When thieving weeds attack

An international group of scientists that includes assistant professor of genetics Dave Nelson has discovered how parasitic plants, which steal their nutrients from another living plant, evolved the ability to detect and attack their hosts. Their findings were  published recently in the journal Science:

As plant roots grow, they release hormones called strigolactones into the soil. This is a signal that normally helps fungi form a beneficial connection to the plant, in which they each trade nutrients. But the seeds of parasitic plants also possess the ability to sense strigolactones, which prompt them to germinate, attach to the host root and syphon off nutrients.

"It's kind of like root radar," said Nelson, who is also a member of UGA's Plant Center. "But the incredible thing is that this strigolactone detection system seems to have evolved from plant genes that normally control a seed's ability to detect fire."

When a forest burns, compounds in the smoke and ash leach into the soil. Many plants have evolved the ability to detect these compounds, which signal that their competition-large shady trees or dense ground cover-has been destroyed and it might be an opportune time to grow.

The extraordinary life of plants continues to unfold. It seems that our fascination with the natural world took a hiatus during the industrial/atomic age - an inattention that arguably unleashed very destructive tendencies in the name of progress. But developments in fundamental genetics, and the accompanying informatics capabilities among other forces, have ushered in a new era of breakthroughs and researchers like Nelson. Promising new agricultural practices are desperately needed by humans as well as flora. Great work and congratulations on this high-profile publication.

Image: Dave Nelson, assistant professor in the department of genetics, takes samples to extract DNA from arabidopsis thaliana plants in his lab in the Davison Life Sciences Building.