Stronger by the bushel

Stronger by the bushel

McGill breakthrough in epigenetics will help prevent costly crop damage for wheat farmers
March 24, 2014

When wheat germinates before it’s harvested, it ruins the crop, a problem that costs the global wheat industry as much as $1 billion a year. Since wheat is Canada’s largest crop — we exported $6.7 billion worth of the grain in 2013 — it’s a problem familiar to Canadian farmers.

Luckily, a team at McGill University led by Jaswinder Singh may have found a solution. Prolonged rainfall and high humidity were long thought to be the main factors that caused what is known as pre-harvest sprouting (PHS). For more than two decades, scientists around the world tried to breed PHS-resistant wheat with little success. Singh and his team recently discovered the epigenetic factors that, in addition to environmental conditions, could lead to PHS in wheat. (Epigenetics refers to changes within a species caused by something other than DNA. “Epi” literally means “above” in Greek.)

The researchers identified an important genetic trigger that acts as a switch that determines whether or not a plant will germinate when exposed to high humidity and excess rainfall. This switch is found in a gene called ARGONAUTE4_9. Singh’s team used genomic and molecular imaging tools funded by the Canada Foundation for Innovation to identify specific ARGONAUTE4_9 genes, and then compared how these genes are expressed in PHS-resistant versus PHS-susceptible wheat, thereby pinpointing molecular markers that can be used to consistently identify PHS-resistant wheat.

Singh is currently developing a screening tool to do this quickly and efficiently in wheat varieties from around the world, which can then be bred to eliminate this costly problem for wheat growers.