While Goldsbrough prods vegetables to change the way they take up toxic metals, another Purdue researcher pushes tobacco plants to clean up radioactive waste.
Purdue botany Professor Mary Alice Webb uses tobacco seedlings to take up strontium, a contaminant made famous by the Chernobyl accident. Strontium 90 is one of the radioactive wastes that billowed up in the smoke of the Chernobyl fire, then fell and contaminated land around the blown reactor. In humans, radioactive strontium can cause bone tumors and, possibly, leukemia.
Webb hadn't set out to clean up radioactive waste. Her work started with calcium, but led to strontium. She was, and still is, fascinated by the way certain plants take up and store calcium. Plants need a large amount of calcium for normal growth and development, but too much can kill them.
"Most plants have cells that serve as calcium dumps," Webb says. "Plants have a tremendous ability to store calcium oxalate." Some plants contain almost half as much calcium by weight as does an average human body, and all without a calcium-rich skeleton.
Webb found a way to isolate bunches of calcium oxalate crystals from grape leaves and to study how they formed. Her work was reported in The Plant Journal.
As she worked with calcium, Webb became aware of research that showed how strontium can mimic calcium in biological systems.
"I theorized that since calcium and strontium are so similar, plant cells might take up strontium and incorporate it into calcium oxalate crystals, and that should increase the plants' capacity for strontium," Webb says.
She and undergraduate Christina Rinderle found that tobacco picks up strontium just
as it does calcium. They already have grown tobacco seedlings that take up more than
1 percent of their dry weight in strontium. If they can find ways to increase the
percentage, they could create super-plants that would more quickly pull
Contact: Rebecca Goetz