Green seed damage | University of Calgary researcher identifies a gene network regulating colour
A University of Calgary researcher believes he has figured out a way to permanently eliminate the biggest downgrading factor in canola.
Marcus Samuel, an assistant professor at the university’s biological sciences department, has discovered a gene regulatory network that prevents green seed damage caused by frost.
The discovery was made in arabidopsis, a close relative of canola.
Samuel and his team, which included researchers from the University of Toronto and the University of Bordeaux in France, discovered a mutant line of arabidopsis in which seeds never turn brown.
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The mutant line provided the team with the clues to figure out the gene and the associated plant regulatory network responsible for de-greening.
“We figured out a pathway on how de-greening happens and what genes are important in the pathway,” said Samuel.
The research has been published in the Proceedings of the National Academy of Sciences of the United States of America, a peer reviewed journal.
Researchers were able to use the information they gleaned from the mutant line to transform a normal arabidopsis plant to over-express the de-greening factor.
They then exposed it to two to three days of mimicked harsh cold stress treatments during seed maturation.
“This transgenic line was able to take the hit from the frost and still was able to produce brown seeds,” said Samuel.
Other researchers repeated the experiment in the lab and confirmed the results. Samuel said it was phenomenal to see the plants brush off the frost.
He knew they were onto something big that could eventually become a stackable trait in canola.
“You won’t have this green seed problem anymore. You will have seeds that will actually become brown or black,” said Samuel.
That is music to the ears of Rick White, general manager of the Canadian Canola Growers Association.
“Research that eliminates green seed and lets the plant do it is a great solution that will save the industry money,” he said.
Veronique Barthet, program manager of oilseeds with the Canadian Grain Commission, said green seed is the biggest downgrading factor for canola.
Its impact on the industry varies widely from year to year. It wasn’t a big issue this year, but that wasn’t the case in 2004.
“The first frost was in mid-August. All the canola was green. There was a big issue,” she said.
Successfully introducing the trait in canola could save farmers losses of $15 per tonne due to downgrading.
The U.S. Department of Agriculture estimates green seed causes $150 million in annual losses to North America’s canola crop.
The unwanted seeds result in a chlorophyll pigment that gives canola oil an unfavourable taste and odour and decreases its shelf life.
The grain commission allows a maximum of six percent green seed for a crop to be considered No. 2 or better.
However, exposure of maturing seeds to freezing temperatures can easily result in more than 20 percent green seed. In 1992, a severe frost put 70 percent of the crop in the No. 2 and No. 3 grades.
White said there are plenty of times when canola in the swath is dry enough to harvest but can’t be put through the combine because of high green seed counts.
“Lots of times you’ll have to leave that swath lay another week, and that’s a risky venture,” he said.
He believes a de-greening trait would be well received by western Canadian farmers.
Samuel’s research team is working with Siniazo Biotech, an Ottawa biotechnology firm, to patent the transgenic technology.
He hopes the project will capture the attention of Bayer CropScience, Monsanto and BASF, the three big players in the production of herbicide tolerant canola.
His goal is to prove that the technology performs as well in canola as it did in Arabidopsis, but it will take time and money. He needs $100,000 per year over the next three years to prove it works in canola.
“I’m definitely willing to partner with anybody interested,” said Samuel.
“Anyone that’s willing to fund the program can actually have rights to part of the ownership.”
The research team has already identified the pertinent genes in canola, but the process of transforming a canola plant is a lot more complicated than arabidopsis. As well, tests will need to be performed to ensure oil quality is not affected by the transformation.
Samuel is confident the technology will work in canola, which is 85 percent similar to arabidopsis.
“We are predicting it will essentially do the same thing in canola,” he said.
