What he's doing now: These days, Gershenzon is the managing director of the Max Planck Institute for Chemical Ecology in Jena, Germany. (His language skills are still a work in progress, he notes, but his German-born children are happy to correct him.)
His research looks at using modern molecular methods to manipulate plant characteristics and to isolate and test the effects of terpenes. Although fascinating for a scent enthusiast in its own right, this work has practical implications for agriculture. For instance, Gershenzon and colleagues published a study in Nature in 2005, which found that when the corn root worm attacks corn, the plant produces a terpene that attracts the nematode, a roundworm. Nematodes, conveniently enough, eat root worms. Unfortunately, for most North American corn varieties this defense has been bred out during development—probably accidentally, but at an unforeseen cost.
"Chemical defenses are one of the major factors that determine plant success. Without them, the world wouldn't be as green as it is," says Jack Schultz, director of the Christopher S. Bond Life Sciences Center at the University of Missouri–Columbia. "How defense production is controlled at the gene level is critical for breeding or engineering crop and other plants that are more resistant to pests." Gershenzon's work, he says, has greatly expanded knowledge of how plants make and use terpenes.
After years of sticking his nose in plants, Gershenzon has developed quite an appreciation for the sense of smell, particularly its link to memory and our survival as a species. "It's how our simian ancestors kept themselves from being poisoned," he says. Now, "some of the local women in the market smell every piece of fruit," but this is a dying appreciation. Few people have such finely tuned noses and favorite scents. As for Gershenzon, "I'm still biased to the mint family—peppermint and spearmint, thyme, sage and oregano." Although, "I like flowers, too," he adds. "It'd be hard to choose just one."