Twisting of Plants' Roots Prompted by Barriers, Researchers Find

Through a 3-D time-lapse imaging, physicists and plant biologists at Cornell University have discovered what triggers the twisting of plants' roots. The research team discovered that certain roots form helical spring-like shapes when encountering barriers like a patch of stiff dirt. The finding further explains that when the roots run into barriers, growth causes compression and eventual buckling. The root senses this obstruction and responds by twisting the root tip. These effects combine to give the root a helical geometry.

The study was completed with the help of a 3-D laser sheet imaging technique developed by the research team to record the plant root growth. The setup consists of a laser sheet that illuminates a plane inside a transparent box, which is filled with a dense, translucent gel that acts as the "soil" for the roots. A camera takes a series of images as the box moves through the laser sheet, which effectively scans its contents.

Maria Harrison, chair of the William H. Crocker Research at the Boyce Thompson Institute for Plant Research, explained that the research results could eventually assist in breeding crop plants optimized for growth in areas where climate change or over-farming has led to difficult soil conditions. Itai Cohen, associate professor of physics at Cornell University added that the results also add to a burgeoning interdisciplinary scientific field that marries biology with mechanics.

See Cornell University's news release at http://www.news.cornell.edu/stories/Sept12/plantRoots.html. For more information, visit http://cohengroup.ccmr.cornell.edu/research.php?project=10015.