PULLMAN, WASH. — Researchers from Washington State University have discovered a new wheat gene that may be used for the transfer of valuable genes from other plants to wheat.
The discovery allows for the development of disease- and pest-resistant traits in wheat found in other grasses, and has the potential to reduce crop losses and pesticide use while foregoing the costs of bioengineered organisms.
For all of history, wheat routinely traded genes through accidental cross-breeding, and as cultivated wheat developed, the genetic structure of wheat changed. Instead of being a diploid — two sets of chromosomes like humans — the wheat gene is a polyploidy, with seven sets of six related chromosomes.
In 1958 researchers began to suspect there was a gene that controlled the pairing of wheat chromosomes that would allow for wheat to be a polyploidy. The gene also theoretically prevents wheat from breeding with related plants.
“This gene would not allow rye chromosomes to pair with wheat,” said Kulvinder Gill, a W.S.U. professor, who reported his findings in the journal Proceedings of the National Academy of Sciences. “We cannot get a single gene transfer into wheat as long as this gene is present.”
In 2006, British researchers published in the journal Nature that they had found the gene, but the W.S.U. study shows that they did not.
“Now that we have the gene, we can actually use that gene sequence to temporarily silence the gene and make rye and other chromosomes pair with wheat and transfer genes by a natural method into wheat without calling it G.M.O.,” Mr. Gill said.
The implications of the discovery of the gene are significant, the researchers said.
“Potentially it’s a monumental moment,” said Brett Carver, wheat genetics chair in agriculture at Oklahoma State University. “Gene introgression (transfer via conventional means) from related or ancestral species of wheat is a hallmark of modern wheat breeding, and a stabilizer to food production worldwide. Over one-half of the genes deployed for stem rust resistance in the world came from a species other than common wheat.”
In previous processes of gene introgression, excess genetic baggage is leftover in the transfer. The new gene discovery lowers the amount of baggage, Mr. Carver said.
“This discovery will allow a more rapid and cleaner gene transfer and will open up access to other gene donors severely hampered by excess genetic baggage,” he said.
The actual exchange of genetic material is still similar to what has taken place for a long time, only faster.
“A more rapid gene transfer process equates to accelerated breeding,” Mr. Carver said. “Anything we can do to accelerate the breeding process, keeping other factors equal, will accelerate the overall rate of genetic gain, something we all must do and are committed to doing.”
The impact of the discovery is even greater by its ability to do the genetic transfers while avoiding G.M.O., the researchers noted.The Washington State researcher’s first attempt at implementation of the gene sequence involves transferring a gene from goatgrass, a wild relative to wheat, to confer resistance to strip rust. Stripe rust is an extremely economically damaging wheat fungus, costing U.S. farmers about $500 million in productivity in 2012.