Ian Baldwin works in a lab anyone could love: a large blackened burn area high on a steep slope in the Great Basin Desert of southwestern Utah. Here a distant mountain range shimmers blue and lavender, the nearer craggy cliffs of Veyo Ridge hover in red, and the curves of the desert hills are dotted green by Joshua trees and scrub. Baldwin, a biologist and the director of the Molecular Ecology Department at the Max Planck Institute for Chemical Ecology in Jena, Germany, has stationed his equipment here to launch a new study of how plants defend themselves—a question he has pursued for 20 years.
He and his colleagues are using chemical sensors to investigate plant communications: cries for help, invitations, even warnings, each in the form of odor molecules that float past human noses unnoticed. The harder biologists look for these signals, the more they find. They have already discovered that plants can send chemical cues to repel insect enemies, as well as signals that attract allies—other insects that are pleased to eat the insects eating the plant. But that is only the start of a more complex scenario, for Baldwin and others have also found that nearby plants can listen in to this conversation and gear up their own defenses.
"Eventually, we will use the information we get here to breed agricultural crops that call out to their insect allies more loudly and more consistently," says Baldwin.
The scorched area they're studying was struck by lightning a year ago, clearing the hillside of juniper and sagebrush. Smoke from the fire triggered the germination of wild tobacco seeds dormant in the soil, yielding a field of Nicotiana attenuata. Baldwin's team has tagged many of them for experiments, using Popsicle sticks and small flags made of red nylon. Chatting in German and English, Baldwin's colleagues look expectantly for golden eagles. The day is hot, the air scented with desert cliff rose.
