Inside Iowa State

Aug. 9, 2007

Why sweet corn is sweet and other good fortunes

by Teddi Barron, News Service

"It was on this campus as a student, June 1873, that I found myself..."

When she walks by the commemorative plaque on the boulder near LeBaron Hall, Martha James nods in agreement with the inscription that honors ISU alumnus W.T. Hornaday. A leading wildlife conservationist, Hornaday was the first director of the Bronx Zoo and a cousin of James' grandfather.

"It's probably true for me and many others at the university. It's a place where people can find themselves," James said. "And I've been lucky here in that respect."

For the past 20 years, James has created a successful scientific career at Iowa State as an associate scientist in biochemistry, biophysics and molecular biology. In the laboratory and in the cornfield, she researches how plants make starch.

James was not always a scientist. Nor is she only a scientist.

Recognized as the outstanding senior woman of 1968, James graduated from the University of Colorado - with a degree in economics. She returned to her hometown of Des Moines and had three children "very close together." For the next several years, she was a stay-home mom and a community volunteer.

"When my youngest was eight, I started classes at Drake. And I knew I didn't want a master's in economics," she said.

James fell in love with the sciences. In fact, when she talks about biology, her voice drops to a hushed tone of reverence.

"Biology is fascinating. There's a wonder about it," she said. "There are so many interesting questions. So much is being discovered everyday and remains to be discovered. It's just ripe with opportunity."

She earned a master's in biology at Drake, then came to ISU for her doctoral degree in genetics.

"I'm really fortunate that it was all available for me here in central Iowa," she said.

A central Iowan by choice

James wasn't likely to leave the Des Moines area, not even for one of the tenure-track positions she has been offered over the years. It's not only because of her desire to be close to her family (which has grown to include two step-children and nine grandchildren), but also because of the family business. She and her sister own a real estate development company their father started. In fact, James doesn't need to work at all.

"Frankly, I don't know any scientists who do what they do for financial reasons. We do it because we love it," she said.

James has built her successful career on that love of science, studying the genes that contribute to starch production and structure. Her lab group has cloned many of the genes in the starch biosynthesis pathway and helped determine their specific functions in starch production. And even though she can tell you what makes sweet corn sweet and why the Peaches and Cream variety is extra sweet (more on that later), that's not her reason for studying starch.

"It's more to figure out how plants make starch," she said. "Plants produce starch and then break it down when they need more energy. It's a mechanism for plants to manage their growth and development - by the amount of energy they store. We want to understand how they do it."

Entrepreneurs

In their work, James and her research partner, Alan Myers, professor and chair of biochemistry, biophysics and molecular biology, have successfully modified the biosynthetic pathway of starch to produce two different starches. One type is more slowly digested by humans. It could be useful in foods for people suffering from diabetes, and could possibly help control obesity. The other type is just the opposite - a starch that is more rapidly digestible.

"The second starch has more potential benefit for industry. For example, before either ethanol or high fructose corn syrup can be produced, the starch needs to be broken down to glucose," she said. "That process requires high heat for long periods of time and adds to production costs."

To develop and commercialize the two new starches, James and Myers started a biotech company, Starch Design, in the Plant Sciences Institute's Carver Co-Laboratory.

James finds time to pursue other loves. She serves on the board of the Des Moines Metro Opera and the board and executive committee of Blank Children's Hospital. She adores her book club -"cherishes" the women in it - and likes vegetable gardening. But mostly James loves to spend time with her family. Her two daughters are at home with young children, and her son is an executive at MTV in New York. Her husband, also a scientist, is retired - something that James will be easing into herself next year.

Although she plans to close up shop on her research laboratory, James will write manuscripts to report the results. And she'll focus on the fledgling company, Starch Design.

The secret behind the sweet crunch

Now, about that sweet corn: It's all in the genes.

The first gene James cloned was the classic sweet corn gene called sugary1, one of the oldest mutations described in maize.

"It's been used by humans in South America since pre-Columbian time. Not only as a food, but also as a sweetening agent because of the high concentration of sugars. This is the traditional type of sweet corn," she said. "Locally, we eat of a lot of the sugary1 corn, but the corn we get in the winter typically is a different mutation that accumulates sugars by a different mechanism."

And the peaches and cream variety?

"Actually that's a double mutation. It's sugary1 plus sugary enhancer. We don't yet know what sugary enhancer does in the plant, but we're working on it."

"Frankly, I don't know any scientists who do what they do for financial reasons. We do it because we love it."

Martha James