyannan have already identified crucial rust resistance genes, including the stem rust resistance gene located at the locus Sr33.
“In the case of the stem rust gene (Sr66), until now we have lacked an assembly that had both Sr33 and Sr66 in the same accession,” said Athiyannan in the news release.
This breakthrough confirms that the two genes are distinct, located in different positions within the genome.
Additionally, the team discovered a leaf rust resistance gene encoding a unique wheat tandem kinase protein, a first in resistance class.
The research delves deeper into understanding the intricate contributions of wild relatives to wheat’s genetic diversity.
Cavalet-Giorsa added, “Understanding the contribution from different wild relatives is important to explain the diversity and adaptability of wheat and perhaps also its evolutionary history.”
By tracing the dynamics of specific genetic introgressions, such as L3, this study uncovers how these early gene transfers have enhanced wheat’s genetic diversity and adaptability.
The findings from this study, published in the journal Nature, present a major leap forward in wheat genetics. They hold the promise of enhancing global wheat breeding efforts, equipping crops with better disease resistance and environmental resilience. The project opens new avenues for research and highlights the vital role of genetic diversity in sustaining and improving one of the world’s most important staple crops.