Earth Notes: Wild Tobacco

Jul 25, 2018

Wild tobacco is markedly different from its cultivated cousin. The plant’s chemical properties have been known to Native Americans for a long time. Now, researchers are studying the wild form because of its potency and hardiness in the natural world.

Hawkmoth at wild tobacco
Credit Danny Kessler/Max Planck Institute for Chemical Ecology

The wild form grows in sandy bottomlands and rocky washes, and colonizes fresh fire scars after a burn.

Now this potent native is being grown in field trials in northern Arizona and Utah. Researchers from the Max Planck Institute of Chemical Ecology are studying wild tobacco because it’s closely related to potatoes, tomatoes, and eggplants—and can be grown in the same conditions.

Experiments are showing when it comes to mating, wild tobacco is no pushover.

At night, the plant’s yellowish-white, trumpet-shaped flowers turn skyward and emit bergamotene. This aromatic compound lures nocturnal hawkmoths to keep their proboscis in the flower longer, increasing pollination—and deterring the moth’s hungry caterpillars.

The pollen deposited by the moth generates a burst of ethylene in the bloom. If that burst is big enough, it triggers a pollen tube to head down the flower to the ovule where the seed’s embryo is waiting to be fertilized.

But this is no “first-come-first-served” system. The embryo sends back chemical information on exactly what it needs. Only pollen with the right chemical blend gets to go all the way and fertilize seed.

This remarkable example of plant “choice” is being studied in detail—with the goal of coaxing the picky plants into accepting pollen from mates of the researchers’ choosing—and ultimately improving drought resistance and pest tolerance in important food crops.