The hardy wild grass that could save our bread

An obscure species of wild grass has a resistance to one of the deadliest crop pathogens that can be cross bred into wheat to give immunity.

The stem rust resistance genes from the wild goat grass species were identified by a collaborative international team of researchers.

The John Innes Centre, The Sainsbury Laboratory, and the University of Minnesota collaborated to develop the first accurate genome map of Aegilops.

The genetic potential of this hardy relative of wheat found in Israel and southern Lebanon has been largely unexplored.

The team used the genetic map and Mutant Hunter to look for differences in plants that were immune to stem rust, a disease which has troubled farmers for thousands of years.

The researchers thought the candidate gene was responsible for protecting plants. They isolated the gene of interest and transferred it into a susceptible plant, where it confers strong protection against all tested strains of the wheat stem rust fungus.

Dr. Brande Wulff, a wheat researcher at King Abdullah University of Science and Technology (KAUST), formerly a group leader at the John Innes Centre and one of the authors of the study said, "We now have this blockbuster gene that confers amazing immunity." If I were stem rust, I would be shaking.

It has been a long journey but we have found a gene that confers broad-spectrum resistance. The first author of the study said that they have yet to find an isolated pathogen that can overcome the gene.

Experiments show that the Sr62 gene is involved in the production of a molecule called a tandem protein kinase. Researchers can biologically engineer the mechanism to be more efficient if they look at how this gene functions.

The research team plans to use genetic modification technology to breed the new genes into wheat varieties. More resistance genes will be identified and cloned from populations of Aegilops and other wild grasses using their methods of gene discovery and deployment.

Resistance to major diseases, such as rusts, is a trait of agricultural importance for Aegilops. Its long generation time, tough seed coat, and difficulties of crossing it with wheat cultivars make it less tractable than other species of wild grasses.

Professor Brian Steffenson from the University of Minnesota and co-author of the study explains that the rust resistance genes discovered in this study are even more valuable because of the difficulties in crossing AegilopsSharonensis to wheat. Efforts were made to collect and characterize accessions of this species before they are lost to modernity. It is our hope that the resistance gene cloned in this research will be combined with other genes to give long- lasting resistance to wheat varieties, thereby reducing the threat of the stem rust disease.

Recent developments in Latin America where GM wheat has been approved could potentially pave the way for GM wheat to be bred into wheat more widely in the face of the climate crisis.

Climate change and epidemics of stem rust have made the search for resistance against the disease more urgent.

Stem rust reduces the yield of wheat by 21 percent. The energy that goes into production is equivalent to the amount of grain lost by the pathogen. If we can intervene with genetics, by recruiting the resistance found in this wild-wispy looking grass, then that would be an amazing contribution to agriculture and climate change.

Aegilops sharonensis genome-assisted identification of stem rust resistance genes appears in Nature Communications.

More information: Aegilops sharonensis genome-assisted identification of stem rust resistance gene Sr62, Nature Communications (2022). DOI: 10.1038/s41467-022-29132-8 Journal information: Nature Communications Citation: The hardy wild grass that could save our bread (2022, March 25) retrieved 25 March 2022 from https://phys.org/news/2022-03-hardy-wild-grass-bread.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.