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Based on promising early results, “epigenetics” may help save agriculture from climate change. Epigenetics is already working in sorghum trials, and has cleared initial regulatory barriers too (See Photograph)
In the past 25 years, the agricultural landscape has seen several significant changes, from the advent of herbicide-tolerant crops to precision agriculture systems and soil supplements. Many were dubbed game changers when they were introduced, and we’re glad to have them all, but they also met with unexpected issues like weed resistance, or they didn’t evolve as fast as expected for other reasons.
The science of genetic alterations — RNAi silencing or CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) technology — has also come with great potential for improving plant breeding and enhanced traits. But it too has its challenges, including regulatory agencies in Canada.
The field of genomics is still in a state of growth as it searches for the best ways to enhance plant performance and productivity. At the same time, regulatory agencies are still haggling over definitions and applications. When is a genetic manipulation a “plant novel trait” (PNT)? When is the precautionary principle impairing scientific discovery to its detriment?
Epigenetics has been around for decades but it’s only been recently that researchers have started to manipulate it for field crop advantages, including the development of plants capable of withstanding stress such as drought, heat or cold.
Although there are questions surrounding the reaction of Health Canada or the Canadian Food Inspection Agency (CFIA), one U.S. researcher has uncovered a world of potential for this form of genetic manipulation.
Better yields and resilience
Epigenetics is defined as “the study of heritable changes in gene expression that do not involve changes to the underlying DNA sequence.” In effect, it changes gene expression without altering the genetic makeup of the plant. These changes occur naturally and often in an organism. In humans, as we know, genes can be silent during childhood, then be “activated” as a person ages, and vice versa.
Another example is that some genes are active in an eye cell, for example, yet are completely silent in a kidney cell. Epigenetics is the vehicle for different tissues taking on specialized functions.
In plants, epigenetics can oversee alterations that shift reactions from normal growing conditions to ones that adapt to more stressful conditions, such as drought or cold tolerance. A control point for influencing these epigenetic traits was recently discovered in the plant gene MSH1, a discovery made by Dr. Sally Mackenzie and her colleagues in 2012. Mackenzie had been studying the role of the mitochondria that are responsible for respiration and energy generation in plant cells, trying to understand their influence on plant fertility and their ability to disrupt pollen development.
“It was only later that we found out that MSH1 operates not just in mitochondria but in a different compartment: the chloroplasts,” says Mackenzie, a professor of biology and plant science at Penn State University. “That compartment has an ability to trigger epigenetic changes, and it was purely serendipitous that we discovered this, and we were off and running in a totally different direction.”