Nicotiana plants defend against attack

JENA, Germany, Jan. 22 (UPI) -- Nicotiana attenuata plants defend themselves by producing toxins when attacked by hawkmoth caterpillars, German scientists said.

Hawkmoths pollinate nicotiana plants and then lay eggs, which become caterpillars that eat the plant.

Oral secretions from the caterpillars activate defense responses in nicotiana, including the production of protease inhibitors that decrease the caterpillars' digestive ability, said scientists at the Max Planck Institute for Chemical Ecology, Jena, Germany.

The plants also can change their flowering time to attract different pollinators, Ian Baldwin, the institute's director, wrote in a recent issue of Current Biology.

The nicotiana usually flowers at night, but when under attack from hawkmoth caterpillars it will flower in the morning to attract hummingbirds as pollinators.

Overall, the nocturnal hawkmoths are better pollinators than hummingbirds, which may be why nicotiana plants don't ban hawkmoth pollination entirely, Baldwin told The New York Times.