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Developers seek OK for low-lignin biotech alfalfa

Published on April 23, 2013 3:01AM

Last changed on May 21, 2013 7:50AM


Capital Press

Biotech developers are asking the USDA to deregulate a new variety of transgenic alfalfa that's been genetically engineered for reduced lignin and improved forage quality.

Monsanto and Forage Genetics International have altered the alfalfa cultivar to suppress a "key enzyme" in the plant's synthesis of lignin, which decreases levels of the substance by about 22 percent, according to their petition to USDA.

Lignin is a structural component necessary for plant growth but livestock are unable to digest it.

The goal of the new cultivar is to provide farmers with more harvest flexibility, as they must typically sacrifice quality for yield. As alfalfa grows and increases in tonnage, the crop's lignin levels also rise.

Farmers generally face a short time frame for reaping alfalfa before lignin content surges and crop quality plummets, but the new variety will allow them to postpone the harvest, the petition said.

Aside from higher tonnage, "a grower will benefit from flexibility to accommodate unexpected delays in harvesting forage caused by adverse weather conditions, equipment failure or competing farming activities," the petition said.

According to the developers, the USDA should allow the crop to be grown without restriction because it doesn't pose a plant pest risk and isn't likely to become a weed.

The potential for cross-pollination between transgenic alfalfa and other varieties is limited in commercial hay production because the crop is generally harvested before flowers have fully developed, the petition said.

Gene flow between alfalfa varieties grown for seed is a "higher risk scenario" but can be managed with geographic isolation that's already used to maintain the purity of existing cultivars, the petition said.

The Center for Food Safety, a non-profit that has opposed another cultivar of biotech alfalfa, doesn't believe the altered genes can be contained.

Given the large scale of alfalfa production in the U.S., and the fact it's pollinated by bees that can travel for miles, the genes will eventually spread, said Bill Freese, science policy analyst for the group.

"That doesn't protect conventional and organic farmers," he said. "There is no way this remains isolated."

By silencing a gene responsible for lignin production, the biotech developers could have unwittingly affected other plant mechanisms, Freese said. "It can have off-target effects with unpredictable consequences."

Lignin is also useful for plants due to its ability to stave off insects and disease, which could leave the new cultivar more vulnerable to such threats, he said.

"Should we be messing around with this biosynthetic pathway we still have a lot to learn about?" Freese said.

Another genetically engineered alfalfa cultivar, which can resist glyphosate herbicides, was deregulated in 2011 after the USDA completed a court-ordered environmental review of the crop.

The agency's decision to commercialize the crop was challenged by the Center for Food Safety, with the lawsuit currently pending before the 9th U.S. Circuit Court of Appeals.


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