Whacking the Weed That Wouldn t Wither

Weeds have an arsenal of ways to make any green-thumbed gardener red with anger, and the common morning glory is no exception.

But this wicked weed does its dirty work on a grander scale than just strangling backyard flower gardens. The morning glory is responsible for significant damage to the worldwide agriculture industry.

Regina Baucom, assistant professor of

biology

at the University of Cincinnati, has seen what happens to crops caught in the morning glory’s choke hold. She hopes her current USDA-backed research on the weed’s mating system will uncover ways to break its grip on farmland across the country.

“I’ve seen some fields where there was such a mat of morning glories the farmer had to wait until the first frost to kill them off,” Baucom says. “Such infestations can lead to a high percentage of crop loss.”

The fast-spreading vine with trumpet-shaped blooms has had centuries of evolution to develop biological strategies to ensure its survival. One savvy trick in a morning glory’s repertoire is the use of a mixed mating system, meaning it can reproduce on its own hermaphroditically or with another plant via bumblebee-pollinated outcrossing.

Another nifty if nefarious tactic is the morning glory’s increasing resistance to herbicides such as RoundUp, a commonly used product in all forms of agriculture. When sprayed with this weed killer, many times the common morning glory,

Ipomoea purpurea

, will flourish again and still be capable of reproducing – much to the chagrin of farmers across the Southeast, where its infestation is most pervasive.

Baucom’s research, “Toward A Cohesive Understanding Of Glyphosate Resistance Evolution In The Common Morning Glory: The Mating System, Gene Flow, And Fitness,” has the support of the U.S. Department of Agriculture. Baucom and her fellow researcher, Shu-mei Chang from the University of Georgia, have been awarded a $500,000 grant from the USDA for their project. Baucom plans to use some of the money to fund a post-doctoral research associate at UC for three years.

Baucom has found that when a morning glory plant survives being sprayed by glyphosate, the active ingredient in RoundUp, its methods of reproduction are altered but not eliminated. Baucom says her research is the first to report on the issue of the plant’s male sterility, and the proliferation of these “deformed anther” morning glory plants adds another level of complexity to understanding how to affect the plant’s genetic defense mechanisms.

Baucom and Chang are developing a theoretical tool to help design agricultural practices that can alter the morning glory’s evolutionary trajectory and slow its herbicide resistance. Ultimately, they hope to apply similar strategies to other weed populations that, like morning glories, plague economically critical corn, cotton and soy crops – and the global food supply.

There are other genetic research spinoffs Baucom has in mind. For example, she’s considering studying how plants evolve into weeds – and potential crop killers – in the first place. Baucom says this kind of science fits in well with UC’s renowned human health research, it’s just that she’s taking an uncommon approach to broad-reaching problems such as hunger.

“There’s a big focus on human health at the University of Cincinnati, but this is a unique line that’s focusing on another aspect of that, which is the ability to have food,” she says. “How can we maintain our food supply when we have things like weeds that are decreasing it?”